Background and Aim : Gallstones have been reported to be positively associated with hepatobiliary cancers. However, risks of these cancers by cholecystectomy or in patients with complicated gallstones are controversial. We studied the effect of cholecystectomy on the risk of cholangiocarcinoma (CCA) or hepatocellular carcinoma (HCC) in patients with gallstones and subgroup of complicated gallstones. Methods : Patients with gallstone disease (n = 958 677) and age-matched and sex-matched controls ...