Histopathologic findings of lung carcinoma in German uranium miners

BACKGROUND. This study evaluates the histopathology of lung carcinoma in re lation to underground radon exposure. METHODS, Two hundred forty uranium miners of the former Wismut Company in E astern Germany with histologically or cytologically confirmed primary lung carcinoma were recruited from 3 study clinics between 1991 and 1995. Inform ation on smoking history was obtained by personal interviews, whereas job h istories were derived from original payrolls provided by the Wismut Company . Quantitative estimates of occupational radon exposure were based on a job -exposure matrix. RESULTS, Squamous cell carcinoma (SqCC) was the predominant cell type (43%) , followed by adenocarcinoma (AC; 26%), small cell lung carcinoma (SCLC; 23 %), and other cell types (8%). Nearly all patients were smokers. Time since first occupational exposure was 42 years on average, the mean cumulative r adon exposure 506 working level months. Adenocarcinoma appeared to be more likely than both SCLC and SqCC among miners with low cumulative radiation e xposure, long time since first exposure, an older age at diagnosis, and amo ng ex- and never-smokers. In current smokers, lung carcinomas developed at a much lower level of radiation exposure than in ex- and never-smokers. The increase in the relative frequency of SCLC and SqCC at the expense of AC w ith increasing cumulative radiation exposure was more pronounced among ex- and never-smokers and seemed to be masked among current smokers. CONCLUSION, The authors' data suggest that all cell types were associated w ith radon exposure, but high radiation exposure tended to increase the prop ortion of SCLC and SqCC. Cancer 2000;89:2613-21. (C) 2000 American Cancer S ociety.