Tobacco smoking as an etiologic factor in disease; cancer.

Summary and Conclusions The smoking habits of 82 men with cancer of the lung and 73 men with cancer of the larynx and pharynx were compared with the smoking habits of a control group of 522 patients with miscellaneous tumors. A relatively high percentage of cigarette smokers was found among the patients with cancer of the respiratory tract, as compared to the control. This positive correlation between the incidence of cigarette smoking and the incidence of cancer of the respiratory tract appeared to be both statistically and biologically significant. There is strong circumstantial evidence that cigarette smoking was an etiologic factor in cancer of the respiratory tract.