Document XOpqoY2DGMykjQ8ZaYgLRK6MG

FILE NAME: New York State & NY Times (NY) DATE: 1944 June DOC#: NY006 DOCUMENT DESCRIPTION: Journal Article - The Epidemiology of Cancer [Written by Dr. Levin of NY Dept of Labor] l'<;/. 3- uijwg-g^ mju!wy>:wq The Epidemiology of Cancer From the Viewpoint o f the Health Officer* MORTON L. LEVIN, M.D., D r.P.H., F.A.P.H.A. Assistant Director, Division of Cancer Control, New York State Department of Health, Albany, N. Y. CTIVITIES in cancer control by be of value in the application of cancer public health agencies need not control measures. The health officer and usually do not rest upon the recog who is interested in cancer control must nition of any epidemiological peculi also take stock of the modern advances arities of the disease, in the strict sense in the etiology of cancer and inquire ol tnat term. Tne necessity for per whether these now have any practical suading people who have symptoms to significance in the control of human seek medical care without delay, as cancer. well as the desirability of making it To review broadly the salient features easy for them to secure prompt diag regarding the occurrence of cancer in nosis and adequate treatment, are suffi man, the facts to be considered may be ciently well defined to furnish a secure classified under four general headings: foundation for public health action. (1) environmental or exogenous agents It is recognized that to accomplish these causing cancer; (2) the association of objectives with some degree of com cancer wdth other diseases: (3) evi pleteness is an undertaking of consider dences regarding intrinsic or constitu able magnitude, particularly if all tional factors affecting cancer incidence: persons who reach adult age must and (4) certain aspects of differential be included in the scope of the cancer mortality. program. It should be stated at the outset Because the task of reaching the that cancer of different parts of the entire adult population with any type body and of different pathological of control measure is manifestly great, character in the same part are different the health officer who plans a cancer diseases. Although for some purposes control program seeks to make the it is useful to consider all types of limited forces he can throw into the cancer together, throughout this dis field count for more than may be cussion differences in etiology and in expected of random action directed epidemiological features according to to the public at large. From experience site of cancer will appear. in the control of infectious disease it is evident tnat information regarding EXOGENOUS AGENTS CAUSING CANCER what people re most apt to develop IN MAN cancer or certain kinds of cancer would Attention in the laboratory investi gation of cancer is now focused on Presented before the Health Officers Section of the American Public H ealth Association At the Seventy-second Annual Meeting in New York, N . Y., October 12, 1943. the role of chemical carcinogens, and of x-ray, radium and ultra-violet radi ation in the causation of malignant [611] ~r f/l- * I ... :, - : .X ... : i ; ; : '.l*' s: TM:r::: :: :r: :i 612 A merican J ournal of P ublic H ealth June, 1944 tumors. In human cancer such agents have been identified chiefly in the small group of occupational cancers. The first such observation was made in England in 1775 by Percival P o tt1 who noted in chimney sweeps a greatly increased incidence of scrotal epitheli oma, caused by exposure to soot or some chemical contained in soot. The substances or agents now known to cause cancer in man include arsenic, tar, pitch, paraffin, petroleum oils and derived products, benzol, aniline dye compounds, roentgen rays, radium rays and ultra-violet rays, possibly asbestos, nickel carbonyl and chromates. What common property of these diverse chem icals and radiations makes them poten tially carcinogenic is not clear; possibly all act by interfering with cellular enzymes, as the work of Rhoads 2 sug gests. Most of these agents produce skin cancer. Aniline dve compounds cause chiefly cancer of the bladder; excessive exposure to radium salts has been known to cause bone sarcoma and carcinoma of the lung; leukemia may follow chronic benzol poisoning. With but few exceptions, the carcinogenic effect of these agents has been demon strated in experimental animals as well as in man. A survey of occupations listed3 according to exposure to various hazards shows 146 different occupations in this country in which exposure