Multicenter randomized study of aspirin versus placebo as adjuvant therapy for breast cancer

Observational studies of survivors of breast cancer and prospective trials of aspirin for cardiovascular disease suggest improved breast cancer survival among aspirin users, but prospective studies of aspirin to prevent breast cancer recurrence are lacking. The phase 3 Alliance A011502 trial randomized 3020 patients with high-risk nonmetastatic breast cancer at 534 sites in the United States and Canada to receive aspirin 300 mg or placebo once daily for 5 years. The trial was terminated early because of lack of benefit from aspirin (hazard ratio for invasive disease-free survival for aspirin versus placebo: 1.27; 95% CI 0.99-1.63; p=0.06). The authors conclude that aspirin should not be recommended as an adjuvant breast cancer treatment (visual abstract).