Document O3V0m6rxQ1KJEpEbwKXq06pqK

lHiurt 23, 1967 " 1 ' t .MW 0 CO O LU > sk --J err C_3 oQ CSC U_ oo LU I-- 0 ui oo ; \\N\ 1Hia DOCUMENT f^NOT COm'e'fROM pro '^ndE CANNOT BE AUTHENTICAT J_BB_ 00 07568*7 HO fvi . v* t SG7 THIS OOCUiv.il. *iJ K., J W w PPG INDUSTRIES, INC. DIO NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG.INDUSTRIES* INC. Mesothelioma and Its Association With Asbestosis Maxwell Borov, MD, Alfred Consion, MD, Lawrence L. Livornese, MD, and Sorbert Srhalet, MD n!iZ Within a three-yaqr period yC* community hospital, exist. Since Godwin* in 1957 laid down strict cri 17 cies of mtsothetibrxT, nine of the pleura and eight teria for the diagnosis of pleural tumors and Wins of the peritoneum, were fouad at surgsry.^jTwo of our low and Taylor* in 1960 for peritoneal tumors, the patients contracted this maligqancy w(thyAnjy environ diagnosis of these neoplasms has become more com mental exposure consisting of iWng w a pomrtrtjnity mon. The incidence of primary mesothelioma has adjacent to the asbestos mill. In the sspfe hospital there varied statistically from .02% to .2% of all autop been a high incidence of bronchogenic | carcinoma sies. with a ratio of one to two iri favor of the male. . asbestosis. A review of the autopsy material ^afti^e / The first large series of cases of diffuse meso- r*st decade brought to light only one additional easel /theKoroa was diagnosed histologically in 1957 at the It is our belief that the incidence of mesothelioma is /` Pneumoconiosis Research Unit at Johannesburg, increasing as is incidence of asbestosis, with theX /South Africa.. In trying to explain this mysterious increasing application of this product in many different s^pidemk, Wagner et al,' noting that asbestos bodies industries. ceuld'be ^opnd in^he lunes of some of their pa tients, obtained Retailed life histories of these pa P *4^* t rimary tumors of the serosa)Surfaces are so rare that for years they were considered to be pathologic curiosities. The first reference,9 such tu mors can be found in a report by V^cRntoisLnsky,` who in 1854 described primary tumor^fctije'/fcerjtoneum which he called "colloid cancer.K; Duringthe next 100 years, there were sporadic tients. fey^lSeiythdy ware able to establish an as sociation wit!)/the jCajfc o'KGood Hope asbestos fields, or the industrial ust/of'asbestos, in 32 of 33 patients with hisjrologigiCy proven pleural meso theliomas. The mrioritvyof tbe^ patients had not actually ,,wro*rkke d S* with asbesto^ut *n,dVftimir jjatf/ived in e h^d the left similar types of tumors. However, this entity Vr/-/'vt^.-riod b#tw*>n j, mained so ill defined that there was much doubt M^!&{naoT was 20_to 40 vprtc rv iq averent of to its precise nature. Brown and Johnson' in 1951 ^ taffS fi IL~' agner et considered these mesothelial tumors (roesothelio- al -- ^en,,o--s--e--d- a---t-o--t-a--l---of 8_7. pl-e--u--r-;- ^nd two ma) to be the end result of an inflammatory pro cess, with organization of the exudate. Willis' in his pathologic text made the following statement: "To the present day accounts of supposedly primary serosal tumors continue to be descriptively inade quate and insufficiently critical, displaying a lack of awareness of the possible behavior of small unde tected carcinomas," and he also cautioned the read er to preserve an open mind regarding the exact agenesis of these tumors. In 1954, Ackerman* jd that it was the majority opinion that al* rtnough primary mesotheliomas are me they do peritoneal- mesotheliomas. In only two cases was it not possible to establish a history of exposure to the asbestos dust. Of these 87 cases, 12 had bad industrial exposure and the remainder had had en vironmental exposure from living in the vicinity of the mills and dumps. This association between mesothelioma and asbestosis was made even more intriguing when, in 1955, Bonser et al* described a series of 72 autopsies on patients with asbestosis, in which four cases of peritoneal mesothelioma were found. Subsequently, Mancuso and Coulter1* found five peritoneal mesotheliomas in autopsies on 1,495 asbestos workers, and Hourihane," upon reviewing From th* department* of rurfery tnd pathology, Somerset Hos pital. Somerville, SJ. Reprint request* to 15 Church St. Bound Brook. NJ 08805 (Dr. Borow). the necropsy files of the London Hospital from 1917 to 1962, found 34 cases of mesothelioma, 17 of the pleura and an equal numb**1 -1 ______i `J'bTouot^^I o CO -J IlMl 1..