ATAC

NCT00849030 📎

Regimen

Experimental
Anastrozole 1 mg daily for 5 years (or anastrozole plus tamoxifen, dropped after first analysis).
Control
Tamoxifen 20 mg daily for 5 years.

Population

Postmenopausal women with localized invasive breast cancer (HR-positive majority) completing surgery, randomized to 5 years of anastrozole, tamoxifen, or the combination.

Key finding

ATAC was the first large trial to show an aromatase inhibitor (anastrozole) superior to tamoxifen for adjuvant endocrine therapy in postmenopausal HR+ early breast cancer, reducing recurrence and contralateral disease with a different toxicity profile (more bone events, fewer thromboembolic and endometrial events).

Source: PMID 21087898

Timeline

  • Publication: 2010 Dec

Guideline citations

  • NCCN BREAST