Abstract 2810: Physical activity and colorectal adenomatous polyps: The Minnesota cancer prevention research unit case-control study

Abstract

Abstract Background: Although it is well established that greater physical activity is associated with lower risk of colorectal cancer, there have been few studies of its association with adenomatous polyps, precursors of colorectal cancer. Methods: The 1991-1994 Minnesota Cancer Prevention Research Unit case-control study of 566 colonoscopy-positive adenomatous polyp cases, 687 colonoscopy-negative controls, and 535 community controls investigated the association of physical activity with risk of incident, sporadic colorectal adenomatous polyps. Daily hours of moderate and vigorous physical activity were elicited by a standardized questionnaire and metabolic equivalent (MET) hours were calculated. Results: The age- and sex-adjusted odds ratios (ORs) for adenomas comparing the highest to the lowest quartile of MET hours were 1.02 (95% confidence interval [CI]: 0.73, 1.44) using colonoscopy-negative controls, and 0.96 (95% CI: 0.69, 1.34) using community controls; after multivariate-adjustment the corresponding ORs were 1.11 (95% CI: 0.77, 1.60) and 1.00 (95% CI: 0.70, 1.43). Analyses stratified by nonsteroidal anti-inflammatory drug (NSAID) use excluding aspirin, adenoma size, and adenoma location did not any yield statistically significant results. Conclusions: Taken together with the strong, consistent inverse associations of physical activity with colorectal cancer, our null results suggest the possibility that physical activity may be more related to risk for transitioning from colorectal adenoma to carcinoma than to adenoma genesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2810.