Tobacco smoking as a possible etiologic factor in bronchiogenic carcinoma.

General Increase.--There is rather general agreement that the incidence of bronchiogenic carcinoma has greatly increased in the last half-century. Statistical studies at the Charity Hospital of New Orleans (Ochsner and DeBakey), (1) the St. Louis City Hospital (Wheeler) (2) and the Veterans Administration Hospital of Hines, Ill. (Avery) (3) have revealed that at these hospitals cancer of the lung is now the most frequent visceral cancer in men. Autopsy statistics throughout the world show a great increase in the incidence of bronchiogenic carcinoma in relation to cancer in general. Kenneway and Kenneway, (4) in a careful statistical study of death certificates in England and Wales from 1928 to 1945, have presented undoubted evidence of a great increase in deaths from cancer of the lung. In this country statistics compiled by the American Cancer Society show a similar trend during the past two decades? Tobacco as a Possible Cause of Increase.--The suggestion that smoking, and in particular cigaret smoking, may be important in the production of bronchiogenic carcinoma has been made by many writers on the subject-even though well controlled and large scale clinical studies are lacking. Adler (6) in 1912 was one of the first to think that tobacco might play some role in this regard. Tylecote, (7) Hoffman, (8) McNally, (9) Lickint, (10) Arkin and Wagner, (11) Roffo (12) and Maier (13) were just a few of the workers who thought that there was some evidence that tobacco was an important factor in the increase of cancer of the lungs. Muller (14) in 1939, from a careful but limited clinical statistical study, offered good evidence that heavy smoking is an important etiologic factor. In 1941 Ochsner and DeBakey (15) called attention to the similarity of the curve of increased sales of cigarets in this country to the greater prevalence of primary cancer of the lung. They emphasized the possible etiologic relationship of cigaret smoking to this condition. In a recent paper Schrek (16) concluded that there is strong circumstantial evidence that cigaret smoking is an etiologic factor in cancer of the respiratory tract and finds that his data are in agreement with the results of a preliminary report presented by Wynder and Graham at the National Cancer Conference in February 1949. (17) Purpose of Study.--The purpose of the present study was to attempt to determine, so far as possible by clinical investigations, statistical methods and experimental studies, the importance of various exogenous factors that might play a role in the induction of bronchiogenic carcinoma. In this regard we intended to learn the relative importance of previous diseases of the lungs, rural and urban distribution of patients, various occupations and hereditary background as well as smoking habits. By obtaining all this information, we hoped to determine whether any of these factors, either singly or in combination, have had an effect in increasing the incidence of bronchiogenic carcinoma. In the present paper the chief emphasis will be placed on our findings in regard to smoking. METHOD OF STUDY The results of this study are based on 684 cases of proved bronchiogenic carcinoma. It should be emphasized that the results in this report have not been obtained from hospital records since we learned at the outset of our study that the routine records did not supply satisfactory answers to our questions. It was therefore decided to seek the desired information by special interviews. Six hundred and thirty-four patients reported on in this paper have been personally interviewed, and in 33 cases we obtained the information by mailing a questionnaire. (18) In the remaining 17 cases information for the questionnaire was obtained from a person who had been intimately acquainted with the patient throughout his adult life. Through the cooperation of many hospitals and physicians throughout all parts of the country who permitted us to interview their patients, it is felt that a fairly good cross section of the entire United States has been obtained. …