Aspirin: anticolorectal adenocarcinoma activity in the adjuvant arena?

Evaluation of: Chan AT, Ogino S, Fuchs CS: Aspirin use and survival after diagnosis of colorectal cancer. JAMA 302, 649-659 (2009). Colorectal cancer (CRC) is the second most common cause of cancer-related deaths in Americans. In prior observational studies, aspirin has been associated with significant reductions in colorectal adenoma recurrence, CRC incidence, CRC-associated mortality and overall mortality. In this study of data from two large, long-term cohort studies, Chan et al. identify significant inverse associations in both CRC-related mortality and overall mortality among patients with stage I-III CRC using aspirin versus nonusers. The absolute risk reductions in both parameters in aspirin users are in the order of 4%, but aspirin's potential benefits are restricted to patients with COX-2-overexpressing tumors. The feasibility and impact of aspirin as an adjuvant therapy for nonmetastatic CRC needs confirmation in randomized trials to answer remaining questions regarding the most appropriate dose, frequency and duration of administration, as well as to estimate the relative benefits versus risks of treatment in this setting.