Aspirin's Protective Effect Against Gastrointestinal Cancer, Again

Most studies suggest that aspirin use is associated with lower cancer mortality, particularly for gastrointestinal cancers; however, the 2018 ASPREE study, a large randomized trial, showed higher mortality (both total and colorectal cancer–specific) with aspirin use (NEJM JW Gen Med Oct 15 2018 and N Engl J Med 2018; 379:1519). Other uncertainties include whether obesity mitigates any benefit due to lower bioavailability and a possible lack of protective effect in older adults. In this secondary analysis of observational data from a national cancer screening trial (PLCO), researchers addressed both concerns by identifying 146,000 older participants (age, ≥65) who were followed for a median 13 years and assessing cancer mortality according t…