Cancer Resources > Cancer News > 2005 > August

Cholecystectomy modestly raises colon cancer risk

Last Updated: 2005-08-29 14:14:43 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Cholecystectomy modestly raises the risk of colon but not rectal cancer in men and women, suggest results of a population-based study conducted in the UK. The findings support the "global view" of previous epidemiological studies on the link between gallbladder removal and colon cancer, investigators note in the August American Journal of Gastroenterology.

According to Drs. Theresa Shao and Yu-Xiao Yang from the University of Pennsylvania School of Medicine in Philadelphia "lithogenic bile could be the underlying mechanism."

"It is hypothesized," they explain, that increased mucosal exposure to secondary bile acids and undigested fat following cholecystectomy may lead to mucosal damage and subsequent cellular proliferation, perhaps leading to cancer." The suggestion that cholecystectomy raises the risk of colon but not rectal cancer "is consistent with the bile acid exposure theory."

Drs. Shao and Yang used the UK General Practice Research Database to assess the risk of colorectal cancer after cholecystectomy. Among 55,960 men and women who had the surgery, the incidence of colorectal cancer was 119 per 100,000 person-years, modestly higher than the incidence of 86 per 100,000 person-years among 574,668 patients who did not have the surgery.

"Adjusting for various known and suspected risk factors for colorectal cancer did not change this association," the investigators note. The adjusted incidence rate ratio of colorectal cancer with cholecystectomy was 1.32. The positive association was present for colon cancer but not for rectal cancer, with adjusted rate ratios of 1.51 and 1.00, respectively.

Cholelithiasis also raised the risk of colon cancer to a similar degree as cholecystectomy, which also supports the lithogenic bile acid exposure theory.

The researchers caution, however, 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," they write.

"Studies are needed," they conclude, "to determine whether it would be cost-effective to implement a more stringent colon cancer screening strategy in this patient population."

Am J Gastroenterol 2005;100:1813-1820.

Copyright © 2010 Reuters Limited. All rights reserved.
Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.