Document rBXrYwoM4Mb06Rz3Y4eKGDb47

FILE NAME: Smoking (SMOK) DATE: 1950 June DOC#: SMOK009 DOCUMENT DESCRIPTION: Journal Article - Cancer of the Lung: Consideration of Incidence and Etiology k J - it Na N E W Y O R K M EDICINE / '(Al'lOtl o f the M e d ic a l S o c ie ty of th e C o u n ty of N e w Y o r k '"A 7u I jl'fW-' JL 1 I \ ft | " ;, w ....... *, / JA CANCER OF THE LUNG: ,v CONSIDERATION OF INCIDENCE AND ETIOLOGYs By W h .i.i a .m L. W vrsox, M .I).' $ Introduction : Kvery specialist naturally con siders his professional work to be valuable and important. There seems, however, to be valid reason for jiving serious consideration to the problem of lung cancer. Perhaps the subject warrants considered attention because it has so recently (1933) been brought from the ranks of hopeless new growth into the family of cur able cancers. Its very newness, in this respect, suggests the need for searching discussion of the problem, which in turn may well lead to a method of diagnosis for this disease while it is yet in its beginning phase. The need for prompt diagnosis becomes more compelling when we are made aware that acceptable, almost routine, surgical management of the disease is already at hand, and an insignificant operative mortality and an appreciable five year salvage rate can reasonably he assured the patient and his phy sician. ` PSorecsieetnyteodf atthethCeouMntayrd(iit 2N~ .ewP'5Y0orkm.eeting of the Medical 5 AAtstseoncdia.,te TPhroorfaecsiscor SuorfgiScatul geSreyr,viNcee,w 'MYeomrkoriaUl nivHeorsspitiyta--l;- Bellevue Medical Center. Hcsides the fresh concept of lung cancer brought about by Dr. (iraham's pioneer pneu monectomy in 1933, cancer of the lung war rants attention at this time because the inci dence of this highly fatal form of cancer is most certainly increasing at a startling rate. 'The time has arrived, perhaps, when we should not mince words with the public, or our col leagues, internes, and students because the facts seem to indicate clearly that cancer of the lung is a much more common disease today than it was twenty-five years ago. Incidence. There are numerous possible ex planations for the increased incidence of this deadly disease. First of all, there is an increased awareness of cancer in general on the part of the public and the medical profession. Also, the prominent symptomatology of cancer of the lung lias been well publicized. The antibiotics, penicillin and aureomycin, undoubtedly have played an important role in more frequent and more accurate diagnosis of cancer of the lung. In the past pneumonia in elderly males was a NEW Y ORK MEDICINE I S common cause ol death, and undoubtedly main ut t'tose so-called pneumonias were cases ol pneumonitis secondary to bronchogenic cancer. Nevertheless, the death certificate classed the death as one due to pneumonia. Nowadays, the antibiotics do a great deal to relieve this pneumonitis. I'ewer patients die <>i the inflammatory complications of (.nicer of the hint; in its early stages at least, and therefore mam of them receive further clinical investigatin i which leads to an accurate diagnosis of cancer of the lung. I should estimate that bet ter than 77 per cent of the patients now coming to us with cancer of tile lung have had a pre vious cluneal diagnosis ot virus pneumonia. 1 his a; - diagnosis lias often been substant . oal in competent radiographic studies of the chest. ( )t course, a so-called atypical pneumonia m a patient over forty years of age which recurs, or fails to resolve, should be viewed with considerable suspicion. Perhaps the increase m life expectancy brings into the lung cancer age a considerable number )! patients susceptible to this disease, and one should therefore expect an actual increase in the number ot its victims. Prolonged exposure to factors of chronic irritation, such as smok ing, dust, cifv gas fumes and industrial factors also may piax a part in the increased incidence ot thi; disease. Improved methods of diagnosis due to rou tine chest x-ray studies, extension of hospitali zation, easily available bronchoscopy, the recog nition of specialists trained in thoracic diseases, routine bronchial cytology studies, together with public knowledge ot the possible significance of chronic cough, blood spitting, and so forth, all may prove to he factors in explaining the rapid increase in the number of patients com ing to us with cancer of the lung. Coupled with the foregoing generalizations is the im portant factor of better cancer teaching at the medical school level. Fig. I, compiled from the mortality statistics of ID.1.1 and the vital sta tistics ot the l mted States of 194b, reveals a very sharp rise in respiratory system cancer in the thirteen tear period following the first sur gical cure of cancer of the lung. Table I, compiled by the Statistical Research 16 J U N E 20, 1950 Section of the American Cancer Society, reveals a summary of the lung cancel' deaths in the l nited States during the year 1947. There were 1 deaths due to Qancer of the lung and this represents a death rate per hundred thousand of 10.2. More than twelve per cent of all male cancer deaths, and 3.2 per cent ot all female cancer deaths can be charged to cancer of the lung--or 7.7 per cent of all cancer deaths ( 1947). 