[The epidemiology of parotid tumors. A case control study]

From 1989 to 1991 a case-control study was conducted at the ENT Department of the University of Heidelberg. One hundred and one patients with parotid tumors (84 benign and 17 malignant) were compared with 404 control patients in a matched-pair study design. Using a questionnaire containing 21 sides, all interviews were conducted by the same interviewer. The questionnaire contained such aspects as "professional surroundings and exposure to environmental dusts", "consumption of tobacco and alcohol", "living area", "nutrition", "hobbies" and "social life". Questions about personal and familial diseases, consumption of medicine and exposure to irradiation were also asked. Differences in exposure to occupational dusts were seen. The highest relative risk (RR) for developing a parotid tumor was seen with weekly exposure to nickel during a period of more than 10 years (RR = 6.0; confidence interval, 1.4-25.5). Similar risk was found with exposure to chromium, asbestos and cement dusts (RR chromium = 3.4; confidence interval, 0.9-14.5; RR asbestos + cement = cement 3.0, confidence interval 1.0-8.9). Higher relative risks were also detected in patients exposed to diagnostic dental x-rays.