Hepatitis C virus and risk of extrahepatic malignancies: a case-control study

Epidemiological studies have demonstrated an increased risk of non-Hodgkin lymphoma (NHL) in patients with chronic hepatitis C virus (HCV) infection. Therefore, we investigated the risk of extrahepatic malignancies associated with HCV infection. Inpatients diagnosed with lymphoma, breast, thyroid, kidney, or pancreatic cancer (research group, n = 17,925) as well as inpatients with no malignancies (control group, n = 16,580) matched by gender and age were enrolled from The First Affiliated Hospital of Nanjing Medical University between January 2008 and December 2016. A case-control study was conducted by retrospective analysis. The difference in HCV prevalence was analyzed between the research group and the control group. Also, the research group was compared to the 2006 National Hepatitis C sero-survey in China. A total of 86 cases were positive for anti-HCV in the research group. Compared with the control group (103 cases were anti-HCV positive), no significant associations between extrahepatic malignancies and HCV infection were observed. Meanwhile, compared to the 2006 National Hepatitis C sero-survey, we observed a significant association between the chronic lymphoma leukemia/small lymphocytic lymphoma (CLL/SLL) and HCV seropositivity in females in the research group aged 1-59 years old (OR = 14.69; 95% CI, 1.94-111.01). HCV infection had a potential association with CLL/SLL in females aged 1-59 years old. Our study did not confirm an association between HCV infection and the risk of extrahepatic malignancies. In regions with a low HCV prevalence, the association between HCV infection and extrahepatic malignancies needs further investigation.