The Effect of Cholecystectomy on the Risk of Colorectal Cancer in Patients with Gallbladder Stones.

UNLABELLED

To evaluate the risk of colorectal cancer (CRC) after cholecystectomy for gallbladder stones (GBS).

METHODS

This nationwide population-based cohort study analyzed the inpatient data from the Taiwan National Health Insurance Research Database. The study cohort comprised of 83,963 patients aged 20 years undergoing cholecystectomy for GBS between 2000 and 2010. The control cohort comprised the GBS patients without cholecystectomy, who were propensity matched with the study cohort at a 1:1 ratio based on age, sex, comorbidities, and the index date for cholecystectomy.

RESULTS

The cumulative incidence of CRC within 6 months of follow-up was higher in the cholecystectomy cohort than that in the non-cholecystectomy cohort (aHR (adjusted hazard ratio) = 7.90, 95% confidence interval (CI) = 6.27-9.94; log-rank test, < 0.001). The cumulative incidence of CRC after 6 months of follow-up was lower in the cholecystectomy cohort than that in the non-cholecystectomy cohort (aHR = 0.66, 95% CI = 0.60-0.73; log-rank test, < 0.001), but the reduced risk of CRC for the cholecystectomy cohort was statistically significant only in rectal cancer after separately considering females (aHR = 0.64, 95% CI = 0.46-0.88) and males (aHR = 0.59, 95% CI = 0.44-0.79).

CONCLUSIONS

The positive association between cholecystectomy and the CRC risk within the first 6 months after cholecystectomy might be due to a detection bias or pre-existing CRC. However, cholecystectomy is associated with a decreased risk of rectal cancer, rather than proximal or distal colon cancer, after more than 6 months of follow-up.