Abstract
Uniform conclusions have not yet been drawn as to the frequency and copy number of hepatitis B virus (HBV) DNA in hepatocellular carcinoma (HCC) tissues from patients who are negative for hepatitis B surface antigen (HBsAg). The existence of HBV DNA was investigated with Southern blot hybridization and polymerase chain reaction (PCR) in HCC tissues from 55 patients who were negative for HBsAg and positive for hepatitis C virus antibody (HCVAb). Southern blot hybridization showed that two tissues (4%) contained HBV DNA at a frequency of more than 1 HBV copy per 10 cells. Another 5 tissues were found to be positive for HBV DNA only by PCR analysis but contained less than 3 HBV DNA copies per 10(5) cells. HCC tissues from patients seronegative for HBsAg and seropositive for HCVAb contain HBV DNA less frequently than has generally been claimed.