Chronic hepatitis infection is associated with extrahepatic cancer development: a nationwide population-based study in Taiwan.

Background: Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the major causes of chronic hepatitis infection (CHI). This longitudinal cohort study investigated the association of CHI with hepatic and extrahepatic cancer development in Taiwan.

Methods: Patients with HBV infection and HCV infection were identified from the Taiwan National Health Insurance Research Database. A Cox proportional hazard model was used to calculate hazard ratios (HRs) and 95 % confidence intervals (CIs) for determining the association between CHI and cancer development.

Results: The patients with HBV infection exhibited an increased risk of colorectal cancer (HR: 1.36, 95 % CI: 1.09-1.70), liver cancer (HR: 21.47, 95 % CI: 18.0-25.6), gallbladder and extrahepatic bile duct cancer (HR: 2.05, 95 % CI: 1.07-3.91), pancreatic cancer (HR: 2.61, 95 % CI: 1.47-4.61), kidney cancer (HR: 1.72, 95 % CI: 1.10-2.68), ovarian cancer (HR: 2.31, 95 % CI: 1.21-4.39), and non-Hodgkin's lymphoma (HR: 2.10, 95 % CI: 1.25-3.52). The patients with HCV infection exhibited an increased risk of liver cancer (HR: 25.10, 95 % CI: 20.9-30.2), gallbladder and extrahepatic bile duct cancer (HR: 2.60, 95 % CI: 1.42-4.73), ovarian cancer (HR: 5.15, 95 % CI: 1.98-13.4), and non-Hodgkin's lymphoma (HR: 2.30, 95 % CI: 1.34-3.96).

Conclusion: The present population-based study revealed that in addition to its association with primary liver cancer, CHI is associated with an increased risk of extrahepatic cancer.