- *31 lOCY * W*i '>*' ' MS 'SOTHEUOMA AND ASBESTOSI&-BOROW tAL toneum. All of these patients had pulmonary as* We might attribute our absence of females involved bestosis, even though is a few there was so his with this disease due to a difference in occupational tory of exposure to the asbestos dust. In the same exposure between the male and female workers. year, Enticknap and Smither'* reported 11 cases of However, other studies would not substantiate this, peritoneal mesothelioma in patients exposed to as as there appears to be a high incidence of meso hestosis. theliomas in people just living in the vicinity of In an attempt to determine whether mesothelio the asbestos mines or industries. In Wagner's series ma of the serosal surfaces had any relationship with from South Africa, more than half of the people had asbestos exposure in the United States, Selikoff et not been employed by the asbestos industry. These al`* studied 307 consecutive deaths among asbestos people had had environmental exposure due to liv insulation workers in Northeastern United States. ing in the vicinity of the mills and dumps. The sta They found ten deaths caused by mesothelioma, tistics from the London Hospital, as reported by four pleural and six peritoneal mesotheliomas. In Newhouse and Thompson14 are very much the same, addition, these workers had an extremely high with one half of the patients having only an en death rate attribut*B"T&sxancer of the stomach, vironmental exposure to asbestos. With this infor colon, and rectuny Of the\07 deaths, 40.4% were mation, one wonders why we have not seen similar attributed to cancer, 5.5% ro asbestosis, and 54.1% circumstances in our community, especially since to other causes. In^a second^glu3>vwhere they re there is a large asbestos dump adjacent to a resi viewed 26 consecuti^r-autjfpsies oApatxents with dential area. asbestosis, they found fou .s of the Another interesting observation in our series is pleura and three of the peri the fact that 16 of the 17 patients with mesothelio- One of us (M.B.) has had !xp jriende of ma were diagnosed within the past three years. A re- operating, within the past two years, 11 patient*. view of the autopsy material for the previous decade who proved to have mesothelioma. Six ft these ^ brought to light only one additional case which were of the peritoneum and five of the pledra-JJPhea^ ^initially had been misdiagnosed. Since the refine- cases added to those diagnosed previously aLade a. /me^t'*of the asbestos fiber has been one of the ma- totalof 17 cases of mesothelioma, of which eight were / jyr industries in this geographic area for over 60 peritoneal and nine were pleural mesotheliomas. Air >years, it'is difficult to explain why we are only now 17 cases were diagnosed within the past three years, ^aware.nf this disease. One possible explanation is A review of the autopsy materialist Somerset F thaTTlh poxxgroup,'of patients, once the diagnosis pital, Somerville, NJ, from 194S3iuKough 1965 did was suspected, an intensified effort was made to not disclose any additional cases olizjesothelioma. obtain ah-autopsy whence patient died. However, This high concentration of what is cohwdfred to be prior to our recognition/of tKa-jentity, patients with a rare tumor can be explained by the dosepy&xjmity mesothelioma were m<fst likely "diagnosed as having f a major asbestos milL Approximate]11 a generalized carcinomatosis ar)d little effort was the asbestos fiber which is mined in Nor&iAmbifica m---a--d--e--t-o---o--b--t-a--i-n---a-n---a--u--topsy when they. d. Regard* is converted to commercial use in an industri^J.-fa^n, less whether this reasoning j* cor not, it is dlity which is located only two miles from Somers^W"^PUT distinct impression that the" defi- HospitaL jncrease in incidence of this malignam witbifj The association between pulmonary cancer and 'f&ela&fpw years, asbestosis has been recognized at this institution for many years. The number of patients admitted with these conditions is difficult to determine, as in ear 1. TOtuMaapillar? type mesothelioma <* l. slightly rtobced from xl20). lier years many of them were diagnosed as pulmo nary fibrosis or silicosis. The only accurate statis tics could be obtained from the autopsy materia] of the past decade, 1955 to 