Hepatitis C Virus and Cancers: How Strong Is the Relationship?

Abstract

Non–liver-related malignancies are increasingly seen in patients infected with hepatitis C virus (HCV). Whether this phenomenon is related to the increasing prevalence of chronic hepatitis C (CHC) or to a direct causal role by HCV is unknown. Until recently, most of the evidence supporting the association between these cancers and HCV was based on small and heterogeneous epidemiologic studies. Recent studies addressing this issue are larger; however, they remain largely observational and have significant limitations. The precise mechanism by which HCV causes these malignancies is under investigation, but several studies demonstrated that antiviral therapy can reduce the risk of some malignancies and can increase tumor-free survival following successful tumor-directed therapy. Thus, the role of antiviral therapy for CHC could possibly be expanded to include treatment of certain subgroups of patients with the associated cancers if HCV is identified as a causative agent of these malignancies.