1-iourk I RESPIRATORY SYSTEM CANCER DEATH RATES 8Y AGE United S totee, 1953 and I94S 30 1 g* *0 1 " 30- >? T aiil k I CANCER OEATHS ANO OEATH RATES BY AGE. SEX, AND SITE Z i) United S 10te*-l947 i . Cancer of tun? and Bronchui (International List Not. 47 c ond 47 BOTH SEXES MALE Number of Deoth* Percent of oil Cancer Deoth** Deoth Rot*** Numbor of Deoth* Percent of oil Mole Concer OeottW ALL AGES 14,666 7.7 10.2 I f , 546 123 16 1 I aI oI ' FEMALE Numbor of froths Percent of oil Remote Concer 0*oth* Death Rote** 3.120 3 2 4 3 *Ptcnt conctr death* ot th* lung ond bronchu* in o specitiad group ot off cancer deoth* in that group * * Role* are ttie number ot deoth* in c specified group per 100,000 estimated midyear population of that group, including the armed forces overseas. Source: Vital Statistics of the united State*. 1947 Statistical Research Section, Medico! end Scientific Oept. American Cancer Sac. Now, if the foregoing reasons are used to explain the increased incidence of cancer of the lung, it should he equally valid to use these data to show an increase in the other common types of cancer. Hut, from fig. 11, we see that from 1933 to 194b the incidence of cancer ot the lung in males has shown a sharp in crease in rate without a corresponding increase in the number of cancers of the stomach, pros tate, bladder, skm, esophagus, and so forth, l'ig. ill illustrates the fact that cancer of the lung in females has increased in relation to malignant disease of the ovary, breast, uterus, and stomach. F icure II WHITE MALE CANCER DEATH RATES* Un^ed States, '9 3 3 -1 94 6 BY S IT E In at least two large medical centers in the l.'nited States, it is now reported that cancer ot the lung is a more common disease than cancer of the stomach, so that in these two in stitutions, at least, a relative increase m the frequency of cancer of the lung seems to hate taken plaee. The figures at Memorial Hospital clearly substantiate these reports as shown in fig. 1Y, indicating the relative incidence ot can cer of the lung eases admitted to Memorial Hospital in relation to cancer of the stomach and cancer of the prostate. 1`roni 193f> to 1933, F lO fR K IV MEMORIAL HOSPITAL INCIDENCE CANCER OF LUNG - STOMACH - ' L ' ' " 1 F icurk I I I WHITE FEMALE CANCER DEATH RATES* BY SITE United States , 1953 - 1946 a vert small number of lung cancer patients were seen at Memorial Hospital, but from 1935 to 1940 there teas a sharp rise in the inci dence, and shortly after 1940 the admissions for cancer of the lung crossed the line for cancer of the stomach and went on to a precipitous rise in 1945, and continued through 1949, when a total ot 193 patients with cancer of the lung were seen at Memorial Hospital. It may be of significance that the increase starting in 1935 was more or less coincidental with Dr. (haham's report ot the first successful pneumonec tomy lor cancer of the lung, and the almost vertical rise from 1945 on coincides with the general introduction of the antibiotics, peni cillin, streptomycin and aureomycin. Etiologv: Macklin, in his monograph on this subject, "W hat Causes Primary Cancer of the hung?," makes the statement that his data in dicate the thesis that primary carcinoma of the NEW YORK MEDICINE 17 lung is due to chronic inflammatory changes in :hc lung is unproved. He further states that the role ot chronic bronchitis as a causative agent in the production ot pulmonary cancer lias not been demonstrated. He also believes that emphysema, bronchiectasis, asthma, pulmonan abscess, and so forth, when found asso ciated with cancer of the lung are probably of coincidental interest only. Tuberculosis, pneu monia, and war-gassing have not been proved to he unequivocal factors in the inception of can cer of the lung. F ioukk V Occupational relation to primary cancer of tl e lung is difficult to prove, and efforts along this line hate for the most part been unsuccess ful. The sole exception to this rule being the pulmonarv cancer which occurs iu the miners of Schneeherg and Joaehimstal in Hohemin, the incidence of which is so high in comparison with that of cancer of the lung in other localities, and so high in comparison with the incidence among the neighbors ot the victims who are not working in the mines, that there seems to be little doubt that this occupation is strongly productive of cancer of the lung. Hut even the effect ot close imbreeding and heredity have not been exonerated as possible factors. Chromium dust, iron oxide in silica dust, exposure to coal gas'in the air or coal tar on the skin, and the preparation and sale of tobacco have all been brought forward as possible causes of cancer of the lung. A few cases of asbestosis associated with primary cancer of the T8 JUNE 20, 1950 lung have been reported. Pneumoconiosis has been said to cause cancer of the lung, and yet South African miners have a high incidence ot pneumoconiosis, but a comparatively low inci dence of cancer of the knfg. I have two brothers as patients, each of whom worked thirty years or more in the anthracite coal mines; one has cancer of the lung, and the other has anfhracosis and no cancer. Tarred roads, roentgen rays, motor exhaust fumes, and so forth, have all been suggested as possible causes. When we review all the theories on the cause of pulmonary cancer, we find that not one supposed cause has been proved to be a real cause, and that none of the alleged causes have been investigated