Elevated risk for male breast cancer after occupational exposure to gasoline and vehicular combustion products

Background Automotive gasoline contains benzene, I,S-butadiene, 1,2-dibromo ethane and 1,2-dichloroethane, and the combustion products include certain polycyclic aromatic hydrocarbons, all of which have shown mammary gland car cinogenicity irt long-term bioassays. It is the aim of this paper to invest igate whether men occupationally exposed to gasoline and its combustion pro ducts have an elevated risk of breast cancer: Methods A nationwide register based case control study on male breast cance r morbidity was established among members of a pension fund, compulsory for all employees. Employment histories were reconstructed for each of 230 cas es and 12,880 control subjects based on computerized records. The odds rati os, adjusted for socioeconomic status, were estimated by conditional logist ic regression analysis. Results When a lag time of at least 10 years was included, the odds ratio f or breast cancer among men with over three months of employment in trades w ith potential exposure to gasoline and combustion products was 2.5 (95% con fidence interval: 1.3-4.5). Among men younger than 40 years at the time of first employment, the odds ratio was 5.4 (2.4-11.9). Conclusions This study supports the hypothesis that occupational exposure t o gasoline vapors and combustion products may! play a role in the causation of male breast cancel: This hypothesis warrants further evaluation particu larly in women. Am. J. Ind. Med. 37:349-352, 2000. (C) 2000 Wiley-Liss, Inc .