Risk of colorectal cancer and other cancers in patients with gall stones.

BACKGROUND The occurrence of gall stones has repeatedly been associated with an increased risk for cancer of the colon, but risk associated with cholecystectomy remains unclear. AIMS To evaluate the hypothesis in a nationwide cohort of more than 40,000 gall stone patients with complete follow up including information of cholecystectomy and obesity. PATIENTS In the population based study described here, 42,098 patients with gall stones in 1977-1989 were identified in the Danish Hospital Discharge Register. METHODS These patients were linked to the Danish Cancer Registry to assess their risks for colorectal and other cancers during follow up to the end of 1992. RESULTS The analysis showed a modest increase in the number of cancers at all sites combined (n = 3940; RR, 1.07; 95% confidence intervals (CI), 1.0 to 1.1). A weak association was found for cancer of the colon (n = 360; RR, 1.09; 95% CI 1.0 to 1.2), which remained unchanged when analysed by sex, anatomical subsite, and duration of follow up. Multivariate analysis with adjustment for cholecystectomy and clinically defined obesity did not change these estimates to any significant extent. Excess risks were found for cancers of the pancreas and the small intestine. A non-significant increased risk for breast cancer was seen in women five years after initial discharge for gall stones. CONCLUSION A borderline significant association was seen between gall stones and cancer of the colon, and for cancer of pancreas and small intestine as well as for breast cancer in women.