Histologic differences in occupational risks of lung cancer incidence.

A five-year total community study of lung cancer incidence by occupation revealed that 1) virtually all the cases occurred in smokers; 2) all major histologic types of lung cancer were strongly associated with smoking behavior; 3) in most high-risk occupations the significant elevations of risk were limited to one or two histologic types, a specificity suggestive of the importance of workplace carcinogen exposure; and 4) both sensitivity and specificity of the search for occupations with lung cancer hazards were greatly increased by use of histologic type rates rather than total lung cancer rates. The epidemiologic differences among histologic types suggest that the lung cancers might be a group of neoplastic diseases which share a major risk factor (smoking) in common but which differ in respect to exposure to other carcinogens. Eventual control of our lung cancer epidemic will require the allocation of much greater resources to documentation of the occupational risks.