Despite the numerous studies investigating the association between bladder cancer risk and occupational exposures, results are often inconsistent. In a case-control study performed at the University of Texas M.D. Anderson Cancer Center, we investigated the role of occupational risk factors in bladder cancer. The study included 604 histologically confirmed bladder cancer cases and 604 healthy controls matched to cases by gender, age and ethnicity. Lifetime occupation history was collected by in-person interview. Occupations and industries were then coded according to the occupational codes as defined in Dictionary of Occupational Titles . In addition, data collected also include prior regular (8 hours/week) and prolonged (at least one year) exposures to a defined list of substances. Participants are classified as positive or negative to these substances if they self-reported such an exposure or if they have occupational codes suggesting they had held a job within a relevant industry. Significantly increased bladder cancer risk was observed among agricultural production livestock and animal specialties industry groups (odds ratio [OR]=1.90, 95% confidence interval [CI] 1.03-3.49), occupation as waiters and bartenders (OR=2.84, 95% CI 1.05-7.72), occupations in medicine and health (OR=2.17, 95% CI 1.21-3.92), occupations in electrical assembling installing and repairing (OR=1.69, 95% CI 1.07-2.65), and occupations in communications (OR=1.74, 95% CI 1.00-3.01). When stratified by duration of employment, we observed that employment in general farming for more than 10 years was associated with a 9.58-fold (95% CI 2.18-42.05) increased risk of bladder cancer. Similarly, significantly increased bladder cancer risk was noted among workers employed in plant farming and miscellaneous agricultural occupations for 10 years or more with an increased OR of 7.99 (95% CI 2.36-27.07). We also analyzed data by occupational exposure to substances. An elevated bladder cancer risk was noted among subjects who had exposed to tar, mineral oil (OR=2.63, 95% CI 1.12-6.19), radioactive materials (OR= 2.70, 95% CI 1.00-7.24). Further, exposure to arsenic for 10 years or more was associated with a 4.54-fold increased risk (95% CI 2.15-9.58). Similar results were obtained for prolonged exposure to zinc (OR=4.39, 95% CI 1.24-15.61), pesticides, insecticides, herbicides (OR=3.20, 95% CI 1.58-6.47), fertilizers (OR=2.81, 95% CI 1.33-5.92), and wood dust (OR=3.79, 95% CI 0.99-14.53). In conclusion, our study adds to the current literature of occupational risk factors in bladder cancer. These results should facilitate identification of high-risk subgroups and have implications in bladder cancer prevention. Supported by NCI grants CA74880 and CA91846.
98th AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA