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Biliary Tract Cancer Clinical Trial Timeline: A 16-Year Evolution Map

Tue, 21 Apr 2026 00:00:00 +0000

Biliary Tract Cancer Clinical Trial Timeline: In-depth Report

Coverage: 39 landmark trials cited by NCCN Biliary Tract Cancers V1.2026 (37 published with full PMID traceability + 2 ongoing with only NCT / design paper) + mixed three-subtype enrollment (GBC / ICC / ECC) + eight biomarker-matched pathways

Curated by Dual Brain Lab (csilab.net)

1. One-sentence definition

This report maps the evolution logic and current decision landscape of systemic therapy for biliary tract cancer (BTC; including gallbladder cancer / GBC, intrahepatic cholangiocarcinoma / ICC, extrahepatic cholangiocarcinoma / ECC) over the past 16 years (2010-2026) as reflected in the landmark clinical trials cited by NCCN Biliary Tract Cancers V1.2026, providing frontline clinicians a traceable panoramic map for “who, what, and why” decisions in 2026.

Iron rule: every data point of every trial is traceable to PubMed (PMID) or ClinicalTrials.gov (NCT id) — each [PMID xxxxxxxx] in the text can be opened directly in PubMed for source verification.

2. Vertical: timeline of five treatment paradigms

BTC systemic therapy has gone through five paradigm shifts in the past 16 years: adjuvant chemo upgraded from observation to capecitabine, then expanded to S-1 as a parallel three-way option → advanced 1L GemCis (gemcitabine + cisplatin) dominated uniformly for 12 years → IO (immune checkpoint inhibitor) + GemCis double hit forming a class effect rewrote the 1L backbone → 8 biomarker-matched precision pathways (FGFR2 / IDH1 / HER2 / BRAF V600E / NTRK / MSI-H / NRG1 / KRAS G12C) rolled out in parallel → advanced 2L layered marginal benefit from FOLFOX with an East-West divide on nal-IRI.

Each shift was smaller than in NSCLC but larger than in pancreatic cancer — reflecting BTC’s distinct molecular architecture: ICC is enriched for FGFR2 / IDH1 (10-20%), GBC is enriched for HER2 (15-20%), and all three subtypes share MSI-H / BRAF / NTRK / NRG1 / KRAS G12C tumor-agnostic basket pathways. This “subtype × biomarker dual heterogeneity” makes BTC’s precision-therapy density second only to NSCLC, far exceeding HCC and pancreatic cancer.

2.1 Adjuvant chemo evolution (2015-2024): from GEMOX/gemcitabine failure → capecitabine tacit ascent → S-1 / GemCis-CRT East-West divergence

Story: before BILCAP, adjuvant BTC was observation + some-centers chemo. PRODIGE-12 and BCAT, two European / Japanese phase III trials, both rendered GEMOX and gemcitabine monotherapy adjuvant negative. BILCAP was tacitly accepted globally on a borderline-ITT / significant per-protocol basis; ASCOT delivered a clean ITT-positive result in a Japanese population with S-1; OSTWAL 2024 delivered the first positive DFS for GemCis + CRT in high-risk Indian GBC. An arc from “all fail → marginal win → clean win → subtype-specific.”

PRODIGE-12 [PMID 30707660] (Edeline 2019 J Clin Oncol, N=194): R0/R1 mixed BTC adjuvant GEMOX (gemcitabine + oxaliplatin) vs observation. RFS HR 0.88 (95% CI 0.62-1.25, p=0.48) negative, OS likewise negative. Proved not every adjuvant doublet works — what wins in advanced doesn’t always win in adjuvant.
BCAT [PMID 29405274] (Ebata 2018 Br J Surg, N=225, Japan): ECC-only R0 adjuvant gemcitabine monotherapy vs observation. OS HR 1.01 (95% CI 0.70-1.45, p=0.97) zero difference. The cleanest negative in a subtype-specific adjuvant trial — gemcitabine monotherapy fully exits the adjuvant recommendation. The BCAT + PRODIGE-12 IPD meta-analysis [PMID 35182925] reaffirmed “gemcitabine-based adjuvant doublets do not benefit BTC.”
BILCAP [PMID 30922733] (Primrose 2019 Lancet Oncol, N=447, UK): R0/R1 mixed BTC adjuvant capecitabine × 8 cycles vs observation. ITT mOS 51.1 vs 36.4 months, HR 0.81 (95% CI 0.63-1.04, p=0.097) just missed; per-protocol HR 0.75 (95% CI 0.58-0.97, p=0.028) significant. ESMO/NCCN/CSCO all adopted it as adjuvant standard — rationale: per-protocol significant + real-world dose reduction unavoidable + no better data. This is BTC’s first tacitly-ascendant adjuvant standard in 30 years.
ACTICCA-1 [PMID 26228433] (Stein 2015 BMC Cancer design paper / NCT02170090): European multicenter N≈783 resected mixed BTC, adjuvant GemCis × 8 cycles vs amended capecitabine (control arm amended post-BILCAP). The first direct head-to-head comparison of GemCis doublet vs capecitabine monotherapy as adjuvant; still ongoing as of 2026-04, primary results not yet published. The most anticipated BTC adjuvant phase III.
ASCOT / JCOG1202 [PMID 36681415] (Nakachi 2023 Lancet, N=440, Japan): R0 mixed BTC adjuvant S-1 × 4 cycles vs observation. mOS 62.4 vs 51.1 months, HR 0.69 (95% CI 0.55-0.86, p=0.001) significant. The cleanest ITT-positive adjuvant phase III in BTC to date. Japanese guidelines accordingly list S-1 as adjuvant SoC. In the Asian setting with DPYD polymorphism and S-1 tolerability, this “Eastern-specific” path stands alongside BILCAP.
SWOG-S0809 [PMID 25964250] (Ben-Josef 2015 J Clin Oncol, N=79, single-arm phase II): ECC + GBC only (T2-T4 or node-positive) adjuvant GemCap × 4 cycles → CRT (concurrent capecitabine, 54 Gy). 2-year OS 65% (met pre-specified ≥60% threshold), similar across R0/R1 subgroups. The main evidence basis for NCCN recommending adjuvant CRT in ECC/GBC R1-margin / N+ patients.
OSTWAL-2024-GEMCIS-CRT-GBC [PMID 38958997] (Ostwal 2024 JAMA Oncol, N=80, India Tata Memorial): high-risk GBC only (T3-T4 / N+ / R1) adjuvant GemCis × 4 cycles + CRT vs observation. DFS HR 0.62 (95% CI 0.43-0.89, p=0.009) significant, mDFS 28.0 vs 14.0 months. The first RCT to show positive DFS for adjuvant chemo + CRT in a single GBC subtype, filling the GBC-underrepresentation gap in mixed-subtype trials.

Takeaway: in 2026 adjuvant BTC — capecitabine monotherapy (BILCAP) is the Western default; S-1 × 4 cycles (ASCOT) is the Asian preferred; high-risk ECC/GBC (R1 / N+) adds CRT (SWOG-S0809 / OSTWAL) as intensification; GEMOX and gemcitabine monotherapy no longer used in adjuvant; ACTICCA-1 (GemCis vs capecitabine) readout will definitively rewrite the decision tree.

2.2 Advanced 1L (2010-2025): GemCis dominates 12 years → three triplet challenges all fail → IO double-hit forms class effect

Story: after ABC-02 enshrined GemCis as 1L in 2010, no one dethroned it for 12 full years. Three triplet challenges in different directions (add nab-paclitaxel / switch to mFOLFIRINOX / add S-1) all failed. Not until 2022-2023 did TOPAZ-1 + KEYNOTE-966 — using durvalumab and pembrolizumab, two fully independent PD-(L)1 inhibitors — converge on HR 0.80-0.83, formally establishing IO + GemCis as a class effect.

ABC-02 [PMID 20375404] (Valle 2010 NEJM, N=410, UK): treatment-naive advanced BTC (ICC 39% / GBC 38% / ECC 20% / ampullary 3%) GemCis vs gemcitabine monotherapy. mOS 11.7 vs 8.1 months, HR 0.64 (95% CI 0.52-0.76, p<0.001). The control base for all BTC 1L trials over 12 years; the “backbone drug” status of GemCis underlying every IO + GemCis class-effect trial was established here.
AMEBICA / PRODIGE-38 [PMID 34662180] (Phelip 2022 J Clin Oncol, N=191, France phase II RCT): mFOLFIRINOX vs GemCis 1L. 6-month PFS 44.5% vs 47.3%, PFS HR 0.93, OS HR 0.97 all negative, with markedly higher toxicity (G3-4 AEs ~72% vs ~60%). Regimens that win in pancreatic cancer don’t carry over to BTC.
KHBO1401-MITSUBA [PMID 35900311] (Ioka 2023 J Hepatobiliary Pancreat Sci, N=246, Japan): GCS triplet (GemCis + S-1) vs GemCis. mOS 13.5 vs 12.6 months, ITT HR 0.79 (95% CI 0.60-1.04, p=0.094) just missed; per-protocol HR 0.73 (p=0.046). Occasionally used in Japanese daily practice, not adopted globally as SoC.
TOPAZ-1 [PMID 38319896] (Oh 2022 NEJM Evid, N=685, global, Asia 54% / Europe 30% / Americas 16%): durvalumab (PD-L1) + GemCis vs placebo + GemCis. OS HR 0.80 (95% CI 0.66-0.97, p=0.021), mOS 12.8 vs 11.5 months (delta only 1.3 months); 24-month landmark OS 24.9% vs 10.4% (delta 15 percentage points). Median OS gap is small but the long-tail survivor proportion doubles — IO benefit is not uniformly distributed but enriched in durable responders. FDA approved 2022-09.
KEYNOTE-966 [PMID 37075781] (Kelley 2023 Lancet, N=1069, global): pembrolizumab (PD-1) + GemCis vs placebo + GemCis. OS HR 0.83 (95% CI 0.72-0.95, p=0.0034), mOS 12.7 vs 10.9 months. 55% larger than TOPAZ-1, with HR nearly overlapping TOPAZ-1 (0.80 vs 0.83). Two fully independent teams, two different drugs (PD-L1 vs PD-1), two different regimens (durvalumab maintenance vs pembrolizumab monotherapy maintenance), HR converging on 0.80-0.83 — a textbook class effect. FDA approved 2023-10.
SWOG-1815 [PMID 39671534] (Shroff 2025 J Clin Oncol, N=441, US): GemCis + nab-paclitaxel triplet vs GemCis doublet 1L. mOS 11.8 vs 11.4 months, HR 0.93 (95% CI 0.75-1.16, p=0.52) negative. Phase II single-arm data had raised expectations; the phase III closed the “add-taxane” path.

Takeaway: 2026 advanced BTC 1L SoC = IO + GemCis (durvalumab or pembrolizumab, HR 0.80-0.83 class effect). Three triplet concepts (add taxane / switch to FOLFIRINOX / add S-1) all failed. The core branchpoint in daily clinical practice is “which IO fits this patient” rather than “add IO or not” — see §3.2.

2.3 Advanced 2L (2019-2024): FOLFOX marginal + nal-IRI East-West divergence + IO/regorafenib monotherapy historical value

Story: 2L BTC has hovered near the “6-month OS floor” for 16 years. ABC-06 delivered a marginal win with FOLFOX and became standard; NIFTY and NALIRICC used the same drug (nal-IRI + 5FU/LV) in Korea vs Germany and reached opposite conclusions; IO monotherapy (nivolumab) and regorafenib produced modest results in unselected populations, but established the early signal that “IO has enrichment in the MMR-deficient subgroup of refractory BTC.”

ABC-06 [PMID 33798493] (Lamarca 2021 Lancet Oncol, N=162, UK): after gemcitabine-class failure, mFOLFOX + active symptom control (ASC) vs ASC alone. mOS 6.2 vs 5.3 months, HR 0.69 (95% CI 0.50-0.97, p=0.031); 12-month OS 25.9% vs 11.4%. BTC’s first positive 2L RCT, establishing mFOLFOX as 2L standard. Delta only 0.9 months — low ceiling.
NIFTY [PMID 36951834] (Hyung 2023 JAMA Oncol, N=174, Korea): after gemcitabine-class failure, liposomal irinotecan (nal-IRI) + 5FU/LV vs 5FU/LV alone. PFS HR 0.56 (95% CI 0.39-0.81, p=0.002), mPFS 7.1 vs 1.4 months. OS HR 0.82 (p=0.27) negative, but the PFS signal is the strongest in BTC 2L history.
NALIRICC [PMID 38870977] (Vogel 2024 Lancet Gastroenterol Hepatol, N=100, Germany AIO): same nal-IRI + 5FU/LV vs 5FU/LV, OS HR 0.68 (95% CI 0.44-1.04, p=0.074) borderline non-significant, mOS 8.2 vs 6.9 months. Same drug, same 2L setting, same control — Korean PFS+ but German OS negative — East-West population PK / molecular background (HBV / liver fluke vs sporadic) / ICC-to-ECC ratio differences could all plausibly explain it.
KIM-2020-NIVO-BTC [PMID 32352498] (Kim 2020 JAMA Oncol, N=54, US phase II single-arm): gemcitabine-class refractory BTC nivolumab monotherapy. ORR 22% (12/54), mPFS 3.7 months, mOS 14.2 months. The 22% ORR in an unselected population is well above the historical 5-10% chemo-refractory ORR — but responses enriched in the MMR-deficient subgroup, providing proof-of-concept for IO moving into 1L via TOPAZ-1 / KN-966.
SUN-2019-REGO-BTC [PMID 30561756] (Sun 2019 Cancer, N=43, US phase II single-arm): after gemcitabine-class failure, regorafenib 160 mg. DCR 56%, ORR 11%, mPFS 2.0 months, mOS 7.4 months. Multikinase TKI shows only marginal activity in BTC; no phase III followed. In 2026 still occasionally used as “palliative when no better option exists,” not SoC.

Takeaway: in 2026 advanced BTC 2L and beyond — mFOLFOX + ASC (ABC-06) is the global default; nal-IRI + 5FU/LV is used in Korea / parts of Asia-Pacific based on NIFTY PFS data, while the West is cautious after NALIRICC OS negative; IO monotherapy is recommended only for MSI-H / TMB-H selective populations; regorafenib used occasionally when all other options are exhausted. The ceiling of these 2L chemo paths will be rewritten by the biomarker-matched strategies in §2.4.

2.4 Biomarker-matched precision therapy (2018-2026): eight pathways + 2/3 ICC three-subtype reshaping

Story: in 2018, NAVIGATE (larotrectinib for NTRK fusion) opened the door with the FDA’s first tumor-agnostic approval. In 2020, four landmark trials published the same year — FIGHT-202 (pemigatinib for FGFR2 fusion) + ClarIDHy (ivosidenib for IDH1 mutation) + ROAR (dabrafenib + trametinib for BRAF V600E) + KEYNOTE-158 (pembrolizumab for MSI-H) — densely opened the ICC precision-therapy door. From 2021-2024, four HER2 pathways with different mechanisms (MyPathway → HERIZON-BTC-01 → SGNTUC-019 → DESTINY-PanTumor02) rolled out in the GBC-enriched population. In 2025 zenocutuzumab (NRG1 fusion) and in 2026 TRIDENT-1 (repotrectinib, next-gen TRK for NTRK fusion) completed the final two pieces. 8 biomarker-matched pathways collectively cover ~30-40% of BTC patients, making BTC’s precision-therapy density the highest solid-tumor map outside NSCLC.

2.4.1 FGFR2 pathway (ICC-exclusive, 10-15% of ICC patients)

FIGHT-202 [PMID 32203698] (Abou-Alfa 2020 Lancet Oncol, N=146, single-arm phase II): FGFR2 fusion / rearrangement+ CCA (>95% ICC) 2L pemigatinib. Cohort A (FGFR2 fusion, n=107) ORR 35.5% (95% CI 26.5-45.4), mDoR 7.5 months, mPFS 6.9 months, mOS 21.1 months; Cohort B (other FGFR alteration) ORR 0%; Cohort C (no FGFR alteration) ORR 0%. Fusion is the true driver, not all FGFR alterations are equivalent. FDA accelerated approval 2020-04 — BTC’s first precision drug.
FOENIX-CCA2 [PMID 36652354] (Goyal 2023 NEJM, N=103, single-arm phase II): 100% ICC, FGFR2 rearrangement+ 2L futibatinib (covalent / irreversible FGFR1-4 inhibitor). ORR 41.7% (95% CI 32.1-51.9), mDoR 9.7 months, mPFS 8.9 months, mOS 20.0 months. Covalent binding may overcome some resistance mutations to reversible inhibitors. FDA accelerated approval 2022-09.
RAGNAR [PMID 37541273] (Pant 2023 Lancet Oncol, N=217 across ≥15 tumor types / BTC n=27): FGFR1-4 alteration tumor-agnostic erdafitinib. Overall ORR 30%; BTC subgroup ORR ~26%. FDA accelerated approval 2024-09 for tumor-agnostic FGFR-altered solid tumors — providing a third path for BTC patients with FGFR1/3/4 alterations (not the mainstream FGFR2 fusion).
FIGHT-302 [PMID 32677452] (Bekaii-Saab 2020 Future Oncol design paper / NCT03656536): 1L FGFR2 rearrangement+ ICC pemigatinib vs GemCis head-to-head phase III. ESMO 2024 oral reported positive PFS; full manuscript still unpublished as of 2026-04. If formally published as positive, it would switch FGFR2+ ICC 1L SoC from IO + GemCis to pemigatinib — the first example of “molecular-selected 1L replacing IO + GemCis.”

2.4.2 IDH1 pathway (ICC-enriched, 10-20% of ICC patients)

ClarIDHy [PMID 32416072] (Abou-Alfa 2020 Lancet Oncol, N=185; OS update [PMID 34554208] Zhu 2021 JAMA Oncol): IDH1 mutation+ (R132 hotspot) CCA (90% ICC) ≥1 prior line ivosidenib vs placebo (2:1 randomization, crossover allowed). mPFS 2.7 vs 1.4 months, HR 0.37 (95% CI 0.25-0.54, p<0.001); ITT OS 10.3 vs 7.5 months, HR 0.79 (p=0.093) — diluted by 70% crossover; crossover-adjusted OS HR 0.49. BTC’s first truly phase III biomarker trial (FIGHT-202 / FOENIX were both single-arm phase II). FDA approved 2021-08.

2.4.3 HER2 pathway (GBC-enriched, 15-20% of GBC patients; lower in ICC/ECC)

Four different mechanisms in parallel — in solid tumors this level of target richness is matched only by HER2+ breast cancer.

MyPathway-BTC [PMID 34339623] (Javle 2021 Lancet Oncol, N=39 BTC cohort single-arm): HER2+ (IHC 3+ or IHC 2+/FISH+) BTC pertuzumab + trastuzumab. ORR 23.1% (95% CI 10.7-39.9), mPFS 4.0 months, mOS 10.9 months. First prospective HER2-doublet data in BTC; IHC 2+/FISH+ enrollment dilutes the signal but establishes proof-of-concept.
HERIZON-BTC-01 [PMID 37276871] (Harding 2023 Lancet Oncol, N=87 single-arm phase IIb): HER2 amplification (IHC 3+ or IHC 2+/ISH+) BTC (GBC 40% / ICC 35% / ECC 25%) 2L+ zanidatamab (HER2 bispecific antibody, simultaneously binding domain 2 + 4). ORR 41.3% (95% CI 30.7-52.5), mDoR 12.9 months, mPFS 5.5 months, mOS 15.5 months. FDA accelerated approval 2024-08 — BTC’s third biomarker-targeted approval (after FGFR2 / IDH1).
SGNTUC-019 [PMID 37751561] (Nakamura 2023 J Clin Oncol, N=30 BTC cohort single-arm basket): HER2+ BTC tucatinib (HER2-selective small-molecule TKI) + trastuzumab. ORR 46.7% (95% CI 28.3-65.7), mPFS 5.5 months, mOS 13.5 months — the highest BTC HER2-doublet numbers historically (small N, interpret cautiously).
DESTINY-PanTumor02 [PMID 37870536] (Meric-Bernstam 2024 J Clin Oncol, N=41 BTC cohort single-arm): HER2-expressing (IHC 3+ or 2+) solid tumors 7-cohort trastuzumab deruxtecan (T-DXd ADC). BTC ORR 36.6% (IHC 3+ 56.3% / IHC 2+ 20.0%), mPFS 7.0 months, mOS 9.9 months. FDA tumor-agnostic accelerated approval 2024-04 for HER2 IHC 3+ solid tumors — expanding the BTC HER2-eligible population from “amplification” to “overexpression.” ILD risk requires monitoring.

2.4.4 BRAF V600E pathway (ICC-enriched, 3-5% of ICC)

ROAR-BTC [PMID 32818466] (Subbiah 2020 Lancet Oncol, N=43 BTC cohort single-arm basket): BRAF V600E+ BTC (85% ICC) 2L dabrafenib + trametinib. ORR 51% (95% CI 36-67), mPFS 9.0 months, mOS 11.7 months — historically the highest ORR for any BTC biomarker cohort. FDA tumor-agnostic accelerated approval 2022.
NCI-MATCH-H [PMID 32758030] (Salama 2020 J Clin Oncol, N=35 pan-tumor / BTC subgroup n=7-8): BRAF V600E+ non-melanoma non-NSCLC solid tumors dabrafenib + trametinib independent NCI validation. Overall ORR 38%, mPFS 11.4 months. BTC subgroup results consistent with ROAR — providing an independent replication beyond ROAR and strengthening the BRAF V600E + dab/tram evidence package.

2.4.5 NTRK fusion pathway (cross-subtype, <1% of BTC)

Three NTRK inhibitors in parallel + next-gen for resistance mutations.

NAVIGATE-LAROTRECTINIB [PMID 29466156] (Drilon 2018 NEJM, N=55 pan-tumor / BTC n=2-3): TRK fusion+ solid tumors larotrectinib. Overall ORR 75% (95% CI 61-85). FDA’s first tumor-agnostic biomarker approval 2018-11 — a regulatory milestone. BTC patient numbers very small but responses consistent.
STARTRK-ENTRECTINIB [PMID 31838007] (Doebele 2020 Lancet Oncol, N=54): NTRK fusion+ solid tumors entrectinib (pan-TRK/ROS1/ALK, good CNS penetration). Overall ORR 57.4% (95% CI 43.2-70.8), mDoR 10.4 months. BTC subgroup not reported separately due to small N. FDA tumor-agnostic approval 2019-08.
TRIDENT-1 [PMID 41639379] (Besse 2026 Nat Med): NTRK fusion+ solid tumors repotrectinib (next-gen TRK, active against NTRK G595R / G667C / F589L resistance mutations). TRK-naïve cohort ORR 58% (95% CI 37-77), TRK-pretreated cohort ORR 50% (95% CI 28-72). FDA approved 2023-11 — providing a sequential precision option for BTC patients resistant to larotrectinib / entrectinib.

2.4.6 MSI-H / dMMR / TMB-H pathway (cross-subtype, BTC MSI-H ~2-3%)

KEYNOTE-158-MSIH [PMID 31682550] (Marabelle 2020 J Clin Oncol, N=233 pan-tumor / BTC cohort K n=22; long-term [PMID 35680043] Maio 2022 Ann Oncol): MSI-H / dMMR non-CRC solid tumors pembrolizumab. Overall non-CRC MSI-H ORR 34.3%; BTC subgroup ORR 40.9% (95% CI 20.7-63.6). BTC-specific data supporting the FDA tumor-agnostic approval of 2017.
ANDRE-2023-DOSTARLIMAB [PMID 37917058] (André 2023 JAMA Netw Open): dMMR solid tumors dostarlimab. Overall dMMR ORR 38.7% (95% CI 31.6-46.2), 24-month DoR rate 69.0%. BTC subgroup consistent with overall cohort. Provides an anti-PD-1 equivalent option to pembrolizumab for MSI-H / dMMR BTC.
CHECKMATE-848 [PMID 39107131] (Schenker 2024 J Immunother Cancer, N≈200 TMB-H pan-tumor): TMB-H (≥10 mut/Mb) solid tumors nivolumab + ipilimumab vs nivolumab monotherapy. ORR 43.3% vs 26.0%, PFS HR 0.72 (95% CI 0.60-0.88). BTC-specific data not separately published, but establishes randomized evidence that “TMB-H is an optional biomarker for IO combinations (overlapping ~40-50% with MSI-H).”

2.4.7 NRG1 fusion pathway (cross-subtype, <1% of BTC)

ENRGY [PMID 39908431] (Schram 2025 NEJM, N=64 pan-tumor / BTC subgroup n=3-5): NRG1 fusion+ solid tumors zenocutuzumab (HER2×HER3 bispecific, competitively blocking NRG1-HER3 signaling). Overall ORR 34% (95% CI 22-47), mDoR 11.1 months, mPFS 6.8 months. BTC subgroup consistent with the overall cohort. FDA accelerated approval 2024-08 for NRG1 fusion+ NSCLC and pancreatic cancer — tumor-agnostic data supports BTC use.

2.4.8 KRAS G12C pathway (cross-subtype, ~1-2% of BTC)

KRYSTAL-1-BTC [PMID 37099736] (Bekaii-Saab 2023 J Clin Oncol, N=12 BTC subgroup single-arm basket): KRAS G12C+ BTC adagrasib 600 mg BID. BTC ORR 33.3% (95% CI 9.9-65.1), DCR 83.3%. BTC is the first GI tumor beyond NSCLC / CRC to demonstrate KRAS G12C inhibitor activity — adding an eighth biomarker-matched pathway.

2.4.9 RET fusion pathway (cross-subtype, <1% of BTC)

LIBRETTO-001-BTC [PMID 36108661] (Subbiah 2022 Lancet Oncol, N=45 non-lung non-thyroid / BTC n=7): RET fusion+ solid tumors selpercatinib. ORR 43.9% (95% CI 29.5-59.3), mDoR 24.5 months. BTC subgroup ORR consistent with overall cohort. FDA tumor-agnostic approval 2022.
ARROW-BTC [PMID 35962206] (Subbiah 2022 Nat Med, N=29 non-lung non-thyroid): RET fusion+ solid tumors pralsetinib. ORR 57% (95% CI 37-76), 12-month DoR rate 81%. BTC data sparse but equivalent to selpercatinib. FDA tumor-agnostic accelerated approval 2022-08.

Takeaway: in 2026, a newly diagnosed advanced BTC patient must have comprehensive molecular profiling (NCCN V1.2026 strongly recommended) covering FGFR2 / IDH1 / HER2 / BRAF V600E / NTRK / MSI-H / dMMR / TMB-H / NRG1 / KRAS G12C / RET. 8 biomarker-matched pathways collectively cover 30-40% of patients — the biggest difference from HCC (0 biomarker-matched) and pancreatic cancer (POLO + 5%). If FIGHT-302 publishes as 1L positive, it will be the first precedent of “molecular-selected 1L replacing IO + GemCis.”

2.5 Ongoing phase III and pending readouts (key 2026-2028 inflection points)

Story: BTC’s key 2026-2028 readouts concentrate on two fronts: adjuvant setting (ACTICCA-1 GemCis vs capecitabine) and 1L FGFR2-selective setting (FIGHT-302 pemigatinib vs GemCis). Either outcome will directly rewrite the decision tree.

FIGHT-302 [PMID 32677452] (Bekaii-Saab 2020 Future Oncol design / NCT03656536): 1L FGFR2+ ICC pemigatinib vs GemCis. ESMO 2024 reported positive PFS readout; full manuscript still pending as of 2026-04.
ACTICCA-1 [PMID 26228433] (Stein 2015 BMC Cancer design / NCT02170090): adjuvant GemCis × 8 cycles vs amended capecitabine (control arm amended after BILCAP). Designed as the only direct head-to-head comparison of GemCis doublet vs capecitabine monotherapy in adjuvant. Primary completion expected 2026-2027.
GEMSTONE-202 (China CStone Pharmaceuticals sugemalimab + GemCis 1L phase III, positive readout reported at ASCO GI 2024/2025): as of 2026-04, the primary manuscript and public NCT ID are both unregistered — this knowledge base strictly follows the “PMID / NCT traceable” principle, not currently included in the main database. Will add as a v2 supplement once the primary publication appears.

Takeaway: the key variables of BTC decision-tree in 2026-2028 = (a) whether adjuvant GemCis beats capecitabine (ACTICCA-1) + (b) whether 1L FGFR2+ switches to pemigatinib monotherapy (FIGHT-302) + (c) whether the Chinese domestic IO + GemCis data GEMSTONE-202 is published. Each will recalibrate §3’s horizontal decision landscape.

3. Horizontal: 2026 current decision landscape (six dimensions)

Projecting the vertical evolution onto the 2026 clinical decision tree, the following are six key branchpoints and the evidence basis for each.

3.1 Newly diagnosed BTC: immediate comprehensive molecular profiling

NCCN V1.2026 explicitly recommends comprehensive molecular testing (tissue or ctDNA) for all newly diagnosed advanced BTC, covering: FGFR2 fusion / rearrangement + IDH1 R132 mutation + HER2 amplification / overexpression + BRAF V600E + MSI-H / dMMR + TMB-H + NRG1 fusion + NTRK fusion + RET fusion + KRAS G12C. Molecular testing results directly affect:

2L targeted accessibility (FGFR2 → pemigatinib / futibatinib / erdafitinib; IDH1 → ivosidenib; HER2 → zanidatamab / T-DXd / tucatinib + trastuzumab; BRAF V600E → dabrafenib + trametinib; NTRK → larotrectinib / entrectinib / repotrectinib; MSI-H → pembrolizumab / dostarlimab; NRG1 → zenocutuzumab; G12C → adagrasib; RET → selpercatinib / pralsetinib)
1L regimen selection (if the FIGHT-302 manuscript is positive, FGFR2+ ICC 1L may switch to pemigatinib monotherapy replacing IO + GemCis)
Clinical trial enrollment (FIGHT-302 / ACTICCA-1 / GEMSTONE-202 and other domestic / global recruitment)

Missing any biomarker = missing an ORR 30-50% high-yield responder population — in BTC, a tumor with 8-9 parallel biomarker pathways, the cost of non-testing is far higher than in NSCLC.

3.2 Advanced 1L: the two PD-(L)1 choices in the IO + GemCis class effect for fit patients

2026 mainstream: treatment-naive advanced BTC (regardless of PD-L1 status) preferred option = IO + GemCis × 8 cycles → IO maintenance — two independent phase III datasets with HR converging on 0.80-0.83.

Subgroup	Preferred	Alternative
All-comers PD-L1 unselected fit	durvalumab + GemCis [TOPAZ-1 PMID 38319896] or pembrolizumab + GemCis [KEYNOTE-966 PMID 37075781]	GemCis alone (when IO is not tolerated)
FGFR2 fusion+ ICC	(current) IO + GemCis; (once FIGHT-302 manuscript published) pemigatinib 1L replacement [FIGHT-302 PMID 32677452 ESMO 2024]	IO + GemCis fallback
Chinese / Asian patients	durvalumab / pembrolizumab + GemCis	Awaiting GEMSTONE-202 manuscript
ECOG 2 / IO-intolerant	GemCis alone [ABC-02 PMID 20375404]	Gemcitabine monotherapy (most frail)

Contraindicated / not recommended in 2026:

Triplet GemCis + nab-paclitaxel (SWOG-1815 PMID 39671534 negative)
Triplet mFOLFIRINOX replacing GemCis (AMEBICA PMID 34662180 negative)
Triplet GCS (GemCis + S-1, KHBO1401-MITSUBA PMID 35900311 ITT negative)

NCCN 2026: durvalumab + GemCis and pembrolizumab + GemCis are co-listed as Category 1 preferred (treatment-naive advanced BTC, regardless of subtype / PD-L1).

3.3 Adjuvant regimen: capecitabine vs S-1 vs GemCis-CRT three paths

2026 mainstream:

Western / international default: capecitabine × 8 cycles (BILCAP per-protocol significant / ITT borderline, PMID 30922733) — globally adopted by guidelines
Asian / Japanese preferred: S-1 × 4 cycles (ASCOT ITT positive HR 0.69, PMID 36681415) — the “Eastern-specific” path standing alongside BILCAP, well-tolerated given DPYD polymorphism background
R1-margin / N+ ECC / GBC: adjuvant chemo → CRT (SWOG-S0809 PMID 25964250 / OSTWAL 2024 PMID 38958997, the latter being the first GBC-only DFS-positive RCT)
Not recommended as adjuvant: GEMOX (PRODIGE-12 PMID 30707660 negative) + gemcitabine monotherapy (BCAT PMID 29405274 negative, IPD meta PMID 35182925 reaffirmed)

Key unresolved question: GemCis doublet vs capecitabine monotherapy in adjuvant — only ACTICCA-1 (PMID 26228433 design paper, NCT02170090) can answer directly; still ongoing as of 2026-04. Before ACTICCA-1 readout, 2026 clinical practice still uses capecitabine (West) / S-1 (Japan) as baseline.

NCCN V1.2026: capecitabine = Category 1 adjuvant standard for resected BTC. S-1 = Category 2A (based on ASCOT, not restricted to Asia but Western data lacking). CRT retained as Category 2B option in R1 / N+ settings.

3.4 Precision therapy eight pathways: which biomarker → which drug

Biomarker	BTC-enriched subtype	Prevalence (BTC overall / enriched subtype)	Preferred drug (FDA approval status)	Key trial
FGFR2 fusion / rearrangement	ICC	~10-15% ICC	pemigatinib (2020-04 FDA accelerated) / futibatinib (2022-09) / erdafitinib (2024-09 tumor-agnostic)	FIGHT-202 [PMID 32203698] / FOENIX-CCA2 [PMID 36652354] / RAGNAR [PMID 37541273]
IDH1 R132 mutation	ICC	~10-20% ICC	ivosidenib (2021-08 FDA approved)	ClarIDHy [PMID 32416072]
HER2 amp / overexp	GBC	~15-20% GBC	zanidatamab (2024-08 FDA accelerated) / T-DXd (2024-04 tumor-agnostic) / tucatinib + trastuzumab (off-label) / pertuzumab + trastuzumab	HERIZON-BTC-01 [PMID 37276871] / DESTINY-PanTumor02 [PMID 37870536] / SGNTUC-019 [PMID 37751561] / MyPathway-BTC [PMID 34339623]
BRAF V600E	ICC	~3-5% ICC	dabrafenib + trametinib (2022 tumor-agnostic)	ROAR-BTC [PMID 32818466] / NCI-MATCH-H [PMID 32758030]
NTRK fusion	cross-subtype	<1% BTC	larotrectinib / entrectinib / repotrectinib (next-gen)	NAVIGATE [PMID 29466156] / STARTRK [PMID 31838007] / TRIDENT-1 [PMID 41639379]
MSI-H / dMMR	cross-subtype	~2-3% BTC	pembrolizumab / dostarlimab	KEYNOTE-158 [PMID 31682550] / ANDRE-2023 [PMID 37917058]
TMB-H	cross-subtype	~3-5% BTC	nivolumab + ipilimumab	CHECKMATE-848 [PMID 39107131]
NRG1 fusion	cross-subtype (KRAS-WT enriched)	<1% BTC	zenocutuzumab (2024-08 FDA accelerated)	ENRGY [PMID 39908431]
KRAS G12C	cross-subtype	~1-2% BTC	adagrasib	KRYSTAL-1-BTC [PMID 37099736]
RET fusion	cross-subtype	<1% BTC	selpercatinib / pralsetinib (tumor-agnostic)	LIBRETTO-001 [PMID 36108661] / ARROW-BTC [PMID 35962206]

Clinical decision implication: 2026 BTC precision therapy = “test without fail for 2L, test as early as possible for 1L.” The 2L decision window requires NGS report in hand within 4-6 weeks; FGFR2 fusion + IDH1 mutation + HER2 amp + BRAF V600E are the four ICC/GBC-enriched high-yield must-tests.

3.5 Advanced 2L+: FOLFOX + East-West nal-IRI divergence + IO/regorafenib fallback

2026 mainstream:

Global default: mFOLFOX + ASC (ABC-06 PMID 33798493, HR 0.69 marginal win)
Asia / Korea: nal-IRI + 5FU/LV based on NIFTY PFS data (PMID 36951834 PFS HR 0.56 positive) — note OS negative
West: nal-IRI + 5FU/LV used cautiously — NALIRICC (PMID 38870977) OS negative / borderline
MSI-H / dMMR / TMB-H selective: anti-PD-1 monotherapy (pembrolizumab / dostarlimab) or nivo + ipi (CHECKMATE-848 data)
Biomarker-negative + multiline exhausted: regorafenib (SUN-2019-REGO-BTC PMID 30561756, DCR 56% / ORR 11% palliative only)

Clinical implication of the East-West nal-IRI divergence: do not extrapolate NIFTY Korean data to Western BTC, or vice versa. BTC’s cross-population heterogeneity is larger than typically assumed — possible PK / molecular background differences (HBV / liver fluke vs sporadic) / ICC-to-ECC ratio differences need to be considered separately.

3.6 Three-subtype differences (GBC / ICC / ECC): biomarker enrichment and decision triage

Although most registration trials enrolled mixed three subtypes (TOPAZ-1 ICC 56%, KEYNOTE-966 GBC 30%, BILCAP mixed three-subtype, etc.), biomarker enrichment differences determine subtype-specific triage for precision therapy:

Subtype	Enriched biomarker	Priority precision testing	Notes
ICC (intrahepatic cholangiocarcinoma)	FGFR2 fusion 10-15% / IDH1 mutation 10-20% / BRAF V600E 3-5%	FGFR2 + IDH1 + BRAF V600E triad	ICC is the most precision-therapy-dense BTC subtype
GBC (gallbladder cancer)	HER2 amp / overexp 15-20%	HER2 IHC + ISH must-test	GBC + HER2 = BTC’s second-largest precision niche; OSTWAL 2024 suggests GemCis-CRT intensification in high-risk GBC adjuvant
ECC (extrahepatic cholangiocarcinoma)	no single obvious enriched biomarker	comprehensive NGS looking for BRAF / NTRK / MSI-H / NRG1 / RET	ECC has the lowest precision hit rate; SWOG-S0809 CRT intensification in R1 / N+ setting
Three subtypes shared	MSI-H ~2-3% / NTRK <1% / NRG1 <1% / KRAS G12C ~1-2% / RET <1%	tumor-agnostic basket pathways	shared cross-subtype, not subtype-restricted

4. Research Gaps: the ten unresolved clinical questions

This report identifies the following gaps, all concretely defined questions (not the cliché of “more research needed”):

GemCis doublet vs capecitabine monotherapy in adjuvant head-to-head: post-BILCAP all guidelines adopted capecitabine but on a borderline ITT; ACTICCA-1 (NCT02170090) answers directly, still no readout as of 2026-04, key 2026-2027 inflection point.
FGFR2+ ICC 1L pemigatinib vs IO + GemCis: FIGHT-302 (NCT03656536) reported positive PFS at ESMO 2024, full manuscript and OS data still unpublished as of 2026-04; if published positive, it would be BTC’s first precedent of “molecular-selected 1L replacing class-effect IO + chemo.”
East-West nal-IRI 2L divergence: NIFTY (Korea PFS positive PMID 36951834) vs NALIRICC (Germany OS negative borderline PMID 38870977) — same drug, same 2L, different results — which of PK / molecular background / ICC-vs-ECC ratio / trial design is the dominant explanation? No matched prospective analysis exists.
IO benefit biomarker enrichment in TOPAZ-1 and KEYNOTE-966: neither phase III used PD-L1 selection but the 24-month landmark shows long-tail enrichment — who are the “long-tail responders”? Need pre-specified PD-L1 / TMB / dMMR / IFN-γ signature retrospective analysis and prospective validation.
HER2 IHC 3+ vs 2+ differentiated decisions: DESTINY-PanTumor02 BTC cohort IHC 3+ ORR 56% vs IHC 2+ 20% (PMID 37870536) — suggesting IHC score should be a stratification variable for treatment intensity, but a unified algorithm integrating IHC + ISH + NGS is missing.
MSI-H in BTC only 2-3%: KEYNOTE-158 BTC ORR 40.9% (PMID 31682550) is significant but N=22 too small; does BTC need a microsatellite + TMB + dMMR IHC tripartite panel to improve detection?
High-risk GBC adjuvant CRT with GemCis vs capecitabine choice: OSTWAL 2024 (PMID 38958997, India, GemCis + CRT positive) vs SWOG-S0809 (PMID 25964250, US, GemCap + CRT single-arm) — head-to-head between the two different chemo backbones is missing.
GEMSTONE-202 absent: China sugemalimab + GemCis 1L phase III data reported positive at ASCO GI 2024-2025 but manuscript and NCT registration both untraceable as of 2026-04; Chinese IO + GemCis practice evidence lacks a rigid 1L benchmark.
NRG1 / KRAS G12C / RET fusion in BTC cohorts too small: ENRGY BTC subgroup n=3-5, KRYSTAL-1-BTC n=12, LIBRETTO-001 BTC n=7 — all tumor-agnostic basket subsets, lacking BTC-only confirmatory data.
Late-line (3L+) BTC data nearly blank: all phase III concentrated on 1L/2L; beyond 3L there is no standard regimen, no large RCT, no ctDNA-guided treatment rotation protocol.

5. 2024-2026 latest developments

5.1 FDA / NMPA new approvals (ten key entries)

Drug	Agency	Date	Indication / supporting trial
zanidatamab (Ziihera)	FDA	2024-08-29	2L+ HER2 amp BTC / HERIZON-BTC-01 [PMID 37276871]
pembrolizumab + GemCis	FDA	2023-10-31	1L advanced BTC (regardless of PD-L1) / KEYNOTE-966 [PMID 37075781]
durvalumab + GemCis	FDA	2022-09-02	1L advanced BTC (regardless of PD-L1) / TOPAZ-1 [PMID 38319896]
trastuzumab deruxtecan (Enhertu)	FDA	2024-04-05	tumor-agnostic HER2 IHC 3+ solid tumors (including BTC) / DESTINY-PanTumor02 [PMID 37870536]
futibatinib (Lytgobi)	FDA	2022-09-30	2L+ FGFR2 rearrangement+ ICC / FOENIX-CCA2 [PMID 36652354]
erdafitinib (Balversa)	FDA	2024-09-23	tumor-agnostic FGFR-altered solid tumors (including BTC) / RAGNAR [PMID 37541273]
zenocutuzumab (Bizengri)	FDA	2024-08-26	NRG1 fusion+ NSCLC and pancreatic cancer (tumor-agnostic data supports BTC) / ENRGY [PMID 39908431]
ivosidenib (Tibsovo)	FDA	2021-08-25	2L+ IDH1+ CCA / ClarIDHy [PMID 32416072]
pemigatinib (Pemazyre)	FDA	2020-04-17	2L+ FGFR2+ CCA / FIGHT-202 [PMID 32203698]
repotrectinib (Augtyro)	FDA	2023-11-15	tumor-agnostic NTRK fusion+ solid tumors (BTC applicable) / TRIDENT-1 [PMID 41639379]

(This section shows 10 key approvals; the complete BTC-related approval record also includes dabrafenib + trametinib tumor-agnostic 2022 / pembrolizumab MSI-H 2017 / dostarlimab dMMR 2021 / larotrectinib 2018 / entrectinib 2019 / selpercatinib + pralsetinib RET tumor-agnostic 2022 / adagrasib NSCLC KRAS G12C 2022 and other tumor-agnostic pathways)

5.2 Key conference readouts (2024-2026, lower-weighted tagging)

The following entries are candidate-pool only before formal peer review, not in the main database. Those with PMIDs have been promoted to the main database.

FIGHT-302 ESMO 2024 oral (Bekaii-Saab et al.): 1L FGFR2+ ICC pemigatinib vs GemCis PFS-positive readout; full OS / ORR / safety manuscript still not published in a peer-reviewed journal as of 2026-04 — will rewrite the §3.2 decision tree once published.
GEMSTONE-202 ASCO GI 2024-2025 (CStone Pharmaceuticals): China sugemalimab + GemCis 1L phase III positive readout — manuscript and NCT ID both untraceable as of 2026-04.
TRIDENT-1 long-term follow-up (TRK-naive BTC subgroup data): awaiting 2026 H2 update.
ACTICCA-1 interim safety (reported 2024-2025): no primary readout yet, awaiting 2026-2027 H1.
HERIZON-BTC-302 phase III (zanidatamab 1L in HER2+ BTC): ongoing, readout awaited 2027+.

5.3 Ongoing phase III (2025-2028 readout highlights)

FIGHT-302 (NCT03656536, pemigatinib 1L vs GemCis in FGFR2+ ICC) — 2026 H2 full manuscript expected
ACTICCA-1 (NCT02170090, GemCis vs capecitabine adjuvant head-to-head) — 2026-2027 primary completion
HERIZON-BTC-302 (zanidatamab 1L combination phase III in HER2+ BTC) — 2027+
GEMSTONE-202 (China sugemalimab + GemCis 1L) — manuscript pending publication
Multiple IDH1 / FGFR2 / HER2 / NRG1 / KRAS G12C confirmatory phase III / single-arm registrational trials ongoing for 2026-2028

6. Convergent insights and judgments

6.1 Vertical × Horizontal: the 2026 BTC landscape is shaped by three “resonances”

Overlaying vertical paradigm evolution and horizontal current decision landscape, the 2026 BTC landscape is a superposition of three resonances:

GemCis dominates 12 years → IO double-hit class effect (HR 0.80-0.83 narrow-band convergence): the GemCis uniform standard starting from ABC-02 in 2010 persisted for 12 years, rewritten simultaneously by TOPAZ-1 + KEYNOTE-966 using two independent PD-(L)1 inhibitors — HR converging at 0.80-0.83 this narrow band is the textbook definition of class effect. Homologous to the pembro + chemo / atezo + chemo multi-IO class effect in NSCLC.
8 biomarker-matched pathways in parallel + three-subtype biomarker enrichment differences: FGFR2 / IDH1 enriched in ICC 10-20%, HER2 enriched in GBC 15-20%, BRAF / NTRK / MSI-H / NRG1 / KRAS G12C / RET shared cross-subtype. Collectively covering 30-40% of patients — this density is second only to NSCLC (10+ biomarkers covering 50%+), far exceeding HCC (0 biomarkers) and pancreatic cancer (POLO + 5%). BTC is the second GI tumor after NSCLC to truly enter the “molecular-selected first” era.
Three-path adjuvant parallelism + East-West divergence: capecitabine (BILCAP, West), S-1 (ASCOT, Asia), GemCis-CRT (SWOG-S0809 / OSTWAL 2024, R1/N+ ECC/GBC) three paths + ACTICCA-1 head-to-head pending. East-West BTC is not only epidemiologically different (Asia GBC-heavy / West ICC-heavy / India high-risk GBC), but treatment selection itself diverges East-West.

These three resonances together explain one clinical phenomenon: the 1L decision tree for a newly diagnosed advanced BTC patient in 2026 has 4 more decision layers than in 2018 (subtype classification → full-panel molecular testing → IO + GemCis vs FGFR2-selective 1L → Chinese / Western IO selection + clinical trial enrollment).

6.2 Clinical decision takeaways (for junior-mid oncologists)

“Panel first, then decide” is already SoC: in 2026, starting IO + GemCis for a newly diagnosed advanced BTC without comprehensive molecular profiling is wrong — missing any of FGFR2 / IDH1 / HER2 / BRAF / MSI-H / NRG1 / KRAS G12C / RET equals missing an ORR 30-50% response path.
Advanced 1L defaults to IO + GemCis class effect: durvalumab + GemCis (TOPAZ-1) and pembrolizumab + GemCis (KEYNOTE-966), choose one, HR converging 0.80-0.83. Do not use GemCis monotherapy as 1L SoC anymore.
Triplet 1L rejected by three independent phase III: SWOG-1815 (add nab-pac) / AMEBICA (switch to mFFX) / KHBO1401-MITSUBA (add S-1) all failed — do not try triplet combinations replacing the GemCis backbone again.
2026 adjuvant default capecitabine (West) / S-1 (Asia): GEMOX and gemcitabine monotherapy adjuvant exit the recommendation (PRODIGE-12 / BCAT negative, IPD meta reaffirmed). Reassess whether to switch to GemCis only after ACTICCA-1 readout.
R1 / N+ ECC/GBC add CRT: SWOG-S0809 (ECC + GBC) and OSTWAL 2024 (GBC only) supporting data — not universal adjuvant, but high-risk subgroup intensification.
ICC patients: focus on FGFR2 + IDH1 + BRAF V600E triad: ICC is the most precision-therapy-dense subtype; any one positive in the triad opens a phase III-level targeted path.
GBC patients: HER2 IHC + ISH must-test: GBC is BTC’s second-largest precision niche; HER2+ GBC has 4 mechanistically distinct targeted options (zanidatamab / T-DXd / tucatinib + trastuzumab / pertuzumab + trastuzumab) to choose from.
2L FOLFOX is default + note East-West nal-IRI divergence: mFOLFOX + ASC (ABC-06) is global default. Do not extrapolate NIFTY Korean PFS-positive to the West — NALIRICC was OS-negative borderline in Germany.
Late-line IO monotherapy recommended only for MSI-H / dMMR / TMB-H: in unselected populations IO monotherapy ORR 22% looks useful but PFS is short (KIM-2020-NIVO-BTC); use only after biomarker selection.
The 9 BTC drug classes to know in 2026: durvalumab + pembrolizumab + GemCis (1L backbone) / mFOLFOX (2L) / pemigatinib + futibatinib + erdafitinib (FGFR2) / ivosidenib (IDH1) / zanidatamab + T-DXd + tucatinib + trastuzumab + pertuzumab + trastuzumab (HER2) / dabrafenib + trametinib (BRAF V600E) / pembrolizumab + dostarlimab (MSI-H) / zenocutuzumab (NRG1) / adagrasib (KRAS G12C) / selpercatinib + pralsetinib (RET) / larotrectinib + entrectinib + repotrectinib (NTRK) — 16 years ago BTC had only the GemCis one-size-fits-all option; 2026 is already a complex decision map of 16+ drugs and 8 parallel precision pathways.

7. Information sources

The metadata of the 39 trials in this report was independently verified via PubMed and ClinicalTrials.gov. Each [PMID xxxxxxxx] in the text can be directly verified on PubMed.

Published trials: 37, covering 2010-2026 (all PMID-verifiable)
Ongoing / design papers: 2 (FIGHT-302 PMID 32677452 design paper + ACTICCA-1 PMID 26228433 design paper, primary-result manuscripts pending)
NCCN guideline citations: 39/39 directly hit NCCN Biliary Tract Cancers V1.2026 reference section or extended evidence base
2017-2024 FDA new approvals: 10+ (durvalumab / pembrolizumab + GemCis / pemigatinib / futibatinib / erdafitinib / ivosidenib / zanidatamab / T-DXd / zenocutuzumab / repotrectinib / dabrafenib + trametinib / larotrectinib / entrectinib / selpercatinib / pralsetinib / pembrolizumab + dostarlimab MSI-H / dMMR / nivo + ipi TMB-H and other tumor-agnostic pathways)
2024-2026 key conference readouts: 3 (FIGHT-302 ESMO 2024 / GEMSTONE-202 ASCO GI 2024-2025 / TRIDENT-1 long-term follow-up) — awaiting manuscript upgrade
Supporting PMIDs (cited in text but not in main trial table): 3 (ClarIDHy OS update PMID 34554208 / KEYNOTE-158 long-term follow-up PMID 35680043 / BCAT + PRODIGE-12 IPD meta PMID 35182925)
Research gaps: 10

7.1 Report-body citation list (sorted by PMID)

The table below lists the PMIDs bracket-cited in the report body, each clickable for PubMed URL verification.

PMID	Trial / Paper	Year	Journal	Text location
20375404	ABC-02	2010	NEJM	§2.2 / §3.2
25964250	SWOG-S0809	2015	J Clin Oncol	§2.1 / §3.3
26228433	ACTICCA-1 (design paper)	2015	BMC Cancer	§2.1 / §2.5 / §3.3 / §4
29405274	BCAT	2018	Br J Surg	§2.1 / §3.3
29466156	NAVIGATE-LAROTRECTINIB	2018	NEJM	§2.4.5 / §3.4
30561756	SUN-2019-REGO-BTC	2019	Cancer	§2.3 / §3.5
30707660	PRODIGE-12	2019	J Clin Oncol	§2.1 / §3.3
30922733	BILCAP	2019	Lancet Oncol	§2.1 / §3.3
31682550	KEYNOTE-158-MSIH	2020	J Clin Oncol	§2.4.6 / §3.4 / §4
31838007	STARTRK-ENTRECTINIB	2020	Lancet Oncol	§2.4.5 / §3.4
32203698	FIGHT-202	2020	Lancet Oncol	§2.4.1 / §3.4 / §5.1
32352498	KIM-2020-NIVO-BTC	2020	JAMA Oncol	§2.3 / §6.2
32416072	ClarIDHy (primary)	2020	Lancet Oncol	§2.4.2 / §3.4 / §5.1
32677452	FIGHT-302 (design paper)	2020	Future Oncol	§2.4.1 / §2.5 / §3.2 / §4
32758030	NCI-MATCH-H	2020	J Clin Oncol	§2.4.4 / §3.4
32818466	ROAR-BTC	2020	Lancet Oncol	§2.4.4 / §3.4
33798493	ABC-06	2021	Lancet Oncol	§2.3 / §3.5
34339623	MyPathway-BTC	2021	Lancet Oncol	§2.4.3 / §3.4
34554208	ClarIDHy OS update	2021	JAMA Oncol	§2.4.2 (supporting)
34662180	AMEBICA / PRODIGE-38	2022	J Clin Oncol	§2.2 / §3.2
35182925	BCAT + PRODIGE-12 IPD meta	2022	Eur J Cancer	§2.1 (supporting) / §3.3
35680043	KEYNOTE-158 long-term follow-up	2022	Ann Oncol	§2.4.6 (supporting)
35900311	KHBO1401-MITSUBA	2023	J Hepatobiliary Pancreat Sci	§2.2 / §3.2
35962206	ARROW-BTC	2022	Nat Med	§2.4.9 / §3.4
36108661	LIBRETTO-001-BTC	2022	Lancet Oncol	§2.4.9 / §3.4
36652354	FOENIX-CCA2	2023	NEJM	§2.4.1 / §3.4 / §5.1
36681415	ASCOT / JCOG1202	2023	Lancet	§2.1 / §3.3
36951834	NIFTY	2023	JAMA Oncol	§2.3 / §3.5 / §4
37075781	KEYNOTE-966	2023	Lancet	§2.2 / §3.2 / §5.1
37099736	KRYSTAL-1-BTC	2023	J Clin Oncol	§2.4.8 / §3.4
37276871	HERIZON-BTC-01	2023	Lancet Oncol	§2.4.3 / §3.4 / §5.1
37541273	RAGNAR	2023	Lancet Oncol	§2.4.1 / §3.4 / §5.1
37751561	SGNTUC-019	2023	J Clin Oncol	§2.4.3 / §3.4
37870536	DESTINY-PanTumor02	2024	J Clin Oncol	§2.4.3 / §3.4 / §4 / §5.1
37917058	ANDRE-2023-DOSTARLIMAB	2023	JAMA Netw Open	§2.4.6 / §3.4
38319896	TOPAZ-1	2022	NEJM Evid	§2.2 / §3.2 / §5.1
38870977	NALIRICC	2024	Lancet Gastroenterol Hepatol	§2.3 / §3.5 / §4
38958997	OSTWAL-2024-GEMCIS-CRT-GBC	2024	JAMA Oncol	§2.1 / §3.3 / §4
39107131	CHECKMATE-848	2024	J Immunother Cancer	§2.4.6 / §3.4
39671534	SWOG-1815	2025	J Clin Oncol	§2.2 / §3.2 / §6.2
39908431	ENRGY	2025	NEJM	§2.4.7 / §3.4 / §5.1
41639379	TRIDENT-1	2026	Nat Med	§2.4.5 / §3.4 / §5.1

7.2 Verification conventions

Each PMID is directly accessible for verification via https://pubmed.ncbi.nlm.nih.gov/{PMID}/
Each NCT id is accessible via https://clinicaltrials.gov/study/{NCT_id}/
Conference abstracts (ASCO GI / ESMO / EORTC) are searched via official conference systems; all conference citations in this report are lower-weight tagged — not peer-reviewed, final data defers to journal publication
FIGHT-302 / ACTICCA-1 are cited via “design-paper PMID + ESMO/ASCO oral readout” before manuscript publication; the PMID will be updated once the formal manuscript is published
If you find a trial name / year / conclusion in this report inconsistent with PubMed for any PMID, corrections are welcome

The trial timeline lives here

Chinese: /trials/btc/ English: /en/trials/btc/

Each trial has an independent detail page, including:

Full intervention / comparator regimens
Primary endpoint values + 95% CI
Key findings + clinical significance
Clickable links to PMID / NCT original sources

39 trials · 4 chapters · 2010 to 2026 · synced with NCCN Biliary Tract Cancers V1.2026.

Closing

BTC has undergone a unique evolution in oncology over the past 16 years — from 2010’s ABC-02 enshrining GemCis as 1L unchallenged for 12 years, to 2022-2023’s TOPAZ-1 + KEYNOTE-966 writing IO into the 1L backbone with a narrow-band HR 0.80-0.83 class effect, to 2018-2026’s dense rollout of eight-to-nine biomarker-matched pathways (FGFR2 / IDH1 / HER2 / BRAF / NTRK / MSI-H / NRG1 / KRAS G12C / RET) covering 30-40% of patients.

BTC’s precision-therapy density is second only to NSCLC, far exceeding HCC (0 biomarker-matched approvals) and pancreatic cancer (POLO + 5%). What drives this difference is not incidence (BTC global incidence <3/100,000, well below gastric / liver cancers), but the uniqueness of molecular architecture — ICC enriched for FGFR2 fusion + IDH1 mutation, GBC enriched for HER2 amp, three subtypes sharing the MSI-H / BRAF / NTRK / NRG1 / KRAS G12C / RET tumor-agnostic basket pathways. This “subtype × biomarker dual heterogeneity” makes BTC a “PMID-traceable + mandatory-panel + multi-pathway-parallel” highly-precise tumor type.

The value of this report lies not in “exhaustively listing all trials” (PubMed can), but in compressing 16 years of evolution + current decisions + unresolved gaps into the cognitive bandwidth of a single read. Next time you face a newly diagnosed BTC patient, every branch of the decision tree will have this map to consult, trace, and question.

Clinician × AI = Research Superpower + Clinical Decision Amplifier

—— Dual Brain Lab · 2026-04-21

Breast Cancer Clinical Trials Landscape · NCCN v2.2026 Roadmap

Tue, 21 Apr 2026 00:00:00 +0000

Curated by Dual Brain Lab (csilab.net) · Eleventh tumor type on the map Data cutoff: 2026-04 · Guideline anchor: NCCN Breast Cancer v2.2026 (Feb 27, 2026)

This post indexes all 86 landmark trials under /trials/breast/ into a full-view timeline, laid out along the 7-chapter skeleton of NCCN v2.2026. Breast cancer is the first tumor type on this site to introduce subtype-stratified narrative — §2 and §3 each split internally into three H3 tracks: HR+/HER2- / HER2+ / TNBC.

Quick entries by subtype:

→ HR+/HER2- (endocrine + CDK4/6 + PI3K/mTOR + SERD)
→ HER2+ (anti-HER2 + T-DXd + TKI)
→ TNBC / BRCA (IO + PARP + TROP2 ADC)

1. Clinical Landscape

The world’s largest female solid tumor. GLOBOCAN 2022: 2.3 M new cases and 670 k deaths worldwide, making breast cancer the #1 cancer in women globally. China’s 2022 NCCR data show ~400 k new cases (second only to lung cancer), with a notably lower mortality rate than the West — the combined result of early screening, standardized adjuvant care, and public-healthcare access.

Three subtypes, decades of groundwork. Breast is the first solid tumor to be opened up by molecular subtyping:

1975 — Jensen defines ER (estrogen receptor), establishing the HR+/HR- axis.
1987 — Slamon identifies HER2 overexpression; trastuzumab enters Phase I two years later; FDA approval in 1998 makes it the first targeted therapy for any solid tumor.
2005 — Perou proposes the PAM50 molecular subtype and the name TNBC (triple-negative breast cancer), locking in the modern HR / HER2 / TNBC three-pillar framework.

The 2023 re-stratification. In 2023, ASCO-CAP updated HER2 testing guidelines, renaming IHC 2+/1+ (FISH-negative) as HER2-low and adding HER2-ultralow (IHC > 0 but < 1+). The move directly brought the positive populations of DESTINY-Breast04 and DB06 — both trastuzumab deruxtecan (T-DXd) randomized trials — into the guidelines. “HER2-negative” is no longer a homogeneous population.

The rhythm of treatment. Breast cancer has gone through five paradigm shifts in the past 25 years:

Foundation era (1990s–2000) — tamoxifen / ATAC / HERA / NSABP B-31·N9831.
Anti-HER2 expansion (2000–2015) — trastuzumab → pertuzumab (CLEOPATRA) → T-DM1 (EMILIA / KATHERINE).
CDK4/6 × HR+ precision (2015–2025) — PALOMA / MONALEESA / MONARCH families × advanced 1L/2L × adjuvant extension (monarchE / NATALEE).
ADC reshaping (2020–2025, the headline act) — DESTINY-Breast 03/04/06/09 · ASCENT / TROPION-Breast02 · SHR-A1811 · RC48.
IO breakthrough (2020–2025) — KEYNOTE-522/355 · IMpassion130 · ASCENT-04 IO+ADC combos.

China’s pace. NMPA approvals of domestic or independent Phase IIIs from 2021–2025 include DAWNA-1/2 (dalpiciclib) · PHOEBE (pyrotinib vs lapatinib) · PHILA (pyrotinib + trastuzumab 1L HER2+) · SHR-A1811 (disitamab deruxtecan-like ADC) · RC48 (disitamab vedotin) · TORCHLIGHT (toripalimab + chemo 1L TNBC) · CAMBRIA (camrelizumab + chemo). In 2025, breast accounted for ~20% of new oncology approvals in China — the #2 most active tumor type.

Epidemiologic divergence drives treatment divergence. Chinese breast cancer has a median age of ~45–55 at diagnosis (vs 60–65 in the West), with a markedly higher share of premenopausal patients. This directly shapes: the OFS + AI vs tamoxifen premenopausal adjuvant pathway; the carboplatin threshold in neoadjuvant regimens; fertility-preservation and reproductive-endocrine counseling pathways; and the uptake of third-generation oral SERDs. China’s 1L breast cancer data now enter the global conversation as independent contributions, not merely as “confirmatory supplements” to international Phase IIIs.

Three drivers of falling mortality. Breast cancer mortality has dropped ~40% in the West and ~25% in China’s tier-1/2 cities over the past 30 years. Three stacked drivers: (1) early screening (mammography + MRI) has pushed the early-stage diagnosis share from ~30% to 60%+; (2) standardization of adjuvant therapy (5–10 years of endocrine + 1 year of anti-HER2 + individualized chemo) has lowered recurrence; (3) dense launches of late-stage drugs (CDK4/6 / T-DXd / sacituzumab / KEYNOTE-522 / OlympiA) have pushed median OS up another notch. The three-layer effect makes breast cancer the flagship for “early screening × standardization × innovative drugs” as a combined success story in oncology.

2024–2026 regulatory highlights.

2024-02 FDA — elacestrant (EMERALD) approved for ESR1mut 2L+ post-CDK4/6 HR+/HER2- mBC.
2024-06 FDA — capivasertib + fulvestrant (CAPItello-291) approved for HR+/HER2- mBC with AKT pathway alterations post-endocrine.
2024-10 FDA — inavolisib + palbociclib + fulvestrant (INAVO120) approved for PIK3CAmut HR+/HER2- mBC 1L.
2024-08 FDA — datopotamab deruxtecan (Dato-DXd, TROPION-Breast01) approved for HR+/HER2- mBC post-endocrine + 1 line chemo.
2024-09 FDA — T-DXd expansion into HER2-ultralow (IHC > 0 but < 1+) endocrine-resistant HR+/HER2- mBC (DESTINY-Breast06).
2025-Q1 NMPA — dalpiciclib + letrozole 1L HR+/HER2- mBC (DAWNA-2 supporting).
2025 ASCO — DESTINY-Breast09 topline: T-DXd + pertuzumab 1L HER2+ mBC vs CLEOPATRA backbone — challenging a ten-year standard.
2025 ESMO — ASCENT-04 sacituzumab govitecan + pembrolizumab 1L mTNBC PD-L1+ data matures.
2025 SABCS — SERENA-6 camizestrant ctDNA-guided switch is positive — the first Phase III proof of ctDNA-guided precision therapy in breast cancer.

2. Current Treatment Paradigms

Breast cancer treatment must be laid out by molecular subtype — the drug arsenal is almost entirely non-overlapping across the three types: HR+/HER2- centers on the endocrine backbone; HER2+ on the anti-HER2 backbone; TNBC has only chemo + IO + PARP + ADC. This chapter walks through all three.

HR+/HER2-

Share and backbone. HR+/HER2- is about 65–70% of breast cancer — the largest subtype. The backbone has gone through four generations of layering: endocrine (SERM / AI / fulvestrant) → CDK4/6 inhibitor addition → PI3K/mTOR/AKT pathway drugs keyed to mutations → oral SERD (selective estrogen receptor degrader) as the newest layer.

The endocrine backbone. ATAC (2010) established anastrozole’s adjuvant advantage in postmenopausal ER+ early breast cancer — 10-year DFS 79.9% vs tamoxifen 77.6%. MA.17 / MA.17R extended letrozole into a 10-year AI regimen, supporting extended adjuvant in high-risk postmenopausal patients. ATLAS (2013) extended tamoxifen adjuvant from 5 to 10 years, establishing the extension strategy for premenopausal women or those intolerant of AIs. The twin trials SOFT / TEXT established the DFS benefit of “ovarian function suppression (OFS) + AI” in high-risk premenopausal patients. This endocrine backbone remains, as of 2026, the foundation for the vast majority of HR+/HER2- patients.

CDK4/6 enters the late-stage setting. From 2015 to 2020, three CDK4/6 inhibitors arrived almost in lockstep:

Palbociclib — PALOMA-2 (1L + letrozole) and PALOMA-3 (fulvestrant + palbo 2L), establishing the 2L endocrine + CDK4/6 standard.
Ribociclib — MONALEESA-2 (postmenopausal 1L) · MONALEESA-3 (fulvestrant combo) · MONALEESA-7 (premenopausal + OFS), the unique trio that delivered an OS benefit.
Abemaciclib — MONARCH-2 (fulvestrant 2L) · MONARCH-3 (1L), showing OS advantage.

All three pushed median PFS from endocrine mono’s 9–14 months up to 24–28 months — the deepest single reshape of the HR+/HER2- metastatic landscape.

CDK4/6 extends into the adjuvant setting. monarchE (abemaciclib × 2 years, for N+ ≥ 4 or 1–3+ with high-risk features) and NATALEE (ribociclib × 3 years, for node-any including stage IIA) carried CDK4/6 from advanced into adjuvant. The two trials differ in enrollment breadth, follow-up duration, and DFS HR — creating a real clinical-choice tension in 2026 (see §3).

PI3K / AKT / mTOR precision.

PIK3CA mutation → SOLAR-1 (alpelisib + fulvestrant) · INAVO120 (inavolisib + palbo + fulvestrant, 2024 NEJM, mPFS 15.0 vs 7.3 months).
AKT pathway (PIK3CA / AKT1 / PTEN mutations) → CAPItello-291 (capivasertib + fulvestrant, 2023 NEJM, mPFS 7.3 vs 3.1 months).
mTOR pathway → BOLERO-2 (everolimus + exemestane) as the historical cornerstone.

The oral SERD era.

EMERALD (elacestrant 2L post-CDK4/6, ESR1mut subgroup mPFS 3.8 vs 1.9 months) is the first oral SERD to win approval.
SERENA-6 (camizestrant ctDNA-guided ESR1mut switch, 2024) shows the precision-adjust pattern: detect resistance early via ctDNA → switch drugs preemptively.
EMBER-3 (imlunestrant ± abemaciclib, 2024 NEJM) opens options via its multi-arm design.
PADA-1 was the early proof-of-feasibility for ESR1mut-driven switching.

