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FILE NAME Kent KNT DATE 1944 June DOC KNT110 DOCUMENT DESCRIPTION Journal Article - The Epidemiology of Cancer - American Journal of Public Health TH June 1944 for decision in stu- them the tricks of t'it is no substitute wledge of the theory losophy of a subject inistration must in golden mean between ent on the one hand verness on the other se system would not f administrators that ic health are anxious d as an adjunct to teaching it might improve the interest e present courses in inistration RENCES srett Training for LeaderHarvard Business Review Jucation for Public Adminis blic Administration of Social 1941 Adjusting the Sights for Presidential Address AmeriIministration Dec. 28 1940 Vol 34 1944 The Epidemiology of Cancer From the Viewpoint of the Health Officer* MORTON L. LEVIN M.D. DR.P.H. F.A.P.H.A. Assistant Director Division of Cancer Control New York State Department of Health Albany N. CTIVITIESCTIVITIES in cancer control by public health agencies need not and usually do not rest upon the recognition of any epidemiological peculi- arities of the disease in the strict sense of that term The necessity for persuading people who have symptoms to seek medical care without delay as well as the desirability of making it easy for them to secure prompt diagnosis and adequate treatment are sufficiently well defined to furnish a secure foundation for public health action It is recognized that to accomplish these objectives with some degree of completeness is an undertaking of considerable magnitude particularly if all persons who reach adult age must be included in the scope of the cancer program Because the task of reaching the entire adult population with any type of control measure is manifestly great the health officer who plans a cancer control program seeks to make the limited forces he can throw into the field count for more than may be expected of random action directed to the public at large From experience in the control of infectious disease it be of value in the application of cancer control measures The health officer who is interested in cancer control must also take stock of the modern advances in the etiology of cancer and inquire whether these now have any practical significance in the control of human cancer To review broadly the salient features regarding the occurrence of cancer in man the facts to be considered may be classified under four general headings 1 environmental or exogenous agents agents ' causing cancer 2 association of cancer with other diseases 3 evi- dences regarding intrinsic or constitutional factors affecting cancer incidence and 4 certain aspects of differential mortality It should be stated at the outset that cancer of different parts of the body and of different pathological characterin the same part are different diseases Although for some purposes it is useful to consider all types of . cancer together throughout this dis- cussion differences in etiology and in epidemiological features according to - site will site of cancer will appear is evident that information regarding what people are most apt to develop cancer or certain kinds of cancer would * Presented before the Health Officers Section of the American Public Health Association at the Seventy Annual Meeting in New York N. Y. October 12 1943 EXOGENOUS AGENTS CAUSING CANCER IN MANlaboratory So - Attention in the laboratory investi- gation of cancer is now focused on the r^le of chemical carcinogens and causation of xray radium and violet radi- | ation in the of malignantmalignant . 611 612 AMERICAN JOURNAL OF PUBLIC Health 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 Pott who noted in chimney sweeps a greatly increased incidence of scrotal epithelioma 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 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 periodic pre- ventive measures including periodic examinations have been adopted in some plants especially in the aniline dye industry often the hazards are not compounds roentgen rays radium rays and violet rays possibly asbestos nickel carbonyl and chromates What common property of these diverse chemicals and radiations makes them poten- tially carcinogenic is not clear possibly all act by interfering with cellular enzymes as the work of Rhoads sug- gests Most of these agents produce skin cancer Aniline dye compounds recognized or not properly guarded against Exposure to aniline dye compounds occurs not only 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- cause chiefly cancer of the bladder crease this number in the future 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 man 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 Fowler's solution and in the Argentine from drinking water contaminated by arsenic ores The influence of ultra- A survey of occupations listed according to exposure to various hazards shows 146 different occupations in this country in which exposure to known 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 carcinogenic agents may occur ever the number of reported How- occu- as for its high incidence among out- door workers in the North pational cancers is quite small 4 Hueper estimates that the total cases reported The relationship of carcinogenic chemicals and