1965, when 1,330 autop sies were performed. In this group, there were 22 cases of bronchogenic cancer with pulmonary asbes tosis, as well as the 17 cases of mesothelioma. An interesting observation is that, despite the fact there were large numbers of women also employed at this industrial facility and many contracted as- beitosis, there is only one female with mesothelio ma in our series, and she never worked in the as bestos plant but lived nearby. This experience is in contrast to other reported series, particularly those from South Africa where there was a significant number of females afflicted with mesothelioma. Newhouse and Thompson," in studying the occu pational histories of 83 patients with mesothelio ma, noted that 42 of these patients were female. t-A ri*-;J . `^ i . 5ft V;* . i--- r. n 94 BB 0007570 JAMA, Aug 21. 1967 Vol 201, No 8 ,r, 589 / - ; ,V . - .i'i * i--* '. -/ : - 11- '* r r * \ t / *; *-* / . c r 1 ' r>:'*v ' r'- 4 i i* <r M \~a s* I Death the surface, and all other organs were unremarkable. Microscopic examination demonstrated an extensive in terstitial fibrosis of the lungs with many asbestos bodies (Fig 2). The hypertrophied heart showed areas of fibrosis and acule necrosis. The tumor was characteristic of meso thelioma with cuboids! cells showing some pleomorphism and superficial papillstion. Case 2.--A Si-year-old white man was admitted to Som erset Hospital because of abdominal pain. For 25 years be was an-employee at an asbestos refining plant. He smoked leas than one pack of cigarettes per day. Results of physical examination were normal, and all laboratory studies were unrevealing. Chest x-ray showed a r fibrotic infiltration of both lower lobes. An upper gastro intestinal roentgenographic series demonstrated duodeni e*. tis and gastritis. He was discharged on a regimen (or ul cer convalescence only to be readmitted seven month* ' 2. Asbestosis of the lu Report of 120). later with postprandial abdominal pain and a 10-lb weight loss. On palpation the abdomen appeared board-like, though there was no tenderness, and an extraluminal mass could be palpated through the anterior portion of the rectal wall. A barium enema demonstrated rigidity and narrowing of the Case 1.--A 52-year-old white ai /dmitUrd\ tie sigmoid colon. At surgery, the abdominal cavity was found liospital with increasing constipation, an enlarged ab^oise^ to be almost completely obliterated by large masses of neo y. one month's duration, and an ill-define<^bdomina plastic tissue which had enveloped the intra-abdominal or jHe had been retired with a medicaJ disabiUW.(i-jWpulrool gans and was infiltrating the parietal peritoneum. A diag ; nary asbeslosii after working 28 years at an as&estov^nill nosis of mesothelioma was made from a biopsy specimen. ';He suffered a myocardial infarction two years before a<t /Tha-patient died four months later. Emission. He smoked only occasionally, ( ( / Pertinent findings at autopsy included numerous large Physical examination revealed a slightly emphysematous* plaques'on the parietal pleura and congestion at the bases /, chest with harsh breath sounds and abdominal distention. No intra-abdominal masses could be palpated at that time. of 'both lungs. The peritoneal cavity was virtually obliterat ed by a^rge^A-eJlowish-white herd tumor which wa* com Chest x-ray of the lungs demonstrated basilar fibrosis, pletely``encasing''the abdominal organs (Fig 3). Except bilaterally, interpreted as most likely due to asbestosis. for this surface, involvement, the organs were unremark An anteroposterior x-ray film, without contrast material, able. y l yv. of ** abdomen demonstrated a ground glass appearance Microscopic examination .demonstrated bronchial pneu at ve of ascites. Some attenuation of the rectosig- monia with "a "mi Id pulmonary fibrosis and many asbestos i the x-ray film taken after , evacuation of the bodies. The tumor"'consisted iff. fusiform cells in a hyali- enema raised me possibility .of ^ pelvic mass. A nlzed stroma with papillary' formation characteristic of ^^Kracenlesi* yielded approximately 1,500'ce of straw-col mesothelioma (Fig /1 / ored fluid. Surgical exploration revealed the visceral and Case 3.--A 47-year-old/white man w dmitted to the parietal serosal surfaces to be studded with ne-p*pillary, hospital with a nonproductive jeodg; SU-defined dia almost granular-like, projections. A diagnosis of 'papilloma comfort in the right lower lofyfoi lling. JThe initial mesothelioma was made from a biopsy specimen (Fjf'.