to known carcinogenic agents mav occur. How ever, the number of reported occu pational cancers is quite small. Hueper4 estimates that the total cases reported in the world literature is from 8.000 to 9,000, of which approximated 400 have been reported from the United States. A partial explanation for the small number of reported cases of occupa tional cancer may be the fact that, although the period of exposure neces sary to produce cancer may be as little as one year, the time from such expo sure until the appearance of the tumor may be as long as 30 years, averaging for some agents approximately 16 years, so that the tumor may not appear until long after the worker has changed his occupation. There is also a natural reluctance on the part of industrial management to release information on occupational cancer. Although pre ventive measures, including periodic ex aminations, have been adopted in some plants, especially in the aniline dye industry, often the hazards are not recognized or not properly guarded against. Exposure to aniline dye com pounds occurs not onlv in the dye industry but in many others, including plants handling rubber and those man ufacturing explosives. It is probable that the number of occupational cancers is greater than indicated by identified cases and that the enormous expansion of certain industries may further in crease this number in the future. Obviously, exposure to the carcino genic chemicals and radiations need not be occupational. Arsenic cancer of the skin has been observed following prolonged medicinal administration of Fowlpr'c cnlufjnn 3rd. in th? ^*r,Tcntine' from drinking water contaminated bv arsenic ores. The influence of ultra violet radiation is believed responsible for the higher general incidence of skin cancer in the South as compared with the North in this country, as well as for its high incidence among out door workers in the North. The relationship of carcinogenic chemicals and radiations to the common run of malignant tumore in man jc j> matter of speculation. It has been suggested that part of the increase in cancer mortality of modern times may be attributable to 'the increased exposure to 'such substances accom panying the industrial age. The diffi culties in the way of testing such a hypothesis may be appreciated from the fact that a chemicallvr' induced__ Vo!. 34 E pidemiology of Cancer 613 tumor does not differ histologically from one arising in the same organ apparently spontaneously, and that such a tumor may appear long after the chemical agent has been eliminated from the body. We may anticipate that a great deal of future investigations on the causes of cancer in man will center on the possible presence of chemical carcino gens in food, water, and dust. Although the significance of the known carcino genic agents in the etiology of the vast majority of human cancers is at present unknown, continued medical observa tion of workers exposed to carcinogenic agents, even after they have left the employment where such exposure oc curred, is clearly indicated. This is rarely done now and presents a field for possible public health action. DIFFERENTIAL CANCER MORTALITY AMONG SOCIAL-ECONOMIC GROUPS In addition to the small group of identified occupational cancers, a con siderable array of statistical evidence points to increased mortality from cer tain forms of cancer in those economic groups among which industrial workers are largely found. Stevenson 5 analyzed cancer mortality statistics for males in England and Wales on the basis of social-economic class, dividing the population into pro fessional workers, skilled workers, un skilled workers, and two inter mediate groups. A progressive in crease in cancer mortality wTas found in each " lower " social-economic group. This increase was confined to cancer of the skin, lip, larynx, and the ali mentary canal from mouth to pylorus. For these sites, the standardized rates in unskilled workers was twice that of professional workers. In married women, classified by husband's occupation, a similar though less marked relationship appeared for the same sites of cancer and also for cancer of the uterus, indi cating that factors other than those due directly to occupation must be considered in explaining these facts. In married women also, a reverse rela tion w'as found for cancer of the breast, ovary, and thyroid, in which the higher rates were in the higher classes. The same differences appeared among single females, classified by social-economic ' status. In this country, broadly similar findings have been reported by Knight and Dublin 6 in life insurance data, and by Whitney,7 for total cancer not sub divided according to site. In Massa chusetts, Lombard and Doering 8 found that the foreign born and those oi foreign parentage had higher mortality rates for buccal cavity and stomach cancer; but not for other sites. They concluded that a sufficiently close rela tionship exists between these nativity groups and the lower social classes of England to justify the opinion that eco nomic social conditions are a factor in the incidence of cancer. It is of interest that the first analysis of cancer mor tality by economic status in this country was made bv Charles V. Chapin 9 on the mortalitv returns of Providence. R. I., for 1865. He found the rate twice as high in the lower as compared with the higher economic class. Greater diagnostic accuracy in the medical care available to the higher income groups does not readily explain these differences in cancer mortality in social classes for the reason that better diagnosis increases rather than decreases the total number of recorded cancers. Also the types of cancer in whicfi tine differences are found include both easily diagnosed sites, such as the skin, and poorly diagnosed sites, such as the stomach. Moreover, one of the most accurately diagnosed forms of cancer, that of the breast, shows opposite social selection to that observed for almost equally easily diagnosed sites, such as the lip, the buccal cavity, U11&* -4 * 4 #' 614 A merican J ournal of P ublic H ealth June, 1944 h - -5' jj| % 5 7* , 1 W 4 - - --- - - f f *iT"'' "- ---- -- `-'.ttf*te?* !.?- -: " z. ~ * . j *. x . f :ttf % *4 *14 !>! \ ' 11 * -- - M TE_ ; ' ; . R i ill - - 1 ; -- j - ! U.` '; ' t * i i - - : t" | is! i .. _ - i t 1';:! ; {: and the uterus. Better therapeutic results might explain lower mortality from skin and lip cancer in the higher economic groups, but not lower mor tality from esophageal and stomach cancer, and certainly not the higher mortality from breast cancer in these groups. The differences in cure rates for stomach cancer in the best clinics as contrasted with the average would be insufficient to account for differences in cancer mortality as pronounced as those observed. The findings with respect to the higher cancer mortality in unskilled and industrial economic groups are f . ,* v-vi tk,-v1j fc*.-' . ,iMuc-u.v--s- 4L'xji.i;i fk*I-*..-- living conditions of these groups in volve greater exposure to " exogenous carcinogens." Aside from specific occu pational carcinogens, we are unable to identify w'hat these agents may be. Regardless of the explanations for the higher mortality from certain forms of cancer in unskilled and industrial workers, the need for concentrating attention on such groups in applying cancer control measures is evident. ASSOCIATION or CANCER W ITH OTHER D ISEA SES It has long been noted that cancer occurs more frequently than normal in tissues the seat of the so-called pre cancerous lesions. The evidence far significant association is often far from conclusive. Precancerous lesions have been described in the skin, lip, liver, mouth, bones, thyroid, gastrointestinal tract, breast, ovary, uterus, and vulva. The greatest number have been de- JtC1i V_1 111 CAit. J ik il.i -**- " -A twenty-two different precancerous states are said to occur.10 It should be noted that in most cases of cancer, a specific precancerous lesion cannot be identified. The subsequent incidence of cancer in persons with precancerous lesions varies greatly, from a few (xeroderma pigmentosum; erythroplasia of Queyrat) in which cancer always supervenes, to many in which it is only an occasional occurrence. For the most part, figures which are reported refer not to secon dary incidence but to frequency of association. Where secondary incidence is stated, the factors of age and duration of observation are usually not taken into account. For most precancerous lesions, the available information does not permit accurate estimation of the degree of increased risk of cancer which they carry. t There is adequate evidence that in women with chronic cystic mastitis11 the subsequent incid"nce of breast can- u , L fro.:. : to 10 time: as great as the average. Epithelioma of the tongue occurs in syphilitic males about 5 times more frequently than would be expected normally, and recently there have been presented data 12 indi cating that a similarily high incidence of cervix carcinoma