Epidemiologic patterns in lung cancer by histologic type.

Three thousand and ninety-seven lung cancer patients interviewed in different U.S. hospitals in 1977-1984 were classified into Kreyberg I and Kreyberg II categories. In both sexes, Kreyberg II patients were found to be younger and more frequently Jewish; among the male patients only, Kreyberg II cases were higher in educational and occupational level. These differences remained when the effect of cigarette smoking was controlled. Study data showed an increase in the frequency of Kreyberg II cases over time, and significantly, a decrease with younger age of the Kreyberg I:Kreyberg II ratio in both sexes. It is concluded that the observed secular increase in Kreyberg II is real and not merely due to changes in diagnostic methodology. On the basis of demographic differences noted, possible etiologic factors that may have contributed to the recent changes in lung cancer distribution by cell type are suggested.