Associations of low-dose aspirin or other NSAID use with prostate cancer risk in the Danish Diet, Cancer and Health Study

Purpose Epidemiologic studies suggest that use of aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce prostate cancer risk. We examined these associations overall and according to clinical and lifestyle parameters. Methods We identified male participants in the Danish Diet, Cancer and Health Study ( n = 26,339), holding information on anthropometric measures and lifestyle factors. From Danish nationwide registries and medical records, we retrieved complete prescription histories and prostate cancer occurrence and characteristics. Cox regression was used to estimate hazard ratios (HRs) for prostate cancer associated with low-dose aspirin or nonaspirin NSAID use, overall and by clinical characteristics, anthropometric measures, and lifestyle factors. Results We identified 1,927 prostate cancer cases during a median follow-up of 17.0 years. Low-dose aspirin use was not associated with overall prostate cancer risk, but a reduced HR for nonaggressive prostate cancer (high use [≥ 1,825 tablets]: 0.79; 95% confidence interval (CI) 0.60–1.04) and an increased HR for aggressive disease (high use: 1.27; 95% CI 1.00–1.61) was observed with low-dose aspirin use. Long-term, high-intensity use (≥ 10 years with ≥ 0.25 defined daily doses/day) of nonaspirin NSAIDs was associated with an increased HR for prostate cancer (1.35, 95% CI 0.99–1.84), confined to localized and nonaggressive disease. No consistent variation in HRs was seen in analyses stratified by height, body mass index, smoking, and alcohol use. Conclusion Low-dose aspirin or other NSAID use was not associated with reduced prostate cancer risk, neither overall nor according to anthropometric measures, smoking, or alcohol use. The variation according to outcome characteristics warrants further investigation.