Hepatitis B And C Viruses In Hepatocarcinogenesis Of Qidong, China

Background: Both hepatitis B and C viruses (HBV and HCV) have been identified in different geographical areas as risk factors of hepatocellular carcinoma (HCC). Data also indicate the possible interactive effect of the two hepatitis viruses. The carcinogenic and co-carcinogenic role of HCV needs to be accurately assessed in the high incidence area of HCC in China, where multiple risk factors including dietary aflatoxin B1 are known to exist.Purpose: A case-control study was conducted to evaluate the strength of association between the development of HCC and the infection with HCV, HBV and the two viruses together in Qidong, China. The structural feature of the local HCV RNA was explored by cloning and sequencing of its conserved 5' untranslated region for its uniqueness.Methods: 112 HCC patients and 846 non-HCC gender- and age group-matched controls were studied. Serum hepatitis B surface antigen (HBsAg) were assayed by radioimmunoassay (RIA) and anti-hepatitis B core antigen (anti-HBc) by Corzyme enzyme immunoassay (EIA). Antibodies to HCV (anti-HCV) was measured by second generation EIA. HCV RNA was analyzed by reverse transcription PCR (RT-PCR), Southern analysis and sequencing at its 5' end after cloning. The strength of association of HCV and/or HBV with HCC was evaluated on the magnitude of the odds ratios (OR) and its 95% confidence interval (CI) calculated by Epilnfo software using Fisher's Exact Test. The pattern of hot spot mutations in the highly conserved 5' end of HCV RNA of the local HCV strain was examined and compared with those reported in different geographical areas of the world.Results: The strong positive association between HCC and HBV infection was further substantiated by an odds ratio of 30.5 (95%CI: 16-58) and 97% positivity rate of anti-HBc in the HCC group (109/112). Anti-HCV were...