title: Unaltered risk of colorectal cancer within 14-17 years of cholecystectomy: updating of a population-based cohort study.
abstract: The incidence of colorectal cancer after cholecystectomy was analysed in a historical population-based cohort study comprising 16,439 patients who were completely followed up for 14-17 years after operation. The observed number of colorectal cancers (150) was lower than the expected number of 166.3 (relative risk (RR) = 0.90:95 per cent confidence limits 0.77-1.05) and the overall risk for colon cancer (RR = 0.95) did not differ significantly from that of rectal cancer (RR = 0.82). Separate analyses by sex, age at operation and duration of follow-up revealed relative risks close to or lower than unity. Some deviations indicating a substantially reduced risk might have been due to the play of chance alone. Our results contradict the idea both of a causal and of a non-causal association-through common aetiological factors-between surgically confirmed gallbladder disease and colorectal cancer.
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002763:Cholecystectomy / Q000009:adverse effects*; D003110:Colonic Neoplasms / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000209:etiology*; D012306:Risk