Theranostics and Precision Medicine for the Management of Hepatocellular Carcinoma: Chapter 17 - Comparative genomics and molecular epidemiology on hepatitis virus–induced hepatocellular carcinoma

Hepatitis (H) is caused by five distinct kinds of viruses (V): hepatitis A virus, hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus. Moreover, HBV, HCV, and HDV have also been linked to hepatocellular carcinoma (HCC). The role of HDV in causing cancer is debatable as it was shown dependent on HBV infection. In the modern era, advanced molecular techniques are successfully utilized in the detection, characterization, and classification of the microbial pathogens. Molecular epidemiology and genotyping would provide greater grasp of the molecular markers of emerging and novel pandemics of infection. The epidemiology, severity of infection, and response to antiviral treatments are shown to be associated with genotypes and the subtypes. Hence, the identification of high- and low-risk pathogens is vital in understanding the pathogenesis and determining the best suited therapy for it. Molecular epidemiological features and relative frequencies of HBV and HCV provide better understanding of chronic inflammatory liver disease and its progression into HCC. The chapter presents the current view of the pathogenesis of HBV and HCV along with the report on their relation to the genotypes.