China’s contribution. DAWNA-1 / DAWNA-2 (dalpiciclib + fulvestrant, 2L post-CDK4/6) build a domestic data chain with China’s own CDK4/6i. postMONARCH (2024 SABCS) repositions abemaciclib for continued use after CDK4/6 resistance. BG01-2201L is a domestic oral SERD data extension.

2026 HR+/HER2- decision tree skeleton:

Premenopausal low-risk N0 early → tamoxifen 5–10 years (ATLAS) or OFS + AI (SOFT/TEXT high risk).
Postmenopausal early HR+/HER2- → AI 5 years + extension (MA.17R / ATAC).
N+ ≥ 4 or 1–3+ with high-risk features → adjuvant abemaciclib × 2 years (monarchE) or ribociclib × 3 years (NATALEE) on top of the endocrine backbone.
Advanced 1L HR+/HER2- → CDK4/6i + endocrine (any of palbo / ribo / abema, chosen by access + toxicity profile).
1L PIK3CAmut → INAVO120 inavolisib + palbo + fulv (2024 SABCS positive).
2L post-CDK4/6 → three branches by biomarker: ESR1mut → elacestrant / camizestrant (EMERALD / SERENA-6) · PIK3CAmut → alpelisib (SOLAR-1) · AKT pathway → capivasertib (CAPItello-291) · all negative → everolimus (BOLERO-2).

HER2+

Share and groundwork. HER2+ is about 15–20% of breast cancer. The 25-year treatment history is oncology’s most complete precision-therapy narrative arc — from trastuzumab to T-DXd, each of four drug generations pushed mortality risk down another notch.

Anti-HER2 backbone (adjuvant).

HERA (2005 NEJM, trastuzumab × 1 year adjuvant vs observation) and NSABP B-31 / NCCTG N9831 joint analysis rewrote the HER2+ early post-op standard in 2005, with DFS HR ~0.5–0.6.
BCIRG-006 (docetaxel + carbo + trastuzumab, TCH regimen) provided an anthracycline-sparing alternative.
APHINITY (pertuzumab added to trastuzumab + chemo adjuvant, 2017 NEJM) delivered iDFS benefit in high-risk (N+) subgroups — marginal in low-risk.
APT (2015 NEJM, low-risk T1N0 HER2+, paclitaxel + trastuzumab × 12 weeks adjuvant) set a de-escalation precedent — 7-year iDFS 93%.
ATEMPT (T-DM1 adjuvant vs THx in low-risk HER2+) — T-DM1 is an option in low-risk, but toxicity doesn’t favor it.
ExteNET (neratinib extended adjuvant) — marginal benefit in the HR+/HER2+ subgroup, use limited by toxicity.

Neoadjuvant standard.

NeoSphere (pertuzumab + trastuzumab + docetaxel neoadjuvant, pCR 45.8% vs 29%) is the proof-of-concept for dual-target neoadjuvant therapy.
TRYPHAENA (TCHP regimen safety) supports the regimen’s feasibility.
KRISTINE (T-DM1 + pertuzumab neoadjuvant vs TCHP) — the T-DM1 arm’s pCR was lower than TCHP (44% vs 56%), so TCHP remains the neoadjuvant first choice.
KATHERINE (2019 NEJM) is the inflection point for HER2+ neoadjuvant residual disease: in non-pCR patients, switching to T-DM1 vs continuing trastuzumab yielded iDFS HR 0.50, splitting adjuvant into two tracks: “pCR → trastuzumab / non-pCR → T-DM1”.

Advanced HER2+, 1L to 2L.

CLEOPATRA (Baselga 2012 NEJM PFS + Swain 2015 NEJM OS, pertuzumab + trastuzumab + docetaxel 1L mBC, mOS 56.5 vs 40.8 months, HR 0.68) has been the HER2+ advanced 1L standard for a full decade.
PHILA (pyrotinib + trastuzumab + docetaxel vs placebo + TH, China 2024) gives a domestic pan-HER TKI a 1L pathway.
EMILIA (T-DM1 2L vs lapatinib + capecitabine) · TH3RESA (T-DM1 3L+) established T-DM1’s position in anti-HER2 2L+.
MARIANNE (T-DM1 ± pertuzumab vs THx 1L) was negative on its primary endpoint — T-DM1 not recommended in 1L.
EGF104900 (lapatinib + trastuzumab dual-target vs lapatinib monotherapy) was the early evidence of dual-blockade advantage.
DESTINY-Breast03 (2022 NEJM, T-DXd vs T-DM1 in 2L HER2+ mBC, mPFS 28.8 vs 6.8 months, HR 0.33; OS HR 0.64) fully rewrote the 2L standard — T-DM1 in 2L now occupies only the “T-DXd unavailable / intolerable” slot.
DESTINY-Breast02 (T-DXd vs TPC post-T-DM1 resistance) confirmed T-DXd’s benefit in later lines.
DESTINY-Breast09 (T-DXd ± pertuzumab 1L HER2+ mBC, 2025 ASCO / NEJM) is challenging CLEOPATRA’s ten-year iron throne.

The CNS / brain metastasis line. HER2+ has a high brain-met risk (~30–50% of advanced patients), spawning an independent treatment line:

HER2CLIMB (2020 NEJM, tucatinib + trastuzumab + capecitabine vs TPC) is the first Phase III with intracranial PFS data in active brain metastases.
TUXEDO-1 — T-DXd in active brain mets, small Phase II positive.
DEBBRAH — T-DXd brain-met evidence.
PHENIX (pyrotinib + capecitabine 2L China 2019 Lancet Oncology) · PHOEBE (pyrotinib vs lapatinib 2L+ China 2021 Lancet Oncology) fill in the brain-met data for domestic TKIs.

The ADC new wave. Beyond T-DXd, China-originated ADCs are entering HER2+ later lines:

SHR-A1811-102 — Phase II HER2+ post-T-DM1 evidence for SHR-A1811 (a domestic HER2 ADC with topoisomerase payload).
HOPES — a China 2021 reinforcement of HER2+ TKI + chemo data.
RC48-C006 — RC48 (disitamab vedotin, China’s first domestic ADC) expanding HER2+ urothelial / breast indications.

2026 HER2+ decision tree skeleton:

Stage I T1N0 low-risk → adjuvant paclitaxel + trastuzumab × 12 weeks (the APT de-escalation path).
Stage II-III node+ high-risk → neoadjuvant TCHP × 6 cycles → surgery → if pCR, trastuzumab + pertuzumab to complete 1 year (APHINITY); if non-pCR, switch to T-DM1 × 14 cycles (KATHERINE).
Advanced 1L HER2+ mBC → pertuzumab + trastuzumab + docetaxel (CLEOPATRA, the ten-year standard); if DB09 confirms positive, may shift toward T-DXd + pertuzumab.
2L HER2+ mBC → T-DXd (established by DESTINY-Breast03).
3L+ HER2+ mBC → tucatinib + trastuzumab + capecitabine (HER2CLIMB, the first choice for active brain mets) · T-DM1 (retained for T-DXd-unavailable situations) · neratinib · lapatinib + cape · margetuximab.
Active brain mets → HER2CLIMB (tucatinib-based) or T-DXd (TUXEDO-1 / DEBBRAH).

TNBC

Share and genetics. TNBC is 10–15% of breast cancer — younger, more aggressive, with common brain / visceral metastasis; germline BRCA1/2 is enriched (~15–20% of TNBC). The four therapeutic cards are chemo + IO + PARP + ADC.

Chemotherapy backbone.

GeparSixto (2014 Lancet Oncology) · CALGB-40603 (2015 JCO) laid the evidentiary foundation for adding carboplatin to neoadjuvant TNBC chemotherapy — pCR improved, though DFS benefit had to be stratified in later trials.
BEATRICE (bevacizumab adjuvant TNBC) was negative on primary endpoint; bev is not considered for adjuvant.
BrighTNess (carbo + veliparib + paclitaxel neoadjuvant) validated the carbo pCR benefit; veliparib added no incremental value.

IO enters (the pivotal inflection).

IMpassion130 (2018 NEJM, atezolizumab + nab-paclitaxel 1L mTNBC, PD-L1+ subgroup mOS 25.0 vs 15.5 months) brought IO into mTNBC 1L for the first time — but IMpassion131 (paclitaxel backbone) failed to reproduce, creating tension in the choice of chemo backbone.
KEYNOTE-355 (2020 NEJM → 2022 final, pembrolizumab + chemo 1L mTNBC, CPS ≥ 10 subgroup mPFS 9.7 vs 5.6 months, mOS 23 vs 16 months) established pembro + chemo as the CPS ≥ 10 mTNBC 1L standard.
KEYNOTE-522 (2020 NEJM → 2024 EFS/OS, pembrolizumab + chemo neoadjuvant → pembro adjuvant in stage II-III TNBC, pCR 64.8% vs 51.2%, EFS HR 0.63, OS HR 0.66) pushed IO into TNBC early adjuvant — without PD-L1 screening.
KEYNOTE-119 (pembrolizumab monotherapy vs chemo 2L+ mTNBC) — negative; IO monotherapy 2L+ is not approved.
KEYNOTE-158 (pembrolizumab tumor-agnostic MSI-H) — TNBC subgroup evidence supports the MSI-H basket.
GeparNuevo (durvalumab + neoadjuvant chemo) — German Phase II that paved the way for KN-522.
IMpassion031 (atezolizumab + chemo neoadjuvant TNBC) — pCR benefit supported.

PARP enters.

OlympiAD (2017 NEJM, olaparib 2L+ germline BRCA1/2 mBC, mPFS 7.0 vs 4.2 months).
EMBRACA (2018 NEJM, talazoparib 2L+ gBRCA mBC).
OlympiA (2021 NEJM, olaparib × 1 year adjuvant gBRCA HER2- high-risk, iDFS HR 0.58, OS HR 0.68) is the dawn of the BRCA-targeted adjuvant era, pushing PARP from “germline BRCA advanced 2L” into adjuvant.

TROP2 ADC enters.

ASCENT (2021 NEJM, sacituzumab govitecan 2L+ mTNBC, mPFS 5.6 vs 1.7 months, mOS 12.1 vs 6.7 months, HR 0.48) is the TROP2 ADC cornerstone in mTNBC 2L+.
TROPION-Breast02 (datopotamab deruxtecan, 2025 ASCO) — Dato-DXd in mTNBC 1L vs TPC, expanding the TROP2 ADC footprint.
ASCENT-04 (sacituzumab govitecan + pembrolizumab 1L mTNBC PD-L1+) — early readout of an IO + ADC combo.

PI3K/AKT in TNBC. LOTUS (ipatasertib + paclitaxel 1L mTNBC) · PAKT (capivasertib + paclitaxel 1L mTNBC) provided the early AKT-inhibition signal in TNBC; after CAPItello-291’s approval in HR+/HER2-, the TNBC direction remains unsettled.

China’s contribution. TORCHLIGHT (toripalimab + nab-paclitaxel 1L mTNBC, China 2023 Nature Medicine) · CAMBRIA (camrelizumab + chemo neoadjuvant) · FUTURE-SUPER (Fudan umbrella trial matching treatment to the LAR / IM / BLIS / MES four-subtype classification) · NeoTRIP (atezolizumab neoadjuvant) form China’s TNBC data line. The LAR / BL1 / IM / MES four-subtype classification (Fudan Shao’s team) is the international-grade original contribution from China to TNBC molecular subtyping.

2026 TNBC decision tree skeleton:

Stage II-III TNBC neoadjuvant → pembrolizumab + carbo + taxane → AC → surgery → complete 1 year of pembro (KEYNOTE-522, no PD-L1 screening).
Non-pCR residual → capecitabine adjuvant (CREATE-X logic) · if gBRCA+, olaparib × 1 year adjuvant (OlympiA).
Stage I T1N0 TNBC → dose-dense AC-T or carbo-taxane; IO adjuvant is not yet covered.
Advanced 1L mTNBC → first check CPS (22C3 assay): CPS ≥ 10 → pembrolizumab + chemo (KEYNOTE-355) · CPS < 10 and gBRCA+ → talazoparib / olaparib (EMBRACA / OlympiAD) · otherwise → chemo (paclitaxel or eribulin).
2L+ mTNBC → sacituzumab govitecan (ASCENT, TROP2 ADC, no screening required) · if gBRCA+ and PARP-naive, PARP is still an option.
Post-resistance → Dato-DXd (TROPION-Breast02, pending approval) · ASCENT-04 IO + ADC combinations in later lines.

3. Current Controversies

Each subtype has its own “top unsolved questions”. Writing them separately by subtype reveals the tension points more clearly than mixing them together.

HR+/HER2-

CDK4/6 adjuvant coverage debate. monarchE restricts to node ≥ 4 or 1–3+ with high-risk features (Ki67 / grade / tumor size), abemaciclib × 2 years; NATALEE covers stage IIA-III node-any, ribociclib × 3 years. NATALEE’s broader enrollment brings in low-risk node+ patients, but the absolute benefit is smaller and the toxicity exposure longer. The 2026 clinical tension: how heavily should individual-risk tools (Oncotype / MammaPrint / Ki67) weigh into first-line and adjuvant decisions? NCCN v2.2026 recommends both in parallel, individualized to the patient’s risk profile and expected tolerability.

The sequencing war in endocrine resistance. ESR1mut → elacestrant (EMERALD) · PIK3CAmut → alpelisib (SOLAR-1) / inavolisib (INAVO120) · AKT pathway → capivasertib (CAPItello-291) — three molecular branches whose ordering is debated: by ctDNA detection order + prior therapy, or by mutation priority? SERENA-6’s ctDNA-guided switch tentatively supports “switch immediately once ESR1mut appears”; the path for AKT / PIK3CA double-positives still lacks randomized evidence.

Continue CDK4/6 after CDK4/6 resistance? postMONARCH (2024 SABCS) showed marginal PFS benefit (mPFS 6.0 vs 5.3 months) for abemaciclib + fulvestrant after CDK4/6 resistance — is this clinically meaningful enough to continue, or should patients switch to SERD / PI3K/AKT directly?

TAILORx / RxPONDER re-stratification. TAILORx (2018 NEJM) used Oncotype DX in N0 HR+ to spare patients with Recurrence Score 11–25 from adjuvant chemo — a paradigm of genomic testing as a decision tool. RxPONDER (2021 NEJM) applied Oncotype in N1 HR+ and found premenopausal vs postmenopausal populations benefit differently: premenopausal N1 derives significant chemo benefit, postmenopausal does not. The 2026 real-world tension is the accessibility and cost of Oncotype at Chinese county hospitals — can clinical-pathologic surrogates substitute?

Adjuvant CDK4/6 vs extended endocrine — cost effectiveness. monarchE’s 2-year abemaciclib total cost, adverse events (diarrhea / VTE / fatigue management), and real-world compliance (most patients cannot adhere for 2 full years) — compared to the low-cost strategy of extending AI from 5 to 10 years (MA.17R) — is the marginal iDFS benefit worth it? This debate has different answers in regions with different reimbursement coverage (Japan / Korea vs West).

SONIA’s reverse question. SONIA (Phase III, 2024 JAMA) ran a head-to-head on whether CDK4/6 belongs in 1L or 2L: 1L endocrine mono → progression → 2L CDK4/6 vs 1L CDK4/6 + endocrine → 2L endocrine. SONIA’s primary endpoint PFS2 (cumulative PFS over two lines) showed no significant difference — suggesting that for lower-burden HR+/HER2- mBC, CDK4/6 can be delayed. Whether 2026 clinical practice accepts this “delayed” strategy remains contested.

HER2+

HER2-low / HER2-ultralow boundaries. After the ASCO-CAP 2023 reclassification: HER2-low (IHC 1+ or 2+/FISH-) was approved via DESTINY-Breast04 (2022 NEJM, T-DXd vs TPC, HR+ subgroup mPFS 10.1 vs 5.4 months / HR 0.51); HER2-ultralow (IHC > 0 but < 1+) via DESTINY-Breast06 (2024 NEJM, T-DXd vs TPC 1L HR+ endocrine-resistant), pushing T-DXd further upstream and expanding into ultralow. The traditional “HER2-negative” label is essentially dismantled in 2026 — only HER2 IHC 0 with FISH-negative remains as true-negative, treated TNBC-like. The real clinical tension is HER2-low vs ultralow detection reproducibility + pathology report workflow. China-originated ADCs MRG002 (2024 SABCS) · SHR-A1811-HER2low (Phase II) are also pushing through this window.

Will adjuvant T-DXd replace KATHERINE? KATHERINE (2019 NEJM) replaced trastuzumab with T-DM1 as the adjuvant for non-pCR patients after neoadjuvant — only 6 years ago. DESTINY-Breast05 (T-DXd vs T-DM1 adjuvant non-pCR high-risk HER2+, ongoing) · DB11 (T-DXd adjuvant in earlier stages) — if these are positive, the T-DM1 adjuvant standard will hand over in 2027–2028.

TCHP vs AC-THP neoadjuvant choice. Whether anthracycline-sparing is safe in node-positive HER2+ still has marginal debate. BCIRG-006 supports the TCH / TCHP pathway, but some high-risk patients are still directed to AC-THP. NCCN 2026 recommends both in parallel, individualized by cardiac risk + pCR goals + tumor burden.

Pertuzumab in low-risk — benefit dispute. APHINITY’s primary endpoint was positive but overall benefit was marginal (iDFS HR 0.81), with the real benefit concentrated in N+ or high-risk node- subgroups. Do low-risk N0 HER2+ patients need dual-target? The APT de-escalation pathway says no — T+H × 12 weeks of paclitaxel alone is enough. In 2026 clinical practice, the cutoff is at T1c N0: T1c+ gets TCHP; T1ab N0 low-risk uses the APT simplified regimen.

HER2+ BC brain-met screening strategy. HER2+ mBC has a 30–50% brain-met rate — should baseline MRI be done at metastatic diagnosis? NCCN 2026 recommends a lower threshold for MRI beyond symptom-driven. HER2CLIMB / TUXEDO-1 / DEBBRAH all support the early-detection-and-active-treatment strategy, but the cost-effectiveness of asymptomatic screening remains contested.

CLEOPATRA’s ten-year standard challenged by DESTINY-Breast09. If DB09’s T-DXd ± pertuzumab 1L confirms OS benefit, the HER2+ mBC 1L standard will shift from “pertuzumab + trastuzumab + docetaxel (CLEOPATRA)” to “T-DXd + pertuzumab” — but ADC early toxicity management (ILD interstitial lung disease ~10%) + CNS activity comparison are the two branching debates.

TNBC / BRCA

IO biomarker thresholds aren’t unified. KEYNOTE-522 (neoadjuvant) doesn’t screen PD-L1 — all-comers use; KEYNOTE-355 (1L mTNBC) requires CPS ≥ 10; KEYNOTE-119 (2L+) was negative. Same drug, different thresholds across settings — is the tumor immune microenvironment more active in early stage? Or is pCR a more sensitive surrogate?

The IMpassion130 vs IMpassion131 backbone mystery. Atezolizumab + nab-paclitaxel was positive (IMpassion130), + paclitaxel was negative (IMpassion131). Possible reasons: pre-medication steroid impact on IO response, nab chemo’s own immunomodulatory effects, sample PD-L1 distribution differences — no head-to-head RCT resolved this. Atezolizumab’s use script has narrowed in most Western guidelines.

germline BRCA-only for PARP, reasonable? OlympiA cemented germline BRCA1/2 adjuvant PARP, but can somatic BRCA / HRD-positive TNBC be extrapolated? Current evidence is insufficient; NCCN strictly restricts to germline + high-risk. The clinically common “hereditary + sporadic double-positive” subgroup lacks evidence.

LAR / BL1 / IM / MES molecular subtype’s clinical translation. Fudan Shao’s team TNBC four-subtype (LAR luminal androgen receptor · BL1 basal-like 1 · IM immunomodulatory · MES mesenchymal) has been validated in Chinese umbrella trials FUTURE-SUPER / FUTURE-C-PLUS. International acceptance is incomplete; in 2026, this remains a China-led candidate framework for TNBC precision therapy.

ASCENT-04 vs ASCENT sequencing. After using sacituzumab govitecan + pembrolizumab in 1L, how should 2L+ connect the ADC / IO chain? TROPION-Breast02 / ASCENT-04 / KN-522 — the three-axis sequencing is still being figured out.

KN-522 adjuvant pembro timing. KEYNOTE-522 runs 1 year of pembro throughout; do patients achieving pCR still need the full adjuvant IO? A de-escalation trial analogous to HER2+’s “pCR → T-DM1 downshift / non-pCR → T-DM1 upshift” is being designed for TNBC, but no Phase III readout yet.

Capecitabine CREATE-X path vs PARP OlympiA path. For non-pCR TNBC residual disease, choose capecitabine adjuvant (CREATE-X logic) or olaparib (gBRCA+ subset)? For the mixed “gBRCA+ non-pCR TNBC” patient, which should be prioritized? Sequential or parallel? Evidence is lacking.

FUTURE-SUPER / Fudan subtyping’s international acceptance. LAR / BL1 / IM / MES was proposed by the Fudan Zhongshan Hospital Shao team in 2019, paired with the FUTURE-SUPER umbrella trial that matches treatment to subtype: LAR → anti-androgen · IM → IO + chemo · BLIS → chemo intensification · MES → VEGF/EGFR pathway. International guidelines (NCCN / ESMO) have not adopted it as of 2026 — main concerns: subtype reproducibility, RNA-seq panel accessibility, subtype switching rate (the same tumor biopsied multiple times may yield different subtypes). But this is China’s most original contribution to breast cancer precision therapy, and 2027–2028 international replication is worth watching.

ADC-naive vs ADC-exposed resistance mechanisms differ. Sacituzumab govitecan and Dato-DXd both target TROP2, but payload differences (SN-38 vs DXd) may shape different resistance mechanisms. After T-DXd enters HER2-low, if HER2-null reappears, can patients return to the TNBC path via TROP2 ADC? Or does TROP2 downregulate simultaneously? This sequencing lacks systematic real-world molecular data.

4. Biomarker Framework

Breast cancer’s biomarker panel is the most complete and earliest-established of all solid tumors. In 2026, a newly diagnosed breast cancer needs a minimum panel of at least 8 items:

Core typing:

HR (ER / PR) — classic binary classification since the 1990s; ER+ PR+ double-positive vs ER+ alone stratifies endocrine sensitivity.
HER2 — IHC 4 tiers (0 / 1+ / 2+ / 3+) + FISH; ASCO-CAP 2023 added HER2-low (IHC 1+ or 2+/FISH-) and HER2-ultralow (> 0 but < 1+). The four tiers map to treatment branches: 3+ → anti-HER2; 2+/FISH+ → anti-HER2; 1+ or 2+/FISH- → HER2-low (DB04 / DB06); ultralow → DB06.
PAM50 intrinsic subtype (Luminal A / B · HER2-enriched · Basal-like · Normal-like) is increasingly used in adjuvant decisions and CDK4/6 adjuvant extension. Oncotype DX / MammaPrint / Prosigna are clinical surrogates.

Endocrine resistance + precision targeting:

ESR1 mutation — endocrine resistance marker, sensitive to SERDs (elacestrant / camizestrant); ctDNA dynamic detection has become SERENA-6’s gating biomarker.
PIK3CA mutation — the biomarker for SOLAR-1 alpelisib / INAVO120 inavolisib, present in ~40% of HR+/HER2- patients.
AKT1 / PTEN mutation — the extension biomarker for CAPItello-291 capivasertib.
BRCA1/2 germline / somatic / HRD score — mandatory for PARP (olaparib / talazoparib); all HER2- breast cancers should have germline testing.

ADC targets:

TROP2 — broadly expressed across breast cancer; no clinical screening required for sacituzumab govitecan / Dato-DXd.
HER2 payload-aware — HER2-low / ultralow detection is critical for T-DXd / SHR-A1811 / MRG002 use.

Immunotherapy:

PD-L1 CPS — KEYNOTE-355 CPS ≥ 10 (22C3 assay) gates 1L mTNBC pembro; Ventana SP142 is the assay-difference source for atezolizumab positivity.
Stromal TILs — strong neoadjuvant pCR predictor; not used for treatment decisions in 2026.

Uncommon but critical:

MSI-H / dMMR — < 2% incidence in breast cancer but KEYNOTE-158 tumor-agnostic applies.
NTRK fusion — < 1%; larotrectinib / entrectinib tumor-agnostic applies.
AR (androgen receptor) — LAR subtype (Fudan classification) biomarker; enzalutamide / bicalutamide in TNBC LAR subgroup clinical exploration.
ctDNA dynamics — SERENA-6 pushed ctDNA from a prognostic marker to a treatment-switching trigger — 2026 marks breast cancer’s entry into ctDNA-guided decision-making with first Phase III proof.

The 2026 reality of biomarker testing. IHC stability in lumpectomy specimens remains the bottleneck for HER2-low / ultralow deployment — different pathologists have limited agreement on IHC 0 vs 1+ and 1+ vs 2+ (kappa ~0.6); the same specimen sliced at different times may cross tiers on retest. Clinical practice recommends: before T-DXd decision, repeat IHC (at least two independent pathology reports) + confirm score boundary judgment. Future pan-HER2 quantitative assays (HERmark / digital quantitative IHC) may replace the current 4-tier system.

5. Time-Space Overview

Five paradigms laid out in parallel, 1990–2025. Mapping the 86 landmark trials by paradigm + year produces five parallel evolutionary tracks:

① Foundation era (1990–2000): endocrine + anti-HER2 grounded in parallel

1996 — NSABP B-14 (tamoxifen adjuvant ER+)
1998 — trastuzumab FDA approval (first targeted drug for any solid tumor)
2002 — ATAC (anastrozole vs tamoxifen, postmenopausal adjuvant)
2005 — HERA / NSABP B-31 / N9831 (trastuzumab × 1 year adjuvant HER2+)

② Anti-HER2 expansion (2005–2015): pertuzumab + T-DM1 complete the back-line arsenal

2011 — NeoSphere (dual-target + docetaxel neoadjuvant HER2+)
2012 — EMILIA (T-DM1 2L HER2+ mBC)
2012 — CLEOPATRA (pertuzumab + trastuzumab + docetaxel 1L HER2+ mBC)
2013 — APHINITY enrolls (pertuzumab added to adjuvant HER2+)
2015 — APT (low-risk HER2+ T+H de-escalation × 12 weeks)
2019 — KATHERINE (non-pCR → T-DM1 adjuvant)

③ CDK4/6 × HR+ precision (2015–2025): advanced 2L and adjuvant extension

2016–2019 — PALOMA-1/2/3 · MONALEESA-2/3/7 · MONARCH-2/3 (the three CDK4/6 families)
2018 — TAILORx (Oncotype DX N0 chemo sparing)
2020 — SOLAR-1 (alpelisib PIK3CAmut 2L)
2021 — RxPONDER · monarchE (abema adjuvant N+ high risk)
2023 — NATALEE (ribo adjuvant node-any) · CAPItello-291 (capivasertib AKT) · EMERALD (elacestrant ESR1mut)
2024 — INAVO120 (inavolisib + palbo + fulv) · SERENA-6 (ctDNA-guided switch) · EMBER-3 (imlunestrant) · DAWNA-2

④ ADC reshaping (2020–2025, the headline act): T-DXd + TROP2 ADC dual axis

2021 — ASCENT (sacituzumab govitecan 2L+ mTNBC) · DESTINY-Breast01 (T-DXd 2L+ HER2+ mBC accelerated)
2022 — DESTINY-Breast03 (T-DXd vs T-DM1 2L HER2+, mBC standard inflection) · DESTINY-Breast04 (T-DXd in HER2-low)
2023 — DESTINY-Breast02 (T-DXd post-T-DM1)
2024 — DESTINY-Breast06 (HER2-ultralow T-DXd 1L endocrine-resistant)
2025 — DESTINY-Breast09 (T-DXd + pertuzumab 1L HER2+, CLEOPATRA challenger) · TROPION-Breast02 (Dato-DXd 1L mTNBC) · ASCENT-04 (sacituzumab + pembro 1L mTNBC) · SHR-A1811 / MRG002 / RC48 (China-originated ADCs)

⑤ IO breakthrough (2020–2025): TNBC + early adjuvant

2018 — IMpassion130 (atezo + nab-pac 1L mTNBC PD-L1+)
2020 — KEYNOTE-522 (pembro + chemo neoadj → adj stage II-III TNBC) · KEYNOTE-355 (pembro + chemo 1L CPS ≥ 10)
2021 — OlympiA (olaparib adjuvant gBRCA HER2- high risk)
2023 — TORCHLIGHT (toripalimab + nab-pac 1L mTNBC, China)
2024 — KEYNOTE-522 EFS/OS final · ASCENT-04 IO+ADC

Clinical read-out of the five lines in parallel. In 2026, the decision tree for any newly diagnosed breast cancer patient = subtype triage (① endocrine / ② HER2 / ③ TNBC) → stage pathway (neoadj / adj / advanced) → biomarker panel (HR / HER2 four-tier / PIK3CA / BRCA / CPS) → paradigm assignment. No single paradigm dominates alone — they layer in parallel.

Vertical cross-section along the five paradigms. The adjuvant plan for the same “HR+ N+ HER2+ stage II female” patient — 2000 vs 2026:

2000 could offer: AC × 4 chemo + tamoxifen × 5 years + trastuzumab (available in a few centers after 1998 approval).
2026 can offer: pre-op MRI + neoadjuvant TCHP × 6 cycles → surgery → if pCR, T+P to complete 1 year / if non-pCR, switch to T-DM1 × 14 cycles → adjuvant AI + OFS × 5 years → if high-risk, add monarchE / NATALEE CDK4/6 → extend AI to 10 years.

In 26 years, the same patient’s adjuvant cycle has extended from ~6 months to ~24–36 months; drug categories from 3 to 8–10; 10-year OS from ~85% to ~93%. This is the miniature of oncology’s precision-stratification era.

Vertical × horizontal: the 2026 landscape is shaped by four-way resonance

Overlaying the five paradigms with three subtypes, the 2026 breast cancer landscape is the product of four-way resonance:

HR endocrine backbone (30 years) + CDK4/6 (2015–2020) + precision drugs (2020–2026, SERD / PI3K / AKT / mTOR) — pushed HR+/HER2- 1L mPFS from endocrine mono’s 9–14 months to CDK4/6 combo’s 24–28 months, then to INAVO120 / SERENA-6 ctDNA-guided precision increments.
Anti-HER2 four generations (trastuzumab → pertuzumab → T-DM1 → T-DXd) — rewrote the HER2+ “death sentence” from 1998’s “1-year OS ~30%” to 2025’s “metastatic 1L mOS ~57 months” (CLEOPATRA); T-DXd + DB03/04/06/09 extended into HER2-low / ultralow.
TNBC IO breakthrough (2020 KEYNOTE-522) + TROP2 ADC (2021 ASCENT) + PARP adjuvant (2021 OlympiA) + China’s molecular subtyping (Fudan Shao’s LAR/BL1/IM/MES) — pushed TNBC from “only chemo” to four co-constructed treatment axes.
ASCO-CAP 2023 HER2-low/ultralow reclassification + T-DXd DB04/06 — dismantled the traditional “HER2-negative” category into three layers: 3+/2+ FISH+ / 1+ / 2+ FISH- / > 0 but < 1+ / true-negative — giving new targeted pathways to 60–70% of patients previously treated TNBC-like.

These four resonances together explain: the adjuvant or 1L decision for a newly diagnosed breast cancer in 2026 has 3 more decision layers than in 2016 (HR + HER2 four-tier → PIK3CA + BRCA + CPS → CDK4/6 adjuvant intensity choice → China-accessibility branch).

6. Full Trial Index

All 86 landmark trials listed by subtype and ascending year, with one-sentence positioning. Each trial’s detail page lives at /en/trials/breast/<trial_id>/, with click-through links to PubMed / ClinicalTrials.gov.

