Lung carcinoma by histologic type in coal miners.

Histologic types of lung carcinoma were studied in 171 coal miners in the National Coal Workers' Autopsy Study. These miners had an average underground mining tenure of 29 +/- 14 years and an average smoking history of 31 +/- 23 pack-years. The proportion of carcinomas by cell type were: squamous cell carcinoma, 30%; adenocarcinoma, 27%; small-cell undifferentiated carcinoma, 26%; large-cell undifferentiated carcinoma, 9%; and other carcinomas, 8%. More tumors were observed in the right lung and in the upper lobes of both lungs than in the left lung and in the lower lobes of both lungs, respectively. The majority of the tumors were centered on cartilaginous airways (81%) as compared with the peripheral regions of the lung (19%). Squamous cell carcinomas predominated in the older miners and in larger airways. Adenocarcinomas were more common in the peripheral lung. No significant interaction was demonstrated between cell type and years of underground mining. The data indicate that lung carcinoma in coal miners differs little in its pathologic features from men in the general population who smoke cigarettes. No effect of coal mine dust exposure on lung carcinoma histogenesis was demonstrated.