Occupational exposure to endocrine-disrupting compounds and biliary tract cancer among men.

OBJECTIVES This study investigated the association between cancer of the extrahepatic biliary tract and exposure to endocrine-disrupting compounds. METHODS Altogether 183 men with histologically confirmed carcinoma of the extrahepatic biliary tract and 1938 matched controls were interviewed between 1995 and 1997 in the frame of an international multicenter case-control study in six European countries (Denmark, France, Germany, Italy, Spain, and Sweden). Self-reported job descriptions were converted to semiquantitative variables (intensity, probability, and duration of exposure) for 14 endocrine-disrupting compounds. The cases were compared with 1421 population controls and 517 colon adenocarcinoma patients. Odds ratios (OR) and 95% confidence intervals (95% CI) were obtained with unconditional logistic regression and adjusted for age, country, and gallstones. RESULTS Occupational exposure to endocrine-disrupting compounds resulted in an OR of 1.4 (95% CI 1.0-2.1) with no dose-effect relationship for cumulative exposure (low: OR 1.3, 95% CI 0.6-3.0; medium: OR 1.5, 95% CI 0.8-2.7; high: OR 1.4, 95% CI 0.9-2.4) (only index participants). The elevated risk was restricted to extrahepatic bile ducts and ampulla Vateri (OR 1.7, 95% CI 1.0-2.6). The adjusted OR for cancer of the extrahepatic biliary tract after exposure to polychlorinated biphenyls was 2.8 (95% CI 1.3-5.9, only index participants). CONCLUSIONS The data show some associations between exposure to endocrine-disrupting compounds in the workplace and the risk for cancer of the extrahepatic biliary tract among men, particularly for the extrahepatic bile duct and ampulla of Vater. Polychlorinated biphenyls could possibly be a strong risk factor.