Regular use of aspirin and prostate cancer risk (United States).

It has been hypothesized that aspirin and other nonsteroidal anti-inflammatory drugs can decrease the risk of developing prostate and other cancers, although observational studies have not been very conclusive. The current study examined the effects of regular aspirin use on prostate cancer risk in 1,029 patients with primary, incident cancer of the prostate and 1,029 hospital controls frequency-matched to cases by 5-year age group and period of questionnaire completion. Patients who reported use of aspirin for at least once a week for at least 6 months were classified as regular users, with others classified as non-users. Results indicate that regular aspirin use may not be associated with decreased prostate cancer risk [odds ratio (OR) 1.05, 95% confidence interval (CI) 0.89-1.25], frequency of use (OR for at least seven/week 0.91, 95% CI 0.73-1.13), duration of use (OR for at least 10 years of use 1.17 95% CI 0.93-1.46) or tablet years (defined as tablets per day x years of use). A similar lack of association was observed when analyses were performed examining stage of the cancer. These data suggest that aspirin use may not be associated with reduced risk of prostate cancer.