occurs in women who have had syphilis. Other con ditions apparently associated with sub sequent cancer which may be mentioned are multiple polyposis, with intestinal cancer; cirrhosis of the liver with pri- marv liver cancer; Paget's disease of bone with osteogenic saicoma, airopnv of the buccal and esophageal mucous membranes, attributed to Vitamin B deficiency, with buccal and esophageal cancer. Rhoads 13 has stressed the fact that many of the precancerous lesions are atrophic in nature. This is in accord with the observations that in experi mental liver cancer produced by the carcinogenic chemical, butter yellow, ' ' '* i] ' c; cc" : pr ecc-de' the development of cancer. Kensler and his associates14 have shown further that in experimental animals this proc ess can be prevented by supplying xtra quantities of riboflavin and casein in the diet. From the standpoint of cancer con trol, the existence of precancerous Vol. 34 E pidemiology of Cancer 615 lesions presents the possibility of insti lies and which becomes malignant in tuting case finding procedures to dis cover individuals having such lesions, to be followed by treatment where possible, and by continued observation so that if cancer develops, it may be at least 25 per cent of cases; multiple neurofibromatosis which occurs in half the children if one parent is affected, and of which 13 per cent are reported to develop sarcoma; and certain benign treated early in its course. . bone tumors. In addition, there have been described CONSTITUTIONAL FACTORS IN HUMAN `` cancer families,'' in which cancer, CANCER often of the tsame organ, such as the Although certain of the precancer ous lesions (leukoplakia, farmer's skin) are attributable to environmental agents, breast, uterus, or stomach, occurred in several brothers or sisters. What pro portion of cancer patients come from others such as familial intestinal poly posis and multiple neurofibromatosis are apnarentlv the result of hereditary or at least familial influences. Further, even in the effects of identified exoge nous carcinogenic agents, the degree of inherent susceptibility or resistance probably plays a rle, as is indicated by the many workers who, although exposed for long periods to carcino genic chemicals, do not develop cancer. As in most other diseases, both the constitutional factor and the environ mental must be considered in the etiology of malignant tumors. The information available concerning T-*rpcijmcjV1v r r m c t i t n t i n n ^ l f a r f n r t p f f p r - such families is not known. With regard to the common forms of cancer, studies have been made to determine whether the parents and sib lings of cancer patients have any greater cancer mortality than the general popu lation. The majority of such studies do show increased mortality in both parents and siblings, ranging from 20 to 60 per cent higher than expected. When cancer occurs in the same family, there is also a definite tendency for it to appear in the same organ.1"'*0 It should be noted that such findings do not necessarily indicate a general familial concentration of cancer, but could be accounted for bv assuming ting cancer incidence in man comprises that a relatively small percentage of data on ( 1) hereditary forms of cancer cancer patients come from cancer fami or of benign tumors; (2) the occurrence lies. For example, in Crabtrees data,1" of cancer families; (3) the familial among 1,029 families there occurred incidence of cancer; and (4) the inci an excess of 93 cancer deaths (37 per dence of secondary primary cancers in cent) over that expected in parents patients following successful treatment and siblings together. An increase of first cancer. above normal of one case in 9 per In a few rare tumors a hereditary cent of the families would thus account mechanism is generally accepted, al- for all of the observed excess of cancer thnnnh the effect of unknown environ deaths, with a normal incidence in the mental factors cannot be excluded en remaining 91 per cent of families. It tirely. Retinoblastoma of the eye is probably superfluous to point out occurs with sufficient frequency in sib that an increased familial incidence i lings and in descendants of cured of cancer does not necessarily indicate patients to justify advice against mar that hereditary or genetic factors are riage or having more children. Examples responsible, since similar environmental of hereditary benign tumors are familial factors may also run in families. intestinal polyposis which occurs