Histopathology studies were continued in order to identify the conditions under which silicotic lung lesions are accompanied by alveolar type II epithelial hyperplasia and associated with lung carcinomas. A pilot study of 300 autopsy cases was completed from a large population of uranium miners from the Saxony region in Germany, that received heavy exposures to silica and radiation. This population includes over 15,000 cases of silicosis and 5,000 cases of lung cancer, for which exposure histories and autopsy records are available for over 90% of cases. In this study, designed in collaboration with NIOSH and NCI epidemiologists, four pathologists independently classified epithelial proliferative lesions and lung cancers by histologic type. The autopsy cases were selected based on a hierarchical, stratified sampling scheme designed to sample cases with varying levels of exposure to radon and quartz dust. The levels of agreement between pathologist pairs ranged from 90.6% to 94.3% for small cell undifferentiated carcinoma, 87.8%-92.9% for squamous cell, 87.7%-95.1% for adenocarcinoma, and 85.4%-96.5% for large cell carcinoma. The data will be further analyzed and additional materials will be examined.