radiations to the common in the world literature is from 8,000 to 9,000 of which approximately 400 have been reported from the United States A partial explanation for the small run of malignant tumors in man is a matter of speculation It has been suggested that part of the increase in cancer mortality of modern times may be attributable to the increased number of reported cases of occupational cancer may be the fact that although the period of exposure necessary to produce cancer may be as little - as one year the time from such expo- exposure such substances accom- industrial panying the age The diffi- culties in the way of testing such a hypothesis may be appreciated from the fact that a chemically induced HEALTH June 1944 e appearance of the tumor ong as 30 years averaging nts approximately 16 years tumor may not appear ter the worker has changed n There is also a natural n the part of industrial to release information on cancer Although preures including periodic exhave been adopted in some cially in the aniline dyc ten the hazards are not or not properly guarded posure to aniline dye comrs not only in the dye in many others including ng rubber and those man- xplosives It is probable ber of occupational cancers an indicated by identified it the enormous expansion adustries may further inumber in the future exposure to the carcinoals and radiations need pational Arsenic cancer is been observed following edicinal administration of tion and in the Argentine g water contaminated by The influence of ultra- on is believed responsible er general incidence of In the South as compared th in this country as well gh incidence among out- in the North ionship of carcinogenic radiations to the common nant tumors in man is a eculation It has been it part of the increase ortality of modern times butable to the increased such substances accom- Industrial age The diffi- way of testing such a ay be appreciated from 1 a chemically induced Vol 34 EPIDEMIOLOGY 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 carcinogens 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 occurred is clearly indicated This is rarely done now and presents a field for possible public health action DIFFERENTIAL CANCER MORTALITY AMONG 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 economic class dividing the population into professional workers skilled workers un- skilled workers and two workers inter- mediate groups A progressive in- in crease cancer mortality was found in each " lower economic group This increase was confined to cancer of the skin lip larynx and the alimentary 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 was 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 economic status In this country broadly similar findings have been reported by Knight and Dublin fi in life insurance data and by Whitney for total cancer not sub- divided according to site In Massa- chusetts Lombard and & Doering found that the foreign born and those of 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 by Charles V. A Chapin on the mortality 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 which the 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 614 AMERICAN JOURNAL OF PUBLIC HEALTH June 1944 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 frequently cited as evidence that the living conditions of these groups in- volve greater exposure to " exogenous carcinogens Aside from specific occu- pational carcinogens we are unable to identify what 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 OF CANCER WITH OTHER DISEASES It has long been noted that cancer occurs more frequently in tissues the seat of the cancerous lesions The than normal called preevidence for 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 described in the skin where at least twenty different precancerous states are said to occur 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 no 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 There is adequate evidence hat in women with chronic cystic mastitis " the subsequent incidence of breast can- cer is from 2 to 10 times 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 indicating that a similarily high incidence of cervix carcinoma occurs in women who have had syphilis Other conditions apparently associated with sub- sequent cancer which may be mentioned are multiple polyposis with intestinal cancer cirrhosis of the liver with primary liver cancer Paget's disease of bone with osteogenic sarcoma atrophy 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 experimental liver cancer produced by the carcinogenic chemical butter yellow atrophy of the liver cells precedes the development of cancer Kensler and his associates have shown further that in experimental animals this proc- ess can be prevented by supplying extra quantitieosf riboflavin and casein in the diet oN From the standpoint cancer con~ trol the existence of precancerous pr ti da or of inc dej pai of me the me tire OCC ling pat riag inte one- June 1944 ervenes to ^ occasional art figures t to secon- quency of y incidence nd duration not taken recancerous nation does tion of the incer which ice that in mastitis 11 breast can- s as great ma of the nales about han would d recently 32 ata indi- ^ incidence in women Other con1 