in The evidence regarding familial can one-third the children of affected fami cer, although far from conclusive, is 616 A m erican J ournal of P ublic H ealth Jwv", 1944 j sufficiently impressive so that in some the population are susceptible to can clinics a family history of cancer, par cer and, consequently, that among can ticularly of the breast and uterus, is cer patients, who are susceptible, of regarded as indicating need for in course, the annual age-specific mor creased watchfulness for the possible tality rates should be 5 times that of development of a similar tumor in other the general population. There is no members of the family. Certainly no known method of determining suscepti' objection will be raised to such an bility to cancer and no reason to assume interpretation, which can lead only to that only those who develop cancer , 4 . a increased chance of early diagnosis with are susceptible. The available experi f; 'i correspondingly increased probability of mental evidence indicates that environ successful treatment. mental factors can alter incidence Obviously, the time has not yet markedly. " come to look upon the occurrence of From the practical standpoint the cancer in one member of a family as significant fact is that the incidence i the signal for examination and con of second cancer in cancpr patients ic tinued follow-up of the patient's broth not greatly different from that of the | %n >. ers and sisters. In identified cancer general population. This suggests that it families this procedure is justified. increased susceptibility to cancer, what K Without further information, its em ever its nature, is not general but more f ployment in families where only one probably is organ specific, as is the case has occurred would be experi case in certain high tumor strains of B mental. The principle is being applied mice and rats. n;j by some physicians and clinics, but it The role of hereditary factors in the 3 has not reached the stage of public causation of human cancer and the * health practice. extent to which such factors are modi Related to the problem of the nature fiable by environmental agents, remains H of inherent susceptibility to cancer is obscure. There seems little doubt that the question whether the development such factors do exist for some tumors of canrer in one organ denotes an and in snmp families, but the available increased susceptibility to cancer in evidence indicates that they are of only other parts of the body. This question minor importance in the majority of i has been approached by studying the cases. ISM subsequent incidence of other primary cancer in persons successfully treated DIFFERENTIAL MORTALITY FROM CANCER for one malignant tumor. The subject The known facts regarding the eti has been investigated extensively by ology of cancer, fragmentary as they Peller,-1 and more recently by Lombard are, can be correlated with only a few and Warren.2- Their findings are sim of the differential characteristics of ilar and indicate that _the incidence of cancer mortality. These characteris second cancer is not significantly differ tics, however, have intrinsic interest ent lrom that of the general population. from the standpoint of a control It should be emphasized that the oppo program. site conclusion of Peller rests not on Although great stress has been laid 1 different findings but on the theoretical on the errors of diagnosis inherent assumption that in cancer patients the in mortality statistics of cancer, many I subsequent expected incidence should of the differences in cancer mortality be 5 times that of the general popu observed in different population groups lation. This is based on the further are not readily explainable by diag assumption that only 20 per cent of nostic error. The extent to which **w. Vol. 34 E pidemiology of Cancer 617 diagnostic errors are responsible for noses verified by pathological exami- differences in mortality in different pop- nation, there is no reason to believe ulation groups must be considered that, for the same site of cancer, diag- separately for each group and each site nostic accuracy is different in the two of cancer where such differences are sexes. For this reason, as Gover has found. pointed out, the more rapid increase in mortality for certain internal types tr e n d of ca n cer m ortality of cancer in males than in females is The continued upward trend of can- probably real and not due entirely to eer mortality has made eancer one of improved