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FILE NAME State of the Art Literature SAL DATE 1952 DOC SAL053 DOCUMENT DESCRIPTION Journal Article - Survey of Some Current British and European Studies of Occupational Tumor Problems 4 * o GeEAae, Se Be 2. eT PATtere oleae te Eas tage Cate. erties a ns tee . Be, we 1952 . work has he made | : 4 dermatitis which I s STUDIES SURVEY OF SOME CURRENT BRITISH AND EUROPEAN . OF OCCUPATIONAL TUMOR PROBLEMS WILLIAM E. NEW SMITH YORK M.D. IN JUNE 28 1950 I sailed from New York with the object of visiting iniividuals engagedin the study of occupational tumor problems abroad Experi- ence gained from these visits provides the material of this report and will be presented under the following headings I. Shale Oil II Petroleum III Asbestos . IV Dyestuffs V. V. Sources Sources of of StatSitsattiicsatlical Data Data on OccOucpcatuipoantalional FacFatcotorrss iinn CancCaencrer 1. SHALE OIL Skin cancers in paraffin workers in the Scottish shale industry were noted as long ago as 1876. In 1923 a detailed study of this problem with a report of 65 cases was prepared by Dr. Alexander Scott ' at the request of the Scottish shale industry Dr. Scott has continued since that time to serve as medical consultant for the industry and as works physician I had the privilege of visiting him at the Pumpherston Works in Calder Scotland where I also had the pleasure oi meeting Mr. Alan Anderson the works manager Dr. E. Smith the chief chemist and Mr. Crombie works chemist Mr. Crombie gave me a tour of the plant He stated that oil shale the material taken out of the earth is retorted at 1600 to 1900 F. at four plants in Scotland to yield naphtha ammonia and crude oil The products are then sent to the Pumpherston Works where they are processed yield gasoline industrial naphthas paraffin diesel oil coke and acid sludge The paraffin is obtained by a pressing operation to be commented on in more detail later Presented at a meeting of the Cancer Prevention Committee in New York Oct. 18 1951 Dr. Smith is Assistant Professor Department of industrial Medicine Graduate Medical School New York University Travel expenses involved in the preparation of this survey were met by grants frove the Anna Fuller Fund and from New York University 1. Scott A On the Occupation Cancer of the Paraffin and Oil Workers of the deit Shale Oil Industry British M. J. 1108-1100 Dec. 9 1922 The Occupation Dermaks Sente f the Paraffin Workers of the Scottish Shale Oil Industry with a Description of the Sente Adopted and the Results Obtained at the Periodic Examinations of These Workmen Eiget Scientific Report Imperial Cancer Research Fumil London 1923 pp 1-94 Shale Oil Industry at Occupation and Health Report No. 242. International Labour Office Geneva 1925 2. A Brief Description of the Operations of the Scottish Shale Oil Industry Scottish QizLtd. Glasgow 1948. 32 pp 242 Case1 varying siz va The erythe : Case 2 ; in Case 1 scars the : arms - and ; 30 years - 3 CAST They were _ 10 years a 4 CASE four kerat : skin over S. but Dr. from an fading de The latte : : obstructic . They paraff had paraff this case Fe to be em . All abnorm abnorm In this in area oil or wor tumors The in the 3 remove : is allo S scaly 3 paraffi latore " existit aS 0 exper been s case ( large that a ET ON REE Sas ARCHIVES HYGIENE OCCUPATIONALMED ~ AMA re anee -lea ee a. OF INDUSTR : I OCCUPATIONAL 5 242-263 : 242-263 wes be we 73 . . : i _ i } 7 r . t $ X22a2a ng ---- ap ed ble . lls for ~ - = auldSenalblabaaboinee: oere ons BRITISH AND EUROPEAN TUMOR PROBLEMS 249 He then covered his arm again with the lubricating oil but this time rubber it off with cotton soaked in a colorless technical grade of white oil Almost all the fluores- cence was thus removed onlya little remaining in very few scattered hair follicles human Dr. Cruickshank stated that he had not found dermatitis result in washed repeatedly with white oil provided the skin was healthy to start with skin Cases of irritation occurred when the oil was applied under dressings Further discussion of ways to protect the skin against oilsis contained in my section on Shale Oil