Gallbladder removal and colon cancer risk

Gallbladder removal or cholecystectomy raises the risk of colon but not rectal cancer. Still, experts note that the risk is only slightly increased and, therefore, should not influence the decision to undergo this procedure if it's necessary. According to researchers from the University of Pennsylvania School of Medicine in Philadelphia, stone-forming bile could be the underlying mechanism. It is hypothesised that increased exposure of the colon lining to bile acids and undigested fat following cholecystectomy may lead to damage that ultimately results in cancer. The suggestion that cholecystectomy raises the risk of colon but not rectal cancer is consistent with the bile acid exposure theory.The researchers analysed data from more than 600,000 subjects to assess the risk of colorectal cancer after cholecystectomy. The findings suggest that if 10,000 people who underwent the surgery were followed for 10 years, 119 would develop colon cancer. By contrast, among subjects who did not undergo cholecystectomy, the number was slightly lower - 86. Simply having gallstones raised the risk of colon cancer to a similar degree as cholecystectomy, which also supports the bile acid exposure theory.The researchers caution that for an individual patient, such a modest risk increase should weigh little in the decision to undergo elective cholecystectomy. However, owing to the high prevalence of gallstone disease and cholecystectomy in the general population, even an association of relatively small magnitude could have important public health implications.