HEPATITIS-B AND C VIRUS-INFECTION, ALCOHOL-DRINKING, AND HEPATOCELLULAR-CARCINOMA - A CASE-CONTROL STUDY IN ITALY

We performed a case-control study to assess the association of hepatoc ellular carcinoma (HCC) with hepatitis B virus (HBV) and hepatitis C v irus (HCV) infection and alcohol drinking. We recruited as cases 172 s ubjects with an initial diagnosis of HCC, who were admitted to the two major hospitals in the province of Brescia, northern Italy, and 332 s ubjects, sex-, age-, and hospital-matched, who were admitted to the De partments of Ophthalmology, Dermatology. Urology, Cardiology, and Inte rnal Medicine, as controls. Of the HCC cases, 23.8% were positive for HBsAg and 37.8% for HCV RNA; among the controls, 5.4% were positive fo r HBsAg and 4.8% for HCV RNA. History of heavy alcohol intake (>80 g o f ethanol per day for at least 5 years) was found among 58.1% of the c ases and among 36.4% of the controls. The relative risks (RRs) for HBs Ag, HCV RNA positivity, and heavy alcohol intake were, respectively: 1 1.4 (95% confidence interval: 5.7-22.8), 23.2 (95% confidence interval : 11.8-45.7), and 4.6 (95% confidence interval: 2.7-7.8). Positive int eractions (synergisms) between both HBsAg positivity and HCV RNA posit ivity and heavy alcohol intake were found, suggesting more than additi ve effects of viral infections and alcohol drinking on the risk of HCC . Infection with HCV genotype 1b showed a higher risk than type 2 (RR = 2.9; 95% confidence interval: 0.9-10), suggesting a major role for t he former type in causing HCC. On the basis of population attributable risks (AR), heavy alcohol intake seems to be the single most relevant cause of HCC in this area (AR: 45%), followed by HCV (AR: 36%), and H BV (AR: 22%) infection.