[Breakthrough in human hepatocellular carcinogenesis--from hepatitis B virus to hepatitis C virus].

Since demonstration of causative relationship of hepatocellular carcinoma (HCC) and persistent hepatitis B virus (HBV) infection, nation-wide preventive measures have made remarkable progress in Japan. This will contribute to minimizing the probability to create new sources for HBV infection resulting in reduction of the incidence with liver cirrhosis and HCC due to HBV infection in the next generation. Currently, however, HCC not due to HBV increased twice in the pastdecade up to three quarters of total HCC cases and 30-40% of them had previous history of blood transfusion. Hepatitis C virus (HCV) antibody test revealed that at least three quarters of them are due to HCV infection. Seroepidemiological studies demonstrated that transmission route of HCV in mainly blood borne horizontal infection and partly by sexual contact. Transfusion of blood or blood products is major route in Japan. Elimination of HCV infected blood for blood transfusion and improvement of sanitary condition especially in health care system will be most effective counter measures for prevention of HCV infection. Antiviral therapy specially with interferon will be the most promising measure to intervene clinical progression of HCV infected cases to HCV related liver cirrhosis or HCC.