Environmental associations and histopathologic patterns of carcinoma of the lung: the challenge and dilemma in epidemiologic studies

An update of histopathologic classification schemes is provided for carcinoma of the lung and factors that influence proportional distributions of cell types, i.e., sources and preparations of tissue specimens, observer variability, and use of secondary sources of information. Consideration is given to the natural history and to current knowledge of the demographic characteristics of cell types of carcinoma of the lung. A review of studies reporting histopathologic associations with environmental exposures suggests that no single type of carcinoma of the lung is specifically associated with exposure to tobacco smoke, arsenic, or beryllium. Furthermore, studies concerned with exposure to asbestos, chloroethers, chromates, nickel, vinyl chloride, and radioactivity lack sufficient information to conclude definitively that only one specific lung cancer cell type is associated with these exposures. In conclusion, an exclusive association of a single cell type of carcinoma of the lung with exposure to the physical or chemical agents reviewed has not been demonstrated.