Cholecystectomy and the incidence of cancer of the large bowel

As part of an epidemiologic study of cancer of the large bowel in women, female residents of King and Pierce counties (Washington) who were diagnosed during 1976–77 were interviewed regarding previous gallbladder surgery. Their responses were compared with those of a random sample of women from the same population. A history of cholecystectomy was somewhat more frequent among patients with colon cancer than among controls—we estimate the colon cancer risk in women without a gallbladder to be 1.4 times that of other women—but the 95% confidence limits of the relative risk included 1.0 (0.8–2.5). There was no association between cholecystectomy and rectal cancer and, among the subsites of colon cancer, the magnitude of the excess risk failed to show any consistent right‐left gradient. Nonepidemiologic data suggest that cholecystectomy could increase the risk of colon cancer. However, if such an association truly exists it is not a strong one, and studies larger than those conducted to date are needed to detect this association reliably.