Background: The association between gall bladder removal (cholecystectomy) and hepatocellular carcinoma warrants investigation. An increased intrahepatic bile duct pressure following cholecystectomy might cause chronic inflammation in the surrounding liver tissue, which might induce cancer development.
Methods: A nationwide Swedish population-based cohort study in 1965-2008 included 345,251 patients undergoing cholecystectomy because of gallstone. The number of observed hepatocellular carcinoma cases was divided by the expected number, calculated from the corresponding background Swedish population, thus providing standardised incidence ratios (SIRs) with 95% confidence intervals (CIs).
Results: During follow-up of 4,854,969 person-years, 333 new cases of hepatocellular carcinoma were identified, rendering an overall increased risk (SIR 1.24, 95% CI: 1.11-1.38). The risk increased with longer follow-up (P for trend=0.003). Among patients who underwent cholecystectomy 30-43 years earlier, SIR was 2.00 (95% CI: 1.32-2.87). The results were similar after exclusion of 15,634 patients with any recorded risk factor, that is, diabetes, obesity, hepatitis, liver cirrhosis, alcoholism, or blood transfusion.
Conclusion: Cholecystectomy might be associated with a long-term increased risk of hepatocellular carcinoma.