Primary liver cancer incidence-rates related to hepatitis-C virus infection: a correlational study in Osaka, Japan.

Osaka, Japan, has one of the highest, primary liver cancer (PLC) incidence-rates in the world, although hepatitis-B virus (HBV) is not endemic. This paper addresses the question of whether the PLC-incidence variation within Osaka Prefecture is due to differences in the prevalence of hepatitis-C virus (HCV) infection. The screening data of antibody to HCV (anti-HCV) and of hepatitis-B virus antigen (HBsAg) in 111,069 male blood-donors, and the incidence data of male PLC obtained from the Osaka Cancer Registry were examined. In a multiple-weighted regression analysis, the age-standardized incidence rate of PLC in the 61 counties within Osaka was correlated significantly with the age-standardized prevalence of anti-HCV with adjustment for that of HBsAg (regression coefficient [RC] = 7.26, P < 0.0001). This finding was consistent with the relationship between the PLC incidence rate and the prevalence of high-titer (> or = 2(12)) anti-HCV (RC = 11.18, P < 0.0001). There was significant association between the prevalence of HBsAg and the PLC incidence rate with adjustment for that of anti-HCV (RC = 7.08, P = 0.018). These findings suggest that the PLC-incidence variation within Osaka is correlated with the geographic pattern of HCV infection as well as that of HBV infection among the residents.