Increased incidence of gallstones and prior cholecystectomy in patients with large bowel cancer.

In a retrospective study, the frequency of occurrence of gallstones and cholecystectomy in 479 patients with colorectal cancer was compared with that of 483 matched control patients with other malignancies. The mean interval between cholecystectomy and colon cancer diagnosis was 15.1 +/- 9.9 yr (range 2-53 yr), and there was no statistically significant difference, compared with the control group at 13.9 +/- 8.2 yr (range 2-31 yr). In patients with colon cancer, the general increased relative risk of concomitant diagnosed gallstones (relative risk 1.73, p = 0.0123) and the relative risk of cholecystectomy (relative risk 2.08, p = 0.0074) was statistically significant. However, when the data with regard to sex were analyzed, significant differences were observed only in women. Women affected by right colon cancer also had a statistically significant higher incidence of previous cholecystectomy (relative risk 2.86, p = 0.0096), but no significantly higher incidence of concomitant gallstones. The general increased relative risk in patients with right colon cancer and decreased risk in patients with left colon cancer of concomitant gallstones and prior cholecystectomy was statistically significant. Our data provide evidence for the hypothesis that both gallstones and cholecystectomy increase the general risk of large bowel cancer. Therefore, they are also compatible with the possibility that common risk factors causes the association between gallstones and large bowel cancer.