HR+/HER2- (29 trials)

MA.17 (letrozole extension post-tamoxifen × 5 years)
ATAC (anastrozole vs tamoxifen, 10-year DFS 79.9% vs 77.6%)
BOLERO-2 (everolimus + exemestane post-AI resistance)
ATLAS (tamoxifen 10 vs 5 years, OS benefit)
SOFT (premenopausal OFS + AI, high-risk adjuvant)
TEXT (SOFT’s twin, OFS + AI premenopausal)
PALOMA-3 (palbociclib + fulvestrant 2L post-endocrine)
PALOMA-2 (palbociclib + letrozole 1L mBC)
MONALEESA-2 (ribociclib + letrozole 1L postmenopausal)
MONARCH-2 (abemaciclib + fulvestrant 2L)
MONARCH-3 (abemaciclib + AI 1L)
TAILORx (Oncotype DX N0 RS 11–25 chemo sparing)
MONALEESA-3 (ribociclib + fulvestrant 1/2L)
MONALEESA-7 (ribociclib + OFS premenopausal)
SOLAR-1 (alpelisib + fulvestrant PIK3CAmut 2L)
monarchE (abemaciclib × 2 years adjuvant N ≥ 4 or 1–3+ high-risk)
RxPONDER (Oncotype N1 pre/postmenopausal stratification)
DAWNA-1 (dalpiciclib + fulvestrant 2L, China-originated)
EMERALD (elacestrant oral SERD ESR1mut 2L post-CDK4/6)
CAPItello-291 (capivasertib + fulvestrant AKT pathway alterations)
PADA-1 (ctDNA-driven ESR1mut switch feasibility)
DAWNA-2 (dalpiciclib + letrozole 1L, China)
NATALEE (ribociclib × 3 years adjuvant node-any stage IIA-III)
postMONARCH (abema + fulv continued post-CDK4/6 resistance)
INAVO120 (inavolisib + palbo + fulv PIK3CAmut 1L, mPFS 15.0 months)
SONIA (CDK4/6 at 1L vs 2L sequencing strategy trial)
SERENA-6 (camizestrant ctDNA-guided ESR1mut switch)
EMBER-3 (imlunestrant ± abemaciclib)
BG01-2201L (Chinese SERD data extension)

HER2+ (30 trials)

HERA (trastuzumab × 1 year adjuvant vs observation, 2005 NEJM)
NSABP B-31 / NCCTG N9831 joint (2005 NEJM, adjuvant)
EGF104900 (lapatinib + trastuzumab dual-target, later lines)
BCIRG-006 (TCH vs AC-TH, anthracycline-sparing adjuvant)
NeoSphere (dual-target + docetaxel neoadj pCR 45.8%)
CLEOPATRA (P + T + docetaxel 1L mBC, ten-year standard; Swain 2015 OS update)
EMILIA (T-DM1 vs lapatinib + capecitabine 2L)
TRYPHAENA (TCHP neoadj safety)
TH3RESA (T-DM1 3L+)
APT (T+H × 12 weeks low-risk HER2+ de-escalation)
ExteNET (neratinib extended adjuvant)
APHINITY (pertuzumab added to adjuvant HER2+)
MARIANNE (T-DM1 ± pertuzumab vs THx 1L, negative)
KRISTINE (T-DM1 + P neoadj vs TCHP, negative)
KATHERINE (non-pCR → T-DM1 adjuvant, iDFS HR 0.50)
PHENIX (pyrotinib + capecitabine 2L, China)
DESTINY-Breast01 (T-DXd 2L+ HER2+ mBC, accelerated 2020)
HER2CLIMB (tucatinib + T + cape, active brain mets)
HOPES (China HER2+ TKI + chemo)
PHOEBE (pyrotinib vs lapatinib 2L+ China 2021)
DESTINY-Breast03 (T-DXd vs T-DM1 2L HER2+ mPFS 28.8 vs 6.8 months)
TUXEDO-1 (T-DXd in active brain mets, Phase II)
ATEMPT (T-DM1 adjuvant low-risk HER2+ vs THx)
DESTINY-Breast02 (T-DXd post-T-DM1)
PHILA (pyrotinib + T + docetaxel 1L HER2+, China)
DEBBRAH (T-DXd brain-met evidence)
SHR-A1811-102 (China-originated HER2 ADC post-T-DM1, Phase II)
DESTINY-Breast09 (T-DXd + P 1L HER2+ mBC, CLEOPATRA challenger)

HER2-low / HER2-ultralow ADC (5 trials)

RC48-C006 (disitamab vedotin, China’s first domestic ADC)
DESTINY-Breast04 (T-DXd in HER2-low mBC, mPFS 10.1 vs 5.4 months)
MRG002-HER2low (China-originated ADC in HER2-low)
SHR-A1811-HER2low (China-originated ADC in HER2-low, Phase II)
DESTINY-Breast06 (T-DXd in HER2-ultralow 1L endocrine-resistant)

TNBC / BRCA · IO + PARP + TROP2 ADC (22 trials)

BEATRICE (bevacizumab adjuvant TNBC, negative)
GeparSixto (carbo neoadj TNBC pCR improvement)
CALGB-40603 (carbo neoadj TNBC pCR)
LOTUS (ipatasertib + paclitaxel 1L mTNBC)
BrighTNess (carbo + veliparib + pac neoadj TNBC)
IMpassion130 (atezo + nab-pac 1L mTNBC PD-L1+, mOS 25 months)
GeparNuevo (durvalumab + neoadj chemo TNBC)
KEYNOTE-522 (pembro + chemo neoadj → adj stage II-III TNBC, EFS HR 0.63 / OS HR 0.66)
IMpassion031 (atezo + chemo neoadj TNBC pCR benefit)
KEYNOTE-355 (pembro + chemo 1L mTNBC CPS ≥ 10, mOS 23 months)
KEYNOTE-158 (pembro MSI-H basket, includes breast)
PAKT (capivasertib + pac 1L mTNBC)
IMpassion131 (atezo + pac, negative)
ASCENT (sacituzumab govitecan 2L+ mTNBC, HR 0.48)
KEYNOTE-119 (pembro monotherapy 2L+ mTNBC, negative)
NeoTRIP (atezo neoadj TNBC)
FUTURE-SUPER (Fudan umbrella, LAR/BL1/IM/MES subtype matching)
TORCHLIGHT (toripalimab + nab-pac 1L mTNBC, China 2023)
CAMBRIA (camrelizumab + chemo neoadj, China)
ASCENT-04 (sacituzumab + pembro 1L PD-L1+ mTNBC)
TROPION-Breast02 (Dato-DXd 1L mTNBC vs TPC)
OlympiAD (olaparib 2L+ gBRCA mBC)

Cross-subtype (all breast cancer) · PARP adjuvant (2 + 1 cross-subtype adjuvant)

EMBRACA (talazoparib 2L+ gBRCA mBC)
OlympiA (olaparib × 1 year adjuvant gBRCA HER2- high risk, iDFS HR 0.58 / OS HR 0.68)

Key Research Gaps (10 excerpts)

monarchE vs NATALEE head-to-head missing: 2-year abemaciclib (N ≥ 4 or 1–3+ high-risk) vs 3-year ribociclib (node-any stage IIA-III) with no RCT — clinicians are forced into cross-trial choice.
Clinical meaning of continuing CDK4/6 after CDK4/6 resistance: is postMONARCH’s mPFS 6.0 vs 5.3 months enough to justify 6–8 months more toxicity exposure post-progression?
HER2-low / ultralow testing reproducibility: IHC 0 vs 1+ kappa ~0.6 — should dual pathologist validation be mandatory before T-DXd decision?
KN-522 adjuvant pembro de-escalation: do TNBC patients achieving pCR still need 1 year of pembro? The de-escalation trial is still being designed.
ADC sequencing: T-DXd → Dato-DXd → sacituzumab govitecan — is the resistance mechanism target downregulation or payload cross-resistance? Real-world molecular data is insufficient.
IO-chemo backbone in TNBC neoadj: IMpassion130 vs 131 chemo backbone mystery (atezo + nab-pac vs atezo + pac) is unattributed.
LAR / BL1 / IM / MES international replication: the reproducibility of Fudan TNBC four-subtype FUTURE-SUPER results in international populations is pending.
CDK4/6 adjuvant biomarker: multiple stratification tools (Ki67 + 21-gene + IHC4 + CTS5) were not prospectively isolated in monarchE / NATALEE subgroup analyses.
Premenopausal HR+ SOFT/TEXT vs simple tamoxifen: is OFS + AI over-treatment in low-Ki67 patients?
HER2+ active brain mets — T-DXd vs tucatinib vs RT integration: the three axes have not been systematically stratified; TUXEDO-1 / DEBBRAH / HER2CLIMB extended integration data has not yet formed a unified algorithm.

7. Sources & Methodology

All 86 trials indexed in this overview come from data/trials/breast.yaml, extracted by 4-way parallel subagents (A HR+/HER2- · B HER2+ · C TNBC · D China-lead) from NCCN Breast Cancer v2.2026 primary source + NMPA / CSCO / ESMO Asia abstracts, bilingual fields completed by translate-trials.py, and rendered into the static site via Hugo.

7.1 Pivotal trial PMID inventory

PMID backfill uses a three-filter pipeline: NCT [si] tag-based PubMed esearch + year/journal hard match + breast keyword title guard — name-based fallback is prohibited (lesson from the 58% fabrication rate of agent “best-effort PMID” in early 2026-04). Of the 86 trials, 55 received verified PMIDs (pilot 5/5 + random spot-check 10/10 = 0% fab rate); 31 remain null (ASCO/ESMO abstract-only 7 · NCT not [si] indexed 9 · year/journal mismatch 11 · ambiguous 4). Inline PubMed hyperlinks are now in place in the §2–§5 narrative for trials with PMIDs — click [Year Journal] to jump to the PubMed primary publication. Full per-trial PMID + source-ref is on /en/trials/breast/<trial_id>/.

HR+/HER2- (29 trials):

MA.17 · ATAC · BOLERO-2 · ATLAS · SOFT · TEXT · PALOMA-3 · PALOMA-2 · MONALEESA-2 · MONARCH-2 · MONARCH-3 · TAILORx · MONALEESA-3 · MONALEESA-7 · SOLAR-1 · monarchE · RxPONDER · DAWNA-1 · EMERALD · CAPItello-291 · PADA-1 · DAWNA-2 · NATALEE · postMONARCH · INAVO120 · SONIA · SERENA-6 · EMBER-3 · BG01-2201L

Among these, the 2023–2025 new arrivals (CAPItello-291 / EMERALD / NATALEE / INAVO120 / SERENA-6 / EMBER-3 / postMONARCH / BG01-2201L) form the newest 8-trial pivotal evidence chain in HR+/HER2- precision therapy.

HER2+ / HER2-low (33 trials):

HERA · NSABP B-31·N9831 · EGF104900 · BCIRG-006 · NeoSphere · CLEOPATRA · EMILIA · TRYPHAENA · TH3RESA · APT · ExteNET · APHINITY · MARIANNE · KRISTINE · KATHERINE · PHENIX · DESTINY-Breast01 · HER2CLIMB · HOPES · PHOEBE · DESTINY-Breast03 · TUXEDO-1 · ATEMPT · DESTINY-Breast02 · PHILA · DEBBRAH · SHR-A1811-102 · DESTINY-Breast09 · RC48-C006 · DESTINY-Breast04 · MRG002-HER2low · SHR-A1811-HER2low · DESTINY-Breast06

The DESTINY-Breast family 01–09 + RC48 / SHR-A1811 / MRG002 form the 10-trial pivotal chain of ADC reshaping — the most dramatic drug-class change in the breast cancer landscape from 2020–2025.

TNBC / BRCA (24 trials):

BEATRICE · GeparSixto · CALGB-40603 · LOTUS · BrighTNess · IMpassion130 · GeparNuevo · KEYNOTE-522 · IMpassion031 · KEYNOTE-355 · KEYNOTE-158 · PAKT · IMpassion131 · ASCENT · KEYNOTE-119 · NeoTRIP · FUTURE-SUPER · TORCHLIGHT · CAMBRIA · ASCENT-04 · TROPION-Breast02 · OlympiAD · EMBRACA · OlympiA

KEYNOTE-522 (stage II-III TNBC EFS / OS dual benefit) + ASCENT (sacituzumab govitecan 2L+ mOS 12.1 months) + OlympiA (gBRCA HER2- adjuvant iDFS benefit) form the TNBC three pillars of the past 5 years, paired with Fudan’s LAR/BL1/IM/MES molecular subtyping and China’s TORCHLIGHT / CAMBRIA domestic IO combinations — shaping the global TNBC treatment landscape’s main trunk.

7.1.1 Phase III trials in progress (2025–2027 expected readouts, curated)

Ten selected readouts from breast 2025–2027 Phase III pipeline that are “likely to change practice”:

DESTINY-Breast05 (T-DXd vs T-DM1 adjuvant high-risk non-pCR HER2+) — if positive, KATHERINE’s T-DM1 adjuvant standard hands over.
DESTINY-Breast11 (T-DXd adjuvant earlier-stage HER2+)
DESTINY-Breast12 (T-DXd mBC CNS-preserving subset)
PATINA (palbociclib + endocrine + trastuzumab maintenance HR+ HER2+ mBC)
TROPION-Breast03 (Dato-DXd 2L mTNBC post-ASCENT)
ASCENT-03 / 05 (sacituzumab govitecan expansion to more settings)
KEYNOTE-522 adjuvant de-escalation (ongoing)
RASTRUM / CTDX series (ctDNA-guided adjuvant / switch)
PIK3CA genotype 1L head-to-head (inavolisib vs alpelisib)
FUTURE-C series (Fudan TNBC subtype umbrella extension)

7.2 Guideline citation

NCCN Clinical Practice Guidelines in Oncology · Breast Cancer · V2.2026 (Feb 27, 2026) — primary source; this post’s 7-chapter skeleton and subtype stratification are aligned with that version.
ASCO-CAP 2023 HER2 testing updates — HER2-low / HER2-ultralow definitions and testing guidance.
FDA approval letters + NMPA drug approval announcements — public-domain regulatory reference.
Fudan University Zhongshan Hospital TNBC molecular subtyping series (Shao Z-M team, LAR / BL1 / IM / MES, FUTURE series umbrella trials) — China’s original contribution to TNBC precision subtyping.

7.3 Methodology

This overview is produced by a clinical-trials pipeline: 4-way parallel subagent extract (A HR+/HER2- · B HER2+ · C TNBC · D China-lead hunt) × NCCN Breast Cancer v2.2026 primary source × translate-trials.py (B8 upgraded auto-retry, 0% fail rate) × Hugo static render. 86 trials × 4 bilingual fields per trial (interventional arm · comparator arm · key finding · clinical relevance) × 0 schema drift.

Breast is the first tumor type where the pipeline introduces subtype-stratified content expansion (L2 H3 three-split) — a template candidate for future multi-subtype tumors such as lymphoma / sarcoma. The PMID backfill backlog completed on 2026-04-22 (NCT [si] hunt + 3-filter gate + 5-gate ladder + 0% fabrication rate over 15 spot-checks); see memory/data-pipeline-patterns.md §6 for methodology.

Takeaways for junior-to-mid-level oncologists:

“Test panel first, then decide” is now standard of care. In 2026, entering treatment decisions without having tested HR / HER2 (including low/ultralow tiers) / gBRCA / PIK3CA is wrong. Missing HER2-low means missing DB04/06 T-DXd; missing gBRCA means missing OlympiA adjuvant and OlympiAD/EMBRACA in advanced disease; missing PIK3CA means missing INAVO120’s 1L increment.
Premenopausal HR+ N+ high-risk: always consider OFS + AI (SOFT/TEXT), don’t default to tamoxifen.
Choose monarchE vs NATALEE by enrollment risk: N ≥ 4 → monarchE evidence is stronger; 1–3+ high-risk features can go monarchE; stage IIA node-any wanting adjuvant CDK4/6 can only go NATALEE.
HER2+ non-pCR post-neoadjuvant: always switch to T-DM1 (KATHERINE) — don’t continue trastuzumab.
HER2+ mBC 2L first choice is T-DXd (DESTINY-Breast03); T-DM1 in 2L now hands over when T-DXd is accessible.
HER2+ active brain mets → HER2CLIMB (tucatinib regimen), don’t use the old lapatinib + capecitabine.
TNBC stage II-III all-comer KEYNOTE-522 regimen (no PD-L1 screening); but don’t apply KN-522 to stage I small tumors — avoid over-treatment.
mTNBC 1L: check CPS first. CPS ≥ 10 → pembro + chemo; CPS < 10 and gBRCA+ → consider PARP; otherwise → chemo backbone.
All HER2-, germline BRCA1/2 is mandatory testing — it drives adjuvant (OlympiA) + advanced (OlympiAD / EMBRACA) + TNBC fertility decisions.
China-originated drugs are reasonable alternatives under reimbursement-accessible scenarios: dalpiciclib / pyrotinib / disitamab vedotin / toripalimab / camrelizumab — their Phase III data stand independently, and price × accessibility is the main driver of insurance-coverage decisions.

This post is a 2026-04-22 snapshot; it does not substitute for clinical judgment. Each trial’s specific use setting should defer to NCCN v2.2026 / CSCO 2025 / drug label / local reimbursement availability.

Clinical Trials Timeline

Chinese: /trials/breast/ English: /en/trials/breast/

Each trial has an independent detail page containing:

Full intervention / comparator regimen.
Primary endpoint numerical values + 95% CI.
Key findings + clinical significance.
Click-through links to NCT / PMID source.

86 trials · 4 subtype groups · 1995 to 2025 · global multi-center + China-originated contributions · NCCN v2.2026 aligned.

Closing

Over the past 25 years, breast cancer has been oncology’s most extensively subtyped, most fully equipped, and most divergent-by-subtype tumor type. From ER’s discovery in 1975, HER2’s identification in 1987, to TNBC’s naming in 2005, the three-pillar framework was established — then in 2023 ASCO-CAP split out HER2-low / HER2-ultralow. Categories finer, therapy more precise.

All five paradigms reached maturity simultaneously in 2020–2025. ADC reshaping (DESTINY series + TROP2 ADC) is the headline act: T-DXd pushed HER2+ 2L mPFS from 6.8 to 28.8 months (HR 0.33) via DESTINY-Breast03 in 2022, and in 2025 DESTINY-Breast09 began challenging CLEOPATRA’s ten-year iron throne at 1L; sacituzumab govitecan / Dato-DXd gave TNBC — traditionally the “only chemo” hardest subtype — its first targeted pathway. China-originated ADCs (SHR-A1811 / MRG002 / RC48) and CDK4/6 (dalpiciclib DAWNA series) advance in parallel with the international track, taking ~20% of NMPA oncology approvals in 2025.

HR+/HER2-, the largest-share (65–70%) subtype, completed four-generation leaps over the same period: CDK4/6 pushed advanced 1L mPFS from 9–14 months to 24–28 months (PALOMA / MONALEESA / MONARCH families); monarchE / NATALEE pushed CDK4/6 into adjuvant; INAVO120 / SERENA-6 / CAPItello-291 layered precision by PIK3CA / ESR1 / AKT. Premenopausal high-risk adjuvant uses OFS + AI (SOFT / TEXT); postmenopausal extends AI to 10 years (MA.17R) — the endocrine backbone was not replaced but became the increasingly precise foundation of combinatorial layering.

TNBC, the 10–15%-share but “hardest to treat” subtype, in 5 years climbed out of the “only chemo” isolation: KEYNOTE-522 standardized IO + chemo as the stage II-III TNBC neoadjuvant backbone; ASCENT placed sacituzumab govitecan in 2L+ advanced; OlympiA extended PARP to gBRCA HER2- high-risk adjuvant; Fudan Shao’s LAR / BL1 / IM / MES four-subtype + FUTURE-SUPER umbrella is China’s original contribution to TNBC molecular subtyping on the international scene; TORCHLIGHT / CAMBRIA give China independent IO data. TNBC’s 2026 landscape change magnitude is the largest in the past 20 years.

This overview’s value is not in exhaustively enumerating 86 trials (/trials/breast/ does that) but in compressing the crossed structure of 25 years × three-subtype three-world × five-paradigm rotation × ADC reshaping into a single reading’s cognitive bandwidth. The next time you face a newly diagnosed breast cancer patient — HR / HER2 / TNBC branching + neoadj / adj / advanced pathways + five-paradigm anchoring — every layer of the decision tree has this map to consult, trace, and question.

Each of the 86 trials has a name + time + scenario + conclusion. Stitched together, they form the 1990–2025 breast cancer treatment evolution map. ADC reshaping’s headline act has just opened its first page; the chapters of DB09 / DB11 / TROPION-Breast series are still unfolding; ctDNA-guided precision therapy is spreading to more settings after SERENA-6; the optimal duration and biomarker stratification of CDK4/6 adjuvant are still under discussion.

Clinician × AI = Research Superpower + Clinical Decision Amplifier

Colorectal Cancer Clinical Trial Timeline: A Paradigm Map of 60 Years and 74 RCTs

Tue, 21 Apr 2026 00:00:00 +0000

Colorectal Cancer Clinical Trial Timeline — In-depth Report

Coverage: 74 landmark trials cited by NCCN Colon + NCCN Rectal V1.2026 (every PMID traceable) + 6 treatment paradigms + 5 precision pathways (MSI-H / BRAF V600E / HER2 / KRAS G12C / NTRK) + rectal TNT and organ preservation

Curated by Dual Brain Lab (csilab.net)

1. One-sentence definition

This report traces the evolution and current decision landscape of systemic therapy for colorectal cancer (CRC; comprising colon cancer and rectal cancer as two major subtypes; histology >95% adenocarcinoma) over the past 60 years (1960s 5-FU backbone → 2025 precision + immunotherapy combinations), as cited by landmark clinical trials referenced in NCCN Colon V1.2026 and NCCN Rectal V1.2026. It serves as a traceable panoramic map for frontline clinicians making “who, what, and why” decisions at the 2026 time point.

CRC is the world’s third most common (1.9 million new cases in 2022) and second most lethal (~900,000 deaths) malignancy; in China, ~510,000 new cases and ~240,000 deaths annually, with both incidence and mortality continuing to rise. Clinical staging runs in parallel across stage I-IV (colon) / locally advanced rectal (LARC) / metastatic (mCRC); biomarkers include six major stratification pathways — RAS (KRAS/NRAS, ~50%) / BRAF V600E (~8%) / MSI-H·dMMR (stage IV ~4-5%, stage II ~15-20%) / HER2 amp (~3%) / KRAS G12C (~3%) / NTRK fusion (<1%). Scope: systemic therapy (chemotherapy / targeted / immune / perioperative TNT); excludes metastasis ablation / HAI (hepatic arterial infusion) / peritoneal HIPEC / hereditary CRC (Lynch syndrome screening itself).

Iron rule: every data point of every trial is traceable to PubMed (PMID) or ClinicalTrials.gov (NCT id) — every [PMID xxxxxxxx] in the text can be opened directly to verify against the PubMed source.

2. Longitudinal: evolution timeline of six treatment paradigms

CRC systemic therapy has gone through six paradigm shifts in the past 60 years: 5-FU backbone established (1960s-2000) → FOLFOX / FOLFIRI dual-backbone era (2000-2004) → metastatic biologic-targeted breakthrough vs concurrent adjuvant triple failure (2004-2014) → MSI-H immune reversal (2015-2025) → BRAF V600E / HER2 / KRAS G12C / NTRK precision rockets (2019-2025) → rectal TNT and organ preservation (2020-2023).

Each shift used 2-4 phase III trials to push the old standard of care (SoC) into 2L. The biggest lesson across 60 years, in one sentence: metastatic-effective ≠ adjuvant-effective — bevacizumab, cetuximab, and irinotecan are backbones in metastatic disease; transplanted into adjuvant, all failed. FOLFOX is the sole exception (MOSAIC successfully moved the metastatic doublet into adjuvant). This extrapolation trap produced 4 negative phase IIIs in CRC (NSABP C-08 / AVANT / N0147 / CALGB 89803 + PETACC-3), cumulatively enrolling over 10,000 patients.

2.1 Establishing the 5-FU / FOLFOX / FOLFIRI backbone (1990s-2004): from monotherapy to doublet

Story: 5-FU (5-fluorouracil) was synthesized in 1957 and remained the sole CRC systemic drug for the next 40 years; in the 1990s leucovorin (LV) sensitization + infusional schedules pushed ORR from 10% to 20%. In 2000, two independent phase III trials were published in the same year: de Gramont 2000 (FOLFOX2) + Saltz 2000 (IFL, irinotecan + 5-FU/LV) pushed 1L metastatic mOS from 11 months to 14-17 months. In 2004, N9741 three-arm head-to-head firmly placed FOLFOX above IFL. Also in 2004, MOSAIC (adjuvant FOLFOX4 vs 5-FU/LV) moved FOLFOX from metastatic into stage III adjuvant — the only case across CRC’s 60 years where “a metastatic-successful drug moved into adjuvant with a positive phase III.”

de Gramont FOLFOX2 [PMID 10944126] (de Gramont 2000 J Clin Oncol, N=420): advanced CRC 1L oxaliplatin + 5-FU/LV infusion (FOLFOX2) vs 5-FU/LV alone. mPFS 9.0 vs 6.2 months, mOS 16.2 vs 14.7 months, ORR 50.7% vs 22.3%. Foundation of the FOLFOX backbone — platinum crossed from ovarian / lung cancer into CRC.
SALTZ IFL [PMID 11006366] (Saltz 2000 N Engl J Med, N=683): advanced CRC 1L irinotecan + 5-FU/LV (IFL regimen) vs 5-FU/LV. mPFS 7.0 vs 4.3 months, mOS 14.8 vs 12.6 months. First CRC 1L phase III positive for irinotecan — but toxicity was high (neutropenia, diarrhea); later replaced by the infusional FOLFIRI schedule.
N9741 [PMID 14665611] (Goldberg 2004 J Clin Oncol, N=795): advanced CRC 1L FOLFOX4 vs IFL vs IROX three-arm head-to-head. FOLFOX4 mOS 19.5 months > IFL 15.0 months > IROX 17.4 months; ORR 45% vs 31% vs 35%. FOLFOX decisively beat IFL in 1L metastatic — “FOLFOX is the backbone, FOLFIRI is the backup” entered guidelines from here.
GERCOR-TOURNIGAND [PMID 14657227] (Tournigand 2004 J Clin Oncol, N=220): FOLFIRI-then-FOLFOX6 vs FOLFOX6-then-FOLFIRI as 1L→2L sequences. No difference in mOS: 21.5 vs 20.6 months — classic evidence that “which doublet comes first doesn’t matter, but both should be used.”
MOSAIC [PMID 15175436] (André 2004 N Engl J Med, N=2,246): stage II-III colon cancer after curative resection FOLFOX4 × 6 months vs 5-FU/LV × 6 months adjuvant. Stage III subgroup 5-year DFS 66.4% vs 58.9% (HR 0.80); stage II overall negative. First phase III to successfully move a metastatic-effective doublet into adjuvant — but stage II did not benefit, planting the seed for “don’t add oxaliplatin in low-risk stage II.” 10-year follow-up [PMID 26527776] (André 2015 J Clin Oncol): stage III DFS HR still 0.80, OS HR 0.85 (p=0.046) — long-term benefit maintained, but BRAFm / dMMR subgroups did not benefit.
X-ACT [PMID 15987918] (Twelves 2005 N Engl J Med, N=1,987): stage III colon cancer after curative resection capecitabine monotherapy vs IV 5-FU/LV adjuvant. 3-year DFS 64.2% vs 60.6% (HR 0.87, p=0.053 non-inferiority met). Oral fluoropyrimidine monotherapy equivalent to IV 5-FU/LV — added a convenience option to chemotherapy regimens.
XELOXA (NO16968) [PMID 21383294] (Haller 2011 J Clin Oncol, N=1,886): stage III colon cancer after curative resection CAPOX (capecitabine + oxaliplatin) vs 5-FU/LV adjuvant. 3-year DFS 70.9% vs 66.5% (HR 0.80). CAPOX equivalent to FOLFOX — “IV or PO doublet both usable” became SoC.
QUASAR [PMID 18083404] (QUASAR Collaborative Group 2007 Lancet, N=3,239): stage II (91%) + low-risk stage III colorectal cancer after curative resection, adjuvant 5-FU/LV vs observation. 5-year OS 80.3% vs 77.4% (HR 0.82), absolute benefit 3.6%. Largest phase III for stage II adjuvant chemotherapy — absolute benefit small; decisions require individualization (T4 / poorly differentiated / lymphovascular invasion / obstruction / perforation are high-risk features).

Takeaway: 2000-2004 laid CRC’s backbone in four years — 1L metastatic FOLFOX > IFL, stage III adjuvant FOLFOX4 or CAPOX replaced 5-FU/LV monotherapy; infusional irinotecan (FOLFIRI) as 1L alternative and 2L; capecitabine monotherapy left an option for those intolerant of IV. But this backbone benefited only low-risk stage II, and BRAFm / dMMR subgroups did not benefit — planting the seed for the MSI-H reversal in 2015.

2.2 Metastatic biologic-targeted breakthrough vs adjuvant triple failure (2004-2014): the same drug, different fate — the extrapolation trap

Story: In 2004, Hurwitz’s AVF2107 added bevacizumab (anti-VEGF) to IFL — mOS pushed from 15.6 to 20.3 months (HR 0.66), CRC’s first metastatic targeted-drug phase III positive. That same year, cetuximab and panitumumab (anti-EGFR) entered 1L KRAS/RAS wild-type populations through five phase IIIs across 2004-2009. But in the five years 2011-2014, three parallel attempts to “move metastatic-effective targeted drugs into adjuvant” all failed: NSABP C-08 / AVANT (bev) + N0147 (cetuximab) + CALGB 89803 / PETACC-3 (irinotecan) — cumulatively enrolling >10,000 patients. This is CRC’s biggest clinical lesson across 60 years.

2.2.1 Metastatic: three breakthrough routes — bev / cet / FOLFOXIRI

AVF2107 [PMID 15175435] (Hurwitz 2004 N Engl J Med, N=813): advanced CRC 1L IFL + bevacizumab vs IFL + placebo. mOS 20.3 vs 15.6 months (HR 0.66, p<0.001); mPFS 10.6 vs 6.2 months; ORR 44.8% vs 34.8%. CRC’s first metastatic targeted phase III positive — VEGF-pathway tumor angiogenesis became a druggable target, and simultaneously planted the extrapolation-trap seed for the 2011-2012 adjuvant bev failures.
CRYSTAL [PMID 19339720] (Van Cutsem 2009 N Engl J Med, N=1,198): advanced CRC 1L FOLFIRI + cetuximab vs FOLFIRI. Overall population mPFS HR 0.85 (positive but marginal); KRAS wild-type subgroup mPFS 9.9 vs 8.4 months (HR 0.70); mOS 23.5 vs 20.0 months (HR 0.80). Foundational trial establishing KRAS as a stratification biomarker — “without biomarker stratification, no benefit is visible.”
OPUS [PMID 19114683] (Bokemeyer 2009 J Clin Oncol, N=337): FOLFOX + cetuximab vs FOLFOX 1L. KRAS WT subgroup ORR 61% vs 37% (OR 2.55); mPFS HR 0.57. OPUS + CRYSTAL together pinned the 1L indication for anti-EGFR to KRAS WT.
AMADO-KRAS-ANALYSIS [PMID 18316791] (Amado 2008 J Clin Oncol, N=427 chemo-refractory mCRC reanalysis): reanalysis of panitumumab in chemo-refractory mCRC phase III by KRAS status: KRAS WT ORR 17%, KRAS mut ORR 0%. Landmark subgroup analysis — pinned KRAS mutation as an “absolute resistance” predictor for anti-EGFR therapy; from then on, all anti-EGFR trials mandated KRAS/RAS testing.
PRIME [PMID 20921465] (Douillard 2010 J Clin Oncol, N=1,183): FOLFOX4 + panitumumab vs FOLFOX4 1L. KRAS WT subgroup mPFS 9.6 vs 8.0 months (HR 0.80); mOS 23.9 vs 19.7 months. Panitumumab established in 1L. Extended RAS reanalysis [PMID 24024839] (Douillard 2013 N Engl J Med): patients with KRAS exon 3/4 + NRAS exon 2/3/4 mutations also did not benefit, and may have been harmed — the definition of “KRAS wild-type” was extended to “RAS wild-type.”
CRYSTAL-RAS-EXTENDED [PMID 25605843] (Van Cutsem 2015 J Clin Oncol, N=1,198 reanalysis): extended RAS analysis of CRYSTAL. All-RAS wild-type subgroup mOS 28.4 vs 20.2 months (HR 0.69); RAS-mut subgroup no benefit. PRIME + CRYSTAL extended analyses together established “all-RAS wild-type” as the 2015 SoC gate for anti-EGFR eligibility.
PEAK [PMID 24687833] (Schwartzberg 2014 J Clin Oncol, N=285 phase II): FOLFOX6 + panitumumab vs FOLFOX6 + bevacizumab in KRAS WT (later extended to RAS WT) 1L. RAS WT subgroup mOS 41.3 vs 28.9 months. First pan vs bev 1L head-to-head exploration — small-sample phase II, but 41-month mOS was a sensational number in 2014.
FIRE-3 [PMID 25088940] (Heinemann 2014 Lancet Oncol, N=592): FOLFIRI + cetuximab vs FOLFIRI + bevacizumab head-to-head in KRAS WT 1L. Primary endpoint ORR 62.0% vs 58.0% (p=0.18) — no difference; but mOS 28.7 vs 25.0 months (HR 0.77, p=0.017) significantly favored cetuximab. First phase III to open the “anti-EGFR vs anti-VEGF in 1L — which to pick” question.
CALGB-80405 [PMID 28632865] (Venook 2017 JAMA, N=1,137): FOLFIRI / FOLFOX + cetuximab vs + bevacizumab head-to-head in KRAS WT 1L (US NCI-sponsored). mOS 30.0 vs 29.0 months (HR 0.88, p=0.08) — no difference — contradicting FIRE-3.
CALGB-80405-SIDEDNESS [PMID 34061178] (Yin 2021 J Natl Cancer Inst, CALGB 80405 reanalysis by tumor location): left-sided colon mOS cet 32.9 vs bev 29.3; right-sided colon mOS cet 13.7 vs bev 29.2 (right-sided reversed!). Foundational reanalysis establishing primary tumor sidedness as a stratification biomarker — the FIRE-3 vs CALGB-80405 contradiction was resolved: left-sided RAS WT favors cet; right-sided RAS WT favors bev.
PARADIGM [PMID 37071094] (Watanabe 2023 JAMA, N=802, Japan / partial China): mFOLFOX6 + panitumumab vs mFOLFOX6 + bevacizumab dedicated prospective RCT in RAS WT + left-sided colon mCRC 1L. mOS 37.9 vs 34.3 months (HR 0.82) significantly favored panitumumab. Upgraded “sidedness guides anti-EGFR selection” from retrospective analysis to prospective phase III evidence — by 2023, the 1L anti-EGFR use case was formally pinned to left-sided RAS WT.
TRIBE [PMID 25337750] (Loupakis 2014 N Engl J Med, N=508): FOLFOXIRI + bev triplet vs FOLFIRI + bev 1L. mPFS 12.1 vs 9.7 months (HR 0.75); mOS 29.8 vs 25.8 months. Triplet + bev established in 1L for fit patients — but with significantly higher toxicity. TRIBE-UPDATED [PMID 26338525] (Cremolini 2015 Lancet Oncol) OS update: BRAFm subgroup mOS 19.0 vs 10.7 months (HR 0.54) — BRAFm mCRC cannot wait for a chemo doublet long-term; the triplet wins the race.

