Quantitative DNA. Comparative studies of a cellular marker for bronchogenic carcinoma

During the course of induction of bronchogenic carcinoma in a colony of standard-bred beagles, serial cytologic and biopsy material was obtained under direct bronchoscopy. Cytological changes followed the sequence from metaplasia to carcinoma, closely simulating those features observed in humans, but with subtle differences characterized as species variations. Quantitative DNA done by image analysis correlated directly with the severity of cytologic atypia and also corresponded well with data obtained from humans. Equivalent studies in human bronchogenic carcinoma have shown similar results and strongly suggest that graded hyperploidy accurately reflects atypia in the lung and qualifies as an interspecies tumor marker.