Abstract A75: Nonsteroidal anti-inflammatory drugs (NSAIDs) and colorectal cancer risk in the National Institutes of Health-AARP Diet and Health Study

Abstract

Abstract Background and Aims: Prolonged nonsteroidal anti-inflammatory drug (NSAID) use has been associated with lower colorectal cancer risk; however, little is known about the association of NSAID use within colorectal subsites or among individuals with a family history of colon cancer. This study assessed NSAID use and colorectal adenocarcinoma by subsite, including subanalysis of individuals with a family history of colon cancer. Methods: Using Cox proportional hazard regression, we estimated hazard ratios (HR) and 95% confidence intervals (CI) for the association between NSAID use and colorectal cancer incidence among 301,240 participants; of whom 26,994 individuals reported having a first degree relative with history of colon cancer. We accrued 3,894 colorectal cancer cases during 10 years of follow-up; 372 cases had a first degree relative with colon cancer. Results: Use of aspirin or non-aspirin NSAIDs (yes versus no) reduced colorectal cancer risk (HR=0.91, 95% CI: 0.85, 0.98; HR=0.82, 95% CI: 0.77, 0.87, respectively); these risks were lowered with increasing frequency of use (HR=0.86, 95% CI: 0.79, 0.94; HR=0.71, 95% CI: 0.63, 0.80 for daily use compared to non-users of aspirin or non-aspirin NSAIDs, respectively). Participants with a first degree relative with colon cancer who used non-aspirin NSAIDs daily had reduced colon cancer risk specifically (HR: 0.49, 95% CI: 0.29, 0.82). Conclusions: NSAID use reduced colorectal cancer risk; the magnitude of this association varied with NSAID type and tumor location. Daily non-aspirin NSAID use was associated with a 50% lower risk of colon cancer in those with a first degree relative with this malignancy. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A75.