diagnosis, the major health problems of our time. One-third of the increase in mortality c a n c e r m o r t a l it y by color a n d is due to increased " aging " of the g eographic reg io ns in f h e population. The remaining increase is u n it ed states sometimes written off as reflecting in- The possible association of cancer creased recognition of cancer rather of the buccal cavity and of the liver man increased incidence. with certain dietary deficiencies and In upstate New \ ork, comparison the association of tongue cancer and of age-standardized mortality from 1931 probably cervix cancer with preexisting to 1941 shows an increase during this syphilis suggest that mortality statis- period of 10 per cent in male mortality; tics in this country might reflect corre- and a decrease of 6 per cent in female sponding differences for cancer of these mortality. Mortality from cancer of sites between geographic sections and the buccal cavity, skin, and lip, has between white and colored. For ex- decreased slightly in both sexes. Death ample, we might expect a relatively rates from cancer of the stomach and high mortality from buccal and liver the liver have decreased significantly cancer in those southern states with in both sexes. Cancer of the breast widespread gross dietary deficiency as increased only slightly; mortality from indicated by high mortality from'pel- uterine cancer decreased by approxi- lagra: also, colored malec would he mately 16 per cent. The increase in expected to haye a higher mortality mortality from certain types of cancer from tongue cancer; and colored females in males is sufficient to raise the total from cancer of the cervix, mortality above that in the earlier Govers data 24 for the years 1930 to period. The most marked increase 1932 show that age-standardized mor- occurred in cancer of the lungs and tality from total cancer in both sexes other respiratory organs, mortality from in this country is highest in the North- which increased threefold in males but east and on the Pacific coast, lowest in only slightly in females. In females the South and Southwest. The only the decline in certain sites, notably the exceptions are cancer of the skin, which stomach, the liver, and the uterus, more is highest in the South, and cancer chaii onsets tne increased rate tor other of the mouth and pharynx, which is types of cancer. Since there is no highest in southern females and second reason to believe that diagnostic accu- highest in southern males. All other racy lessened during the past decade, forms of cancer, including cancer of it is probable that this decrease fore- the liver and biliary passages, show shadows a continued downward trend lower rates in the South. These rela in cancer mortality among women. tive differences in site distribution of From data regarding hospitalization cancer between North and South appear of cancer cases and proportion of diag- in hospital deaths as well as in all %" \ Ik 4 M!i' wme*.--. ! - &-- - *-- y i: r: I!IU. i,. f :?; f. > I uI 'rl-tI ; " i; A m erican J ournal of P ublic H ealth June, 1944 i recorded deaths. The differences, how ever, are not so marked in morbidity data. The expected difference in can cer mortality in the South is thus present for buccal cavity cancer but not for cancer of the liver. Comparison between white and col ored cancer mortality in the United States shows that for most forms of cancer, colored mortality is lower than among whites. The differences are less marked in the North than in the South, presumably due to the fact that Negroes in the North obtain better medical care. A peculiar feature of cancer mortality in Neprnes is that ation of tongue and cervix cancer with syphilis are not found for tongue can cer. but are for uterine cancer. Obvi ously, such a finding is merely cor roboratory and does not establish the fact of an association between syphilis and uterine cancer. Regardless of its cause, the markedly high mortality from uterine cancer among colored females deserves greater attention than it has received, both from the standpoint of investigation and from that of administration of cancer control programs. Cancer of the uterus and of the it is lower only in the age groups above 54 years; in younger age groups it is as high or slightly higher than among whites. Mortality from tongue cancer is lower in colored females, and only slightly higher in colored males than in whites. - The forms of cancer showing mark edly higher mortality in the colored race are cancer