A case-control study of hepatitis B and C virus infection as risk factors for hepatocellular carcinoma in Henan, China.

Background: Hepatocellular carcinoma (HCC) is one of the most common cancers in the world and is particularly prevalent in China. China is also a hyperendemic area for hepatitis B virus (HBV) infection. Although a strong association between HBV infection and HCC has been established previously, the role of hepatitis C virus (HCV) infection and the interaction between HBV and HCV in the development of HCC has not been adequately explored. The major objective of this study is to determine the relationship between HBV or HCV infection and HCC by use of case-control study in Henan, China.
Method: In all, 152 HCC patients and 115 control patients were collected from four hospitals in Henan, China between January 1994 and October 1995. The demographic characteristics of the two groups were comparable. In further analysis, a 1:1 pair-matched case-control study was performed. Of 152 HCC patients, 113 were randomly selected to be pair-matched by sex and age (+/-5 years) to controls with non-hepatic disease. All the cases and controls were interviewed during hospitalization by two specially trained interviewers using a standard questionnaire. All sera were tested for HBV and HCV markers. Odds ratios (OR) and 95% CI for HCC risk factors were calculated by logistic regression model controlling for possible confounding factors such as sex and age. The multivariate analysis was done on the basis of the univariate analysis.
Results: The results of this study indicated that the prevalence of hepatitis B surface antigen (HBsAg) and antibody to HCV (anti-HCV) were much higher in HCC patients (63.2% and 11.2% respectively) than in the control patients (5.2%, 3.5%). The difference between two groups was significant (P < 0.05). Risk factor analysis revealed that both HBV and HCV infection were important factors for HCC in Henan, China and HBV appeared to have a key role in the development of HCC. Odds ratios of HBsAg and HBV infection were 28.82 (95% CI: 11.18-78.78) and 31.22 (95% CI: 13.86-72.15), respectively. Moreover, the risk of developing HCC increased significantly and showed an additive effect when both viral markers of HBV and HCV infection were considered (OR = 42.85). Results from the 1:1 pair-matched case-control study also showed that HBV infection was an important risk factor for HCC, which was consistent with the results from the group-matched case-control study.
Conclusion: This is the first reported case-control study of HCC in Henan, China. This study provides further evidence that chronic HBV infection is strongly associated with the development of HCC among this population. Our results have demonstrated that HCV and HBV infection are independent and probably additive risk factors for HCC.