Cholecystectomy and the risk of colon cancer

Objective: The relationship between cholecystectomy and the occurrence of s ubsequent colon cancer has been controversial. Using data collected as part of an incident case-control study of colon cancer conducted in northern Ca lifornia, Minnesota, and Utah, we evaluated this association.,Methods: Part icipants were between 30 and 79 Sr of age and had a first primary colon can cer diagnosed between October 1, 1991 and September 30, 1994. Analyses were adjusted for age, gender, family history of colorectal cancer, body mass i ndex, dietary energy and fiber intake, use of aspirin or nonsteroidal antii nflammatory drugs, and long-term leisure-time vigorous physical activity. R esults: A weak positive association between cholecystectomy and proximal co lon cancer (odds ratio [OR] and 95% confidence interval [CI] 1.3 [1.0-1.6]) was observed. This was counterbalanced by a weak, nonsignificant negative association (OR 0.8, 95% CI 0.6-1.1) with distal colon cancer leading to no overall association (OR 1.0, 95% CI 0.9-1.2). The association between colo n cancer and cholecystectomy did not differ by gender or race, but it did d iffer by study area, with most of the increased association being attribute d to the Minnesota population. The elevated risk of proximal colon cancer i ncreased after cholecystectomy but disappeared after 14 years. Conclusions: Our results suggest that cholecystectomy or the underlying gallstone disea se that prompts it may be related weakly to the risk of subsequent proximal colon cancer. However, the association may differ by geographic area of th e country, and mag be artifactual at least in Dart. (C) 1999 by Am. Cell. o f Gastroenterology.