Abstract #LB-223: Non-steroidal anti-inflammatory drugs and bladder cancer: A pooled multi-cohort study.

Abstract

Background: Several case-control studies have shown that regular use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with decreased risk of bladder cancer, but few prospective studies have evaluated this association. Methods: We investigated the relationship between self-reported NSAID use and bladder cancer risk in three large prospective cohort studies (NIH-AARP Diet and Health Study, Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, and U.S. Radiologic Technologist Health Study). The frequency of aspirin and non-aspirin NSAID use one year prior to baseline was ascertained using mailed questionnaires. Study-specific hazard ratios (HR) were estimated using the Cox proportional hazards model with age as the time metric. A meta-analytic estimate was calculated using a random effects model. The Q statistic was used to test for heterogeneity between studies. We then pooled the individual cohort data and jointly analyzed all 508,807 individuals with a total of 2,553 incident bladder cancer cases (2,116 men, 437 women) during a median of 7 years of follow-up time. Results: A statistically non-significant reduction in bladder cancer risk was observed in the pooled analysis for regular use (more than 2 times per week) of non-aspirin NSAIDs compared to no use of non-aspirin NSAIDs (HR= 0.91, 95% CI (0.80-1.04)), after adjusting for smoking status, cigarettes per day, study, gender, aspirin, race, and body mass index. A statistically significant inverse association for regular use of non-aspirin NSAIDs was observed among nonsmokers (HR=0.55, 95% CI (0.38-0.80); p-interaction=0.03), with the strongest inverse association seen with daily use (HR=0.50, 95% CI 0.31-0.80; p-trend=0.01). No association was observed between aspirin use and bladder cancer overall (HR:1.07, 95% CI (0.97-1.19)) or among nonsmokers (HR=1.15, 95% CI (0.88-1.49)). Conclusion: In this pooled analysis, regular use of non-aspirin NSAIDs, but not aspirin, was associated with a significant reduction in risk for bladder cancer among non-smokers.

Citation Information: In: Proc Am Assoc Cancer Res; 2009 Apr 18-22; Denver, CO. Philadelphia (PA): AACR; 2009. Abstract nr LB-223.