Dr. Cruickshank and Prof. Squire have described warts that occurred on the skin of 33 oi a group of 138 machine operators exposed to sprays of cutting oil which they found capable of inducing skin tumors in animals fb had an oppor- tunity to examine many excellent photographs of these men Sone of the lesions were flat white keratoses others were raised rugose and pigmented Histologied sections showed the latter to be papillomas One man had a scrotal cancer sections of which I saw Photographs of his arms showed half a dozen small papillomas Prof. J. W. Cook at the University of Glasgow is attempting to identify the biologic chemical nature of the carcinogens in the petrol oils under Birmingham Prof. Cook was away from Glasgow witen ! visited biologic test at laboratory laboratory but the work was described to me by Carrubers vacuum distillation chromatography his assistant Dr. W on alumina and purifi Ity high- with perio side with acid they have isolated a chrysens general procedure is to extract the oils with a long sulfursulfur dioxide alumina columns and elute with petroleum benzin compounds crystalline as yet unidenti^-ed of which two has been obtainedin sufficient quantity for Mobagio test bat re hand find They havefailed to benzpyrene aromatics with sulfuric acid regenerate the Dr. Hieger cence spectroscopy II.. of unsuccessfully also said to have searched unsuccessfully for benzpyrene in hardinos simple genic at Birmingham I may notehere that a very Robert procedure its dea desc- tion of benzpyrene was demonstrated to me by Mr. Kennaway's laboratory in London An account Cancer in the British Journal of was useless as a means of All parties agreed and emphasized the need fluorescence fluorescence for spectroscopy spectroscopy spectroscopy spectroscopy spectroscopy The 1947 report of the Chief Inspector of lungs cancer of the or the pieura 31 the 23 yearsfrom 1924 through 1940. ati aard of whether lung cancer is so which phases of the industry aard The data cited above were Fustries Dr. R. A. tn 18. 18. Cruickshark C. Use The Use of MMiinenrealral Oil Bril Merewarher oe20wa;te,aifatnrdspao lvtn ryy Seessale sae yeed Ptah esetee}Ne StS SS us Boas : eS ise! > 3 tf 9 PET, , 1% cn ayy? ext te oh, jets = - : { - ag ; } ii : { -j i . a i i | r : wi . . SGC ! - ; ' : r ; ] 250 INDUSTRIAL HYGIENE AND OCCUPATIONAL MEDICINE Dr. Merewether referred to the governmental report publishedin 1930 by hini- self and C. W. Price This report showed that asbestosis developed in 80G +! men employed 20 or more years in the 1Th industry and that in various groups workers the percentage in which asbestosis developed varied directly with the dust ness of the process in which the groups were engaged These findings led t the adoption of laws requiring ventilation of asbestos work rooms in Great Brita Asbestos Industry Regulations 1931 Detailed specifications for safety equip- ment are contained in Factory Orders 1944. It should be noted that there is mining of asbestos in England Hence the British figures refer only to individua engaged in weaving or other manufacturing or handling operations A first problem was whether the apparent association of lung cancer and asbes tosis means merely that workmen's compensation procedures funneler all chest diseases into one group This possibility cannot be supported however for such high incidence of lung cancer has been found in cases of silicosis which are likewise reported to and reviewed by the Pneumoconiosis Board Cancer of the lungs or the pleura was notedin only 91 1.32 of 6,884 cases of silicosis recorded from 1930 through 1946.14 The incidence of cancer was thus 10 times greater in asbes- 4 totic lungs than in silicotic lungs Data on the average age at death in this silicotie group were not given but the same report listed a series of 1,037 silicotics who died at an average age of 38.2 years compared with a group of 160 asbestotics who died at an average age of 47.5 years Therefore the difference in cancer incidence : { in the two diseases could not be attributed to death of silicotics before they reached the cancer age in fact the silicotics would appear to have had