Occupational risk factors for urothelial carcinoma: agent-specific resultsfrom a case-control study in Germany

Background This multicentre population-based case-control study was conduct ed to estimate the urothelial cancer risk for occupational exposure to arom atic amines, polycyclic aromatic hydrocarbons (PAH), and chlorinated hydroc arbons besides other suspected risk factors. Methods In a population-based multicentre study, 1035 incident urothelial c ancer cases and 4298 controls matched for region, sex, and age were intervi ewed between 1991 and 1995 for their occupational history and lifestyle hab its. Exposure to the agents under study was self-assessed as well as expert -rated with two job-exposure matrices and a job task-exposure matrix. Condi tional logistic regression was used to calculate smoking adjusted odds rati os (OR) and to control for study centre and age. Results Urothelial cancer risk following exposure to aromatic amines was on ly slightly elevated. Among males, substantial exposures to PAH as well as to chlorinated solvents and their corresponding occupational settings were associated with significantly elevated risks after adjustment for smoking ( PAH exposure, assessed with a job-exposure matrix: OR = 1.6, 95% CI: 1.1-2. 3, exposure to chlorinated solvents, assessed with a job task-exposure matr ix : OR = 1.8, 95% CI: 1.2-2.6). Metal degreasing showed an elevated urothe lial cancer risk among males (OR = 2.3, 95% CI : 1.4-3.8). In females also, exposure to chlorinated solvents indicated a urothelial cancer risk. Becau se of small numbers the risk evaluation for females should be treated with caution. Conclusions Occupational exposure to aromatic amines could not be shown to be as strong a risk factor for urothelial carcinomas as in the past. A poss ible explanation for this finding is the reduction in exposure over the las t 50 years. Our results strengthen the evidence that PAH may have a carcino genic potential for the urothelium. Furthermore, our results indicate a uro thelial cancer risk for the use of chlorinated solvents.