[Bronchopulmonary precancerous conditions and tumors--risk groups from the occupational medicine viewpoint]

Risk groups with regard to bronchopulmonary precancerous and tumor diseases of occupational origin can be deduced from current occupational disease statistics. Most prominent are those working with asbestos. Each year about 250 asbestos-associated bronchial carcinomas and 400 mesotheliomas are recognized and compensated; the tendency is increasing. Because of the long latency time, the frequency peak will probably be reached in about 15 years in spite of the prohibition of asbestos usage. The second place is probably taken by malignomas among the underground uranium mine workers in Thuringia and Saxony (SDAG Wismut). Next come bronchial carcinomas with silicosis (carcinoma in scar tissue) after exposure to chromium(VI) and arsenic compounds as well as various other chemicals and metals. Dose-activity relationships are significant for all occupational carcinogenic agents, as there are also often syncancerogenic influences (especially smoking). From the data on previous loading, high risk groups, for example, among the insulation workers exposed to asbestos or uranium miners in the so-called "wild years", can be defined. A suitable screening method for the detection of bronchopulmonary tumors in the early stages has not yet been established. Medical checkups for the respective risk groups concentrate on the early X-ray detection of circular foci. As shown by recent studies, cytological sputum diagnosis, (fluorescence) bronchoscopy, and BAL cytology must be employed much more frequently in the high risk groups so that the prognostically more favorable stages of preneoplasm and carcinoma in situ can be detected and possibly treated curatively. These procedures are currently reaching a considerably higher sensitivity with the help of modern molecular biology techniques (e.g. detection of tumor-associated genetic changes and gene products). This contributes to an improvement in surveillance examinations with increasing detection of the curable early forms of tumors. However, only the further development of primary prevention, i.e. the greatest possible minimization or, if possible, total elimination of contact with carcinogenic agents and the consequent control of occupational protection will lead to a drastic reduction in the occupational risk of cancer.