2.2.2 Adjuvant: three drug classes, three concurrent failures

NSABP-C-08 [PMID 20940184] (Allegra 2011 J Clin Oncol, N=2,672): stage II-III colon cancer after curative resection, mFOLFOX6 × 6 months + bevacizumab × 12 months vs mFOLFOX6 × 6 months adjuvant. 3-year DFS 77.4% vs 75.5% (HR 0.89, p=0.15) — negative. First large negative phase III for adjuvant bev — metastatic-1L-effective bev did not benefit in adjuvant.
AVANT [PMID 23168362] (de Gramont 2012 Lancet Oncol, N=3,451): stage III or high-risk stage II colon cancer after curative resection, FOLFOX-4 or XELOX + bev × 12 months vs FOLFOX-4 or XELOX. mDFS HR 1.17 (FOLFOX+bev) / 1.07 (XELOX+bev) — negative vs control; mOS HR 1.27 (p=0.02) — directional harm in FOLFOX+bev. Second negative adjuvant bev phase III + OS numerical harm. Roche subsequently abandoned adjuvant bev development.
N0147 [PMID 22474202] (Alberts 2012 JAMA, N=2,686): stage III colon cancer after curative resection, mFOLFOX6 × 6 months + cetuximab × 6 months vs mFOLFOX6 × 6 months adjuvant (KRAS WT subgroup n=1,863 main analysis). KRAS WT 3-year DFS cet+ 75.8% vs mFOLFOX6 78.2% (HR 1.21) — negative; in the ≥70-year subgroup, the HR trended unfavorably. Adjuvant cet phase III negative.
CALGB-89803 [PMID 17687149] (Saltz 2007 J Clin Oncol, N=1,264): stage III colon cancer after curative resection IFL (5-FU + LV + irinotecan) vs 5-FU + LV adjuvant. 5-year DFS 61% vs 63% (p=0.88) — negative; G4 neutropenia 39% vs 24%. “First adjuvant defeat for metastatic-effective irinotecan.”
PETACC-3 [PMID 19451425] (Van Cutsem 2009 J Clin Oncol, N=2,094 stage III main analysis): stage II-III colon cancer after curative resection FOLFIRI vs 5-FU/LV adjuvant. Stage III 5-year DFS 56.7% vs 54.3% (HR 0.90, p=0.106) — negative. Second adjuvant defeat for irinotecan — combined with CALGB 89803 / French Accord 02 / FFCD 9802 (four negative phase IIIs), closed the door on “moving irinotecan into adjuvant.”

Takeaway: across 2004-2014, metastatic disease pushed 1L mOS from 15 to 30 months via bev / cet / pan / FOLFOXIRI, but adjuvant phase IIIs in the same period failed six times across three drug classes (bev / cet / iri), cumulatively >10,000 patients — the largest “metastatic → adjuvant extrapolation trap” in CRC history. MOSAIC’s successful move of FOLFOX into adjuvant is the lone exception (the mechanism may be that FOLFOX’s direct cytotoxic action still applies to micrometastases). The clinical lesson of this era condenses into one line: “effective in metastatic ≠ effective post-operatively” — adjuvant must prove itself with its own phase III data.

2.3 Later-line: refinement of maintenance / 2L / 3L+ (2007-2023)

Story: In 2007-2014, four phase IIIs — E3200 / RAISE / ML18147 / VELOUR — pushed 2L mOS from 9-10 months to 13 months. In 2013-2023, CORRECT / RECOURSE / FRESCO / FRESCO-2 / SUNLIGHT took 3L+ refractory mCRC from “no drug” to “at least 3 options.” China’s FRESCO / FRESCO-2 fruquintinib became one of the few mCRC 3L drugs originating in China to be pushed to global FDA approval.

E3200 [PMID 17442997] (Giantonio 2007 J Clin Oncol, N=829): 2L mCRC (bev-naïve) FOLFOX4 + bevacizumab vs FOLFOX4 vs bev. FOLFOX4+bev mOS 12.9 months vs FOLFOX4 10.8 months (HR 0.75). Foundational data for bev in 2L.
TML-ML18147 [PMID 23168366] (Bennouna 2013 Lancet Oncol, N=820): after progression on 1L bev-containing, 2L chemotherapy ± bevacizumab continuation (continued bev with a switched chemo backbone) vs chemo alone. mOS 11.2 vs 9.8 months (HR 0.81). Established the “bev beyond progression” concept — resistance is not because bev fails; continue its use.
VELOUR [PMID 22949147] (Van Cutsem 2012 J Clin Oncol, N=1,226): 2L mCRC (oxaliplatin-pretreated) FOLFIRI + aflibercept (VEGF-trap) vs FOLFIRI. mOS 13.5 vs 12.1 months (HR 0.82). Aflibercept (Zaltrap) FDA-approved for 2L mCRC in 2012.
RAISE [PMID 25877855] (Tabernero 2015 Lancet Oncol, N=1,072): 2L mCRC (after progression on 1L bev + oxaliplatin + fluoropyrimidine) FOLFIRI + ramucirumab (anti-VEGFR2) vs FOLFIRI + placebo. mOS 13.3 vs 11.7 months (HR 0.84). Third anti-angiogenic mechanism in 2L (bev / aflibercept / ramu) — anti-angiogenic therapy in 2L became standard.
CORRECT [PMID 23177514] (Grothey 2013 Lancet, N=760): 3L+ refractory mCRC regorafenib 160 mg d1-21 q4w vs placebo. mOS 6.4 vs 5.0 months (HR 0.77); mPFS 1.9 vs 1.7 months. Absolute benefit small but the first effective option “after all roads exhausted.” FDA approved in September 2012.
RECOURSE [PMID 25970050] (Mayer 2015 N Engl J Med, N=800): 3L+ refractory mCRC TAS-102 (trifluridine/tipiracil) vs placebo. mOS 7.1 vs 5.3 months (HR 0.68). Oral nucleoside antimetabolite — FDA approved September 2015.
FRESCO [PMID 29946728] (Li 2018 JAMA, N=416, 28 Chinese centers): 3L+ refractory mCRC fruquintinib (selective VEGFR1/2/3 TKI) vs placebo. mOS 9.3 vs 6.6 months (HR 0.65); mPFS 3.7 vs 1.8 months. China-originating, NMPA approved September 2018 — the first registrational phase III for a China-developed oncology drug in CRC 3L.
FRESCO-2 [PMID 37331369] (Dasari 2023 Lancet, N=691, international multi-center + partial China): 3L+ refractory mCRC (resistant to or unsuitable for TAS-102 / regorafenib) fruquintinib vs placebo, international validation. mOS 7.4 vs 4.8 months (HR 0.66). FDA approved November 2023 — a China-originating drug won a global label in mCRC.
SUNLIGHT [PMID 37133585] (Prager 2023 N Engl J Med, N=492): 3L+ refractory mCRC TAS-102 + bevacizumab vs TAS-102 monotherapy. mOS 10.8 vs 7.5 months (HR 0.61). Old drug + bev breakthrough — 3L mOS crossed 10 months for the first time. FDA approved August 2023.
IMBLAZE370 [PMID 31003911] (Eng 2019 Lancet Oncol, N=363): 3L MSS/pMMR mCRC atezolizumab + cobimetinib (MEK inhibitor) vs regorafenib vs atezolizumab monotherapy. All three arms failed — demonstrated that MSS/pMMR CRC does not respond to IO, and that MEK + IO combinations cannot “heat” cold tumors.
REGOTORI [PMID 34622226] (Wang 2021 Cell Rep Med, Chinese phase Ib/II): MSS/pMMR refractory mCRC regorafenib + toripalimab (domestic PD-1). ORR 15.2%, DCR 36.4%; mPFS 2.1 months. Early signal + gut-microbiome analysis — left hypothesis-generating data for subsequent MSS CRC exploration.

Takeaway: in 2023, 3L+ refractory mCRC SoC = one of fruquintinib (FRESCO-2) / TAS-102 + bev (SUNLIGHT) / regorafenib (CORRECT). 2L is one of FOLFIRI + bev / aflibercept / ramucirumab plus anti-EGFR switching (if RAS WT and not previously used). MSS/pMMR CRC is cold to IO (IMBLAZE370 failed); only the MSI-H subgroup is CRC’s true immunotherapy battlefield (§2.4).

2.4 MSI-H / dMMR immune reversal (2015-2025): from refractory advanced to 1L to 100% cCR in rectal

Story: In 2015, early work by Le DT et al. used ~40 MSI-H / dMMR solid-tumor cases in a phase II to demonstrate pembrolizumab ORR 40-50% in this subgroup (that early foundational trial is not among the 74 main trials here), establishing the tumor-agnostic biology of “MMR status predicts IO response.” In 2017, CheckMate-142 nivo monotherapy achieved ORR 31% in MSI-H mCRC 2L+; nivo+ipi ORR 55%. In 2020, KEYNOTE-177 used phase III data to push pembrolizumab mPFS in MSI-H mCRC 1L vs chemo from 8.2 to 16.5 months (HR 0.60). In 2022, Cercek’s rectal dMMR trial achieved 100% clinical complete response (cCR) with dostarlimab monotherapy in dMMR locally advanced rectal cancer — a rare precedent of “immunotherapy replacing surgery” in oncology. In 2024, CheckMate-8HW pushed MSI-H mCRC 1L from pembro monotherapy to nivo+ipi dual IO (24-mo PFS 72% vs 14%, HR 0.21, one of the largest HRs in history). Over these 7 years, the MSI-H / dMMR subgroup went from “chemo-insensitive refractory” to “immune-SoC reversed.”

KEYNOTE-164 [PMID 31725351] (Le 2020 J Clin Oncol, N=124 single-arm phase II): MSI-H / dMMR mCRC ≥2L (cohort A ≥3L / cohort B ≥2L) pembrolizumab monotherapy. Overall ORR 33% (cohort A) / 34% (cohort B); mDoR not reached; mPFS 2.3-4.1 months, mOS 31.4-47.0 months. KEYNOTE-164 + the earlier Le 2015 NEJM established the core CRC data underpinning the FDA 2017 tumor-agnostic MSI-H approval.
CHECKMATE-142 [PMID 29355075] (Overman 2018 J Clin Oncol, nivo+ipi cohort, N=119): MSI-H mCRC ≥2L (76% ≥2L) nivolumab + ipilimumab. ORR 55%, 9-month PFS 76%, 9-month OS 87%. Dual IO far outperformed monotherapy in MSI-H.
CHECKMATE-142-NIVO-MONO [PMID 28734759] (Overman 2017 Lancet Oncol, nivo mono cohort, N=74): MSI-H mCRC 2L+ nivolumab monotherapy. ORR 31%, 12-month PFS 50%, 12-month OS 73%. First large-cohort signal for MSI-H / IO — from then on, all CRC IO studies were stratified by MMR status.
KEYNOTE-177 [PMID 33264544] (André 2020 N Engl J Med, N=307): MSI-H / dMMR mCRC 1L pembrolizumab vs investigator’s choice chemo (FOLFOX/FOLFIRI ± bev ± cet). mPFS 16.5 vs 8.2 months (HR 0.60, 95% CI 0.45-0.80, p=0.0002); ORR 43.8% vs 33.1%; G3-5 AE 22% vs 66%. First positive IO 1L phase III in CRC — MSI-H became the hard gate for 1L immunotherapy selection.
KEYNOTE-177-5YR [PMID 39631622] (André 2025 Ann Oncol): 5-year follow-up. mPFS 16.5 vs 8.2 months maintained; mOS HR 0.73 (95% CI 0.54-0.99) long-term benefit reached significance; OS remained significant despite an initial 60% crossover rate — long-tail OS benefit for MSI-H 1L pembro was confirmed.
CHECKMATE-8HW [PMID 39602630] (André 2024 N Engl J Med, N=839): MSI-H / dMMR mCRC 1L (main analysis) or 2L+ nivolumab + ipilimumab vs nivo mono vs chemo. 1L nivo+ipi vs chemo 24-mo PFS 72% vs 14% (HR 0.21, 95% CI 0.13-0.35) — one of the largest HRs ever in a CRC phase III. nivo+ipi vs nivo mono HR 0.62 significant. FDA approved nivo+ipi for MSI-H 1L in 2025 — MSI-H 1L moved from pembro monotherapy toward dual IO (in fit patients).
CERCEK-DMMR-RECTAL-CANCER-DOSTARLIMAB [PMID 35660797] (Cercek 2022 N Engl J Med; expanded cohort 2025): dMMR stage II/III locally advanced rectal adenocarcinoma neoadjuvant dostarlimab (PD-1) monotherapy × 6 months with organ-preservation intent (if cCR achieved, avoid CRT + surgery). Initial cohort N=12 all reached cCR (100%); expanded to 42 patients, all with sustained cCR. A rare precedent in oncology of “IO monotherapy replacing surgery + radiotherapy” — a must-discuss clinical branchpoint for dMMR rectal cancer in 2026.
NICHE-2 [PMID 38838311] (Chalabi 2024 N Engl J Med, N=115, Netherlands): dMMR non-metastatic locally advanced stage II-III colon cancer, neoadjuvant nivolumab + ipilimumab × 2 doses followed by surgery. pCR 67%, MPR 95%; 3-yr DFS 100%; no recurrences. Neoadjuvant IO in non-metastatic dMMR colon cancer — an astonishing early signal of “neoadjuvant IO pushes DFS to 100% in dMMR colon”; awaiting phase III-scale validation.
ATEZOTRIBE [PMID 35636444] (Antoniotti 2022 Lancet Oncol, N=218 phase II): mCRC 1L unselected for MMR status FOLFOXIRI + bev ± atezolizumab. Overall mPFS 13.1 vs 11.5 months (HR 0.69) positive; dMMR subgroup HR 0.27 / pMMR subgroup HR 0.78. A phase II hope signal for pMMR CRC + IO — but phase III-level MSS CRC + IO data is still lacking (IMBLAZE370 / REGOTORI both small / negative).

Takeaway: in 2026, the MSI-H / dMMR decision = advanced 1L SoC is dual IO (nivo+ipi, CheckMate-8HW) or mono IO (pembro, KEYNOTE-177); non-metastatic locally advanced dMMR colon — consider neoadjuvant IO (NICHE-2 early signal); dMMR rectal — prioritize dostarlimab monotherapy for organ preservation (Cercek expanded cohort still 100% cCR); MSS/pMMR CRC — IO mono / IO+ICI all negative. CRC is the cancer type where “MMR determines everything.”

2.5 Biomarker-matched precision rockets (2016-2025): four dedicated pathways — BRAF / HER2 / KRAS G12C / NTRK

Story: In 2019, BEACON CRC pushed encorafenib + cetuximab (2-drug) in BRAF V600E mutant mCRC 2L+ from “chemo-given-up” to SoC (mOS 9.3 vs 5.9 months). In 2025, BREAKWATER advanced encorafenib + cetuximab + mFOLFOX6 (3-drug) into 1L — BRAFm finally had “a usable 1L regimen.” In 2016, HERACLES opened HER2+ CRC (trastu + lapatinib); in 2021, DESTINY-CRC01 used T-DXd (ADC) to win HER2-amp CRC 2L+ with ORR 45.3%; in 2023, MOUNTAINEER achieved ORR 38% with tucatinib + trastu (two drugs, avoiding ADC ILD risk). In 2022-2023, KRYSTAL-1 + CodeBreaK 300 extended KRAS G12C (CRC ~3%) from NSCLC-exclusive to CRC. In 2018-2020, NAVIGATE + STARTRK (larotrectinib / entrectinib) opened the NTRK-fusion tumor-agnostic pathway; the CRC subgroup is <1% but ORR >50%. The four pathways combined cover ~13-15% of CRC patients, forming the core map of metastatic CRC precision therapy.

2.5.1 BRAF V600E pathway (mCRC ~8%, poor prognosis)

SWOG-S1406 [PMID 33356422] (Kopetz 2021 J Clin Oncol, N=106 phase II RCT): BRAF V600E mut mCRC 2L irinotecan + cetuximab ± vemurafenib (triplet) vs irinotecan + cetuximab (doublet). mPFS 4.4 vs 2.0 months (HR 0.50); ORR 17% vs 4%. Mechanistic validation for the triplet — BRAF inhibition + EGFR inhibition synergy opened the CRC BRAFm therapeutic window.
BEACON-CRC [PMID 31566309] (Kopetz 2019 N Engl J Med, N=665 phase III): BRAF V600E mut mCRC 2L (1-2 prior lines) encorafenib + cetuximab (2-drug) vs encorafenib + binimetinib + cetuximab (3-drug) vs chemo (FOLFIRI + cet or irinotecan + cet). 2-drug vs chemo: mOS 9.3 vs 5.9 months (HR 0.61); ORR 20% vs 2%; 3-drug vs chemo HR 0.52. FDA approved enco+cet for 2L BRAFm mCRC in April 2020. Triplet-arm toxicity was significantly higher; the doublet became standard — 2L BRAFm SoC established.
BREAKWATER [PMID 40444708] (Elez 2025 N Engl J Med, N=637 phase III): BRAF V600E mut + RAS WT mCRC 1L encorafenib + cetuximab + mFOLFOX6 (3-drug) vs investigator’s choice chemo (FOLFOX ± bev or FOLFOXIRI ± bev). mPFS 12.8 vs 7.1 months (HR 0.53); ORR 60.9% vs 40.0%; mOS interim HR 0.49 (p=0.0015). First positive phase III in BRAFm 1L — pushed 1L mOS from 12-15 months to 30+ months (interim); FDA granted accelerated approval in 2024, full NEJM publication 2025. BRAF flipped from “metastatic’s worst-prognosis subgroup” to a turnaround story.

2.5.2 HER2 pathway (mCRC ~3%, enriched in RAS WT)

HERACLES [PMID 27108243] (Sartore-Bianchi 2016 Lancet Oncol, N=27 phase II): HER2+ + KRAS exon 2 wild-type mCRC 3L+ trastuzumab + lapatinib doublet. ORR 30%, mPFS 21 weeks. First prospective phase II signal for CRC HER2 + established CRC-specific HER2+ criteria (differing from breast-cancer Dako scoring — HERACLES required IHC 3+ or IHC 2+/FISH+ with >50% positive cells).
MOUNTAINEER [PMID 37142372] (Strickler 2023 Lancet Oncol, N=117 phase II): HER2+ + RAS WT mCRC 3L+ tucatinib (HER2-selective TKI) + trastuzumab. ORR 38.1%, mDoR 12.4 months, mPFS 8.2 months. The two-drug combination avoids ADC ILD risk + small-molecule TKI is convenient — FDA granted accelerated approval for HER2+ mCRC 3L+ in January 2023.
DESTINY-CRC01 [PMID 33961795] (Siena 2021 Lancet Oncol, N=78 phase II): HER2-expressing mCRC 3L+ trastuzumab deruxtecan (T-DXd, ADC) across three cohorts by IHC 3+ / IHC 2+ FISH+ / IHC 2+ FISH-. Cohort A (IHC 3+, n=53) ORR 45.3%, mPFS 6.9 months, mOS 15.5 months. Landmark ADC data in HER2+ CRC; ILD risk must be monitored.
DESTINY-CRC02 [PMID 39116902] (Raghav 2024 Lancet Oncol, N=122 phase II): HER2+ mCRC 2L+ T-DXd dose-finding (5.4 mg/kg vs 6.4 mg/kg). 5.4 mg/kg ORR 37.8%, 6.4 mg/kg ORR 27.5%. Established 5.4 mg/kg as the CRC dose + demonstrated activity in RAS-mut population — first benefit signal for RAS mut in the HER2 pathway.

2.5.3 KRAS G12C pathway (mCRC ~3%)

KRYSTAL-1 [PMID 36546659] (Yaeger 2023 N Engl J Med, N=43+28 phase II): KRAS G12C mut mCRC 3L+ adagrasib monotherapy vs adagrasib + cetuximab combination. Adagrasib monotherapy ORR 19%, mPFS 5.6 months; adagrasib + cetuximab ORR 46%, mPFS 6.9 months. Dual targeting (KRAS + EGFR feedback blockade) significantly outperformed KRAS G12C monotherapy — confirmed CRC-specific adaptive resistance (EGFR feedback activation).
CODEBREAK-300 [PMID 37870968] (Fakih 2023 N Engl J Med, N=160 phase III): KRAS G12C mut mCRC 3L+ (≥2 prior lines) sotorasib + panitumumab vs sotorasib + panitumumab low-dose vs investigator’s choice trifluridine/tipiracil or regorafenib. Sotorasib 960 mg + pan arm mPFS 5.6 vs 2.2 months (HR 0.49), ORR 26% vs 0%. FDA approved sotorasib + panitumumab for KRAS G12C+ mCRC 3L+ in January 2024 — the second positive phase III in CRC precision therapy (after BEACON).

2.5.4 NTRK fusion (mCRC <1%, tumor-agnostic)

LAROTRECTINIB-NAVIGATE [PMID 29466156] (Drilon 2018 N Engl J Med, N=55 tumor-agnostic, CRC n=5): TRK fusion+ solid tumors larotrectinib. Overall ORR 75% (95% CI 61-85); CRC subgroup data sparse but responsive. FDA’s first tumor-agnostic biomarker approval in November 2018 — regulatory milestone.
ENTRECTINIB-STARTRK [PMID 31838007] (Doebele 2020 Lancet Oncol, N=54 tumor-agnostic, CRC subgroup reported separately): NTRK fusion+ solid tumors entrectinib (pan-TRK/ROS1/ALK, good CNS penetration). Overall ORR 57.4%; CRC subgroup small N but consistent ORR. FDA tumor-agnostic approval in August 2019.

Takeaway: in 2026, CRC precision therapy = “every newly diagnosed advanced CRC must undergo comprehensive molecular profiling” — among RAS / BRAF V600E / MMR·MSI / HER2 IHC + ISH / KRAS G12C / NTRK fusion, any positive biomarker → a prospective phase III / phase II evidence-level SoC is available. Missing detection = missing a high-yield response subgroup with ORR 30-60%.

2.6 Rectal TNT and organ preservation (1990s-2023): from “surgery is mandatory” to “surgery is optional”

Story: over the past 30 years, rectal cancer moved from the basic question of “preoperative vs postoperative concurrent chemoradiotherapy (neoadjuvant vs adjuvant CRT)” → the optimization questions of “short-course vs long-course radiation,” “add oxaliplatin or not,” “radiation or chemo first” → the structural paradigm shift of 2020-2023 TNT (total neoadjuvant therapy) + organ preservation. Core tension: rectal-cancer radiotherapy side effects (sexual function / proctitis / bowel function) are heavy, and surgery itself carries permanent ostomy risk → don’t resect the organ if you can avoid it.

GERMAN-CAO-ARO-AIO-94 [PMID 15496622] (Sauer 2004 N Engl J Med, N=823): T3-4 or N+ rectal cancer, preoperative CRT (50.4 Gy + 5-FU) vs postoperative CRT. 5-yr local recurrence 6% vs 13% (p=0.006); acute G3-4 toxicity preop 27% vs postop 40%. Preoperative CRT replaced postoperative CRT as LARC (locally advanced rectal cancer) SoC — all rectal trials over the next 20 years iterated on top of preoperative CRT.
EORTC-22921 [PMID 24440473] (Bosset 2014 Lancet Oncol, N=1,011): T3-4 rectal 2×2 factorial design (preop CRT vs preop RT + postop 5-FU vs observation) long-term follow-up. Postop 5-FU adjuvant did not improve 10-yr OS (HR 0.97); preop CRT significantly improved local recurrence but did not affect OS. Cast doubt on “post-preop-CRT adjuvant chemotherapy.”
POLISH-I [PMID 16983741] (Bujko 2006 Br J Surg, N=312): T3-T4 rectal short-course radiation (5×5 Gy + immediate surgery) vs long-course CRT (50.4 Gy + concurrent 5-FU). No difference in 4-yr local recurrence or OS. Short-course radiation as equivalent alternative to long-course CRT — shorter duration (1 week vs 5-6 weeks) + better patient compliance.
ACCORD-12 [PMID 20194850] (Gérard 2010 J Clin Oncol, N=598): T3-4 rectal preop capecitabine + 45 Gy vs capecitabine + oxaliplatin + 50 Gy (dose escalation + oxaliplatin). ypCR 13.9% vs 19.2% (p=0.09, not significant); toxicity clearly higher in oxaliplatin arm. Adding oxaliplatin to preop CRT did not benefit — consistent with STAR-01 / NSABP R-04.
CAO-ARO-AIO-04 [PMID 26189067] (Rödel 2015 Lancet Oncol, N=1,236): LARC preop 5-FU + oxaliplatin + CRT followed by FOLFOX adjuvant vs standard 5-FU + CRT + 5-FU adjuvant. 3-yr DFS 75.9% vs 71.2% (HR 0.79, p=0.03). The only phase III to demonstrate “throughout-oxaliplatin inclusion (preop CRT + postop adjuvant) improves DFS” — at a toxicity cost.
FOWARC [PMID 31557064] (Deng 2019 J Clin Oncol, N=495, China, Sun Yat-sen University, led by Deng Y): LARC cT3-4 or N+ neoadjuvant mFOLFOX6 + RT vs 5-FU + RT vs mFOLFOX6 alone (no RT). No difference in 3-yr DFS / OS across three arms. Challenged the dogma that “all LARC needs CRT” — mFOLFOX6-alone arm did not receive RT but had similar outcomes. A Chinese forerunner for PROSPECT 2023’s RT-omission decision.
RAPIDO [PMID 33301740] (Bahadoer 2021 Lancet Oncol, N=920): high-risk LARC (cT4a/b, extramural vascular invasion, cN2, MRF+, lateral lymph nodes) short-course 5×5 Gy radiation → 18 weeks CAPOX/FOLFOX total neoadjuvant (TNT) → TME surgery vs standard long-course CRT + TME + postop adjuvant. 3-yr disease-related treatment failure 23.7% vs 30.4% (HR 0.75); pCR 28% vs 14%. First phase III to show TNT short-course branch superior to standard CRT — TNT short-course + CAPOX pathway established.
PRODIGE-23 [PMID 33862000] (Conroy 2021 Lancet Oncol, N=461): LARC cT3-4 N0-2 FOLFIRINOX × 6 cycles induction → CRT → surgery → postop adjuvant (TNT induction branch) vs standard CRT → surgery → postop adjuvant. 3-yr DFS 75.7% vs 68.5% (HR 0.69); 3-yr mOS HR 0.65; ypCR 28% vs 12%. TNT induction branch also positive — together with RAPIDO’s short-course branch, pinned two TNT pathways into 2021 SoC.
STELLAR [PMID 35263150] (Jin 2022 J Clin Oncol, N=599, China, CAMS, led by Jin J): Chinese LARC cT3-4 or N+ short-course radiation + CAPOX TNT vs long-course CRT + postop adjuvant. 3-yr DFS 64.5% vs 62.3% (HR 0.883, non-inferiority met); 3-yr OS 86.5% vs 75.1% (HR 0.67) — a China-led TNT short-course phase III, with DFS non-inferior + OS even superior to the long-course CRT control. Asian-population-specific TNT data.
PROSPECT [PMID 37272534] (Schrag 2023 N Engl J Med, N=1,194): cT2 N+ or cT3 N0-N+ low-risk LARC suitable for sphincter-preserving surgery FOLFOX × 6 cycles → selective CRT reserved only for those not achieving ≥20% tumor shrinkage vs standard long-course CRT + surgery + postop adjuvant. 5-yr DFS 80.8% vs 78.6% (HR 0.92, non-inferiority met); 5-yr OS 89.5% vs 90.2%. RT-omission decision — low-risk LARC can skip RT, using only FOLFOX + surgery. From Sauer 2004’s “all LARC needs CRT” to 2023’s “low-risk skip CRT” — a full circle in 20 years.
OPRA [PMID 35483010] (Garcia-Aguilar 2022 J Clin Oncol, N=324): stage II-III rectal TNT (induction chemo + CRT vs CRT + consolidation chemo, with post-TNT assessment) organ preservation: patients achieving cCR enter watch-and-wait (W&W). 3-yr organ preservation 40% vs 58% (consolidation superior to induction); 3-yr DFS 75% vs 78% (comparable). Phase II-level evidence for organ preservation rate 40-58% + DFS uncompromised — the “cCR→W&W” pathway after TNT was established.
IWWD [PMID 29976470] (van der Valk 2018 Lancet, N=880, international registry across 47 centers in 15 countries): observational registry of rectal cancers achieving cCR after neoadjuvant therapy and entering watch-and-wait. 3-yr distant metastasis-free rate 91.9%; 3-yr regrowth rate 25.2% (97% salvageable by surgery) — after W&W regrowth, salvage surgery remains possible. Largest real-world W&W dataset.
IDEA [PMID 29590544] (Grothey 2018 N Engl J Med, N=12,834, 6-trial pooled): stage III colon cancer adjuvant FOLFOX or CAPOX 3 months vs 6 months. Main analysis non-inferiority not met (HR 1.07); subgroups: T1-3 N1 non-inferior at 3 months with significantly reduced toxicity (G3 neuropathy); T4 or N2 still favored 6 months. 3-vs-6-month by risk group — global SoC: low-risk 3-month CAPOX, high-risk 6-month FOLFOX. Important de-escalation evidence for oxaliplatin-induced neuropathy.
DYNAMIC [PMID 35657320] (Tie 2022 N Engl J Med, N=455): stage II colon cancer ctDNA-guided adjuvant: ctDNA-positive (week 4 or 7 post-op) → chemotherapy; ctDNA-negative → observation, vs standard clinicopathologic decision. ctDNA-positive chemotherapy rate 15% vs standard chemotherapy rate 28% (~50% reduction in chemotherapy use); 2-yr RFS 93.5% vs 92.4% (non-inferiority met). Phase III-level evidence for ctDNA-guided de-escalation — significantly reduced overtreatment in low-risk stage II.

Takeaway: 2026 rectal cancer = risk-adapted, organ-preserving, TNT-centered. High-risk LARC (cT4 / MRF+ / cN2+) → TNT (RAPIDO short-course or PRODIGE-23 induction) + surgery; low-risk LARC (cT2 N+ / cT3 N0) → PROSPECT — RT omission possible; dMMR rectal cancer → prioritize Cercek dostarlimab monotherapy for organ preservation (§2.4); post-TNT cCR → consider W&W (OPRA + IWWD real-world). Chinese data plays an important role in FOWARC + STELLAR (Asian-population validation + RT-omission forerunner).

3. Cross-sectional: 2026 decision landscape (six dimensions)

Projecting the longitudinal evolution onto 2026’s concrete clinical decision trees — the following are six key branchpoints and the evidence behind each.

3.1 Newly diagnosed mCRC: order comprehensive molecular profiling immediately

NCCN Colon V1.2026 + NCCN Rectal V1.2026 both explicitly recommend comprehensive molecular testing (tissue or ctDNA or both) for all newly diagnosed advanced CRC, covering: RAS (full-exon KRAS + NRAS) + BRAF V600E + MMR/MSI (IHC + PCR or NGS) + HER2 IHC + ISH + KRAS G12C (naturally covered during RAS sequencing) + NTRK fusion (optional, <1%). Molecular results directly affect:

1L chemotherapy backbone selection: BRAFm → BREAKWATER 3-drug (enco + cet + mFOLFOX6); MSI-H → dual IO (CheckMate-8HW) or mono IO (KEYNOTE-177); RAS WT left-sided → sidedness-guided anti-EGFR (PARADIGM); RAS WT right-sided → bev; RAS mut → FOLFOX/FOLFIRI + bev.
2L+ targeted accessibility: HER2 amp → MOUNTAINEER / DESTINY-CRC02; KRAS G12C → CodeBreaK 300 (sotorasib + pan); NTRK → larotrectinib / entrectinib; MSI-H 2L (if IO not used in 1L) → pembro / nivo+ipi.
Clinical trial enrollment: BREAKWATER follow-up updates / NICHE-2 follow-up phase III / new pMMR IO combination trials.

Missing RAS → wrong anti-EGFR; missing BRAF → miss BREAKWATER 1L; missing MMR → miss IO; missing HER2 → miss ADC / small-molecule TKI; missing KRAS G12C → miss the sotorasib/adagrasib + pan pathway.

3.2 mCRC 1L: five parallel biomarker-stratified pathways

2026 mainstream: 1L is no longer “FOLFOX + bev” one-size-fits-all — five biomarker-stratified pathways.

Subgroup	First-line preferred	Evidence
MSI-H / dMMR (~4-5% mCRC)	nivolumab + ipilimumab (fit patients, CheckMate-8HW [PMID 39602630], 24-mo PFS 72% vs 14%, HR 0.21) or pembrolizumab monotherapy (KEYNOTE-177 [PMID 33264544], mPFS 16.5 vs 8.2 months)	Category 1 preferred
BRAF V600E mut + RAS WT (~8%)	encorafenib + cetuximab + mFOLFOX6 (3-drug, BREAKWATER) [PMID 40444708], mPFS 12.8 vs 7.1 months, HR 0.53	Category 1 (FDA accelerated approval 2024, full NEJM publication 2025)
RAS WT + left-sided colon (~40% mCRC)	FOLFOX/FOLFIRI + anti-EGFR (cetuximab or panitumumab) (PARADIGM [PMID 37071094] + CALGB-80405-SIDEDNESS [PMID 34061178])	Category 1
RAS WT + right-sided colon (~10-15% mCRC)	FOLFOX/FOLFIRI + bevacizumab (avoid anti-EGFR)	Category 1
RAS mut, or BRAF/MMR results pending + fit	FOLFOX / FOLFIRI / FOLFOXIRI + bevacizumab (TRIBE [PMID 25337750], mOS 29.8 vs 25.8 months)	Category 1

Contraindications:

RAS mut — do not use cetuximab / panitumumab (PRIME [PMID 24024839] + CRYSTAL [PMID 25605843] extended-RAS analyses confirmed harm)
MSS/pMMR — do not use IO monotherapy / MEK + IO combinations (IMBLAZE370 [PMID 31003911] three-arm failure)
BRAFm — pure chemo + bev 1L not recommended (mOS typically <15 months, given BREAKWATER’s better option)

NCCN Colon V1.2026: MSI-H 1L = nivo+ipi / pembro / ipilimumab+nivolumab each Category 1; BRAFm + RAS WT 1L = enco+cet+mFOLFOX6 Category 1; RAS WT left-sided 1L = mFOLFOX6/FOLFIRI + pan/cet Category 1; RAS WT right-sided / RAS mut 1L = mFOLFOX6/FOLFIRI + bev Category 1.

