Aspirin vs Placebo as Adjuvant Therapy for Breast Cancer—Reply

In Reply Alliance A011502, a randomized trial of aspirin 300 mg daily compared with placebo among 3020 survivors of high-risk nonmetastatic breast cancer, was terminated early due to lack of benefit from aspirin. Dr Thorat and colleagues note that for some cancers (eg, colorectal cancer) and different settings (eg, primary prevention), the time course of benefit can differ. However, in the adjuvant setting, it would still be most appropriate to use the standard stopping rules applied to adjuvant treatments such as hormonal therapy for hormone receptor–positive cancers, which, as Thorat and colleagues point out, can have a more indolent course with late recurrences. In our trial, the futility bound was crossed with a numerically worse hazard ratio for invasive disease–free survival (hazard ratio, 1.27; 95% CI, 0.99-1.63; P = .06), making it unlikely that a benefit would have been observed with further follow-up.