Primary liver cancer and occupation in men: A case-control study in a high-incidence area in northern Italy

The objective of our study was to evaluate the association between occupati on and risk of liver cancer. A hospital-based case-control study was carrie d out during 1997-1999 in the Province of Brescia, a highly industrialized area in Northern Italy with a high incidence of this neoplasm. The cases we re 144 male patients with incident liver cancer (96% hepatocellular carcino ma). Controls were 283 male patients, matched to cases on age (+/-5 years), period and hospital of admission. Information on lifetime occupational his tory and alcohol consumption was obtained via interview. Specific occupatio nal exposures to pesticides, solvents and other suspected hepatocarcinogens were evaluated. A blood sample was collected to detect hepatitis B and C i nfections. Odds ratios (OR) of occupational exposure and 95% confidence int ervals (CI), adjusted for age, residence, education, heavy alcohol intake, hepatitis B surface antigen and hepatitis C virus antibodies positivity wer e computed. A statistically significant increased OR was observed for emplo yment in repair of motor vehicles (OR 3.7; 95% Cl 1.1-12.3; 9 exposed cases , 10 exposed controls). Increased ORs, although not statistically significa nt, were found for field-crop farm workers, food and beverage processors, b lacksmiths and machine-tool operators, electrical fitters, clerical workers , manufacture of industrial machinery and personal and household services. A slightly increased OR was noted in workers exposed to toluene and xylene (OR 1.4; 95% Cl 0.7-3.0, 23 cases, 36 controls); the OR was 2.8 (95% Cl 1.0 -7.6, 11 cases, 12 controls) for 20 or more years of exposure and 2.0 (95% Cl 0.9-4.1, 21 cases, 28 controls) for 30 or more years of time since first exposure. The increase in OR seemed to be independent from that of alcohol or viral infections. Our study showed that the role of occupational exposu res in liver carcinogenesis is limited. However, prolonged exposure to orga nic solvents such as toluene and xylene may represent a risk factor for liv er cancer. (C) 2001 Wiley-Liss, Inc.