A Case-Control Study on the Risk Factors for Hepatocellular Carcinoma in Fukuoka, Japan

Abstract

We carried out a case-control study of hepatocellular carcinoma (HCC) including 204 patients with HCC and 410 control subjects in Fukuoka prefecture, where HCC risk is among the highest in Japan. The possible risk factors examined were: a) chronic hepatitis B virus (HBV) infection, b) alcohol consumption and cigarette smoking, c) a past history of blood transfusion and hepatitis C virus (HCV) infection. Chronic HBV infection was strongly associated with the development of HCC (relative risk, RR = 14.6). Heavy drinkers experienced about a two-fold risk increase, yet a relationship between cigarette smoking and HCC was not evident. Blood recipients showed a significantly increased RR of 3.0. Serum antibodies to HCV (antiHCV) were detected by both enzyme-linked immunosorbent assay and recombinant immunoblot assay in 51% of HCCs and 3% of the controls; the RR (and 95% confidence interval) for positive anti-HCV was calculated as 52.3 (23.9-114.3). Among male patients with HCC, the anti-HCV rates were very high in blood recipients (68%), heavy drinkers (62%) and those who had no identifiable risk factors (75%), indicating the possible transmission of HCV via routes other than blood transfusion. We estimated the population attributable risk of HCC at 17% for chronic HBV infection, 13% for heavy drinking, and 49% for HCV infection in Fukuoka. Further investigations are still needed to identify the other infectious routes of HCV besides transfusion.