of the external genitalia in males, and of the uterus and other female genital organs in females. The excess mortality from cancer of the UiPriK amonFc rnlnrpr^ u-n..m...o..n....i-t *7^ rn"c*r cent in the South and 91 per cent in the North, and is sufficient to bring total cancer mortality among colored females slightly above that among 'whites in both sections of the country. In the experience of the Metropolitan 'Life Insurance Company's industrial de partment 2r` from 1917 to 1935, the age-standardized mortality from uterine cancer among colored females was 55 per cent higher t h a n amianp' whiter. We do not as yet have mortality data for cancer of the cervix uteri separated from that of the uterine fundus, but it is known that approximately 85 per cent of uterine cancers arise in the cervix. ferent frequency among women of differ ent marital status. Uterine cancer mortality is highest among married women, while breast and ovarian cancer mortality is higher among single women. The mortality from breast cancer among childless married women Ls as high as in single women. The higher mor tality from breast cancer among single women and childless married women is usually attributed to the absence of normal lactation, while the higher mor tality from uterine cancer in married - t...... - . . . ' i i u i i-n_v.ii i n t c ip i u t e a a i c u u u i t c that injuries resulting from childbirth are causes of uterine cancer. These interpretations have not been fully established. Recent data from Aus tralia, described by Dorn,2c indicate .that uterine cancer mortalit-y is hiCghest among married women who have never borne children. A more complete review of the differ ential mortality of cancer is not within flip prrtrtp fVttc n o m .r Tt 1 - # t " i " I ' - k - said, however, that most of the major forms of cancer exhibit sufficiently dif ferent epidemiological characteristics to indicate that each must be approached as a separate problem in cancer control. The expected differences in cancer su m m a r y a n d d iscu ssio n mortality between white and colored In summary, there is evidence that races because of the apparent associ- the occurrence of human cancer is in Yo!. 34 E pidem iology of C ancer 619 some cases attributable to the influence of specific chemical and physical agents; in others to an association with precan cerous lesions and with other diseases; and, in a relatively small number of cases, familial factors, which may be hereditary, are operative. In a large proportion of cases, none of these etiologic factors can be identified. Con siderable differences appear in mortality from various forms of cancer in persons of different race, economic status, and marital status. Most of these differ ences are not readily explainable by any single hypothesis regarding the causation of cancer. Many of the etiological and differ- Ciilioi ilV-LOi oCSsCU pL/Uil LU puSSilc public health applications in the form of special attention in education, in case finding and in follow-up directed to the groups which have an apparently high mortality and incidence of certain forms of cancer. Examples of such groups are: industrial and unskilled workers (cancer of the skin, lip, mouth, larynx, and stomach); unmarried women (cancer of the breast); syphilis patients (cancer of the vulva, cervix, tongue); Negro women (cancer of the uterus). The experience of the Strang Cancer Prevention Clinic in New i ora city, in case finding among apparently healthy women, indicates that the pro portion of early cancer cases found is comparable to that of early cases of tuberculosis discovered by mass x-ray examinations.1'7 Active case finding ap plied to groups with higher than normal incidence of cancer may be correspond ingly more effective. It seems reasonable to forecast that, Ui u i c i u t u i t , ca.iiE t'i c u u i i u i p r u g i a m s will be guided to a greater extent than in the past by existing knowledge and by further investigation of the epidemi ological characteristics of the disease. These point to a logical development of control activities directed toward population groups which apparently stand in greatest need of such measures and among which they should prove most fruitful. . REFERENCES 1. Pott, Percival. Chirurgical Obscnations. Hower, Clarke & Pollins, London, 1775. 2. Rhoads, C. P. Recent Studies in tbe Produc tion of Cancer by Chemical Compounds, the Con ditioned Deficiency as a Mechanism. Bull. S e n York Acad. Med., 18:53-64 (Jan.), 1942. 