Hepatitis B virus DNA integration in hepatocellular carcinomas and their adjacent non-neoplastic liver tissues

Hepatitis B virus (HBV) DNA integration was studied in 24 hepatocellular carcinoma (HCC) tissues obtained at operations or autopsies. In 11 cases whose sera were positive for hepatitis B virus surface antigen (HBsAg), HBV DNA integration was demonstrated by Southern blot analysis. Only one of 6 cases whose sera were positive for hepatitis B surface antibody (HBsAb) but negative for HBsAg revealed the integration and the other 5 cases revealed no HBV DNA integration. HBV DNA amplification was noted in 4 of these 6 cases in which HBV DNA integration was found when compared with the adjacent liver tissues. The integration pattern of HBV DNA was different in one case between primary HCC tissue and a metastasized lymph node. It is suggested that HBV DNA amplification is not directly related to the development of HCC and that there are polyclonal tumor cells which have different patterns of virus genome integrations.