with sub- mentioned 1 intestinal r with pri- disease of a atrophy al mucous Vitamin B esophageal e fact that lesions are in accord in experied by the er yellow ecedes the ensler and vn further this proc' supplying and casein . ancer con- ecancerous Vol 34 EPIDEMIOLOGY OF CANCER 615 lesions presents the possibility of instituting 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 treated early in its course lies and which becomes malignant in 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 bone tumors , CONSTITUTIONAL FACTORS IN HUMAN CANCER Although certain of the precancerous lesions leukoplakia farmer's skin are attributable to environmental agents others such as familial intestinal poly- posis and multiple neurofibromatosis are apparently the result of hereditary or at least familial influences Further Further even in the effects of identified exoge- nous carcinogenic agents the degree of inherent susceptibility or resistance probably plays a r^le as is indicated by the many workers who although exposed for long periods to carcinogenic 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 presumably constitutional factors affec- ting cancer incidence in man comprises | data on 1 hereditary forms of cancer or of benign tumors 2 the occurrence of cancer families 3 the familial incidence of cancer and 4 the incidence of secondary primary cancers in patients following successful treatment of first cancer In a few rare tumors a hereditary mechanism is generally accepted although the effect of unknown environ- mental factors cannot be excluded en- tirely Retinoblastoma of the eye occurs with sufficient frequency in siblings and in descendants of cured patients to justify advice against mar- riage or having more children Examples of hereditary benign tumors are familial intestinal polyposis which occurs in third the children of affected fami- In addition there have been described cancer families in which cancer often of the same organ such as the breast uterus or stomach occurred in pro- several brothers or sisters portion of cancer patients What come from 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 population The majority of such studies do show increased mortality in both parents and siblings ranging from 20 to 60 per cent higher than expected family When cancer occurs in the same there is also a definite tendency for it to appear in the same organ.15-20 It should be noted that such findings do not necessarily indicate a general familial concentration of cancer but could be accounted for by assuming that a relatively small percentage of cancer patients come from cancer fami- lics For example in Crabtree's data among 1,029 families there occurred an excess of 93 cancer deaths 37 per cent over that expected in parents and siblings together An increase above normal of one case in 9 per cent of the families would thus account for all of the observed excess of cancer deaths with a normal incidence in the remaining 91 per cent of families It - is probably superfluous to point out . that an increased familial incidence of cancer does not necessarily indicate that hereditary or genetic factors are ~ a responsible since similar environmental : factors may also run in families * 2-7. The evidence regarding familial can- --" cer although far from conclusivies - 616 AMERICAN JOURNAL OF PUBLIC HEALTH June 1944 sufficiently impressive so that in some clinics a family history of cancer par- ticularly of the breast and uterus is regarded as indicating need for in- creased watchfulness for the possible development of a similar tumor in other members of the family Certainly no objection will be raised to such an interpretation which can lead only to increased chance of early diagnosis with correspondingly increased probability of successful treatment Obviously the time has not yet come to look upon the occurrence of cancer in one member of a family as the signal for examination and con- tinued follow of the patient's broth- ers and sisters In identified cancer families this procedure is justified Without further information its employment in families where only one case has occurred would be experimental The principle is being applied by some physicians and clinics but it has not reached the stage of public health practice Related to the problem of the nature of inherent susceptibility to cancer is the question whether the development of cancer in one organ denotes an increased susceptibility to cancer in other parts of the body This question has been approached by studying the subsequent incidence of other primary cancer in persons successfully treated for one malignant tumor The subject has been investigated extensively by Peller and more recently by Lombard and Warren Their findings are sim- ilar and indicate that the incidence of second cancer is not significantly different from that of the general population _ It should be emphasized that the oppo- . site conclusion of Peller rests not on different findings but on the theoretical assumption that in cancer patients the subsequent expected incidence should be 5 times that of the general popu- lation This is based on the further assumption that only 20 per cent of the population are susceptible to cancer and consequently that among cancer patients who are susceptible