3.3 mCRC 2L+: precision-targeted routing + anti-angiogenic re-breakthrough after resistance

2026 mainstream: 2L routes by what was used in 1L + biomarker status —

Scenario	First-line preferred
Progression on 1L FOLFOX + bev + RAS WT, anti-EGFR not yet used	FOLFIRI + cetuximab / panitumumab (CRYSTAL + PRIME extended RAS)
Progression on 1L FOLFOX/FOLFIRI + bev	FOLFIRI + aflibercept (VELOUR [PMID 22949147]) or FOLFIRI + ramucirumab (RAISE [PMID 25877855]) or bev beyond progression (TML-ML18147 [PMID 23168366])
BRAF V600E progression	encorafenib + cetuximab (BEACON-CRC [PMID 31566309], 2-drug mOS 9.3 months HR 0.61)
HER2+ (IHC 3+ or 2+/ISH+) + RAS WT 3L+	tucatinib + trastuzumab (MOUNTAINEER [PMID 37142372], ORR 38%) or T-DXd (DESTINY-CRC01 [PMID 33961795] / CRC02 [PMID 39116902], ORR 37-45%; monitor ILD)
KRAS G12C 3L+	sotorasib + panitumumab (CodeBreaK 300 [PMID 37870968], mPFS 5.6 vs 2.2 months) or adagrasib + cetuximab (KRYSTAL-1 [PMID 36546659], ORR 46%)
NTRK fusion any line	larotrectinib (NAVIGATE [PMID 29466156]) or entrectinib (STARTRK [PMID 31838007])
MSI-H IO-naïve 2L	pembro monotherapy (KEYNOTE-164 [PMID 31725351]) or nivo+ipi (CheckMate-142 [PMID 29355075])
3L+ refractory, no biomarker match	fruquintinib (FRESCO-2 [PMID 37331369]) or TAS-102 + bev (SUNLIGHT [PMID 37133585]) or regorafenib (CORRECT [PMID 23177514])

Controversies:

3L+ three-drug sequence: fruquintinib vs TAS-102+bev vs regorafenib — no direct H2H; cross-trial mOS comparisons (7.4 / 10.8 / 6.4 months) versus controls are biased; clinical selection by toxicity profile + prior exposure.
MSS CRC 2L+ IO combinations: IMBLAZE370 negative + REGOTORI early signal; no positive phase III; not recommended outside clinical trials.

3.4 Colon adjuvant: MOSAIC foundation + IDEA de-escalation + DYNAMIC ctDNA pathway

2026 mainstream:

Subgroup	First-line preferred	Evidence
Low-risk stage III (T1-3 N1)	CAPOX × 3 months (IDEA [PMID 29590544] non-inferiority subgroup; significantly reduced neuropathy)	Category 1
High-risk stage III (T4 or N2)	FOLFOX × 6 months or CAPOX × 6 months (IDEA + MOSAIC [PMID 15175436] + XELOXA [PMID 21383294])	Category 1
High-risk stage II (T4 / poorly differentiated / lymphovascular invasion / obstruction / perforation / <12 nodes)	5-FU/LV monotherapy, capecitabine monotherapy, or FOLFOX (individualized)	Category 2A
Low-risk stage II + dMMR	observation (no chemotherapy) — dMMR did not benefit from adjuvant 5-FU monotherapy (MOSAIC-10YR [PMID 26527776] subgroup + QUASAR [PMID 18083404])	Category 1
Stage II ctDNA + feasible precision stratification	DYNAMIC pathway: ctDNA+ → chemotherapy; ctDNA- → observation ([PMID 35657320])	Category 2A
BRAFm stage III	FOLFOX × 6 months (no IO / no enco + cet — neither adjuvant IO nor BRAFm targeted therapy has phase III evidence)	Category 1
MSI-H stage III	still FOLFOX × 6 months (adjuvant IO lacks phase III); consider ATOMIC / NICHE-series trials	Category 1

Contraindications 2026 (three classes + irinotecan):

Adjuvant bev contraindicated: NSABP C-08 [PMID 20940184] + AVANT [PMID 23168362] (OS HR 1.27 potential harm)
Adjuvant cetuximab contraindicated: N0147 [PMID 22474202] (3-yr DFS HR 1.21)
Adjuvant panitumumab contraindicated: no positive phase III, and cet-class mechanism unfavorable
Adjuvant irinotecan contraindicated: CALGB 89803 [PMID 17687149] + PETACC-3 [PMID 19451425] (four negative phase IIIs)

Decision insight: any adjuvant “drug addition” idea must have positive phase III evidence — in 60 years, only FOLFOX successfully moved into adjuvant.

3.5 Rectal: three-way branch — TNT / organ preservation / low-risk RT omission

2026 mainstream:

Subgroup	First-line preferred
High-risk LARC (cT4 / MRF+ / cN2+)	TNT: short-course 5×5 Gy + CAPOX/FOLFOX (RAPIDO [PMID 33301740]) or FOLFIRINOX induction + long-course CRT (PRODIGE-23 [PMID 33862000]) + surgery
Intermediate-risk LARC (cT3 N0-2, adequate margins)	standard long-course CRT + surgery or TNT either acceptable (STELLAR [PMID 35263150] supports short-course TNT in Asian populations)
Low-risk LARC (cT2 N+ or cT3 N0-N+ suitable for sphincter preservation)	PROSPECT [PMID 37272534] pathway: FOLFOX × 6 cycles → selective CRT (add RT only if shrinkage <20%)
dMMR locally advanced rectal cancer	dostarlimab monotherapy × 6 months (Cercek [PMID 35660797], 100% cCR sustained through 42-patient expansion) — first choice for organ preservation
TNT achieves cCR	Watch-and-Wait (W&W): OPRA [PMID 35483010] 3-yr organ preservation 40-58% + IWWD [PMID 29976470] 3-yr regrowth 25% salvageable by surgery

Historical gradient:

German CAO/ARO/AIO-94 [PMID 15496622] (2004) established preoperative CRT
POLISH-I [PMID 16983741] (2006) short-course and long-course equivalent
EORTC-22921 [PMID 24440473] (2014) questioned post-operative adjuvant chemotherapy value
ACCORD-12 [PMID 20194850] (2010) + CAO-ARO-AIO-04 [PMID 26189067] (2015) mixed results for adding oxaliplatin to CRT
FOWARC [PMID 31557064] (2019) China challenged “all LARC needs CRT”
RAPIDO / PRODIGE-23 (2021) TNT positive
STELLAR (2022) Asian short-course TNT
PROSPECT (2023) RT omission

3.6 The dedicated role of Chinese data in CRC

Unlike HCC’s “China-led global IO combinations” or NSCLC’s “parallel independent Chinese PD-1 phase IIIs,” Chinese data in CRC plays the role of “3L+ breakthrough + Asian-population TNT validation + RT-omission forerunner”:

FRESCO [PMID 29946728] + FRESCO-2 [PMID 37331369]: fruquintinib pushed from Chinese 3L (FRESCO 2018) to global 3L+ (FRESCO-2 2023 FDA approval) — a significant case of a China-originating oncology drug obtaining first FDA approval in mCRC.
STELLAR [PMID 35263150] (Jin Jing, CAMS): China-led short-course TNT phase III, OS even superior to long-course CRT — Asian-population-dedicated LARC TNT data.
FOWARC [PMID 31557064] (Deng Yanhong, Sun Yat-sen University): challenged the classical notion that “all LARC needs CRT” — 2019 logical foundation for PROSPECT 2023’s RT omission.
REGOTORI [PMID 34622226] (Wang Feng): regorafenib + toripalimab exploring IO+TKI direction in MSS CRC + gut-microbiome correlative — left hypotheses for subsequent pMMR CRC IO combinations.
PARADIGM (Japan + partial China [PMID 37071094]): though Japan-led, Asian-population data — prospective validation of sidedness.

4. Research Gaps: ten unresolved clinical questions

This report identifies the following gaps, all definable specific questions (not boilerplate “more research needed”):

IO breakthrough in MSS/pMMR mCRC: ~85-95% of CRC; IMBLAZE370 [PMID 31003911] three-arm failure; REGOTORI [PMID 34622226] early signal with small N. ATEZOTRIBE [PMID 35636444] overall-population PFS positive but pMMR subgroup HR 0.78 marginal — how to “heat” cold tumors (MEK / VEGF / LAG-3 / TIGIT / STING agonist) is the largest unmet need in CRC IO.
BRAFm 1L missing H2H — BREAKWATER 3-drug vs FOLFOXIRI + bev: BREAKWATER [PMID 40444708] vs investigator’s choice chemo positive but the control did not fully utilize FOLFOXIRI + bev + anti-EGFR; the cross-trial comparison between TRIBE-UPDATED [PMID 26338525] BRAFm subgroup mOS 19 months and BREAKWATER interim 30 months is biased.
Adjuvant IO in MSI-H colon: NICHE-2 [PMID 38838311] neoadjuvant pCR 67%; ATOMIC phase III 2027+ readout. 2026 SoC remains FOLFOX × 6 months — when to switch to IO, decision tree undefined.
Generalization of ctDNA-guided adjuvant de-escalation: DYNAMIC [PMID 35657320] is stage II phase III; stage III ctDNA stratification (CIRCULATE-US / BESPOKE trials ongoing) 2026-2028 readout.
Left-vs-right sidedness in the RAS-mut subgroup: PARADIGM [PMID 37071094] was done only in RAS WT left-sided; the interaction of RAS mut + sidedness (whether right-sided RAS mut benefits more from FOLFOXIRI) has not been phase III validated.
1L positioning of HER2+ CRC: MOUNTAINEER / DESTINY-CRC01/02 all in 3L+; whether HER2+ 1L should start with cetuximab + HER2 targeted therapy (not FOLFOX + bev) — no phase III.
Non-G12C KRAS mutations (G12D / G12V / G13D) beyond KRAS G12C: currently ~40% of CRC has KRAS mut but only G12C (~3%) is druggable; new pan-KRAS / G12D inhibitors (MRTX1133 / RMC-6236) are in early CRC phase II, phase III pending.
Long-term safety of W&W after TNT: OPRA [PMID 35483010] 3-yr organ preservation + IWWD [PMID 29976470] 3-yr regrowth 25% — 5-10 year data insufficient; early biomarkers (ctDNA + MRI-RECIST) for regrowth prediction not yet standardized.
Replication of dMMR rectal dostarlimab at more centers: Cercek [PMID 35660797] 42-patient expansion still 100% cCR is extremely rare; global 20+ center replication ongoing; long-term local recurrence / distant metastasis rates and cumulative IO toxicity are key observation points.
Modern cost-benefit of stage II adjuvant chemotherapy: QUASAR [PMID 18083404] showed stage II 5-FU/LV absolute OS +3.6%; dMMR subgroup did not benefit; whether ctDNA / circulating immune signatures can refine “who benefits / who doesn’t” in stage II — currently still measured with one stick of clinical high-risk features.

5. 2024-2026 latest updates

5.1 FDA / NMPA new approvals (10 CRC-relevant excerpts)

Drug	Agency	Date	Indication / Supporting trial
encorafenib + cetuximab + mFOLFOX6	FDA	2024-12-20 (accelerated); 2025-05 (full)	1L BRAF V600E mut + RAS WT mCRC / BREAKWATER [PMID 40444708]
nivolumab + ipilimumab	FDA	2025-04	1L MSI-H / dMMR mCRC / CheckMate-8HW [PMID 39602630]
fruquintinib (Fruzaqla)	FDA	2023-11-08	3L+ refractory mCRC / FRESCO-2 [PMID 37331369]
trifluridine/tipiracil + bevacizumab	FDA	2023-08-02	3L+ refractory mCRC / SUNLIGHT [PMID 37133585]
sotorasib + panitumumab	FDA	2024-01-16	KRAS G12C mut mCRC 3L+ / CodeBreaK 300 [PMID 37870968]
adagrasib + cetuximab	FDA	2024-06-21 (accelerated)	KRAS G12C mut mCRC 3L+ / KRYSTAL-1 [PMID 36546659]
tucatinib + trastuzumab	FDA	2023-01-19 (accelerated)	HER2+ RAS WT mCRC 3L+ / MOUNTAINEER [PMID 37142372]
trastuzumab deruxtecan (tumor-agnostic HER2 IHC 3+, incl. CRC)	FDA	2024-04-05	tumor-agnostic HER2 IHC 3+ solid tumors / DESTINY-PanTumor02 + DESTINY-CRC01/02
pembrolizumab (MSI-H mCRC 1L)	FDA	2020-06-29	KEYNOTE-177 [PMID 33264544]
encorafenib + cetuximab (BEACON 2-drug)	FDA	2020-04-08	BRAF V600E mut mCRC 2L+ / BEACON-CRC [PMID 31566309]

(This section shows 10 key approvals; early approvals such as larotrectinib 2018-11 NTRK tumor-agnostic / entrectinib 2019-08 / pembrolizumab MSI-H tumor-agnostic 2017-05 are also CRC-applicable.)

5.2 Key conference readouts (2024-2026, weighted-down)

The following entries are candidate pool only prior to formal peer review; PMID-traceable ones have been promoted to the main library.

BREAKWATER (ASCO GI 2024 + 2025 oral + NEJM 2025 [PMID 40444708]): peer-reviewed published — main library.
CheckMate-8HW (ASCO GI 2024 oral + NEJM 2024 [PMID 39602630]): peer-reviewed published — main library.
KEYNOTE-177 5-yr (ASCO 2024 + Ann Oncol 2025 [PMID 39631622]): peer-reviewed — main library.
Cercek dostarlimab 42-patient expansion (ASCO 2025 + NEJM follow-up): PMID 35660797 primary; expanded data ASCO 2025 cited with down-weighting (no independent peer-reviewed new PMID).
NICHE-3 (dMMR colon adjuvant IO phase III): ongoing, no readout.
ATOMIC (MSI-H stage III adjuvant atezolizumab vs chemo): 2027+ readout expected.
CheckMate-9X8 ([PMID 38485190], MSS 1L mFOLFOX6 + bev ± nivo phase II): peer-reviewed — main library; primary endpoint not met.

5.3 Ongoing phase III (selected 2025-2028 readouts)

ATOMIC (NCT02912559, atezolizumab + mFOLFOX6 vs mFOLFOX6 adjuvant, dMMR stage III colon cancer) — 2027 readout
NICHE-3 / NICHE-4 (dMMR colon neoadjuvant IO series) — 2026-2028
CIRCULATE-US (NCT05174169, stage III colon cancer ctDNA-guided adjuvant de-escalation / escalation phase III) — 2027-2028
BESPOKE CRC (ctDNA + stage II/III CRC observational extension to interventional) — 2026-2028
POLO-like CRC KRAS G12D / pan-KRAS (MRTX1133 / RMC-6236 phase II → III) — early readouts 2026-2027
BREAKWATER long-term OS + subgroups (BRAF extended updates) — 2026 H2

6. Convergence insights and judgments

6.1 Longitudinal × cross-sectional: the 2026 CRC landscape is shaped by four “resonances”

Overlaying the longitudinal paradigm evolution onto the cross-sectional current-decision landscape, the 2026 CRC landscape is a superposition of four resonances:

“5-FU → FOLFOX / FOLFIRI → bev/cet 1L → 2L/3L backfilling” — the refined chemotherapy + targeted pipeline, plus the 60-year biggest lesson “metastatic → adjuvant extrapolation trap”: AVF2107 + CRYSTAL + PRIME + FIRE-3 + CALGB-80405 + PARADIGM — six phase IIIs pushed mCRC 1L mOS from 15 months (2000) to 35 months (2023 PARADIGM left-sided RAS WT + pan arm); in the same period, NSABP C-08 / AVANT / N0147 / CALGB 89803 / PETACC-3 — five adjuvant phase IIIs cumulatively >10,000 patients negative — the only successful adjuvant extrapolation was FOLFOX in MOSAIC. This is the biggest difference between CRC and NSCLC (adjuvant osi / alec both positive) and BTC (adjuvant BILCAP / ASCOT positive) — CRC is the textbook cancer of the “adjuvant extrapolation trap.”
“MSI-H / dMMR from chemo-insensitive to immune-sanctuary” — a complete 7-year reversal: 2015 Le NEJM foundation → 2017 CheckMate-142 → 2020 KEYNOTE-177 1L reversal → 2022 Cercek rectal 100% cCR → 2024 CheckMate-8HW HR 0.21 (among the largest ever) → 2024 NICHE-2 neoadjuvant pCR 67% DFS 100%. The MSI-H / dMMR subgroup flipped over 7 years from worst prognosis (chemo-insensitive) to best prognosis (IO sanctuary) — simultaneously driving Lynch syndrome screening + clinical-routine MMR IHC for every newly diagnosed CRC. This pathway has a cadence similar to BTC’s 15-year FGFR2 / IDH1 precision buildup and NSCLC’s 15-year EGFR TKI iteration — but CRC MSI-H’s endpoint is more disruptive (non-metastatic dMMR rectal 100% cCR replacing surgery).
“BRAF V600E / HER2 / KRAS G12C / NTRK — four precision pathways jointly covering 13-15%” — the precision rockets: BEACON-CRC 2019 → BREAKWATER 2025 pushed BRAFm from “worst prognosis” to “a 1L SoC exists”; MOUNTAINEER + DESTINY-CRC01/02 pushed HER2+ from HERACLES 2016 validation to a 3-drug SoC; CodeBreaK 300 + KRYSTAL-1 extended KRAS G12C from NSCLC to CRC; NAVIGATE + STARTRK opened NTRK-fusion tumor-agnostic therapy. CRC’s precision density in 2015-2025 caught up with NSCLC’s early-10-year cadence — but the core difference is that every CRC biomarker was first established in metastatic (BRAFm / HER2 / G12C / NTRK all unvalidated in adjuvant).
The “subtractive” paradigm of rectal TNT + organ preservation: 2004 German CAO/ARO/AIO-94 established preoperative CRT → 2021 RAPIDO + PRODIGE-23 TNT established → 2023 PROSPECT RT omission → 2022 Cercek dMMR 100% cCR → 2022 OPRA + 2018 IWWD W&W established. Rectal cancer is one of the few CRC subgroups where “treatment shifts from addition to subtraction” — Sauer 2004 “CRT mandatory” → Schrag 2023 “low-risk can skip RT”; Cercek 2022 “dMMR can skip surgery + skip RT.” In direct contrast to colon adjuvant’s “add bev/cet/iri” subtractive failure — rectal subtraction succeeded.

These four resonances together explain a clinical phenomenon: the treatment-intent decision for a newly diagnosed CRC patient in 2026 has 8 more decision layers than in 2000 (mCRC vs locally advanced → colon vs rectal → RAS panel → BRAF V600E → MMR/MSI → HER2 → KRAS G12C → NTRK → sidedness → rectal TNT vs traditional nCRT). The chemo backbone is still 5-FU → FOLFOX/FOLFIRI, but “what to add on top of the backbone” is fully determined by molecular subtype + location.

6.2 Clinical decision takeaways (for junior-mid oncologists)

Newly diagnosed advanced CRC must undergo comprehensive molecular profiling: full-exon RAS + BRAF V600E + MMR/MSI + HER2 IHC/ISH + KRAS G12C + NTRK fusion. Missing any one = missing a high-yield response subgroup with ORR 30-60%. The outpatient decision window is 2-4 weeks; NGS report must be in-hand.
Do not move metastatic-effective drugs into adjuvant: bev / cet / pan / irinotecan are backbones in metastatic disease; in adjuvant phase IIIs, four drug classes failed six times, cumulatively >10,000 patients. Next time a patient asks “should we add this metastatic-effective drug X post-op?” — first ask: is there a corresponding adjuvant phase III? In 60 years only FOLFOX successfully moved into adjuvant.
MSI-H / dMMR is CRC’s only immunotherapy winner: 1L preferred nivo+ipi (CheckMate-8HW, fit patients) or pembro monotherapy (KEYNOTE-177); MSS/pMMR do not use IO (IMBLAZE370 three-arm failure). Every newly diagnosed CRC must undergo MMR IHC + MSI PCR / NGS, no exceptions.
dMMR locally advanced rectal cancer — prioritize dostarlimab monotherapy for organ preservation: Cercek 42-patient expansion still 100% cCR — one of the most stunning datasets in oncology from 2022-2025. In the clinic, for dMMR rectal cancer, first ask: “can we pursue the dostarlimab pathway?”
BRAFm mCRC 1L now has a usable regimen: BREAKWATER 3-drug (enco + cet + mFOLFOX6) — flipped from “worst-prognosis subgroup 2000-2019” to “mOS 30+ months (interim)”; 2L BEACON 2-drug (enco + cet) is already SoC. BRAFm no longer waits for death.
Route RAS WT by sidedness: left-sided RAS WT → anti-EGFR (cetuximab or panitumumab + FOLFOX/FOLFIRI); right-sided RAS WT → bev (avoid anti-EGFR) — PARADIGM + CALGB-80405 sidedness reanalysis. PARADIGM 2023 upgraded retrospective evidence to prospective phase III.
Stratify adjuvant FOLFOX per IDEA: low-risk stage III (T1-3 N1) CAPOX × 3 months (non-inferior + halved neuropathy); high-risk stage III (T4 or N2) FOLFOX × 6 months (still favored). Stage II dMMR — do not use chemotherapy (dMMR does not benefit from adjuvant 5-FU monotherapy).
Rectal cancer — three branches by risk + biomarker: high-risk LARC TNT (RAPIDO / PRODIGE-23); low-risk LARC PROSPECT RT-omission; dMMR rectal Cercek pathway. MRI + CRM + biopsy MMR IHC — the trio decides which branch to take.
3L+ refractory mCRC has 3 options + 1 China-origin: fruquintinib (FRESCO-2) / TAS-102 + bev (SUNLIGHT) / regorafenib (CORRECT) — choose by toxicity profile + prior exposure. China-developed fruquintinib won a global FDA label in 2023 — the first China CRC drug to go global.
2026 must-know 15+ CRC drug classes: 5-FU/LV + capecitabine + oxaliplatin (FOLFOX/CAPOX) + irinotecan (FOLFIRI/FOLFOXIRI) as backbone; bevacizumab + aflibercept + ramucirumab anti-angiogenic; cetuximab + panitumumab anti-EGFR; encorafenib + binimetinib (BRAF/MEK); pembrolizumab + nivolumab + ipilimumab + dostarlimab (IO); tucatinib / trastuzumab / T-DXd (HER2); sotorasib + adagrasib (KRAS G12C); larotrectinib + entrectinib (NTRK); fruquintinib + regorafenib + TAS-102 (3L+) — 60 years ago only 5-FU as a yardstick; in 2026, 15+ drugs across 5 biomarker pathways + TNT / organ preservation running in parallel, a complex decision map.

7. Information sources

The metadata for 74 trials in this report are independently verified via PubMed and ClinicalTrials.gov. Every [PMID xxxxxxxx] in the text can be verified directly in PubMed.

Published trials: 74 entries covering 2000-2025 (all PMIDs verifiable)
NCCN guideline citations: 74/74 hit NCCN Colon V1.2026 or NCCN Rectal V1.2026 references (most hit both)
2020-2025 FDA / NMPA new approvals: 10+ key approvals
Research gaps: 10 items
China-led proportion: ~8% (FRESCO / STELLAR / FOWARC / REGOTORI 4 + PARADIGM Japan-China collaboration)

7.1 Reference list of the report body (sorted by PMID ascending)

The table below lists all 74 trials sorted by PMID ascending. Citation density in the text is high; every PMID in this table can be clicked to the PubMed URL for verification.

PMID	First Author	Year	Journal	Trial / Theme
10944126	de Gramont A	2000	J Clin Oncol	DE-GRAMONT-FOLFOX2 (FOLFOX backbone foundation)
11006366	Saltz LB	2000	N Engl J Med	SALTZ-IFL (IRI 1L foundation)
14657227	Tournigand C	2004	J Clin Oncol	GERCOR-TOURNIGAND (FOLFIRI↔FOLFOX sequence)
14665611	Goldberg RM	2004	J Clin Oncol	N9741 (FOLFOX > IFL three-arm)
15175435	Hurwitz H	2004	N Engl J Med	AVF2107 (bev foundation)
15175436	André T	2004	N Engl J Med	MOSAIC (FOLFOX adjuvant)
15496622	Sauer R	2004	N Engl J Med	GERMAN-CAO-ARO-AIO-94 (preop CRT foundation)
15987918	Twelves C	2005	N Engl J Med	X-ACT (capecitabine adjuvant)
16983741	Bujko K	2006	Br J Surg	POLISH-I (short vs long course)
17442997	Giantonio BJ	2007	J Clin Oncol	E3200 (2L bev foundation)
17687149	Saltz LB	2007	J Clin Oncol	CALGB-89803 (iri adjuvant failure)
18083404	Quasar Collaborative Group	2007	Lancet	QUASAR (stage II adjuvant OS benefit)
18316791	Amado RG	2008	J Clin Oncol	AMADO-KRAS-ANALYSIS (KRAS landmark subgroup)
19114683	Bokemeyer C	2009	J Clin Oncol	OPUS (FOLFOX + cet 1L)
19339720	Van Cutsem E	2009	N Engl J Med	CRYSTAL (FOLFIRI + cet 1L)
19451425	Van Cutsem E	2009	J Clin Oncol	PETACC-3 (iri adjuvant failure)
20194850	Gérard JP	2010	J Clin Oncol	ACCORD-12 (rectal oxaliplatin CRT)
20921465	Douillard JY	2010	J Clin Oncol	PRIME (FOLFOX + pan 1L)
20940184	Allegra CJ	2011	J Clin Oncol	NSABP-C-08 (bev adjuvant failure 1)
21383294	Haller DG	2011	J Clin Oncol	XELOXA (CAPOX adjuvant)
22474202	Alberts SR	2012	JAMA	N0147 (cet adjuvant failure)
22949147	Van Cutsem E	2012	J Clin Oncol	VELOUR (2L aflibercept)
23168362	de Gramont A	2012	Lancet Oncol	AVANT (bev adjuvant failure 2, OS harm)
23168366	Bennouna J	2013	Lancet Oncol	TML-ML18147 (bev beyond progression)
23177514	Grothey A	2013	Lancet	CORRECT (3L regorafenib)
24024839	Douillard JY	2013	N Engl J Med	PRIME-RAS-EXTENDED (RAS extension)
24440473	Bosset JF	2014	Lancet Oncol	EORTC-22921 (rectal 2×2 long-term)
24687833	Schwartzberg LS	2014	J Clin Oncol	PEAK (pan vs bev 1L phase II)
25088940	Heinemann V	2014	Lancet Oncol	FIRE-3 (cet vs bev 1L H2H)
25337750	Loupakis F	2014	N Engl J Med	TRIBE (FOLFOXIRI + bev)
25605843	Van Cutsem E	2015	J Clin Oncol	CRYSTAL-RAS-EXTENDED (RAS extension)
25877855	Tabernero J	2015	Lancet Oncol	RAISE (2L ramucirumab)
25970050	Mayer RJ	2015	N Engl J Med	RECOURSE (3L TAS-102)
26189067	Rödel C	2015	Lancet Oncol	CAO-ARO-AIO-04 (preop + postop oxaliplatin)
26338525	Cremolini C	2015	Lancet Oncol	TRIBE-UPDATED (OS update, BRAFm HR 0.54)
26527776	André T	2015	J Clin Oncol	MOSAIC-10YR (10-year follow-up)
27108243	Sartore-Bianchi A	2016	Lancet Oncol	HERACLES (HER2+ trastu+lap)
28632865	Venook AP	2017	JAMA	CALGB-80405 (cet vs bev 1L H2H US)
28734759	Overman MJ	2017	Lancet Oncol	CHECKMATE-142-NIVO-MONO (MSI-H nivo mono)
29355075	Overman MJ	2018	J Clin Oncol	CHECKMATE-142 (nivo+ipi MSI-H)
29466156	Drilon A	2018	N Engl J Med	LAROTRECTINIB-NAVIGATE (NTRK tumor-agnostic)
29590544	Grothey A	2018	N Engl J Med	IDEA (3 vs 6 months adjuvant)
29946728	Li J	2018	JAMA	FRESCO (Chinese 3L fruquintinib)
29976470	van der Valk MJM	2018	Lancet	IWWD (W&W international registry)
31003911	Eng C	2019	Lancet Oncol	IMBLAZE370 (MSS IO three-arm failure)
31557064	Deng Y	2019	J Clin Oncol	FOWARC (Chinese RT-omission forerunner)
31566309	Kopetz S	2019	N Engl J Med	BEACON-CRC (BRAFm 2L 2-drug foundation)
31725351	Le DT	2020	J Clin Oncol	KEYNOTE-164 (MSI-H ≥2L pembro)
31838007	Doebele RC	2020	Lancet Oncol	ENTRECTINIB-STARTRK (NTRK)
33264544	André T	2020	N Engl J Med	KEYNOTE-177 (MSI-H 1L pembro)
33301740	Bahadoer RR	2021	Lancet Oncol	RAPIDO (TNT short-course)
33356422	Kopetz S	2021	J Clin Oncol	SWOG-S1406 (BRAFm 2L triplet phase II)
33862000	Conroy T	2021	Lancet Oncol	PRODIGE-23 (TNT induction FOLFIRINOX)
33961795	Siena S	2021	Lancet Oncol	DESTINY-CRC01 (HER2+ T-DXd)
34061178	Yin J	2021	J Natl Cancer Inst	CALGB-80405-SIDEDNESS (sidedness reanalysis)
34622226	Wang F	2021	Cell Rep Med	REGOTORI (rego+toripalimab)
35263150	Jin J	2022	J Clin Oncol	STELLAR (Chinese TNT short-course)
35483010	Garcia-Aguilar J	2022	J Clin Oncol	OPRA (TNT organ preservation)
35636444	Antoniotti C	2022	Lancet Oncol	ATEZOTRIBE (MSS + atezo phase II)
35657320	Tie J	2022	N Engl J Med	DYNAMIC (ctDNA-guided stage II)
35660797	Cercek A	2022	N Engl J Med	CERCEK rectal dMMR dostarlimab 100% cCR
36546659	Yaeger R	2023	N Engl J Med	KRYSTAL-1 (KRAS G12C adagrasib ± cet)
37071094	Watanabe J	2023	JAMA	PARADIGM (pan vs bev left-sided RAS WT)
37133585	Prager GW	2023	N Engl J Med	SUNLIGHT (TAS-102 + bev)
37142372	Strickler JH	2023	Lancet Oncol	MOUNTAINEER (HER2+ tucatinib+trastu)
37272534	Schrag D	2023	N Engl J Med	PROSPECT (low-risk RT omission)
37331369	Dasari A	2023	Lancet	FRESCO-2 (fruquintinib global)
37870968	Fakih MG	2023	N Engl J Med	CODEBREAK-300 (sotorasib + pan G12C)
38485190	Lenz HJ	2024	J Immunother Cancer	CHECKMATE-9X8 (MSS 1L + nivo phase II)
38838311	Chalabi M	2024	N Engl J Med	NICHE-2 (dMMR colon neoadjuvant IO)
39116902	Raghav K	2024	Lancet Oncol	DESTINY-CRC02 (HER2 T-DXd dose)
39602630	Andre T	2024	N Engl J Med	CHECKMATE-8HW (MSI-H 1L nivo+ipi)
39631622	André T	2025	Ann Oncol	KEYNOTE-177-5YR (5-year follow-up)
40444708	Elez E	2025	N Engl J Med	BREAKWATER (BRAFm 1L 3-drug)

7.2 Verification conventions

Each PMID can be verified at https://pubmed.ncbi.nlm.nih.gov/{PMID}/
Each NCT id can be accessed at https://clinicaltrials.gov/study/{NCT_id}/
Conference abstracts (ASCO / ASCO GI / ESMO / ESMO GI) are retrievable via the official conference systems; all conference citations in this report are “down-weighted” — not peer-reviewed, with final data to be confirmed by journal publication
If a PMID in this report points to a trial name / year / conclusion inconsistent with PubMed, corrections are welcome

Clinical trial timeline is here

Chinese: /trials/colorectal/ English: /en/trials/colorectal/

Every trial has its own detail page, including:

Complete intervention / comparator regimens
Primary endpoint values + 95% CI
Key findings + clinical significance
Clickable links to PMID / NCT source

74 trials · 6 chapters · 2000 to 2025 · NCCN Colon + NCCN Rectal V1.2026 dual-guideline-synced.

Closing

CRC has completed one of oncology’s most textbook evolutions — “from single-drug backbone to multi-dimensional precision” — over the past 60 years: from 1960s 5-FU monotherapy, 1990s leucovorin sensitization, 2000’s FOLFOX / IFL dual backbones, 2004-2014’s bev / cet / pan established in metastatic but six failures in adjuvant, 2015-2025’s MSI-H immune reversal + four precision rockets (BRAFm / HER2 / KRAS G12C / NTRK), to 2021-2023’s rectal TNT + organ-preservation subtractive paradigm.

CRC’s 60 years condensed its biggest clinical lesson into one line: “metastatic-effective ≠ adjuvant-effective” — paid for by five negative phase IIIs (NSABP C-08 / AVANT / N0147 / CALGB 89803 / PETACC-3), cumulatively >10,000 patients. The only successful adjuvant transplantation was FOLFOX (MOSAIC); bev / cet / pan / irinotecan all failed. Next time a patient asks “should we use this metastatic-effective drug post-op?” — first ask: is there a corresponding adjuvant phase III?

Another equally structural lesson is “MMR determines CRC immunotherapy’s fate”: MSS/pMMR accounts for 85-95% of CRC but IO is all negative (IMBLAZE370 three-arm failure); MSI-H/dMMR accounts for 4-5% (stage IV) to 15-20% (stage II) and flipped from chemo-insensitive to an immune sanctuary — 1L dual IO (CheckMate-8HW HR 0.21) + dMMR rectal dostarlimab monotherapy 100% cCR. All newly diagnosed CRC must undergo MMR/MSI testing, no exceptions.

At the precision-therapy level, the four pathways BRAF V600E / HER2 / KRAS G12C / NTRK jointly cover 13-15% — BEACON-CRC 2019 → BREAKWATER 2025’s six-year BRAF turnaround; MOUNTAINEER + DESTINY-CRC01/02’s HER2 3-drug regimen; CodeBreaK 300 + KRYSTAL-1’s KRAS G12C extension from NSCLC to CRC; NAVIGATE + STARTRK’s NTRK tumor-agnostic regulatory milestone. In newly diagnosed advanced CRC, missing any biomarker = missing a high-yield response subgroup with ORR 30-60%.

At the rectal-cancer level, it is a subtractive paradigm — from 2004’s “mandatory preop CRT” to 2021’s TNT, to 2022’s dMMR monotherapy 100% cCR replacing surgery + radiotherapy, to 2023’s PROSPECT low-risk RT omission. Rectal cancer is one of the few CRC subgroups where “treatment shifts from addition to subtraction”.

The value of this report is not in “exhausting all trials” (PubMed can do that), but in compressing 60 years of evolution + current decisions + unresolved gaps into the cognitive bandwidth of a single reading. Next time you face a newly diagnosed CRC patient, every branch of the decision tree has this map to consult, trace, and question.

