PATHOGENESIS OF HEPATITIS-B AND C-INDUCED HEPATOCELLULAR-CARCINOMA

Hepatocellular carcinoma (HCC) is estimated to have an annual worldwid e incidence of 0.25 to 1.2 million new cases per year. Both the preval ence and incidence of HCC vary markedly as a function of geography and the local prevalence of chronic viral hepatitis. Both chronic hepatit is B and chronic hepatitis C are recognized as risk factors for HCC. T he prevalence of cirrhosis in individuals with HCC and chronic hepatit is B or C is reported to be 80.9% and 75.8%, respectively. HCC occurs at a lower rate in chronic viral hepatitis in the absence of cirrhosis , Moreover, hepatitis C virus (HCV) rather than hepatitis B virus (HBV ) is associated with the majority of non-cirrhotic cases of HCC. It is probable that the ongoing process of hepatocyte necrosis and liver ce ll renewal coupled with inflammation, which is characteristic of chron ic viral hepatitis, causes not only nodular regeneration and cirrhosis but also progressive genomic errors in hepatocytes as well as unregul ated growth and repair mechanisms leading to hepatocyte dysplasia and, in some cases, hepatic carcinoma. Current concepts concerning virus-i nduced HCC are reported and discussed in the following review.