greater opporf tunity by a full decade to yield cancers Similarly the average duration of employ- . ment in these two groups could not account for the difference 34.3 years for the silicotics against 14.9 years for the ashestotics : A measure of the rate at which lung cancer occurs in the general population of E England and Wales can be found in the Registrar General's Statistical Review f 1949 Employing the data given on pages 3 and 145 of the Review one can 7 calculate that 1.36 of all deaths in the three years from 1943 to 1945 were reported { as due to cancer of the lung the bronchus or the pleura It is of interest to note % of attributed in population that the percentage of deaths attributed to lung cancer in the general population is almost identical with the figure of 1.32 for the finding of lung cancer in a large group of silicotic lungs Documentation of the cases of coexistent lung cancer and asbestosis became my next endeavor For this purpose I visited Dr. S. Roodhouse Gloyne at the Institute for Social Medicine in Oxford Dr. Gloyne's studies of the pathology of asbestosis are well known For many years he has received lungs for review on matters of compensation Dr. Gloyne generously gave me permission to cite the data in Table , which he assembled from lungs that he personally examined in the gross and microscopically It is to be hoped that a full account of them will l- 17. a Merewether E. R. A. and Price C. W. Report on Effects ut Asbestos Dust on t Lungs and Dust Suppressionin the Asbestos Industry London His Majesty's Stationery Offic 1930 summarized in J. Indust Hyg & Toxicol 117 1930 and in Tubercle 09-81 10 118 and 152-159 1933-1934 b ibid p 10. Table 3 c ibid p 14. Table 2 , 18. Gloyne .: The Morbid Anatomy and Histology of Asbestosis Tubercle 45-45 493-497 and 550-558 1932-1933 Asbestosis in Silicosis ant Asbestosis edited by Lanza A. ~fi New York Oxford University Press 1938 pp 225-244 published death In add 169 perso those incl 8.3 . gross or i asbestotic 10 men to in incidence sex ratio It wil without f coninses for the g found fr Table 1. = Pot Coa 250- describe this ele continu continu in his in his se scattere The tosis gi tubercu Table catcert brielu found tuit tuit ae .... A. Na [ oY cannot cannot een bere ee BE Parise ; Ne a Beate eae Serta Pht eee ie gt tet ee FRY oke:ign! aes Besti oa Tha I A im- 2 F to tain tip- tip- .12ls eslest are ngs om ese otic vho ace ned or- oy-oythe " . 9 : BRITISH AND EUROPEAN TUMOR PROBLEMS 251 published from a manuscript that was in preparation at the time of his recent death.,, In addition of Table 169 persons without included those 8.3 The to the material 1 Dr. Gloyne also examined the lungs of pneumoconiosis but employed in the same set of industries as in Table 1. Ainong these he found 14 who had primary lung cancer lungs of 11 asbestos workers who had no asbestosis either in the _ gross or microscopically were negative for carcinoma The 17 cases of cancer in asbestotic lungs Table ) were about equally distributed between men and women 10 men 7 women whereas in the normal population in England the ratio is said to be 4 men to every woman with cancer of the lungs In addition to the higher incidence of cancer in asbestotic lungs Dr. Gloyne felt that this difference in the sex ratio afforded evidence for an occupational factor It will be apparent that the lung cancer rate of 8.3 found in the 169 individuals without pneumoconiosis and the rates of 5.1 to 8.9 in the groups with pneumo- conioses other than asbestosis are much higher than the rate of 1.36 estimated for the general population on the basis of death certificates and the rate of 1.32 found from pathological examination of the large group of silicotics previously Table Incidence of Primary Lung Cancer in Groups with larions Types of ( Data of S. Roodhouse Gl^,yne ae Pneumoconiosis __ ; Occupational Group Iron and steel wor0.k ccc ee e eeeccer econs ences Pottery workers .......cccccscessessceecereesecsneeeces Coal miners Stonemasons cece es ee ence reese ........ ss. esce. cecee enee - 22.0.5... seeeecneeceeceescsacsseresecsaes Asbestos workers 22... - neces ec ceeee rect eereseateeeces Persuas with Pneumorniosis Nungber Nungber Nungber 7S 340 233 96 121 Number Perentake withwith Primary with withPrimary 4 5.3 19 -" 19 83 " 5.0 14.0 r . ote ion 1 my , sti- of -- -- the the described It is thus probable that the higher rates reflect closer study Despite this elevation of the base line for comparison the rate in the asbestosis group continued to stand out Dr. Glovne stated that of the total number of lung cancers in his series 7.5 were discovered only on microscopic examination These were scattered through the various groups The type of ** cancer and the degree of asbestosis in the 17 cases of the asbes- tosis group are given in Table 2. Only one individual M. S. had evidence of tuberculosis In the 922 cases comprising the whole of the pneumoconiosis group ' Table ) 20 showed tuberculosis Dr. Gloyne made a special search for pre- cancerous changes in asbestotic lungs and did not detect any Desquamation of bronchial epithelium was occasionally seen but squamous cell metaplasia was not found save in the cancers themselves It will be noted from Table 2 that the degree J og . 19. A brief posthumous publication has appeared Gloyne S. .: Pneumoconiosis A HisPinical Survey of Necropsy Material in 1.205 Cases Lancet 810-813 1951 2. Through the courtesy of Dr. K. F. W. Hinson of the London Chest Hospital we have received lobes from six lungs of Dr. Gloyne's series This material was examined by Dr. Douglas > Als underland of Memorial Hospital New York Two cases C. W. and J. W. classified as : Sjumisous cell cancer by Dr. Gloyne were interpreteads terminal bronchiolar alveolar cell ; carcinoma by Dr. Sunderland es BeB a oe h ost : roe > 3 & = AS od ae. - OOR OT A Pr ICRU POTEET i>,it ig TRUE A046 a GND Se ROOT v A aE 3 RRR a iS e re ANG 3 + q EE Wes Atins wWLA Re dy: Fg oes a Ps0G Ae dodtp we te Se vn oa me f ee Ae rr Be oe meT co ren n AIS cerRTE ay 1 whi Ass) / aa 9 . PERIL: ane : a nF es $4 = phe dG Lt Fe 5 ae A weg RE ages pate E PERS Sud Ce peta PY Ie SRS Sees eee Che ae ete gwekerncg peers ME: se CE fons hn ah Oe Ba AX PRP ITER Sabres R 4 we FeO year SE Taree tee a ao eRe Aer Te LENS thee Va feaes & A tho se ie Re . SO, a] ehS edeeae > Meee ' oat im cae . or ax So Spo. oe eee oe) Sie NEY Sity | n . Sew2 = rf A a F = sent : ath eran 2y- ae : PA Boa 2 aa ers : SAREE af - Pa EF ek : Mite Sikes % i , pt : See ; apa ee ] : eh | ; 5 ropaied 5: ^' ; 4. { : : R-, . Jn ) ap, ~~ oe { fa j ae ie ; 2 4 wie) { Sf wise = ie j Paes ad | - | IKE ae < { ec ohee. H S& ; Kop2395 |i j qn eS 5 : }^' 2 Fis ph oy i x agree ; i Cee Tad : Cee bred f ' $3 eae ; ; a = A ; , : ' : - } s : j ] 4 . 252 INDUSTRIAL HYGIENE AND OCCUPATIONAL MEDICINE of asbestosis in the extensive in group of cancerous lungs was recorded as moderate degree of every case except one where it was mild The estimation or asbestosis was made in every instance by the same observer of the The 17 cases of coexistent Dr. Gloyne cancer were assembled over lung and asbestosis studied by Dr. Gloyne to a period of 20 years 1929 to exposure asbestos prior to 1932 the year modern exhaust 1949 their All had their in conformance with ventilation devices were adopted government regulations plant handling Rhodesian The majority were employed at a blue and South African also blue asbestos Both types are more brittle than Canadian white asbestos hence these At least one patient J. I. however was stated give rise to more dust Canadian white asbestos to have been exposed only to , I next visited London where I Prof. E. had the J. King at the opportunity to British Graduate Medical examine protocols relating to School in the lungs Table Pathological Findings in 10 Men and 7 Women with Asbestosis and Data of S. Roodhouse Gloyne Lung Cancer , Patient Degree of Lubestosis re, Type of Cancer Extensive Extensiva - Moderate Moderate Moderate Moderate Moderate Moderate Moderate Mild Extensive Extensive Moderato Moderate Moderate Moderate Moderate Ost Cell . Oat Cell Squamous Cell Squamous Cell Squamous Cell Squamous Cell Squamous Cell Squamous Cell Squamous Cell Out Call Squamous Cell Squauious Cel Squamous Cell Squamous Cell Out Cell Out Cell