of course the annual specific mortality rates should be 5 times that of the general population There is no known method of determining suscepti bility to cancer and no reason to assume that only those who develop cancer are susceptible The available experi- mental evidence indicates that environmental factors can alter incidence markedly From the practical standpoint the significant fact is that the incidence of second cancer in cancer patients is not greatly different from that of the general population This suggests that increased susceptibility to cancer whatever its nature is not general but more probably is organ specific as is the case in certain high tumor strains of mice and rats The r^le of hereditary factors in the causation of human cancer and the extent to which such factors are modi- fiable by environmental environmental agents remains obscure There seen's little doubt that such factors do exist for some tumors and in some families but the available evidence indicates that they are of only minor importance in the majority of cases DIFFERENTIAL MORTALITY FROM CANCER The known facts regarding the etiology of cancer fragmentary as they arc can be correlated with only a few of the differential characteristics of cancer mortality These characteristics however have intrinsic interest from the standpoint of a control program Although great stress has been laid on the errors of diagnosis inherent in mortality statistics of cancer many of the differences in cancer mortality observed in different population groups are not readily explainable by diag- nostic error The extent to which TH June 1944 susceptible to cantly that among can- are susceptible of il specific mor- be 5 times that of ition There is no determining suscepti . no reason to assume who develop cancer he available experi- dicates that environan alter incidence ical standpoint the that the incidence n cancer patients is at from that of the This suggests that lity to cancer whatnot general but more specific as is the gh tumor strains of ditary factors in the an cancer and the ch factors are modi- ental agents remains ms little doubt that ist for some tumors es but the available hat they are of only in the majority of ALITY FROM CANCER s regarding the etiragmentary as they ted with only a few characteristics of These characterise intrinsic interest int of a control stress has been laid diagnosis inherent ics of cancer many in cancer mortality at population groups splainable by diag extent to which =< Vol 34 EPIDEMIOLOGY OF CANCER ' 617 diagnostic errors are responsible for differences in mortality in different population groups must be considered separately for each group and each site of cancer where such differences are found TREND OF CANCER MORTALITY The continued upward trend of cancer mortality has made cancer one of the major health problems of our time third of the increase in mortality is due to increased aging of the population The remaining increase is sometimes written off as reflecting increased recognition of cancer rather than increased incidence In upstate New York comparison of standardized mortality from 1931 to 1941 shows an increase during this period of 10 per cent in male mortality and a decrease of 6 per cent in female mortality Mortality from cancer of the buccal cavity skin and lip has decreased slightly in both sexes Death rates from cancer of the stomach and the liver have decreased significantly in both sexes Cancer of the breast increased only slightly mortality from uterine cancer decreased by approximately 16 per cent The increase in mortality from certain types of cancer in males is sufficient to raise the total mortality above that in the earlier period The most marked increase occurred in cancer of the lungs and other respiratory organs mortality from which increased threefold in males but only slightly in females In females the decline in certain sites notably the stomach the liver and the uterus more than offsets the increased rate for other types of cancer Since there is no reason to believe that diagnostic accuracy lessened during the past decade it is probable that this decrease fore- shadows a continued downward trend in cancer mortality among women From data regarding hospitalization of cancer cases and proportion of diag- noses verified by pathological exami- nation there is no reason to believe that for the same site of cancer diag- nostic accuracy is different in the two sexes For this reason as Gover has pointed out the more rapid increase in mortality for certain internal types of cancer in males than in females is probably real and not due entirely to improved diagnosis CANCER MORTALITY BY COLOR AND GEOGRAPHIC REGIONS IN THE UNITED STATES The possible association of cancer of the buccal cavity and of the liver with certain dietary deficiencies and the association of tongue cancer and probably cervix cancer with pre^xisting syphilis suggest that mortality statistics in this country might reflect corresponding differences for cancer of these sites between geographic sections and between white and colored For ex- ample we might expect a relatively high mortality from buccal and liver cancer in those southern states with widespread gross dietary deficiency as indicated by high mortality from pellagra also