-l,). chest x-ray film was normal, but a id on* taken two t Following an intraperitoneaJ injection of gold, A.U-19fi,-; days before admission demonstrate small' pleuraLyffu* _ he remained symptom free and ascitic free for"j'h^he ,s' aion in the right costophrenic angle. Though '* months. Fourteen months alter surgery be died from.-'U. insurance agent and more recently w liqy myocardial infarction. ' '/Q* be(-hnd_ worked as a stock boy in an ashes Autopsy examination revealed pleural cavities to be months, 24 year ago. free of tumor. Pleural plaque* were present at. the base* and there were multiple adhesions. The lungs demonstrat ed bullae emphysema with an irregular delicate fibrosis *gi throughout- The heart was enlarged with old scarring and Jw a fresh infarct. The peritoneal cavity yielded 1.000 ee of . slightly mucoid yellowish fluid, and all the coelomic cav- 'C/ j^th`yfioak-examination and complete work-up we veiling, ih$ydjng scalene node and two needle biopsiea. Thbwstoeentesi* yielded 100 cc of straw-co} fluid with some mesothclial cells. At exploratory thorac tomy the patient was found to have a gTeatly thickened parietal and visceral pleura w-ith encasement of a partial S ity organs as well as the parietal peritoneum were cowered with white hard nodules, varying from 5 aim to 5 cm ly atelectatic lung. In certain areas the parietal and vis ceral pleura were intimately adherent to -one another, in diameter and having a mucoid appearance on the cut surface. In many areas there was a tendency for these and could not be separated. There was no nodularity of the serosal surfaces. nodules to coalesce to form larger tumor masses. The tu mors did not penetrate for any appreciable distance be- A diagnosis of pulmonary' asbestosis and mesothelioma was made from a biopsy specimen. Postoperatively he re ceived steroids and cobalt radiation with a poor response, 3. Serosal tumor encasing loops of bowel (case 2). and he died ten months later with bilateral pleural in volvement Clinical Feature* Gp" iI rGo il . *^~r. ` * it i * -- `w ' f _____ .. \ - >* -% * -- * ' , - . Our patients with peritoneal mesothelioma pre sented themselves in one of two ways. Four had as cites of unknown origin and the other three com plained of vague abdominal pain and weight loss. In this latter group an ill-defined mass was usually palpated either through the abdominal wall or on rectal examination. Laboratory-work-up and roent genographic examination of the gastrointestinal X.' JAMA Aug 21.1967 Vol 201, NO 8 95 ---f-007571"7 -7\ 590 Mw vTHELIOMA AND ASBESTOS1S-BOROW E7 tract were unrevealing. The diagnosis was made there is a coalescence of these, nodules, so that t either by surgery or peritoneoscopy and biopsy. the terminal state usually consists of solid, broad, ' Those patients with ascites were found to have thick bands which encompass the viscera and fix small papillary projections studding the visceral them within a dense mass. Often the delineation and parietal peritoneum. The ascitic fluid varied between parietal and visceral peritoneum is lost, so from a clear syrupy to a thin straw-colored consis that the usual autopsy dissection is impossible due tency. Those patients with the palpable masses to this encasement. The tumor is generally white were found on exploration to have complete ob and firm and may have a mucinous appearance on literation of the peritoneal cavity by large tumor the cut surface. masses which were occupying most of the coelo- Histologic Characteristics.--We have seen two mic cavity and invading the parietal peritoneum. major histologic types of mesothelioma. The most We believe that this picture is but the end stage of common variety is the epithelial form where there the disease, while thbse"Patients with ascites repre- are cuboidal or polyhedral cells producing a tubulo- aent an earlier stage. This^s substantiated by the papillary appearance or a solid group of cells with finding of papillary projections at surgery in several out a clear tubular formation. Usually there is a fair of cur patients who having ,.fJ?eserft^d with ascites ly uniform cellular structure, but occasionally and in whom obliteration of the peritoneal cavity bizarre nucleated cells can be seen. Pathologic