Adenocarcinoma asbestos asbestosis of 11 individuals who had been employed in a plant using Canadian white The pathological descriptions were inade by Dr. C. V. Harrison of asbestosis were noted in 8 of these 11 VaryingVarying degrees the 8 asbestotic lungs Au oat cell lungs there were 3 cancers all among male with extensive asbestosis cancer was found in lungs of one patient patients males in of Anaplastic carcinomas were described in two one whom the degree of asbestosis other the asbestosis was minimal The asbestosis was moderate in the remaining erate in the 5 patients remaining patients in this ranged disease from extensive to mod- in whom this disease was complicated cancer Combining the data of Dr. Gloyne and Dr. not complicated by 20 cases of coexistent lung cancer and Harrison one finds that in extensive in 5 moderate asbestosis the degree of asbestosis was in 13 and mild or mininial in 2. was squamous cell in 11 oat cell in 6 anaplastic in 2 The cancer There was no correlation between and adenocarcinoma in . visited next visited Dr. degree type of cancer and of Wyers Hubert Wyers Wyers the medical medical officer for in engaged in manufacturing asbestos products from a company in England Rhodesia blue asbestos mined in ; co wines tet b . BNI) "s ne jae -_ a ae 7 Bs * - _ zo ie ar ? - 6 ! . : : : , - > . : - ; oe 3 < i * i . _ ww aa a I E 7 t < if . b : a , an 8 ts . a: 7 ~ -- C Ke, | * or the | me Soyne osure opted at these dust ly to - xol in ungs an INCEP = _ oo <wt ~~ stos grees nong tient two 1 the nod- by at in was incer in Lt oe fi land YY BRItish and EUROPEAN tumor prOBLEMS 253 or South Africa Dr Wyers is the author of a valuable clinical study of asbestosis He stated that asbestosis was recognized in 1900 and that the industry grew to major stature in the war of 1914-1918 Dr. Wyers has seen only two deaths from asbestosis in people who started to work in the industry after 1932 the year when exhaust ventilation devices were installed In contrast he had seen 115 deaths involving asbestosis in persons employed before 1932. He feels that the regulations in regard to safety conditions in the asbestos industry are therefore a great triumph of preventive medicine The diminution in the severity of the disease in terms of the number of persons affected is further borne out by lessened severity in the individual cases Prior to 1932 the disease was acute with deaths sometimes occur- ring after two years of exposure The disease as it is now seen is much more chronic In the 117 cases of asbestosis seen by Dr. Wyers primary lung cancer was found in 17. Dr. Gloyne examined the lungs in these 17 cases and his pathological diagnoses of the tumors have been given above All of the 17 individuals with asbestosis and lung cancer were exposed before 1932. According to Dr. Merewether the additional 3 cancer patients studied by Dr. Harrison were likewise exposed before 1932. I specifically inquired of Dr. Merewether whether any cases of coexistent lung cancer and asbestosis had been reported in individuals whose exposure had taken place only since 1932. He stated that only one such case has been reported that of a man employed in the industry between 1935 and 1945. This single case might well be expected as part of the normal incidence of lung cancer in any group as large as that employed in the asbestos industry . In summary then I was able to find some information on a total of 21 persons with coexistent lung cancer and asbestosis of whom only one was a man working under conditions now prevailing in the industry The additional 10 patients making the total of 31 described in the Annual Report of the Chief Inspector of Fac- up tories for the year 1947 had all been exposed prior to 1932 and I did not attempt to locate autopsy protocols describing them It was the consensus of Dr. Gloyne Dr. Wyers and Dr. Merewether that the nature of the disease asbestosis as seen in England has changed so that it is less common and less severe in individuals whose employment in the industry has taken place only since 1932. It was the consensus that a lung tumor hazard formerly existed in this industry in Great