Hepatitis viruses, alcohol, and tobacco in the etiology of hepatocellular carcinoma in Italy.

Mortality rates of hepatocellular carcinoma (HCC) are high in Italy compared with other Western countries. To elucidate further the role of hepatitis B virus (HBV), hepatitis C virus (HCV), alcohol drinking, and tobacco smoking in the etiology of HCC, we carried out a hospital-based case-control study in two areas of Italy: the province of Pordenone in the Northeast and the town of Naples in the South. A total of 229 HCC cases (median age, 66 years) and 431 controls (median age, 65 years) answered a questionnaire and provided blood samples between 1999 and 2002. Odds ratios (OR), percent attributable risks, and corresponding 95% confidence intervals were computed using unconditional multiple logistic regression. ORs for hepatitis B surface antigen (HBsAg) positive versus HBsAg negative and for anti-HCV antibody positive versus anti-HCV antibody negative were 20.2 and 15.6, respectively. Positivity for both markers was associated with an OR of 51.6. Sensitive molecular techniques applied to sera in a subset of HCC cases disclosed a very small number of occult hepatites. Maximal lifetime alcohol intake of > or =35 versus <7 drinks/wk was associated with an HBV/HCV adjusted OR of 5.9. Tobacco smoking was unrelated to HCC risk overall but seemed to enhance HCC risk among virus carriers. Overall, 61% of HCC were attributable to HCV, 13% to HBV, and 18% to heavy alcohol drinking. In conclusion, our study confirms the importance of HCV in HCC etiology in Italy where the widespread dissemination of the virus dates back four or five decades.