Long-term aspirin use and colorectal cancer risk: a cohort study in Sweden

Abstract
In a prospective cohort study of 74 250 Swedish women and men, with 7.2 years of follow-up and 705 incident colorectal cancer cases, long duration of aspirin use (>20 years) was associated with a reduced risk of colorectal cancer (multivariate rate ratio: 0.65; 95% confidence interval: 0.45–0.94). Aspirin use for a shorter period was not associated with risk.