Britain but that there is no evidence to show that such a hazard continues to exist under the working conditions now prevailing - It should be further noted that in the 1947 factory report Dr. Merewether shows that a mean exposure of 16.5 years with a range of 1.5 to 40 years existed in the cases of asbestos workers who succumbed to lung cancer Individuals beginning appear their employment in the 1930's are therefore only now reaching the mean age at which tumors might be expected to The size of this group is not known but the fact that it has thus far provided only a single case o coexistent lung cancer and asbestosis argnes that any lung tumor hazard has been greatly diminished at Whether feast in point of time delayed appearanerapearaner remains Prof. King described his there will be any significant umuber of cases with seen to be experimental studies on the use of alumina in puenno- conioses In the case of experimental asbestosis alumina haul no beneficial effect 21. Wyers .: Asbestosis Postgrail M. | 431-437 1950 Maile tsar eon . aS 1 te ey a So yoate : aa Se . : re engi Ree Be + ERE Be cc . Seege a ent : gent BRS bed ie a PER ANS aaa - pee Need RcE eaetPLRSEeS Ape IEA CT Sam en tanLSU re f RAEN AG PRIS MLR) TORUS eT ad EE R Os iv thst ks PF EXT TIS Pn Ns BES " = yr ap Sore bs OY TO Sy gle aS, x:} a Se Fag ig FE . : ! : H , toe { : i t : ; : : { : . : : : : : : ' ; : : rey a : ' ees ; fas | : Rea er wen { . i ran 7 : f } ; booed 0 2 ! : : j ' ; : wf P : : , . ! : : : : ' : . \ | % { ~ E 202 INDUSTRIAL HYGIENE AND OCCUPATIONAL MEDICINE {oe [a : July 1950 a conference was held at sociological and conference conference have environmental factors published * been published with Oxford dealing with cancer in relation to other than occupation Proceedings of this . ABSTRACT OF DISCUSSION Dr. Paul CartIER L'Annonciation Que Canada I have been asked to describe our experie ence at the Thetford Industrial Clinic in Quebec where we see men engaged in the asbesta asbesta mining industry in Canada Table 3 presents data on eight cases of primary cancer of the lung which we have detected among 4.000 asbestos workers between 1940 and 1950 In addition to those listed in the table there was a case in which there was quite a definite clinical and radiological history of cancer of the lung but for which unfortunately no autopsy was performed Also there were three other cases with a strong suspicion in favor of a cancer of the lung but for which no sufficient data are available On analyzing these anyone will be able to the asbestos factor data it seems obvious that many points would need discussion beinre establish a causal relationship between these pathological findings and Is it not more logical to think that the same causal factor will produce the same type of tumor and therefore why do we observe such a variety of malignant tumors TABLE Cases of Carcinoma of the Lungs Detected Among 4,000 Asbestos Workers 1940-1950 = t ( 4 Cases --"-- -- -- 5 --"-- B-- -- : 7 cancer . worke a : great only ( 5 lioma Dr. I cinou ; to ex IG . suico Pneu : re . serie z the t y the : 7600 e t : of li ; f in TITTE Years of Exposure Years TITTE TITTE TITTE TITTE TITTE TITTE TITTE TITTE ' Type of Tumor . z . TITTE TITTE TITTE TITTE TITTE Bronchogeale carcinoma TITTE ey TITTE TITTE TITTE TITTE . Bronchogenic carcinoma TITTE i" TITTE TITTE TITTE TITTE Mediastinal lymphosarcoma : TIT E " with pulmonary metastasis ; TITTE TITTE TITTE TITTE TITTE Bronchogenic carcinoma 3 TITTE TITTE TITTE TITTE TITTE TITTE TITTE Pleural mesothelioma } TITTE TITTE TITTE TITTE TITTE TITTE TITTE TITTE TITTE Bronchogenic carcinoma TITTE . TITTE . Bronchogenic carcinoma . .. 3 . TITTE TITTE None 29 65 None thoracotomy : s Pleural mesothelioma _- Standard New York The Nomenetsture of Diseases and Operations published by the Ameriena Medical Blakiston Company 1922 suggests the term mesothelial sareonia arn Association Ce. 4 pg had had reic tan pac pac me . If for a moment we may assume that the asbestos fibers might produce a bronchogenic carcinoma in asbestotic employees with significant exposure then only two cases of the series would serve as evilence because the cases of mesothelioma or lymphosarcoma and cases without exposure or without asbestosis du not have the conditions required Ay last remark it would appear necessary that any statistics on occupational cancer of the lung to be conclusive should indicate the precise variety of lung cancer ; . . 