Constipatin of Colorectal Cancer.doc

American Journal of Epidemiology Bowel Movement and Constipation Frequencies and the Risk of Colorectal Cancer among Men in the Netherlands Cohort Study on Diet and Cancer Colinda C. J. M. Simons, Leo J. Schouten, Matty P. Weijenberg, R. Alexandra Goldbohm, Piet A. van den Brandt Am J Epidemiol.?2010;171(12):1404-1414.? Abstract The authors investigated the associations between bowel movement and constipation frequencies and colorectal cancer (CRC) endpoints among men in the Netherlands Cohort Study on Diet and Cancer (n?= 58,279) and explored whether dietary fiber intake may modify associations. After 13.3 years (1986–1999), 1,207 CRC cases and 1,753 subcohort members were available for case-cohort analyses. Multivariate analyses showed a significantly increased hazard ratio for CRC overall and rectal cancer in men who reported having a bowel movement 1–2 times per day (second-highest category) as compared with once a day (CRC: hazard ratio (HR) = 1.29, 95% confidence interval (CI): 1.09, 1.53 (P?trend? 0.001); rectal cancer: HR = 1.50, 95% CI: 1.15, 1.95 (P?trend?= 0.001)). Hazard ratios for CRC overall and rectal cancer were significantly decreased and lowest in men who reported suffering from constipation sometimes or more often versus never (CRC: HR = 0.76, 95% CI: 0.58, 0.98 (P?trend?= 0.02); rectal cancer: HR = 0.57, 95% CI: 0.35, 0.90 (P?trend?= 0.01)). No trends in the associations with proximal or distal colon cancer risk were observed. Interactions with dietary fiber intake were not significant. In this study, frequent bowel movements were associated with an increased risk of rectal cancer in men, and constipation was associated with a decreased risk. Introduction Gut motility may be one of the mechanisms linking dietary factors and physical activity with colorectal cancer risk. A hypothesis by Burkitt et al.[1]?predicts that decreased gut motility may increase colorectal cancer risk because carcinogens in stool are held in contact with the colonic muco