colored males would be expected to have a higher mortality from tongue cancer and colored females from cancer of the cervix Govers data 24 for the years 1930 to 1932 show that standardized mortality from total cancer in both sexes in this country is highest in the North- east and on the Pacific coast lowest in the South and Southwest The only exceptions are cancer of the skin which is highest in the South and cancer of the mouth and pharynx which is highest in southern females and second highest in southern males All other forms of cancer including cancer of the liver and biliary passages show lower rates in the South These rela- tive differences in site distribution of cancer between North and South appear in hospital deaths well as in all SN 618 AMERICAN JOURNAL OF PUBLIC HEALTH June 1944 recorded deaths The differences how_ ever are not so marked in morbidity data The expected difference in cancer mortality in the South is thus present for buccal cavity cancer but not for cancer of the liver Comparison between ored cancer mortality States shows that for white and colin the United 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 Negroes is that 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 uterus among colored women is 75 per 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- 25 partment from 1917 to 1935 the standardized mortality from uterine cancer among colored females was 55 per cent higher than among whites We do not as yet have mortality data for cancer of the cervix uteri separated from that of the uterine fundus but approximately it is known that cent of uterine cancers arise 85 per in the cervix The expected differences in cancer mortality between white and colored races because of the apparent associ- 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 corroboratory 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 breast and ovary occur also with dif- ferent frequency among women of differ- ent marital status Uterine cancer mortality is highest among married women while breast and ovarian cancer mortality is higheramong single women The mortality from breast cancer among . childless married women is as high as from in single tality women The higher morbreast cancer among single women and childless married women is usually attributed to the absence of normal lactation while the higher mortality from uterine cancer in married women has been interpreted as evidence 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 indicate that uterine cancer mortality is highest among married women who have never borne children A more completereview ofthe differ- ential mortality of cancer is not within the scope of this paper It may be 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 SUMMARY AND DISCUSSION . In summary there is evidence that the of occurrence human cancer in Ss ALTH June 1944 and cervix cancer with found for tongue canuterine cancer Obvi- nding is merely cor- loes not establish the ation between syphilis cr ts cause the markedly from uterine cancer males deserves greater It has received both point of investigation of administration of ograms ^ uterus and of the occur also with dif- imong women of differtus Uterine cancer ghest among married ast and ovarian cancer r among single women m breast cancer among women is as high as 0. The higher morst cancer among single Idless married women ited to the absence of while the higher mor- ine cancer in married interpreted as evidence ulting from childbirth terine cancer These have not been fully cent data from Aus- by Dorn indicate er mortality is highest vomen who have never ete review of the differ- of cancer is not within is paper It may be nat most of the major exhibit sufficiently dif- gical characteristics to h must be approached blemin cancer control AND DISCUSSION there is evidence that of human cancer is in Vol 34 EPIDEMIOLOGY OF CANCER 619 e some cases attributable to the influence stand in greatest need of such measures of specific chemical and physical agents and among which they should prove page in others to an association with precan- most fruitful cerous lesions and with other diseases REFERENCES and in a relatively small number of 1. Pott Percival Chirurgical Observations Hower . cases familial factors which may he hereditary are operative In a large proportion of cases none of these eti- ologic factors can be identified Con- siderable differences appear in mortality - from various forms of cancer in persons of different race economic status and Clarke & Pollins London 1775 2. Rhoads C. P. Recent Studies in the Produc- tion of Cancer by Chemical Compounds the Conditioned Deficiency as a Mechanism Ball New York Acad Med 53-64 Jan. 1942 3. Dublin L. I. and Vane R. J. Occupation Hazards and Diagnostic Signs Bull No. 582 U. Bureau of Labor Statistics Washingtor 1933 4. Hueper W. C. Cancer in Its Relation to Occupation and Environment Bull Am Soc Control Cancer 25:63 June 1943 . marital status Most of these differ- 5. a The General's Decennial Supple- ences are not readily explainable by ment England & Wales 1921. tional Mortality Fertility and Part II -- --, Infant Mortality --- any single hypothesis regarding the causation of cancer London 1927 b The General's ment England & Wales 1931. Decennial Part IIa SuppleOccupa- Many