with sufficient statistical ac curacy to enable the observer to pass an opinion carrying any great weight. Perhaps there is good reason to believe that there is no one cause for cancer of the lung, but certainly there are additive factors which lead to the inception of cancer of the lung; that is, a number of etio logical factors working together over a period of years probably result in the eventual incep tion of cancer in sensitive tissues which have become altered due to the degenerative changes of age. In this regard, considerable interest has been evidenced in the recent past regarding the significance of prolonged cigarette smoking as a possible factor in the inception of cancer of the lung. Schrek, in the January, 1950, issue ot Cancer Research, discusses tobacco smoking as an etiological factor in cancer and concludes: "A relatively high percentage of cigarette smok ers was found among the patients with cancer of the respiratory tract as compared to the con trol. This positive correlation between the inci dence of cigarette smoking and incidence of am eer of the respiratory tract appeared to be both statistically and biologically significant. There is strong circumstantial evidence that cigarette smoking was an etiological factor in cancer of the respiratory tract." In the United States some recent publicity was given to this subject of smoking and cancer by Dr. Graham's group at St. Louis, and, al though it was not mentioned, one hundred, or one-half of the cases studied, came from Me- ( Continued on page 40) ( ( , 0 1 1 l i ?! l i t i t f I Hi l l p t l f / C 1 8 ) mori.il Hospital, and the figure as first reported seemed to indicate that f)7.'i per cent of our eases were heart' smokers and none of our pa tients with cancer were non-smokers. These figures were widely quoted, hut unfortunately they are inaccurate. Tables II, III and I V show our figures on that series of 100 cases ot cancer of the lung in relation to smoking. Table 11 is, of course, open to criticism, but it is the classification which we finally selected. W e de cided to use three groups: '1 he first group, the non-smokers; the second group, the moderate smokers, or patients who smoked up to 20 ciga rettes per day for twenty years or more with inhalation ; and the third group, the heavy smok ers (chain smokers), or the patients who smoked from 20 to 60 cigarettes per day for twenty or more years with inhalation. We ar bitrarily decided, for purposes of comparison, that one pipe was the equivalent of two and a half cigarettes and one cigar the equivalent of five cigarettes. T.uu.i: H MFMORIAL HOSPITAL SMOKING AND LLX d CANCKR CLASSIFICATION I. Non smokers. II. Moderate smokers; l p to 20 cigarettes per day for 20 years or more with inhala tion. III. Heavy smokers: 20 to 60 cigarettes per day for 20 or more years with inhalation. (1 p pe=2% cigarettes; 1 cigar 5 cigarettes) In 'Table HI, for the Males, we see that in Class I (non-smokers) in the Control Series eleven per cent of men did not smoke, and in the Cancer Series five per cent of men did not smoke; in Class II (moderate smokers) in the Control Series 70 per cent and in the Cancer Series 5K per cent. Hut in Class 111 (heavy smokers) 19 per cent in the Control Series and 27 per cent, or nearly twice the previous figure, in the Cancer Series. We think this latter figure is of considerable significance. And, as can he seen in 'Table IV, for the Females, 60 per cent did not smoke in the Control Series and 58 per cent in the Cancer Series. In Class II (moderate smokers) 37 per cent in the Control 40 JU N E 20, 1950 Series and 33 per cent in the Cancer Scries. Hut, when we come to Class 111 (heavy smok ers), only three per cent of the Control Series of women were classed a*, heavy smokers, but in the Cancer Series 17 per cent were heav_\ smokers. T.un.r: III SMOKING ANI) LUNG CANCKR MFMORIAL HOSPITAL MALLS Control ('.timer Class I-- Non Smoker . . . . 11% 5 0 Class II-- Moderate Smoker 70% 580 Class III-- Heavy Smoker . . 19% 370 T.vnu; IV MFMORIAL HOSPITAL SMOKING AND LI NG CANCKR KK M A L L S Control Ctitieer Class I-- Non Smoker . . . . 60% 530 Class II-- Moderate Smoker 37% 250 Class III-- Heavy Smoker . . 3% 170 si mmary It has been concluded from statistical studies that comparison of the smoking habits of victims of lung cancer with those of control cases ob tained by careful questionnaire affords strong grounds for suspecting the carcinogenic possi bilities of heavy, chronic smoking. Hut, how ever, strongly suggestive, they cannot afford in controvertible proof, especially in the eyes of smokers themselves. Chronic, heavy cigarette smoking may very well be an additive factor in the causation of lung cancer in sensitive in dividuals. However, the individual irritant it self may not be as significant as the chronicity of the patient's exposure to that irritant. In this respect, 1 suppose we are witnessing a vast human experiment never before carried out by man; namely, what will be the long range re sult on the human tissues and structures which come in contact with that chronic smoke stream. Hut, whether we indict cigarette smoking as a cause for cancer of the lung, or whether we admit that we do not know the actual inciting cause of cancer of the lung, the fact remains that the incidence of cancer of the lung has risen sharply since 1926.