Risk factors for intrahepatic cholangiocarcinoma: a systematic review and meta-analysis

Abstract

Background The incidence of intrahepatic cholangiocarcinoma (ICC) has increased worldwide in recent years, but the risk factors of ICC have not yet been clearly defined. The aim of this study was to identify risk factors for ICC. Methods A literature search was conducted in PubMed database for eligible studies published from January 2000 to November 2018. Summary odds ratio (OR) with their corresponding 95% confidence intervals (CI) were calculated using a random-effects model. Results Thirty-two studies (5 cohort, 27 case control) were included in this meta-analysis. Pooled estimates indicated that cirrhosis (OR=11.96, 95% CI 7.53-19.00), hepatitis B virus (HBV) infection (OR=4.09, 95% CI 3.13-5.34), hepatitis C virus (HCV) infection (OR=3.94, 95% CI 2.85-5.45), alcohol consumption (OR=2.68, 95% CI 1.97-3.66), hepatolithiasis (OR=14.94, 95% CI 6.41-34.83), choledochal cyst (OR=21.67, 95%CI 10.83-43.36), primary sclerosing cholangitis (PSC) (OR=93.91, 95%CI 43.99-200.47), diabetes mellitus (OR=1.82, 95% CI 1.57-2.11), non-alcoholic fatty liver disease (OR=2.23, 95% CI 1.65-3.02), liver fluke infection (OR=2.28, 95% CI 1.30-4.01) and smoking (OR=1.26, 95% CI 1.07-1.49) were significantly associated with ICC. Non-significant association was found between ICC and history of cholecystectomy, hypertension, coffee and aspirin. Conclusions Cirrhosis, HBV infection, HCV infection, alcohol consumption, hepatolithiasis, choledochal cyst, PSC, diabetes mellitus, non-alcoholic fatty liver disease, liver fluke infection and smoking are risk factors for ICC.