of the etiological and differential factors discussed point to possible public health applications in the form of special attention in education in case finding and in follow directed to tional Mortality London 1938 6. Knight Augustus S. and Dublin Louis Relation of Cancer to Economic Condition I. The Metro- politan Life Ins Co. New York 1917 7. Whitney Jessamine S. ed Death Rates by Occupation Nat Tuberc Assoc New York June 1934 : 8. Lombard H. L. and Doering Carl R. Cancer the groups which have an apparently high mortality and incidence of certain Studies in Massachusetts Nativity Groups J. Prev 9. Chapin Charles V. III Cancer Mortality in Med 343 1929 Deaths among payers forms of cancer Examples of such groups are industrial and unskilled workers cancer of the skin lip mouth and taxpayers Income Tax Providence 1865 A.J.P.H. 647 Aug. 1924 : 10. Mackee George M. and Cipollaro Anthony C. Cutaneous Cancer and Precancer New York Am J. Cancer 1937 larynx and stomach; unmarried women cancer of the breast; syphilis patients cancer of the vulva cervix tongue Negro women cancer of the uterus 11. Warren Shields The Relation of Chronic " Mastitis to Carcinoma of the Breast Surg Gynec & Obst 257 273Sept. 1940 12. Levin Morton L. Kress Louis C. and Gold- stein Hyman Syphilis and Cancer New York State J. Med 1737 Sept. 15 1942 The experience of the Strang Cancer Prevention Clinic in New York City 13. Rhoads C. Am Soc Control 14. Kensler C. P. Precancerous Lesions Bull Cancer 5-7 Jan. 1943 J. Sugiura K. Young N. F. in case finding among apparently healthy women indicates that the proportion of carly cancer cases found is comparable to that of early cases of tuberculosis discovered by mass ray Halter C. R. and Rhoads C. P. Partial Protec- tion of Rats by Riboflavin with Casein against Liver . Science Cancer Caused by Dimethylaminoazobenzene 308 1941 , 15. Crabtree James A. Familial Incidence of Cancer Observations on Jan. the A.J.P.H. 31:49 Jan. 1941 16. Deelman H. J. Heredity and Cancer Ann examinations Active case finding applied to groups with higher than normal incidence of cancer may be correspondingly more effective It seems reasonable to forecast that Surg Jan. 1931 pp 30-34 17. Wassink W. F. Cancer et H^'r^'cit^'Genetica 103-144 1935 18. Waaler H. M. Ueber die Erblichkeit des Krebses Oslo 1931 19. Wainwright J. Britain and America . M. Breast Cancer in Great Am J. Cancer 15 2610 _- 1931 in the future cancer control programs 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 20. Lombard H. L. Cancer New Eng J. 1938 Studies on Familial Aspects of Med 711-913 Apr. 28 , 21. Peller Sigismund Metachronous Multiple Malignancies in 5876 Cancer Patients Am J. Hyg , Sec A. 1-11 22. Lombard H. July 1941 L. and Warren Shields As- sociation of Other Malignant Tumors with Cancer - of the Skin A.J.P.H. 533-536 533-536 1943 May 23. Pohlen Kurt and Emerson Haven Errors in A.JPH Clinical Statements of Causes of Death A.J.P.H. 32 A.J.P.H. 251-260 Mar. 1942 a 620 AMERICAN JOURNAL OF PUBLIC HEALTH -_ June 1944 1944 24. Gover Mary Mortality in the United States ">" ue I. Trend of Recorded Cancer Mortality in the Death Registration States of 1900 from 1900 to 1935 | Pub Health Bull No. 248 U. S. Public Health Service Washington 1939 II Recorded Cancer Mortality in Geographic Sections of the Death Registration States of 1920 from 1920 to 1935. Pub Health Bull No. 252 U. S. Public Health Service Washington 1940 III Geographic Variation in Recorded Cancer Mortality for Detailed Sites for an Average of the Years 1930-32 Pub Health Bull No. 257 U. Public Health Service Washington 1940 25. Dublin L. I. and Lotka A. J. Twenty Years of Health Progress Metropolitan Life In- surance Co. New York 26. Dorn Harold E. 1937 Cancer and . Marital Status Human Biol 15 No. 1 Feb. 1943 27. Memorial Hospital New York City Annual Report 1942 U. S. Cadet Nurse Corps Induction Pledge At this moment of my induction into the United States Cadet Nurse Corps of the United States Public Health Service I am solemnly aware of the obligations I assume toward my country and toward my chosen profession I will follow faithfully the teachings of my instructors and the guidance of the physicians with whom I work; I will hold in trust the finest traditions of nursing and the spirit of the corps I will keep my body strong my mind alert and my heart steadfast I will be kind tolerant and understanding Above all I will dedicate myself now and forever to the triumph of life over death As a Cadet Nurse I pledge to my country my service in essential nursing for the duration of the war Vol 34 Sero KENNE Research Microbiolo TH diagnosis an lary dysentery increasingly import problem especially period The labor with the problem must provide a raj detailed examination the control official compatible with acc the nature of the in diagnosis has depen on the isolation an the causative organi mens Cultures a from blood and u reactions with pat been of little use tests have value + circumstances.16 Organisms of the stitute a heterogen as to physiological genic structure Alt have recognized pat two types Shige Flexner and S. s encountered in ba the United States Shiga and S. am relatively rare whi S. dispar are gen * Presented before the American Public Health second Annual Meeting 13 1943