3. Dublin, L. I., and Vane, R. J Occupation Hazards and Diagnostic Signs Bull. S o . SS2, U. S. Bureau of Labor Statistics Washington, 1933. 4. Hueper, W. C. Cancer in Its Relation to Occu pation and Environment. Bull. Am . Soc. Control Cancer, 25:63 (June), 1943. 5. (a) The Registrar-General's ment, England & Wales, 1921. tional M ortality, Fertility and London, 1927. Decennial Supple Part II. Occupa Infant Mortality. (b) The Registrar-General's Decennial Supple ment, England & Wales, 1931. Part Ila. Occupa tional M ortality. London, 193S. 6. Knight, Augustus S., and Dublin, Louis I. The titiaiion oj cancer to Economic Condition. M etro politan Life Ins. Co., New York, 1917. 7. W hitney, Jessamine S. (ed.). Death Rates by Occupation. Nat. Tuberc. Assoc., New York, June, 1934. 8. Lombard, H. L., and Doering, Carl R. Cancer Studies in Massachusetts. III. Cancer M ortality in N ativity Groups. J. Prev. Med., 3:343, 1929. 9. Chapin, Charles V. Deaths among Tax-payers and Non-taxpavers, Income Tax. Providence, 1865. A.J.P .H ., 14:647 (A ug.), 1924. 10. Mackee, George M., and Cipollaro, Anthony C. Cutaneous Cancer and Precancer. New York. Am. J. Cancer, 1937. 11. Warren, Shields. The Relation of " Chronic Mastitis " to Carcinoma of the Breast. S u rg., Gyncc. & O b sl, 7:257-273 (Sept ), 1940. 12. Levin, Morton L., Kress, Louis C., and Gold stein, Hvman. Syphilis and Cancer. S e n York State 1. Med., 42:1737 (Sept. 15), 1942. 13. Rhoad.-, C. P. Precancerous Lesions. Bull. r -</,? r - r rr *>? ? fTtir- I C.1' 14. Kensltr, C. J., Sugiura, K., Young, N. F., H alter, C. R., and Rhoads, C. P. Partial Protec tion of Rats by Riboflavin with Casein against Liver Cancer Cau>ed by Dimethylaminoazobcnzene Science, 9 3 :30, 1941. ' ' 15 Crabtree, James A. Observation^ on the Familial Incidence of Cancer. A.J.PJ1., 31:49 (Jan .), 1941. . 16. Deelman, H . J. Heredity and Cancer. Ann. Surg , Jan , 1931, pp. 30-34. 17. Was>ink. W. F. Cancer et Hrdit. Genctuc, 17:103-144, 1935. 18. Waaler, H . M. Veter die Erblichkeit des Krebses Oslo, 1931. - 19. Wainwright, J. M. Breast Cancer in Great Britain and America. Am. J. Cancer, 15, 4:2610, 193! o. Locihat, M. L. Mmes on i-annua. Aspect* oi Cancer. S c u Eng. J. Med., 218:711-713 (Apr. 2S>, 1935. 21. Peller, Sigismund. Metachronous M ultiple Malignancies in 5876 Cancer Patients. Am. J. B yg., 34, 1, Sec. A-- 1-11 (Ju ly J, 1941. .22. Lombard, H. L., and Warren, Shields. As sociation of Other M alignant Tumors with Cancer of the Skin. A .J.P .B ., 33:533-536 (M ay), 1943. 23. Pohien, K urt, and Emerson, Haven. Errors in Clinical Statements of Causes of Death. A J .P .B ., 32: 251-260 (M ar.), 1942. 620 A merican J ournal of P ublic H ealth June, 1944 States.G0Ver' MarJ' CaDCer WrtaIi`>' in *ke United T w v v L Trend l RtCorM Cancer Mortalitv in the Pub. Health"Bull. " k' T Service, Washington, 1939. ' t ' T V 9i5- ' u ,c Health II Recorded Cancer Mortal,\v in Geojrranhi- m o Z 935 D7 \ Rf,,giStrati0n SU te 01 1M0, from i f?. 19iS- Pub Health B ull K 0 2S2 V s Public Health Service, Washington, 1940. ' " Mortal!" Gf S e S i e d 'w !iT Vears iT& C" r * . "5 ", r L E, s r 2 /. M tm onal Hospital, AVa York rVv fit Port, 2P42. iOTk s" " i r Annual \ U. S. Cadet Nurse Corps Induction Pledge of the Unite7s" " es Publk H r a i r & i r i i : 11' U" iled S,a'" CadM N W > 1 t L "ircbosTpi?Ltn.blig"'i0"S1 1<"' ard " > " "" IT and i 'thf ^ i"Slr"C`0rS and " r "ldance I 11, hold in true, the fines, traditions of nursing and the spirit die corps- I1 Will bwe k-inTd, toleyranStt'ann8d, umn>d' emrsit"adndailnegr`;' and " >bear` teadfast-' ' oAi r Vd e i ' Wi" dediCa`e ^ "d >o he triumph iiie the duration of the warf pIedge 10 m-v co"mr.v my service in essentia] nursing for American Journal of Public Health and THE N A TIO N 'S HEALTH ................ \ - \ V o l u m e 34,1944 January ............................ .................... i-. 1 March ................................. .................... A r rU June .................................. ............... INDEX Page-' 1-100 215-316 317-434 567-692 July ................................... ...................... ...................... September .............................................. .................. ...................... December .......................... .................... Pg 693- 816 817- 930 931-1048 1049-1132 -1133-1216 1217-1316 TOMPKINS-McCAW library MEDICAL COLLEGE of VIRGINIA Richm o n d 19, virginia -r>Y't>TTP TtT~*ATfrTJ A 1790 B r o a d w a y N e w Y o r k 19, N Y. *'rT PNX*