Clinician × AI = Research Superpower + Clinical Decision Amplifier

—— Dual Brain Lab · 2026-04-21

Gastric Cancer Clinical Trial Timeline: 58 RCTs Across 25 Years Mapping a Subtyping Revolution

Tue, 21 Apr 2026 00:00:00 +0000

Gastric Cancer Clinical Trial Timeline — In-depth Report

Coverage: 58 landmark trials cited by NCCN Gastric + CSCO Gastric 2025 (all PMID / NCT traceable) + East–West perioperative / adjuvant branches + HER2 / CLDN18.2 / PD-L1 CPS / MSI four-layer subtyping + three subtyping revolutions

Curated by Dual Brain Lab (csilab.net)

1. One-sentence definition

This report traces the evolution logic and current decision landscape of gastric cancer (GC) and gastroesophageal junction cancer (GEJ) systemic therapy over the past 25 years (2001-2026), covering the landmark clinical trials cited by NCCN Gastric V2.2025 and CSCO Gastric 2025, providing frontline clinicians in 2026 a traceable panoramic map for “who, what, why” decisions.

Iron rule: every data point in every trial is traceable to PubMed (PMID) or ClinicalTrials.gov (NCT id) — each [PMID xxxxxxxx] in the text can be clicked open to verify the PubMed source.

Scope boundary: GC refers to adenocarcinoma arising from gastric mucosa; GEJ refers to cardia / esophagogastric junction adenocarcinoma. Of Siewert I-III, Siewert II-III belong to the gastric category (covered here), while Siewert I and esophageal adenocarcinoma (EAC) belong to the esophageal category (not covered). Globally ~970,000 new gastric cancers annually (5th most common malignancy) + ~660,000 deaths (5th leading cancer death), with China accounting for ~44%. HBV / H. pylori infection, chronic atrophic gastritis, and high-salt pickled diets are the main environmental factors; Lauren classification (intestinal vs diffuse) and molecular subtyping (TCGA: EBV / MSI / CIN / GS four types) are the main pathological and molecular axes.

While HCC uniquely walked a “0 predictive biomarker” path, gastric cancer went the opposite way — 25 years, three subtyping revolutions: anatomical subtyping (GEJ vs gastric body) from crude endoscopic split to the manifest HR differences in CheckMate-649 subgroups; East–West path divergence (FLOT4 German perioperative vs CLASSIC Korean adjuvant CAPOX vs INT-0116 US adjuvant chemoRT) with the same stage custom-fit across three continents; HER2 drug 10-year leap (ToGA 2010 trastuzumab + chemo → 2020 DESTINY T-DXd 2L → 2025 DESTINY-Gastric-04 T-DXd 2L standard + KEYNOTE-811 HER2 1L IO combo); biomarker subtyping refinement (HER2 / PD-L1 CPS / CLDN18.2 / MSI four-dimensional checkerboard). By 2026, treatment decisions have completely flipped from “which chemo regimen” to “first get the biomarker panel complete.”

2. Longitudinal: timeline of five treatment-paradigm shifts

Gastric cancer systemic therapy has gone through five paradigm shifts over 25 years: adjuvant / definitive chemoRT (2001 INT-0116) → birth of the perioperative chemo concept (2006 MAGIC → 2019 FLOT4) → HER2 targeted era (2010 ToGA → 2020-2025 T-DXd three-generation evidence) → IO + chemo 1L standard established (2021-2024 four phase IIIs concordantly positive) → CLDN18.2 new subtype + perioperative IO (2023-2025 SPOTLIGHT / GLOW / MATTERHORN).

Each shift had 2-4 phase IIIs pushing the old SoC to second-line. Compared to NSCLC’s “driver-gene × IO dual-engine” and HCC’s “0-biomarker / IO-backbone-alone,” gastric cancer is characterized by “biomarker subtyping started early (2010 HER2) but density grew slowly (CLDN18.2 joined 15 years later), with severe geographic branching (East Asia vs Europe/US vs China, each running its own adjuvant / perioperative playbook)” — which means the 2026 gastric decision tree neither unfolds 10+ drivers horizontally like NSCLC, nor “rides clinical parameters alone” like HCC, but is a “region × biomarker × line” three-dimensional checkerboard.

2.1 Chemotherapy backbone era (2001-2010): adjuvant chemoRT / perioperative chemo / HER2 — three starting points

Story: in 2001 INT-0116 first put adjuvant chemoRT on stage III postoperative gastric cancer standard (US default for 15 years); in 2006 MAGIC first proved the “perioperative chemo” concept in UK/Europe (5-year OS 36% vs 23%, HR 0.75), forming a transatlantic divergence with US adjuvant chemoRT; the same year V325’s DCF triplet pushed advanced chemo OS ceiling to 9.2 months, and REAL-2 (2008) used a 2×2 factorial to bring capecitabine / oxaliplatin into the advanced backbone; 2007-2008 Japan’s ACTS-GC / SPIRITS defined “S-1 as Asian default,” further diverging from Europe/US; in 2010 ToGA made HER2 gastric cancer’s first actionable biomarker — a targeted path that ran alone for 13 years.

INT-0116 [PMID 11547741] (Macdonald 2001 N Engl J Med, N=556): US postoperative 5-FU / LV + 45 Gy chemoradiation vs D0-D1 surgery alone. mOS 36 vs 27 months (HR 1.35, P=0.005, favoring treatment), 3-year OS 50% vs 41%. Established the NCCN “adjuvant chemoRT” branch as the US postoperative default for 15 years — but later ARTIST / ARTIST-2 showed RT adds nothing after adequate D2 dissection, phasing it out of Asian practice.
MAGIC [PMID 16822992] (Cunningham 2006 N Engl J Med, N=503, UK): perioperative ECF (epirubicin + cisplatin + 5-FU) 3 cycles preop + 3 postop vs surgery alone. 5-year OS 36% vs 23% (HR 0.75, P=0.009). The invention moment of the “perioperative chemo” concept — European standard for a decade-plus, until 2019 FLOT4 upgraded the backbone from ECF to FLOT.
V325 [PMID 17075117] (Van Cutsem 2006 J Clin Oncol, N=445): docetaxel + cisplatin + 5-FU (DCF) vs CF advanced 1L. mOS 9.2 vs 8.6 months (HR 0.77, P=0.02), ORR 37% vs 25%, G3-4 neutropenia 82%. First OS-positive triplet backbone, but toxicity too high for wide real-world uptake.
REAL-2 [PMID 18172173] (Cunningham 2008 N Engl J Med, N=1002): 2×2 factorial (epirubicin + platinum + fluoropyrimidine: ECF / ECX / EOF / EOX). Capecitabine non-inferior to 5-FU (HR 0.86), oxaliplatin non-inferior to cisplatin (HR 0.92), best arm EOX mOS 11.2 months. Brought capecitabine + oxaliplatin into the advanced backbone, laying the foundation for 20 years of CAPOX SoC status.
ACTS-GC [PMID 17978289] (Sakuramoto 2007 N Engl J Med, N=1059, Japan): D2 postoperative S-1 for 1 year vs surgery alone. 3-year OS 80.1% vs 70.1% (HR 0.68, P=0.003), 5-year OS 71.7% vs 61.1%. Definitive evidence for Japanese adjuvant S-1; the “Asia primarily adjuvant” tradition was set.
SPIRITS [PMID 18282805] (Koizumi 2008 Lancet Oncol, N=305, Japan): advanced S-1 + cisplatin (SP) vs S-1 monotherapy. mOS 13.0 vs 11.0 months (HR 0.77, P=0.04), ORR 54% vs 31%. SP became Japan’s advanced 1L default for 10+ years, yielding only in the ATTRACTION-4 / CheckMate-649 IO era.
ToGA [PMID 20728210] (Bang 2010 Lancet, N=584): trastuzumab + XP/FP chemotherapy vs chemo in HER2+ (IHC3+ or IHC2+/FISH+) advanced GC/GEJ. mOS 13.8 vs 11.1 months (HR 0.74, P=0.0046), IHC3+ / FISH+ subgroup mOS 16.0 vs 11.8 months (HR 0.65). First positive biomarker-targeted phase III in gastric cancer — HER2 defined the first molecular subtype of gastric cancer, a standard that ran for 13 years until KEYNOTE-811 layered pembrolizumab on top.

Takeaway: the 2001-2010 decade anchored the entire basic framework of modern gastric cancer — US adjuvant chemoRT (INT-0116) / European perioperative ECF (MAGIC) / Japanese adjuvant S-1 (ACTS-GC) / Japanese advanced SP (SPIRITS) / Euro-US advanced DCF + CAPOX (V325 + REAL-2) / global HER2+ trastuzumab (ToGA) — all six branches cemented in these 10 years. Every new drug in the following 15 years only “replaces, stacks, or refines” on these six branches.

2.2 East–West adjuvant / perioperative divergence takes shape (2010-2019): CLASSIC / FLOT4 / ARTIST / RESOLVE / PRODIGY

Story: in 2012 Korea’s CLASSIC took D2 postoperative CAPOX to 3-year DFS 74% vs 59% (HR 0.56), making “adjuvant doublet chemo” the Asian standard; the same year Europe’s CROSS used neoadjuvant CRT (carboplatin + paclitaxel + 41.4 Gy) to push GEJ/EAC OS from 24 to 49 months (HR 0.657) — global GEJ tri-modality SoC was established; 2015 / 2021 Korea’s ARTIST / ARTIST-2 proved RT adds nothing after adequate D2 dissection, closing the “Asian D2 postop RT debate”; 2018 Netherlands’ CRITICS likewise showed that adding postop CRT after preop chemo gives no extra benefit; in 2019 Germany’s FLOT4 used docetaxel + oxaliplatin + 5-FU + leucovorin (FLOT) triplet / quadruplet to push perioperative mOS from ECF’s 35 to 50 months (HR 0.77), establishing the new Euro-US perioperative backbone; 2021 Korea’s PRODIGY proved PFS HR 0.70 with neoadjuvant DOS + adjuvant S-1; the same year China’s RESOLVE established perioperative SOX as China’s perioperative standard.

CLASSIC [PMID 22226517] (Bang 2012 Lancet, N=1035, Korea / China / Taiwan): D2 postoperative CAPOX × 8 cycles (6 months) vs surgery alone. 3-year DFS 74% vs 59% (HR 0.56, P<0.0001), 5-year OS 78% vs 69% (HR 0.66). Asian adjuvant CAPOX 20-year SoC, still the first-choice doublet after D2 today.
CROSS [PMID 22646630] (van Hagen 2012 N Engl J Med, N=366, Netherlands): neoadjuvant carboplatin + paclitaxel + 41.4 Gy vs surgery alone. mOS 49.4 vs 24.0 months (HR 0.657, P=0.003), R0 92% vs 69%, pCR 29%. Global GEJ / EAC tri-modality SoC, still unsurpassed (Neo-AEGIS tried to show FLOT perioperative non-inferior to CROSS but was terminated early due to futility + COVID).
ARTIST [PMID 25559811] (Park 2015 J Clin Oncol, N=458, Korea): D2 postoperative XP ± RT vs XP alone. 3-year DFS 78.2% vs 74.2% (HR 0.740, P=0.0922, NS). Subgroups suggested benefit in node+ / intestinal Lauren, but overall ITT negative — challenged the applicability of US INT-0116 in the Asian adequate-D2 setting.
ARTIST-2 [PMID 33278599] (Park 2021 Ann Oncol, N=538, Korea): node+ gastric cancer D2 postoperative SOX 6 months vs SOX + RT (SOXRT) vs S-1 1 year. 3-year DFS 74.3% (SOX) vs 72.8% (SOXRT) vs 64.8% (S-1); SOX and SOXRT both superior to S-1, but no difference between them (HR 0.971). ARTIST-2 closed the “Asian D2 postop RT” debate — doublet chemo is sufficient, no RT needed.
FLOT4 [PMID 30982686] (Al-Batran 2019 Lancet, N=716, Germany): perioperative FLOT 4+4 cycles vs ECF/ECX 3+3 cycles. mOS 50 vs 35 months (HR 0.77, 95% CI 0.63-0.94), pCR 16% vs 6%. New Euro-US perioperative backbone, on top of which all subsequent perioperative IO layering (MATTERHORN / KEYNOTE-585 FLOT subgroup) is built.
JACCRO GC-07 [PMID 30925125] (Yoshida 2019 J Clin Oncol, N=915, Japan): stage III D2 postoperative S-1 + docetaxel vs S-1 monotherapy. 3-year RFS 66% vs 50% (HR 0.632, P<0.001). Definitive evidence for Japanese stage III adjuvant doublet; “add docetaxel for stage III” written into Japanese guidelines.
CRITICS [PMID 29650363] (Cats 2018 Lancet Oncol, N=788, Netherlands): preop chemo (ECC/EOC) + postop chemo vs postop CRT (45 Gy + capecitabine/cisplatin). mOS 43 vs 37 months (HR 1.01, P=0.90), negative. No benefit from adding postop CRT after preop chemo — same author team / same country as CROSS but opposite result (neoadjuvant CRT vs postadjuvant CRT), highlighting that RT timing is key.
ST03 [PMID 28163000] (Cunningham 2017 Lancet Oncol, N=1063, UK): perioperative ECX + bevacizumab vs ECX. 3-year OS 50.3% vs 48.1% (HR 1.08, P=0.36), negative; esophagogastric anastomotic leak 24% vs 10%. The attempt to “add bev to perioperative” failed completely + increased surgical complications.
PRODIGY [PMID 34133211] (Kang 2021 J Clin Oncol, N=530, Korea): neoadjuvant DOS (docetaxel + oxaliplatin + S-1) × 3 cycles + surgery + adjuvant S-1 vs surgery + adjuvant S-1. 3-year PFS 66.3% vs 60.2%, adjusted HR 0.70 (P=0.023). Definitive evidence for Korea’s “neoadjuvant DOS triplet” — a representative of Asian neoadjuvant-era regimen iteration.
RESOLVE [PMID 34252374] (Zhang 2021 Lancet Oncol, N=1094, China): locally advanced GC/GEJ D2 gastrectomy perioperative SOX vs adjuvant SOX vs adjuvant CAPOX. 3-year DFS 59.4% (perioperative SOX) vs 51.1% (adjuvant CAPOX), HR 0.77 (P=0.028); adjuvant SOX non-inferior to adjuvant CAPOX. Definitive Chinese evidence for perioperative SOX — “perioperative > pure adjuvant” confirmed by RCT in Chinese population.
G-SOX [PMID 25316259] (Yamada 2015 Ann Oncol, N=685, Japan): advanced 1L SOX (S-1 + oxaliplatin) vs CS (S-1 + cisplatin). mOS 14.1 vs 13.1 months, PFS HR 1.004 (non-inferior), SOX fewer G≥3 AEs (nephrotoxicity / neutropenia). SOX established as SP alternative in Japanese / Asian advanced 1L, providing the control-arm background for later ATTRACTION-4 / ORIENT-16.
TOPGEAR [PMID 39282905] (Leong 2024 N Engl J Med, N=574, international): perioperative chemo ± preop CRT. pCR 17% vs 8% (favoring CRT) but mOS 46 vs 49 months (HR 1.05, NS), mPFS 31 vs 32 months (NS). pCR improved but OS did not — textbook case of “pCR as surrogate endpoint is unstable in gastric cancer” (fundamentally different from the strong pCR-OS correlation in breast cancer).

Takeaway: 2026 adjuvant / perioperative SoC is geographically branched — Euro-US first-choice FLOT4 perioperative (4+4 cycles), China first-choice RESOLVE perioperative SOX, Japan stage III first-choice JACCRO GC-07 S-1 + docetaxel adjuvant, Korea first-choice CLASSIC adjuvant CAPOX or ARTIST-2 SOX 6 months, GEJ/EAC first-choice CROSS neoadjuvant CRT. US INT-0116 adjuvant chemoRT has exited Asian practice in the adequate-D2 era (ARTIST-2 closed the debate), preserved only for D0-D1 or inadequate-dissection scenarios. Three “no longer use” paths: bevacizumab perioperative (ST03 negative), postop CRT after preop chemo (CRITICS negative), and judging OS by pCR alone as surrogate (TOPGEAR lesson).

2.3 HER2 era’s 10-year leap (2010-2025): ToGA → T-DXd → KEYNOTE-811 / zanidatamab

Story: after 2010 ToGA made HER2 gastric cancer’s first biomarker pedestal, no second HER2 drug entered gastric cancer SoC for a full 10 years — LOGIC/TRIO-013 (lapatinib + CapeOx vs CapeOx) 2016 negative, TyTAN / GATSBY (T-DM1 vs paclitaxel) negative. Not until 2020 did DESTINY-Gastric-01 use trastuzumab deruxtecan (T-DXd, HER2-ADC) break the stalemate in 2L HER2+; in 2023 KEYNOTE-811 layered pembrolizumab onto trastuzumab + chemo as the new HER2+ 1L backbone; in 2025 DESTINY-Gastric-04 made T-DXd the 2L HER2+ standard (beating the 10-year RAINBOW ramucirumab + paclitaxel); in 2025 HERIZON-GEA-01 topline used zanidatamab (HER2 bispecific antibody, simultaneously binding domains 2 + 4) to challenge the trastuzumab 1L backbone.

LOGIC/TRIO-013 [PMID 26628478] (Hecht 2016 J Clin Oncol, N=545): 1L HER2+ lapatinib + CapeOx vs CapeOx. mOS 12.2 vs 10.5 months (HR 0.91, NS, negative), mPFS 6.0 vs 5.4 months (HR 0.82, P=0.0381), ORR 53% vs 39%. First failure of the HER2 small-molecule TKI path in gastric cancer — lapatinib’s “PFS wins, OS doesn’t” replayed, deepening the view that “trastuzumab is irreplaceable as the HER2 backbone in gastric cancer.”
DESTINY-Gastric-01 [PMID 32469182] (Shitara 2020 N Engl J Med, N=187, Japan/Korea): HER2+ post-trastuzumab T-DXd vs physician’s choice chemo. ORR 51% vs 14% (P<0.001), mOS 12.5 vs 8.4 months (HR 0.59, P=0.01), ILD 9 cases G1-2 / 3 cases G3-4. First positive 2L HER2+ regimen 10 years into the HER2 era, FDA accelerated approval 2021-01.
DESTINY-Gastric-02 [PMID 37329891] (Van Cutsem 2023 Lancet Oncol, N=79, US/EU): HER2+ post-trastuzumab T-DXd 6.4 mg/kg single-arm phase II. Confirmed ORR 42%, mPFS 5.6 months, mOS 12.1 months, ILD 10% (1 G5 fatality). Replicated DG-01 in Euro-US populations — cross-regional consistency of HER2+ 2L T-DXd confirmed; ILD is the key safety signal.
KEYNOTE-811 [PMID 37871604] (Janjigian 2023 Lancet, N=698): HER2+ CPS≥1 advanced 1L pembrolizumab + trastuzumab + FP/CAPOX vs placebo + trastuzumab + FP/CAPOX. mPFS 10.0 vs 8.1 months (HR 0.72, P=0.0002), mOS 20.0 vs 16.8 months (HR 0.84), ORR 72.6% vs 60.1%. First upgrade to the HER2 paradigm after 13 years — IO layered onto the HER2 backbone, CPS≥1 subgroup showing the clearest benefit (FDA 2023-11 restricted the indication to CPS≥1; prior accelerated approval was all-comer).
DESTINY-Gastric-04 [PMID 40454632] (Shitara 2025 N Engl J Med, N=494): HER2+ 2L T-DXd monotherapy vs ramucirumab + paclitaxel head-to-head. mOS 14.7 vs 11.4 months (HR 0.70, P=0.004), mPFS HR 0.74, confirmed ORR 44.3% vs 29.1%. T-DXd beat the 2L SoC for the first time (RAINBOW ramu + paclitaxel), the HER2+ 2L standard has switched — meaning HER2 testing must be redone at 2L (re-biopsy), because post-trastuzumab HER2 loss is ~30%.
HERIZON-GEA-01 (NCT05152147, ESMO 2025 LBA): HER2+ 1L zanidatamab + chemotherapy ± tislelizumab vs trastuzumab + chemotherapy. Topline 2025: both zanidatamab arms PFS HR ~0.65 vs control; zani + tisle + chemo mOS improved >7 months vs trastuzumab + chemo. Zanidatamab’s biepitope simultaneous binding + induced internalization mechanism — if the 2026 full paper confirms, trastuzumab’s 13-year HER2 backbone status could end. As of 2026-04 the full manuscript is unpublished and PMID unassigned, cited here by NCT + ESMO LBA only.

Takeaway: 2026 HER2+ advanced decision path — 1L = pembrolizumab + trastuzumab + FP/CAPOX (KEYNOTE-811, first choice for CPS≥1; CPS<1 remains trastuzumab + chemo per ToGA); 2L = T-DXd (DESTINY-Gastric-04 beat ramu + PTX); 3L+ = ramu + PTX (RAINBOW) / irinotecan / TAS-102. 2L must re-biopsy to recheck HER2 — post-trastuzumab HER2 loss is ~30%, giving T-DXd directly will fail in the HER2-loss population. Zanidatamab is the biggest 2026 suspense: if HERIZON-GEA-01 full paper 2026 confirms positive, the HER2 backbone turns over.

2.4 IO + chemo 1L rewrite (2021-2024): four phase IIIs concordantly positive

Story: in 2017 Japan/Korea’s ATTRACTION-2 made nivolumab positive in 3L+ gastric cancer (mOS 5.26 vs 4.14 months, HR 0.63), opening the gastric IO era; in 2018 KEYNOTE-061 ran pembrolizumab vs paclitaxel in 2L CPS≥1 and hit negative (HR 0.82, P=0.0421 NS), the first failure of IO monotherapy in 2L; in 2020 KEYNOTE-062 again made pembrolizumab in 1L “monotherapy non-inferior but combo not superior,” a first cold-water moment for 1L IO; not until 2021 did CheckMate-649 use nivolumab + FOLFOX/XELOX achieve mOS 14.4 vs 11.1 months (HR 0.71) in CPS≥5 — 1L IO+chemo milestone; then over 3 years KEYNOTE-859 / ORIENT-16 / RATIONALE-305 used three different PD-(L)1s (pembrolizumab / sintilimab / tislelizumab) to replicate concordantly, HRs converging in the 0.71-0.80 narrow band — class effect formally established.

ATTRACTION-2 [PMID 28993052] (Kang 2017 Lancet, N=493, Japan/Korea/Taiwan): ≥2L nivolumab vs placebo. mOS 5.26 vs 4.14 months (HR 0.63, P<0.0001), 12-month OS 26.2% vs 10.9%, ORR 11.2% vs 0%. Starting point of gastric IO — but limited to East Asian 3L+ scenarios.
KEYNOTE-061 [PMID 29880231] (Shitara 2018 Lancet, N=592): 2L CPS≥1 pembrolizumab vs paclitaxel. mOS 9.1 vs 8.3 months (HR 0.82, P=0.0421 NS, negative), CPS≥10 subgroup showed benefit signal, G≥3 TRAE 14% vs 35%. IO monotherapy 2L failure — lesson: “IO worse than chemo” holds in 2L unselected population.
KEYNOTE-062 [PMID 32880601] (Shitara 2020 JAMA Oncol, N=763): 1L CPS≥1 pembrolizumab monotherapy vs pembrolizumab + chemo vs chemo. Pembrolizumab monotherapy vs chemo mOS non-inferior (CPS≥1 10.6 vs 11.1 months), CPS≥10 subgroup 17.4 vs 10.8 months (HR 0.69 but NS), pembrolizumab + chemo vs chemo no significant OS difference. First cold water for 1L IO — revealed that “unselected + IO” is not enough; PD-L1 enrichment required.
JAVELIN Gastric 100 [PMID 33197226] (Moehler 2021 J Clin Oncol, N=499): avelumab maintenance vs continued chemo after 12-week induction chemo. mOS 10.4 vs 10.9 months (HR 0.91, P=0.178, negative), 24-month OS 22.1% vs 15.5%, TRAE ≥G3 12.8% vs 32.8%. IO maintenance strategy failed — even with the “chemo exit lowers toxicity” attraction, no OS-level win.
ATTRACTION-4 [PMID 35030335] (Kang 2022 Lancet Oncol, N=724): HER2- 1L nivolumab + SOX/CAPOX vs placebo + SOX/CAPOX. mPFS 10.45 vs 8.34 months (HR 0.68, P=0.0007), mOS 17.45 vs 17.15 months (HR 0.90, P=0.26, primary OS endpoint not met). PFS wins, OS loses — high Japan/Korea SP/SOX baseline + crossover dilution, failed to reach the global IO standard.
CheckMate-649 [PMID 34102137] (Janjigian 2021 Lancet, N=1581): HER2- 1L nivolumab + FOLFOX/XELOX vs chemo. CPS≥5 mOS 14.4 vs 11.1 months (HR 0.71, P<0.0001), mPFS 7.7 vs 6.0 months (HR 0.68), ORR 60% vs 45%. 1L IO+chemo milestone, FDA approved 2021 (initially all-comer, later restricted to CPS≥5).
ORIENT-16 [PMID 38051328] (Xu 2023 JAMA, N=650, China): HER2- 1L sintilimab + XELOX vs placebo + XELOX. All-comers mOS 15.2 vs 12.3 months (HR 0.77, P=0.009), CPS≥5 mOS 18.4 vs 12.9 months (HR 0.66, P=0.002). First domestic Chinese PD-1 to achieve phase III OS positive in advanced gastric cancer, NMPA approved 2022. Extremely high clinical penetration in China, cost ~1/3 of pembrolizumab.
KEYNOTE-859 [PMID 37875143] (Rha 2023 Lancet Oncol, N=1579): HER2- 1L pembrolizumab + FP/CAPOX vs placebo + FP/CAPOX. ITT mOS 12.9 vs 11.5 months (HR 0.78, P<0.0001), CPS≥10 HR 0.65, mPFS 6.9 vs 5.6 months (HR 0.76), ORR 51.3% vs 42.0%. All-comer positive led FDA 2023-11 to remove the CPS restriction on pembrolizumab in gastric cancer — US practice shifted from “check CPS then give pembro” to “HER2- just give pembro,” but EU and NCCN still retain CPS≥1 / ≥5 recommendations.
RATIONALE-305 [PMID 38806195] (Qiu 2024 BMJ, N=997): HER2- 1L tislelizumab + chemo vs placebo + chemo. PD-L1 TAP≥5% mOS 17.2 vs 12.6 months (HR 0.74), ITT mOS 15.0 vs 12.9 months (HR 0.80, P=0.001). China approved 2024; PD-L1 TAP (tumor area positivity) introduced as an alternative scoring method to CPS.
CheckMate-032 [PMID 30110194] (Janjigian 2018 J Clin Oncol, N=160): advanced esophagogastric nivolumab monotherapy vs nivo + ipi multi-arm early data. ORR: nivo 12% / nivo1+ipi3 24% / nivo3+ipi1 8%; 12-month OS 39% / 35% / 24%. IO + IO ipi dose signal (ipi3 > ipi1), but phase III CheckMate-649 did not pursue an ipi arm — origin of the “dual IO has not become a 1L regimen in gastric cancer” backdrop.

Takeaway: 2026 HER2- advanced 1L IO + chemo class effect established — HRs converge in the narrow 0.71-0.80 band across four PD-(L)1 regimens (nivolumab / pembrolizumab / sintilimab / tislelizumab), choice determined by biomarker CPS threshold × regional access × price × chemo backbone preference. CPS threshold regional policy divergence: FDA removed the threshold (driven by KN-859); NCCN still recommends CPS≥5; EU retains CPS≥1; China NMPA stratifies per each drug’s registered CPS. IO monotherapy 2L (KEYNOTE-061) and IO maintenance (JAVELIN Gastric 100) paths are both closed — don’t walk them again.

2.5 Biomarker triple-subtype year zero + perioperative IO + CAR-T dawn (2023-2026)

Story: 2023 has been called the “gastric biomarker revolution year” — SPOTLIGHT (Shitara, CLDN18.2 + mFOLFOX6) and GLOW (Shah, CLDN18.2 + CAPOX) both published positive phase IIIs the same year, putting zolbetuximab (anti-Claudin-18.2 isoform 2 mAb) on the new CLDN18.2+ HER2- 1L standard (global HER2- gastric cancer CLDN18.2 high-expression rate ~38%); the same year KEYNOTE-811 completed HER2+ 1L IO layering + KEYNOTE-859 removed CPS restriction + ORIENT-16 domestic PD-1 positive. These 3 directions reading out together determined that post-2023 gastric cancer biomarker testing must include the HER2 + CLDN18.2 + CPS + MSI four-panel. In 2024 ATTRACTION-5’s adjuvant IO negative + 2025 MATTERHORN’s perioperative IO positive formed a one-negative-one-positive signal with a key message: “IO requires neoadjuvant exposure to activate.” In 2025 China’s CT041-ST-01 used satri-cel (satricabtagene autoleucel, CLDN18.2 CAR-T) to pull off the world’s first solid-tumor CAR-T RCT win.

FAST [PMID 33610734] (Sahin 2021 Ann Oncol, N=161, phase II): CLDN18.2+ 1L zolbetuximab + EOX vs EOX. mPFS/mOS HR 0.44 and 0.55 (both P<0.0005), CLDN18.2 moderate/strong expression ≥70% subgroup PFS HR 0.38. Early proof-of-concept for CLDN18.2 as a druggable target, paving the way for SPOTLIGHT/GLOW.
SPOTLIGHT [PMID 37068504] (Shitara 2023 Lancet, N=565): CLDN18.2+ (IHC ≥75% 2+/3+) HER2- 1L zolbetuximab + mFOLFOX6 vs placebo + mFOLFOX6. mPFS 10.61 vs 8.67 months (HR 0.75, P=0.0066), mOS 18.23 vs 15.54 months (HR 0.75, P=0.0053). CLDN18.2 became gastric cancer’s third actionable biomarker (after HER2 and PD-L1).
GLOW [PMID 37524953] (Shah 2023 Nat Med, N=507): CLDN18.2+ HER2- 1L zolbetuximab + CAPOX vs placebo + CAPOX. mPFS 8.21 vs 6.80 months (HR 0.687, P=0.0007), mOS 14.39 vs 12.16 months (HR 0.771, P=0.0118). Concordantly replicated SPOTLIGHT — zolbetuximab class effect confirmed, mFOLFOX6 and CAPOX backbones equivalent. FDA approved 2024-10.
ILUSTRO [PMID 37490286] (Klempner 2023 Clin Cancer Res, phase II multi-cohort): CLDN18.2+ advanced zolbetuximab monotherapy (cohort 1A) / + mFOLFOX6 (cohort 2) / + pembrolizumab (cohort 3A). 1L+chemo cohort mPFS 17.8 months / ORR 71.4%; monotherapy 3L+ ORR 0%; zolbetuximab + pembrolizumab 3L+ ORR 0% / mPFS 2.96 months. Key take-home: zolbetuximab fails as monotherapy / + IO at 3L+; must be used 1L with chemo.
TRANSTAR102 cohort G (NCT04495296): high / moderate CLDN18.2 expression 1L osemitamab (TST001, anti-CLDN18.2 ADCC-enhanced antibody) + nivolumab + CAPOX phase II single-arm. Any PD-L1 subgroup mPFS 12.6 months, CPS<5 subgroup mPFS 12.6 months, ORR 66%+. Chinese domestic CLDN18.2 + IO + chemo triplet candidate regimen — PMID not yet assigned as of 2026-04, phase III ongoing.
FRUTIGA (NCT03223376, Xu 2024 published but PMID link anomalous): 2L HER2- / post-chemo fruquintinib (oral VEGFR TKI) + paclitaxel vs placebo + paclitaxel. mPFS 5.6 vs 2.7 months (HR 0.57, P<0.0001, MET), mOS 9.6 vs 8.4 months (HR 0.96, P=0.6064, OS not met), ORR 42.4% vs 22.4%. Chinese domestic VEGFR TKI 2L PFS wins, OS loses — NMPA approved 2023, but limited global impact. The PMID metadata link in yaml is anomalous (see bottom of §7.1); this section primarily indexes by NCT.
KEYNOTE-585 [PMID 40829093] (Shitara 2025 J Clin Oncol, N=1007): resectable GC/GEJ perioperative pembrolizumab + chemotherapy (cisplatin/5-FU or FLOT subgroup) vs placebo + chemotherapy. Main cohort mOS 71.8 vs 55.7 months (HR 0.86, NS), EFS HR 0.81, pathCR improved; but OS primary endpoint not met. “Perioperative IO + old FP backbone failed, FLOT subgroup signal good” — laid the hypothesis foundation for MATTERHORN using FLOT as the backbone.
MATTERHORN [PMID 40454643] (Janjigian 2025 N Engl J Med, N=948): resectable GC/GEJ durvalumab 1500 mg Q4W + perioperative FLOT × 4+4 → durvalumab Q4W × 10 vs placebo + FLOT. 2-year EFS 67.4% vs 58.5% (HR 0.71, P<0.001), pCR 19.2% vs 7.2% (RR 2.69), 2-year OS 75.7% vs 70.4% (OS maturity pending). ASCO 2025 practice-changing — IO finally entered perioperative; KN-585 lesson inherited: must use FLOT backbone, not old FP.
ATTRACTION-5 [PMID 38906161] (Kang 2024 Lancet Gastroenterol Hepatol, N=755, Japan/Korea/Taiwan): post-D2 stage III adjuvant nivolumab + S-1/CapOx vs placebo + chemo. 3-year RFS 68.4% vs 65.3% (HR 0.90, P=0.44, negative). Pure postop addition of IO does not activate immune response — in stark contrast to the positive signals from MATTERHORN / KN-585 neoadjuvant exposure. Mechanistic hypothesis: IO requires “tumor-in-situ priming” — after resection tumor antigen disappears, ICI loses its target.
CT041-ST-01 [PMID 40460847] (Qi 2025 Lancet, N=156): advanced CLDN18.2+ 3L+ satri-cel (CLDN18.2 CAR-T) vs physician’s choice chemo. mPFS 3.25 vs 1.77 months (HR 0.37, P<0.0001), ORR 37% vs 10%, mOS trend favorable. World’s first solid-tumor CAR-T RCT win, NMPA NDA accepted — gastric cancer becomes the cancer type where solid-tumor CAR-T breaks through.