2+ Mr. Edwarn A. Lew New York The difference in the frequency of lung cancer in persons with asbestotic lungs as compared with the large group of silicotics provided by the Pneumo- coniusis Board seems impressive However one might wonder whether the two groups had been examined for cancer with equal care am impressed by the fact that when different groups of hings were studied by the same observer Dr. Gloyne the differences in frequency of lung cancer were much less If we restrict our attention soiely to Dr. G oyne'sseries I am not sure that the differences are statistically significant . . clinically Dr. A. Lanza New York think is important to distinguish between cases of recognizable and fatal lung cancer on one hand and cases in which the diagnosis of lung cancer has been marie as more claim for an association or less of an between lung incidental finding at autopsy on the other The English cancer and asbestosis has been based it seems to me on data obtained from lungs that a pathologist has searched with a microscope I wonder how many _- 31. Conference ni Geographical Pathology and Demography of Cancer J. Nat Cancer Inst 627-662 1950 : i * * * a :. i : ; 3 3 2 . 4 Ps i . . : . . a Pe te = Ro, + Seen > bag ene e ~ - piviea Se pose Darn wee. a a folk aad chicas ; Mts : Se bBiaddadeed Meee fa 5 ido ptt, . EyOY oe iG o ae % _*, C C C i C xperi- topsy pe of BRITISH AND EUROPEAN TUMOR PROBLEMES 263 cases of lung cancer would be found if lungs from any sort of population were subjected to the same minute scrutiny Dr. Smith ^ nregard to Dr. Cartier's query as to the significance of different types of lung cancer it may be pertinent to note that a diversity of tumors was found in the lungs of chromate workers reviewed by Dr. Anna Baetjer Experimentally the polycyclic hydrocarbons evoke & great variety of tumor types If asbestos is carcinogenic I would not expect to see it produce only one type of tumor I am interested in your observation of two cases vi pleural mesothelioma This is a rather rare tumor In examining pathological material sent us from England by Dr. Hinson we found among six cancerous asbestotic lungs two presenting alveolar cell carcinoma These tumors are often diagnosed as pleural mesothelioma I should very much like to exchange slides with you In reply to Mr. Lew and Dr. Lanza it was my understanding that the English cases of silicusis and their cases of asbestosis were handled in the same general fashion through the Pneumoconiosis Board and that the lung cancer rate found in silicotics could therefore serve as a reasonably satisfactory control for the lung cancer rate in cases of asbestosis In Dr. Giloyne's series of 81 cases of lung cancer in the several pneumoconiosis groups and in the control group the tumor was evident in the gross in all except 6. Some of his material was destroyed during the bombing of London but his recollection was that all of the cancers in asbestotics were recognizable in the gross DR JOHN L. Poot New York Have experimental studies thrown any light on the question of lung cancer in relation to asbestosis DR SMITH In 1941 Nordmart and Sorge in Germany claimed to have produced cancer in the lungs of mice by exposing them repeatedly to asbestos dust Their statement that cancer had resultedin 20 of their exposed animalsis occasionally quoted Actually their20 figure referred only to two mice one of which liad a type of tumor that occurs commonly as a spon- a taneous growthin mice The other they considered to be squamous cell carcinoma but their photograph does not impress me as that of epidermoid carcinoma It seems rather to show merely an area of squamous cell metaplasia ation car- muid out the SOTLS ecu : of .cer the . ily cer ish 00 - -- ers Seesoe deat wie = ne : ret faaSS 5 Ts Sphaas othe as = a tt ro te eer 3 S $e me SKEage oe ES ERE RE meeae ~