Hepatitis C virus infection and risk of cancer: a population-based cohort study

BACKGROUND: Hepatitis C virus (HCV) infection is associated with an increased risk of primary liver cancer; however, 5- and 10-year risk estimates are needed. The association of HCV with non-Hodgkin lymphoma (NHL) is uncertain and the association with other cancers is unknown. METHOD: We conducted a nationwide, population-based cohort study of 4,349 HCV-infected patients in Denmark, computing standardized incidence ratios (SIR) of cancer incidence in HCV infected patients compared with cancer incidence of the general population. We calculated 5- and 10-year risks of developing cancer, stratifying our analyses based on the presence of HIV coinfection and cirrhosis. RESULTS: We recorded an increased risk of primary liver cancer (SIR: 76.63 [95% CI: 51.69–109.40]), NHL (SIR: 1.89 [95% CI: 0.39–5.52]), and several smoking- and alcohol-related cancers in HCV infected patients without HIV coinfection. HCV-infected patients without HIV coinfection had a 6.3% (95% CI: 4.6%–8.7%) risk of developing cancer and 2.0% (95% CI: 1.1%–3.8%) risk of developing primary liver cancer within 10 years. CONCLUSION: We confirmed the association of HCV infection with primary liver cancer and NHL. We also observed an association between HCV infection and alcohol- and smoking-related cancers.