Cholecystectomy and colorectal cancer.
BACKGROUND
An increased risk of large bowel cancer, especially of the right colon, following cholecystectomy has been reported in some studies but contradicted in others. The aim of this study was to settle this question by creating a cohort of cholecystectomy patients that was large enough and with a sufficient follow-up time to detect even weak associations.


METHODS
A population-based cohort consisting of 62,615 patients who underwent cholecystectomy was followed up for the occurrence of colorectal cancer up to 23 years.


RESULTS
There were 633 colorectal cancers versus 637.9 expected (standardized incidence ratio [SIR] = 0.99; 95% confidence interval [CI] = 0.92-1.07). Analyses of an extensive number of subgroups including sex, age at operation, duration of follow-up, underlying diagnosis, type of operation, and different cancer sites did not show any association. However, for cancer of the right colon among women, the risk was increased (SIR = 1.24; 95% CI = 1.03-1.48) most prominent 15 years or more after operation (SIR = 1.54; 95% CI = 1.03-2.22).


CONCLUSIONS
Overall, there is no excess risk of colorectal cancer following cholecystectomy, but consistent with some earlier reports, we observed an increased risk among women for right-sided colon cancer 15 years or more after operation.
Cancer Epidemiology Unit, University Hospital, Uppsala, Sweden.
A
A
Ekbom
J
J
Yuen
H O
HO
Adami
J K
JK
McLaughlin
W H
WH
Chow
I
I
Persson
J F
JF
Fraumeni
D000328:Adult; D000367:Age Factors; D000368:Aged; D002763:Cholecystectomy; D002769:Cholelithiasis / Q000150:complications; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications; D012306:Risk; D012737:Sex Factors