Takeaway: 2026 advanced 1L biomarker subtyping must check the HER2 + CLDN18.2 + PD-L1 CPS + MSI/dMMR four-panel — HER2+ / CLDN18.2+ / CPS-high / MSI-H have low cross-overlap (each covers 15-20% / 38% / ~60% / ~5-10%); missing any one = missing a high-responding subgroup with 30-70% ORR. Perioperative IO = must be neoadjuvant-exposed + must use FLOT backbone (MATTERHORN / KN-585 dual validation); pure postop IO doesn’t work (ATTRACTION-5 negative). CLDN18.2+ 3L+ CAR-T path (CT041-ST-01) has opened the door in China; global rollout awaits NMPA NDA completion.

3. Horizontal: the 2026 decision landscape (six dimensions)

Projecting longitudinal evolution onto the concrete 2026 clinical decision tree, the following are the six key branchpoints and the evidence for each.

3.1 Newly diagnosed advanced GC/GEJ: full biomarker four-panel

NCCN Gastric V2.2025 + CSCO Gastric 2025 explicitly recommend biomarker testing for all newly diagnosed advanced GC/GEJ, covering: HER2 IHC/FISH + PD-L1 IHC (22C3 CPS or 58-8 TAP) + CLDN18.2 IHC + MSI/dMMR (IHC or PCR). A positive result in any one directly changes the 1L regimen:

HER2+ (IHC3+ or IHC2+/FISH+, ~15-20%): CPS≥1 → KEYNOTE-811 (pembrolizumab + trastuzumab + FP/CAPOX); CPS<1 → ToGA (trastuzumab + chemo)
HER2- / CLDN18.2+ (IHC ≥75% 2+/3+, ~38%): zolbetuximab + mFOLFOX6 (SPOTLIGHT) or + CAPOX (GLOW)
HER2- / CLDN18.2- / CPS≥5: nivolumab + FOLFOX/XELOX (CheckMate-649) / pembrolizumab + FP/CAPOX (KEYNOTE-859) / sintilimab + XELOX (ORIENT-16) / tislelizumab + chemo (RATIONALE-305), any of them
HER2- / CLDN18.2- / CPS<5: FOLFOX / CAPOX / SOX chemo (limited IO benefit; confirmed by KEYNOTE-062)
MSI-H / dMMR (~5-10%): IO + chemo or pembrolizumab monotherapy (MSI-H has significantly higher response rate; KEYNOTE-062 CPS≥10 subgroup was partly MSI-H–driven)

3.2 Advanced 1L landscape: four PD-(L)1 class effect + CPS threshold policy divergence

2026 mainstream: HER2- advanced 1L SoC = IO + chemo (any of four PD-(L)1s + FOLFOX/CAPOX/SOX backbone), HRs converging in the 0.71-0.80 narrow band.

Subgroup	First choice	Second choice
HER2- CPS≥5	nivolumab + FOLFOX/XELOX [CheckMate-649 PMID 34102137] or pembrolizumab + FP/CAPOX [KEYNOTE-859 PMID 37875143]	sintilimab + XELOX [ORIENT-16 PMID 38051328] (China cost advantage) / tislelizumab + chemo [RATIONALE-305 PMID 38806195]
HER2- CPS 1-4	pembrolizumab + FP/CAPOX (available after US FDA removed CPS limit)	IO not mandatory, chemo alone acceptable
HER2- CPS<1	FOLFOX / CAPOX / SOX chemo [REAL-2 PMID 18172173 / G-SOX PMID 25316259]	limited IO benefit
HER2+ CPS≥1	pembrolizumab + trastuzumab + FP/CAPOX [KEYNOTE-811 PMID 37871604]	trastuzumab + chemo [ToGA PMID 20728210]
HER2+ CPS<1	trastuzumab + FP/CAPOX [ToGA PMID 20728210]	—
HER2- CLDN18.2+	zolbetuximab + mFOLFOX6 [SPOTLIGHT PMID 37068504] or + CAPOX [GLOW PMID 37524953]	IO + chemo (if CLDN18.2 untested / negative)

CPS threshold regional policy differences: FDA removed the pembrolizumab gastric CPS threshold (based on KN-859 all-comer positive) → US HER2- full coverage; NCCN Gastric V2.2025 still recommends CPS≥5 as IO benefit marker; EU EMA retains CPS≥1; China NMPA stratifies per each drug’s registered CPS (nivolumab CPS≥5 / sintilimab CPS≥5 / tislelizumab TAP≥5% etc.).

Contraindicated / not recommended 2026: IO monotherapy 2L unselected (KEYNOTE-061 negative) + IO maintenance (JAVELIN Gastric 100 negative) + lapatinib instead of trastuzumab (LOGIC/TRIO-013 negative).

3.3 Advanced 2L+: HER2 status dominates + mandatory re-biopsy

2026 mainstream: post-IO era, 2L must first confirm HER2 status (re-biopsy), because post-trastuzumab HER2 loss is ~30%.

Population	2L first choice	3L+
HER2+ post-trastuzumab (confirmed still HER2+)	T-DXd [DESTINY-Gastric-04 PMID 40454632] (mOS 14.7 months, HR 0.70)	ramucirumab + paclitaxel [RAINBOW PMID 25240821] / TAS-102 [TAGS PMID 30355453] / irinotecan
HER2-, IO-exposed (mainstream)	ramucirumab + paclitaxel [RAINBOW PMID 25240821] (mOS 9.6 vs 7.4 months, HR 0.807)	docetaxel + ASC [COUGAR-02 PMID 24332238] / TAS-102 / ramucirumab monotherapy [REGARD PMID 24094768]
CLDN18.2+ post-zolbetuximab	ramucirumab + paclitaxel	TAS-102 / satri-cel CAR-T [CT041-ST-01 PMID 40460847] (China pending NMPA)
CheckMate-032 multi-IO failures	chemo fallback	clinical trial
FRUTIGA (fruquintinib + paclitaxel)	China NMPA 2L option (NCT03223376, 2L HER2- CSCO Gastric 2025 Level II recommendation)	—

New challenge: since 2025 the 2L mandatory HER2 / CLDN18.2 re-biopsy workflow has low real-world execution — frontline clinicians habitually go “1L progression → 2L direct RAINBOW,” with high missed-diagnosis rates.

3.4 Adjuvant / perioperative: five East–West paths that never meet

2026 mainstream: geographically branched, no unified global SoC.

Region	Perioperative / adjuvant SoC (2026)	Key evidence
North America / Western Europe (GC majority)	Perioperative FLOT × 4+4 + perioperative durvalumab [MATTERHORN PMID 40454643] (2-year EFS 67.4%)	FLOT4 [PMID 30982686] upgraded backbone to FLOT; MATTERHORN layered IO on top
GEJ/EAC (global)	Neoadjuvant CRT (CROSS regimen) + surgery [CROSS PMID 22646630] (mOS 49.4 months)	Global GEJ tri-modality SoC; Neo-AEGIS [PMID 37734399] did not falsify it
Japan (mostly stage III)	D2 postoperative S-1 + docetaxel adjuvant [JACCRO GC-07 PMID 30925125] (3y RFS 66%)	Japanese “adjuvant-first” tradition + neoadjuvant option PRODIGY [PMID 34133211]
Korea (stage II-III)	D2 postoperative CAPOX adjuvant [CLASSIC PMID 22226517] or SOX adjuvant [ARTIST-2 PMID 33278599]	Doublet chemo sufficient; ARTIST-2 closed post-D2 RT debate
China (locally advanced)	Perioperative SOX [RESOLVE PMID 34252374]	China post-D2 first choice perioperative SOX (HR 0.77 vs adjuvant CAPOX)
Residual disease post-CROSS (any region)	Adjuvant nivolumab 1 year [CheckMate-577 PMID 33789008] (mDFS 22.4 vs 11.0 months)	ASCO 2025 mature OS shows benefit concentrated in PD-L1+ subgroup; ITT OS not significant
Not recommended	bevacizumab perioperative [ST03 PMID 28163000] / postop CRT after preop chemo [CRITICS PMID 29650363] / pure postop IO [ATTRACTION-5 PMID 38906161] / preop CRT on top of perioperative chemo [TOPGEAR PMID 39282905] (pCR improved, OS did not)	All four falsified

Current status of INT-0116 adjuvant chemoRT: 15-year US SoC initially, exited Asian practice in the adequate-D2 era (ARTIST-2 closed debate); US retains for D0-D1 / inadequately-dissected nodes.

The “death” of MAGIC: the 2006 MAGIC ECF perioperative backbone was replaced by FLOT after 2019 FLOT4; ECF is used only occasionally for “FLOT-intolerant” patients, no longer SoC.

3.5 Perioperative IO: MATTERHORN positive + key lessons

2026 mainstream: MATTERHORN [PMID 40454643] 2-year EFS 67.4% vs 58.5% (HR 0.71) + pCR 19.2% vs 7.2% → durvalumab + FLOT perioperative becomes the new North America / Western Europe SoC candidate (FDA 2025-2026 expected approval; as of 2026-04 mature OS not yet reached).

Key lesson 1 (backbone determines IO effect): KEYNOTE-585 [PMID 40829093] used old FP backbone, perioperative pembrolizumab mOS 71.8 vs 55.7 months but NS; MATTERHORN used new FLOT backbone + durvalumab 2-year EFS positive. “Perioperative IO must use FLOT backbone” written into 2025 ASCO consensus.

Key lesson 2 (IO needs neoadjuvant exposure): ATTRACTION-5 [PMID 38906161] pure postop nivolumab + S-1/CapOx adjuvant 3-year RFS 68.4% vs 65.3% (HR 0.90, negative); vs MATTERHORN’s neoadjuvant + adjuvant durvalumab positive — “postop-only IO does not activate immunity,” mechanistic hypothesis: ICI needs tumor-in-situ antigen priming.

Key lesson 3 (pCR ≠ OS): TOPGEAR [PMID 39282905] pCR 17% vs 8% improved but mOS no difference (HR 1.05, NS); KEYNOTE-585 [PMID 40829093] pCR improved but ITT OS NS. “Gastric pCR as surrogate is unstable” — fundamentally different from the strong pCR-OS correlation in breast cancer; clinical trial design needs caution.

3.6 Surgical technique: D2 + laparoscopic consensus + robotic undecided

From 2015-2022 five consecutive laparoscopic phase IIIs (KLASS-01 / KLASS-02 / CLASS-01 / JLSSG0901 / LOGICA) established laparoscopic ≈ open D2 gastrectomy equivalence; two extended-surgery trials — D2+PAND (JCOG9501) and bursectomy (JCOG1001) — were buried.

Category	Standard regimen	Key evidence
Lymph node dissection	D2	JCOG9501 [PMID 18669424] (5-year OS 69.2% vs 70.3%, D2+PAND HR 1.03, no benefit + longer operating time / more blood loss)
Early GC (stage I) distal gastrectomy	Laparoscopic = open	KLASS-01 [PMID 30730546] (5-year OS 94.2% vs 93.3%, non-inferior)
Locally advanced GC distal gastrectomy	Laparoscopic = open	KLASS-02 [PMID 35857305] (5-year OS 88.9% vs 88.7%), CLASS-01 [PMID 31135850] (3-year DFS 76.5% vs 77.8%, non-inferior), JLSSG0901 [PMID 36920382] (5-year RFS 73.9% vs 75.7%, non-inferior)
European total / subtotal gastrectomy	Laparoscopic = open (short-term)	LOGICA [PMID 34581617] (LOS 7 days / both arms, LG less blood loss)
Bursectomy	Abandoned	JCOG1001 [PMID 36369984] (5-year OS 74.9% vs 76.5%, HR 1.03, more abdominal abscesses)
Robotic	Undecided	No phase III oncologic RCT evidence yet

4. Research Gaps: ten unsolved clinical questions

This report identifies the following gaps, each a definable concrete question (not the cliché “more research needed”):

CPS threshold global non-uniformity + real-world execution: FDA removed the pembrolizumab gastric CPS threshold + NCCN retains CPS≥5 + EU CPS≥1 + China NMPA stratifies per drug. Frontline clinicians see multiple thresholds on the same guideline page → real-world PD-L1 IHC (22C3 vs 58-8 TAP) assay differences also unresolved. Unification needed.
No head-to-head among three / four PD-(L)1s (nivolumab / pembrolizumab / sintilimab / tislelizumab) in HER2- 1L: HRs in the 0.71-0.80 narrow band, cross-trial indistinguishable. Choice depends entirely on access × price × CPS threshold × chemo backbone preference.
Is the CLDN18.2 moderate / high-expression threshold optimal: SPOTLIGHT / GLOW enrolled at IHC ≥75% 2+/3+; FAST subgroup ≥70% moderate-strong expression had better PFS HR. Different thresholds may identify different benefit populations — prospective threshold-exploration trials needed.
Is CLDN18.2 × IO combination superior to either alone: ILUSTRO 3L+ zolbetuximab + pembrolizumab cohort ORR 0% (failed); TRANSTAR102 cohort G 1L osemitamab + nivolumab + CAPOX 12.6-month PFS (signal). 1L head-to-head CLDN18.2 + IO + chemo vs CLDN18.2 + chemo has not been done.
1L choice for HER2+ CPS<1 subgroup: KEYNOTE-811 CPS<1 subgroup HR near 1.0, but FDA 2023-11 restricted to CPS≥1 rather than fully excluding CPS<1. Practice remains inconsistent on whether HER2+ CPS<1 uses ToGA or KN-811.
Backbone dependence of perioperative IO: MATTERHORN FLOT + durvalumab positive vs KEYNOTE-585 FP + pembrolizumab negative. Is it the FLOT backbone contribution or an IO mechanism difference? Independent confirmations from perioperative nivolumab + FLOT (CheckMate-Gastric Adjuvant ongoing) and pembrolizumab + FLOT subgroup (KN-585 FLOT subgroup) need time.
Why pure postop adjuvant IO failed in ATTRACTION-5: the mechanistic hypothesis is “tumor-in-situ priming” but has not been directly validated. If future biomarkers can identify “postop still IO-suitable” subgroups (e.g., ctDNA+ residual / MSI-H status), adjuvant IO could restart.
pCR as gastric surrogate endpoint is unstable: both TOPGEAR + KEYNOTE-585 were pCR-positive / OS-negative. Clinical trial design must use pCR as primary endpoint cautiously. Alternative candidates: EFS, ctDNA clearance kinetics.
The five East–West perioperative / adjuvant paths (FLOT4 / RESOLVE / CLASSIC / ARTIST-2 / JACCRO GC-07) have never been head-to-head: each path ran its own phase III in its own country vs surgery alone / old regimen, with no RCTs between them. Real-world OS differences are population differences vs regimen differences? Undistinguishable.
Global rollout path for CLDN18.2 + CAR-T: CT041-ST-01 China phase II positive + NMPA NDA accepted; global phase III and Euro-US regulatory paths not yet launched as of 2026. Whether solid-tumor CAR-T’s gastric breakthrough can extend to other CLDN18.2+ solid tumors (pancreatic, biliary) is unknown.

5. Latest 2024-2026 developments

5.1 FDA / NMPA new approvals (gastric-relevant excerpts)

Drug	Agency	Date	Indication / supporting trial
pembrolizumab + trastuzumab + chemo	FDA	2023-11 (CPS≥1 restricted)	1L HER2+ GC/GEJ / KEYNOTE-811 [PMID 37871604]
pembrolizumab + chemo (CPS restriction removed)	FDA	2023-11	1L HER2- GC/GEJ / KEYNOTE-859 [PMID 37875143]
tislelizumab + chemo	NMPA	2024	1L HER2- PD-L1 TAP≥5% / RATIONALE-305 [PMID 38806195]
zolbetuximab + mFOLFOX6 / CAPOX	FDA	2024-10-18	1L HER2- CLDN18.2+ / SPOTLIGHT + GLOW [PMID 37068504 + 37524953]
T-DXd (trastuzumab deruxtecan) 2L	FDA	2025 (expanded indication after DG-04)	2L HER2+ GC/GEJ / DESTINY-Gastric-04 [PMID 40454632]
durvalumab + perioperative FLOT	FDA	2025-2026 (pending, expected approval)	Perioperative GC/GEJ / MATTERHORN [PMID 40454643]
satri-cel (CLDN18.2 CAR-T)	NMPA	2025-2026 (NDA accepted)	3L+ CLDN18.2+ GC/GEJ / CT041-ST-01 [PMID 40460847]
fruquintinib + paclitaxel 2L	NMPA	2023	2L HER2- GC/GEJ / FRUTIGA (NCT03223376)

5.2 Key meeting readouts (2025-2026, flagged as lower-weight)

The following are candidate pool only pending formal peer review, not in the main library.

HERIZON-GEA-01 (ESMO 2025 LBA): zanidatamab + chemo ± tislelizumab vs trastuzumab + chemo 1L HER2+ positive, mOS improvement >7 months. Full manuscript unpublished as of 2026-04; if confirmed positive within 2026 → HER2 backbone turnover.
MATTERHORN mature OS (ASCO 2025 [PMID 40454643]): 2-year OS 75.7% vs 70.4% (early signal), mature OS 2026-2027 readout.
CheckMate-577 mature OS (ASCO 2025 [PMID 33789008] data): ITT OS not significant; PD-L1+ subgroup benefit — suggests post-CROSS adjuvant IO should be restricted to PD-L1+.
KEYNOTE-585 final analysis (2025 JCO [PMID 40829093]): FLOT subgroup EFS positive signal confirmed by MATTERHORN; FP subgroup OS NS closed the old backbone + IO path.
CT041-ST-01 mOS (Lancet 2025 [PMID 40460847]): mOS trend favorable, data maturing.
TRANSTAR102 cohort G (NCT04495296, ESMO 2024 oral): osemitamab + nivolumab + CAPOX 1L phase II signal good; phase III launched in China.

5.3 Ongoing phase IIIs (2026-2028 readout highlights)

HERIZON-GEA-01 full readout (NCT05152147): 2026 mature OS will determine whether zanidatamab can replace trastuzumab as the HER2+ 1L backbone
osemitamab phase III (NCT05980416 or successor): CLDN18.2+ 1L triplet vs IO + chemo head-to-head
satri-cel global phase III: CLDN18.2 CAR-T expansion outside China
ctDNA-guided adjuvant de-escalation: after ATTRACTION-5 negative, whether ctDNA+ postop residual can identify IO-responsive subgroups — early design
Perioperative IO + CLDN18.2 combination: after MATTERHORN success, CLDN18.2 + perioperative FLOT + IO triplet is the natural next step

6. Synthesis insights and judgments

6.1 Longitudinal × horizontal: 2026 gastric landscape shaped by three subtyping revolutions

Overlaying longitudinal paradigm evolution with the current horizontal decision landscape, the 2026 gastric cancer landscape is a stack of three subtyping revolutions:

Biological meaning of anatomical subtyping made manifest: 2006 MAGIC / 2012 CROSS / 2021 CheckMate-649 step by step pushed “GEJ vs gastric body” from crude endoscopic split to molecular biological subtyping in the IO era — CheckMate-649 subgroup analysis showed GEJ/EAC HR differs from pure gastric body HR (the former ~0.75, the latter ~0.65), suggesting the GEJ microenvironment responds less well to IO. In 2026 GEJ 1L decisions have gone from “treat as gastric cancer” to “Siewert II-III → gastric / Siewert I → esophageal” + perioperative choice CROSS (GEJ) vs MATTERHORN (gastric body majority). This is gastric cancer’s first subtyping revolution.
Persistent East–West path divergence: INT-0116 (US adjuvant chemoRT) / MAGIC → FLOT4 (European perioperative) / CLASSIC (Korean adjuvant CAPOX) / ACTS-GC (Japanese adjuvant S-1) / RESOLVE (Chinese perioperative SOX) — five paths, each completing phase III in its own population, never head-to-head. 2026 practice is not a “unified global SoC” but “choose path by patient’s country / region.” Regional differences + genetic background (DPYD polymorphisms) + reimbursement policies together shape the reality of “East and West never meet.” This is gastric cancer’s second subtyping revolution.
HER2 drug 10-year leap + biomarker four-layer subtyping: 2010 ToGA (trastuzumab + chemo) → 2020 DESTINY-Gastric-01 (T-DXd 2L) → 2023 KEYNOTE-811 (pembro + trastuzumab + chemo 1L) → 2025 DESTINY-Gastric-04 (T-DXd 2L SoC) → 2025 HERIZON-GEA-01 (zanidatamab challenging trastuzumab) — 5 steps in 15 years, HER2 drugs moved from binary targeting to full ADC + IO combo + bispecific coverage. Concurrently CLDN18.2 (SPOTLIGHT / GLOW) + PD-L1 CPS + MSI joined the subtyping grid → HER2 / CLDN18.2 / CPS / MSI four-layer checkerboard decides 1L regimen. This is gastric cancer’s third subtyping revolution and the direct source of the 2026 “check the full biomarker panel first” imperative.

These three revolutions together explain a clinical observation: the 1L decision tree for a newly diagnosed stage IV GC/GEJ patient in 2026 has 4 more decision layers than in 2016 (biomarker panel HER2/CPS/CLDN18.2/MSI → anatomical subtyping GEJ vs gastric body → regional access sintilimab/pembro/nivo/tislelizumab → CPS threshold FDA vs NCCN vs EU). This “deep and wide” decision tree is far more complex than HCC’s “shallow and narrow” (four-way tie within a narrow HR band) — the result of NCCN-level research density plus multinational domestic-drug co-action.

6.2 Clinical decision takeaways (for junior-mid oncologists)

In 2026 the first gastric cancer step is not the chemo regimen — it is a full biomarker panel: HER2 IHC/FISH + PD-L1 CPS + CLDN18.2 IHC + MSI/dMMR must be complete before 1L. Missing any one = missing a high-responding subgroup with 30-70% ORR.
HER2+ 1L standard upgraded since 2023: CPS≥1 use pembrolizumab + trastuzumab + FP/CAPOX (KEYNOTE-811); CPS<1 still trastuzumab + chemo (ToGA). Don’t use ToGA alone for CPS≥1 patients anymore.
CLDN18.2+ HER2- 1L SoC is zolbetuximab + mFOLFOX6/CAPOX: written into NCCN V2.2025 after FDA 2024-10 approval. Missing CLDN18.2 at 1L is the most frequent 2026 gastric cancer clinical error.
Use CPS thresholds per country: US FDA removed the pembrolizumab gastric CPS threshold; NCCN still recommends CPS≥5; EU CPS≥1; China NMPA stratifies per drug. Use the corresponding threshold in your own reimbursement / registration context.
Both IO monotherapy 2L and IO maintenance are closed: KEYNOTE-061 (2L unselected) and JAVELIN Gastric 100 (maintenance) both negative — don’t walk these two paths.
2L must re-biopsy to recheck HER2 + CLDN18.2: post-trastuzumab HER2 loss is ~30%; CLDN18.2 subgroup has similar phenomenon. “1L progression → 2L direct RAINBOW” is the biggest real-world missed-diagnosis source.
HER2+ 2L new standard is T-DXd (DESTINY-Gastric-04 beat RAINBOW): but ILD is the key safety alarm, needing baseline chest CT + dynamic monitoring + timely drug discontinuation.
The perioperative IO era has arrived: North America / Western Europe 2026 expected MATTERHORN (durvalumab + FLOT perioperative) approval; must use FLOT backbone + must have neoadjuvant exposure — both lessons have trial evidence (KN-585 FP backbone failure / ATTRACTION-5 pure postop IO failure) as controls.
Respect regional East–West paths: US walks INT-0116 + FLOT4 → MATTERHORN; Europe walks MAGIC → FLOT4 → MATTERHORN; China walks RESOLVE SOX; Japan walks JACCRO GC-07 S-1 + docetaxel; Korea walks CLASSIC CAPOX / ARTIST-2 SOX. Don’t simply extrapolate one country’s data to another.
Zanidatamab is the biggest 2026 suspense: if HERIZON-GEA-01 full paper 2026 is positive, trastuzumab’s 13-year HER2 backbone could end. Frontline clinicians’ HER2 treatment choices will face a new branchpoint — stay tuned.

7. Information sources

All 58 trial metadata in this report were independently verified via PubMed and ClinicalTrials.gov. Each [PMID xxxxxxxx] in the text is directly verifiable on PubMed.

Published trials: 58, covering 2001-2026
PMID coverage: 56 unique PMIDs (HERIZON-GEA-01 / TRANSTAR102 cohort G are ESMO LBA, PMID pending full manuscript; MAGIC / INT-0116 / CROSS have no NCT because they predate the mandatory NCT registration era)
FDA / NMPA new approvals: 8 key approvals (2023-2026)
2025-2026 key meeting / long follow-up readouts: 6 (HERIZON-GEA-01 / MATTERHORN mature OS / CheckMate-577 mature OS / KN-585 final / CT041-ST-01 / TRANSTAR102)
Research gaps: 10
China-led research proportion: ~25% (ORIENT-16 / FRUTIGA / RESOLVE / CT041-ST-01 / TRANSTAR102 / part of CLASSIC / CLASS-01 etc.)

7.1 Text citation list (by ascending PMID)

The following table is the PMID list of all bracket citations in the text + summary tables; each can be clicked to verify on PubMed.

PMID	First Author	Year	Journal	Trial / topic
11547741	Macdonald JS	2001	N Engl J Med	INT-0116 adjuvant chemoRT
16822992	Cunningham D	2006	N Engl J Med	MAGIC perioperative ECF
17075117	Van Cutsem E	2006	J Clin Oncol	V325 advanced DCF
17978289	Sakuramoto S	2007	N Engl J Med	ACTS-GC Japanese adjuvant S-1
18172173	Cunningham D	2008	N Engl J Med	REAL-2 (ECF/ECX/EOF/EOX)
18282805	Koizumi W	2008	Lancet Oncol	SPIRITS Japanese advanced SP
18669424	Sasako M	2008	N Engl J Med	JCOG9501 D2 vs D2+PAND
20728210	Bang YJ	2010	Lancet	ToGA HER2+ trastuzumab
22226517	Bang YJ	2012	Lancet	CLASSIC Asian adjuvant CAPOX
22646630	van Hagen P	2012	N Engl J Med	CROSS GEJ neoadjuvant CRT
24094768	Fuchs CS	2014	Lancet	REGARD 2L ramucirumab
24332238	Ford HE	2014	Lancet Oncol	COUGAR-02 2L docetaxel
25240821	Wilke H	2014	Lancet Oncol	RAINBOW 2L ramu + paclitaxel
25316259	Yamada Y	2015	Ann Oncol	G-SOX advanced SOX vs CS
25559811	Park SH	2015	J Clin Oncol	ARTIST D2 postop XP ± RT
26628478	Hecht JR	2016	J Clin Oncol	LOGiC/TRIO-013 lapatinib negative
28163000	Cunningham D	2017	Lancet Oncol	ST03 perioperative ECX + bev negative
28993052	Kang YK	2017	Lancet	ATTRACTION-2 3L+ nivolumab
29650363	Cats A	2018	Lancet Oncol	CRITICS postop CRT negative
29880231	Shitara K	2018	Lancet	KEYNOTE-061 2L pembro negative
30110194	Janjigian YY	2018	J Clin Oncol	CheckMate-032 nivo ± ipi multi-arm
30355453	Shitara K	2018	Lancet Oncol	TAGS 3L+ TAS-102
30730546	Kim HH	2019	JAMA Oncol	KLASS-01 early GC LDG
30925125	Yoshida K	2019	J Clin Oncol	JACCRO GC-07 S-1 + docetaxel
30982686	Al-Batran SE	2019	Lancet	FLOT4 perioperative FLOT vs ECF
31135850	Yu J	2019	JAMA	CLASS-01 LDG vs ODG
32469182	Shitara K	2020	N Engl J Med	DESTINY-Gastric-01 2L T-DXd
32880601	Shitara K	2020	JAMA Oncol	KEYNOTE-062 1L cold water
33197226	Moehler M	2021	J Clin Oncol	JAVELIN Gastric 100 maintenance negative
33278599	Park SH	2021	Ann Oncol	ARTIST-2 Korea D2 postop
33610734	Sahin U	2021	Ann Oncol	FAST phase II CLDN18.2 early
33789008	Kelly RJ	2021	N Engl J Med	CheckMate-577 GEJ adjuvant nivolumab
34102137	Janjigian YY	2021	Lancet	CheckMate-649 milestone
34133211	Kang YK	2021	J Clin Oncol	PRODIGY neoadjuvant DOS
34252374	Zhang X	2021	Lancet Oncol	RESOLVE China perioperative SOX
34581617	van der Veen A	2021	J Clin Oncol	LOGICA Europe LG vs OG
35030335	Kang YK	2022	Lancet Oncol	ATTRACTION-4 Japan/Korea nivo + SOX
35857305	Son SY	2022	JAMA Surg	KLASS-02 5-year OS LDG vs ODG
36369984	Kurokawa Y	2022	Br J Surg	JCOG1001 bursectomy negative
36920382	Etoh T	2023	JAMA Surg	JLSSG0901 LADG vs ODG 5-year
37068504	Shitara K	2023	Lancet	SPOTLIGHT zolbetuximab + mFOLFOX6
37329891	Van Cutsem E	2023	Lancet Oncol	DESTINY-Gastric-02 Euro-US T-DXd
37490286	Klempner SJ	2023	Clin Cancer Res	ILUSTRO phase II multi-cohort
37524953	Shah MA	2023	Nat Med	GLOW zolbetuximab + CAPOX
37734399	Reynolds JV	2023	Lancet Gastro Hepatol	Neo-AEGIS CROSS vs MAGIC/FLOT
37871604	Janjigian YY	2023	Lancet	KEYNOTE-811 HER2+ IO + HER2
37875143	Rha SY	2023	Lancet Oncol	KEYNOTE-859 all-comer
38051328	Xu J	2023	JAMA	ORIENT-16 China sintilimab
38734867	—	—	—	FRUTIGA yaml PMID link anomalous (text cites by NCT03223376)
38806195	Qiu MZ	2024	BMJ	RATIONALE-305 tislelizumab
38906161	Kang YK	2024	Lancet Gastro Hepatol	ATTRACTION-5 pure adjuvant IO negative
39282905	Leong T	2024	N Engl J Med	TOPGEAR preop CRT + perioperative chemo
40454632	Shitara K	2025	N Engl J Med	DESTINY-Gastric-04 T-DXd vs RAINBOW
40454643	Janjigian YY	2025	N Engl J Med	MATTERHORN perioperative durvalumab + FLOT
40460847	Qi C	2025	Lancet	CT041-ST-01 satri-cel CAR-T
40829093	Shitara K	2025	J Clin Oncol	KEYNOTE-585 final

7.2 Verification conventions

Each PMID is directly accessible via https://pubmed.ncbi.nlm.nih.gov/{PMID}/
Each NCT id is accessible via https://clinicaltrials.gov/study/{NCT_id}/
HERIZON-GEA-01 / TRANSTAR102 cohort G are at ESMO LBA / ASCO oral stage; PMID pending 2026 full manuscript — this report indexes by NCT
FRUTIGA (PMID 38734867) yaml data has a PubMed metadata link anomaly (the PMID corresponds to an ED medication errors review, not the FRUTIGA main publication); this report primarily indexes the text by NCT03223376, with “yaml PMID link anomalous” honestly disclosed in the §7.1 table; data fix pending v2
MAGIC / INT-0116 / CROSS have no NCT id (predate the 2004 ClinicalTrials.gov mandatory registration / UK MRC internal trial)
If you find any PMID in the report whose trial name / year / conclusion differs from PubMed, corrections are welcome

Clinical trial timeline here

Chinese: /trials/gastric/ English: /en/trials/gastric/

Each trial has its own detail page, containing:

Full intervention / comparator regimen
Primary endpoint values + 95% CI
Key findings + clinical significance
Clickable jump to PMID / NCT source

58 trials · 5 chapters · 2001 to 2026 · synced with NCCN Gastric V2.2025 + CSCO Gastric 2025 dual guidelines.

Closing

Gastric cancer over the past 25 years has completed a unique evolution in oncology — from 2001 INT-0116 putting adjuvant chemoRT on the US postoperative SoC, through the 2006 MAGIC “perioperative chemo” concept invention, 2010 ToGA HER2 as the first biomarker target, 2019 FLOT4 perioperative backbone upgrade, 2021 CheckMate-649 IO + chemo 1L standard, 2023 SPOTLIGHT / GLOW CLDN18.2 new subtype, 2025 MATTERHORN perioperative IO breakthrough, 2025 DESTINY-Gastric-04 HER2+ 2L new standard, and 2025 CT041-ST-01 solid-tumor CAR-T’s first RCT win.

The most essential difference between gastric cancer and other GI major cancers (HCC / BTC / PDAC) is “early biomarker subtyping start but severe geographic branching + HER2 drugs’ 10-year leap is the deepest single-biomarker evolution”. NSCLC’s driver panel is “10+ molecular paths horizontally parallel”; HCC is “0 biomarker, IO backbone alone”; gastric cancer walks “HER2 / CLDN18.2 / PD-L1 CPS / MSI four-layer subtyping + East–West five perioperative / adjuvant paths + multi-country PD-(L)1 class-effect narrow band” three-dimensional checkerboard. This complexity dictates the 2026 gastric decision tree’s “deep and wide” character — 4 more decision layers than HCC, one fewer than NSCLC (no driver-targeted 1L monotherapy).

The most urgent structural problems to solve in 2026 are: the clinical chaos of non-unified global CPS thresholds, unclear 1L choice for HER2+ CPS<1, mechanism validation of why perioperative IO must use FLOT backbone, whether ctDNA-guided adjuvant de-escalation can identify adjuvant-IO benefit subgroups, and the global rollout path for CLDN18.2 CAR-T. Whether the next decade’s HER2 backbone is taken over by zanidatamab (HERIZON-GEA-01 full paper), whether next-generation ADCs (e.g., T-DM1 replacement) can break through T-DXd’s ILD boundary, and whether solid-tumor CAR-T can extend from gastric cancer to other CLDN18.2+ cancer types — these three questions determine the direction of gastric cancer’s next decade.

The value of this report is not “exhaustive enumeration of all trials” (PubMed can do that) but compressing 25 years of evolution + current decisions + unsolved gaps into the cognitive bandwidth of a single read. Next time you face a newly diagnosed gastric cancer patient, every branchpoint in the decision tree has this map to consult, trace, and interrogate.

Clinician × AI = Research Superpower + Clinical Decision Amplifier

—— Dual Brain Lab · 2026-04-21