mito with large tumor masses developed lateiy^s seen at tic cells are rarely found, but doubly nucleated autopsy. f | and multinucleated tumor cells are often seen. The Patients with pleural mesotheliomas all present other variety is the mesenchymal or fibrous type ed with varying degrees of chest pain arid pleural \ of mesothelioma in which spindle cells are arranged effusion. A work-up was likewise unrewarding with in an almost fascicular pattern within a stroma of the exception of positive findings from a pleural abundant hyaline collagen. Occasionally the cells biopsy in one patient. The fluid in the pleural cavi- /'may be arranged loosely in indistinct fasciculi or may ty varied from a gross bloody effusion to straw-col-/ occur in' solid nests. The most striking histologic ored fluid, and the tumor involvement varied from Characteristic of mesothelioma is the structural papillary projections on the parietal and visceral 'variation which may. occur from area to area within pleura to a generalized thickened pleura. In areas the same tumor, so`that in one area the growth may the vise;::.! and parietal pleura were intimitely ad have epithelial structure, while in another a purely herent and could be separated -Only with difficulty. mesenchymal appearance ohsn between combina- Treatment with cobalt radiation therapy, radio active gold and chromium, and chemotherapy, used alone or in combination, had little effect on the tions. athogj n5 course of this disease. Fifty percent of the patients The mode of action of` ucmg neo* suffering either from pleural or peritoneal meso plasia is at present poorly unc rtherfnore, thelioma died within one year and the remainder'by a puzzling feature has been the e oj meso- the second year. ^thelioma in one mining area, while in notcer min- Criteria for Diagnosis `v/C'-jrig'-erea a few miles distant, the disease ^as as yet Be .identified. There are two major muting dis- Although it is now accepted that mesothelial tlitiis iif the Republic of South Africa. In the north tumors of the serosal surfaces do exist and possess west Cape'of'Good Hope province, crocidolite is the a number of characteristics which justify their seg fiber mined, whereas in the Transvaal asbestos field, regation as an entity, the criteria for the identifica both crocidolite and more importantly amosite are tion of these tumors are still largely imprecise. The mined. Up to the present time there has been a currently accepted criteria for the diagnosis of these tumors are that: (1) The diagnosis should be ap plied to those groups'which show an unequivocal predilection to spread along the serosal membranes, re k,ClQ]j&fc!Uo^! * o pp.a wi with either none or only a shallow invasion of the underlying organs. (2) All other sources for the tu mor have been excluded. (3) If metastases are pres ent, they should be limited to the regional lymph nodes, rarely occurring in liver, bone, and lung. Special staining or histologic techniques may aid in a diagnosis of this disease. Wagner et al" have suggested that metadhromatic staining (removable by exposure to hyaluronidase) within a tumor is strong evidence for the diagnosis of mesothelioma in a patient Pathologic Characteristics.--In the earlier stages, the tumor is made up of many small, rounded, firm nodules on the visceral and parietal surfaces. Later, 96 JAMA, Aug 21.1967 Vol 201, No 8 \ MESOTHELIOMA AND ASBESTOSIS-BOROW ET At 591 prevalence of mesothelioma of the pleura and Another concept is the auto-immune theory in oneum in northwest Cape of Good Hope. On which the presence of asbestos bodies in the lung .__ other band no case as yet has been reported is said to elicit the production of an abnormal globu from the Transvaal asbestos area or its surround* lin. Up to the present time, there is little positive infs. Sluis-Cremer'* has studied the geographical evidence for this concept. The serum of patients and environmental differences in these two areas with either asbestosis or neoplasia shows only a and has come to the conclusion that none of the fac slightly raised titer for the rheumatoid factor, and tors examined explained satisfactorily the absence immuncdviorescent staining has not shown evidence of mesothelioma in the Transvaal region. Other of an antigen-antibody aggregate. Recently, Har- than for the mineralogic difference between the two ington and Roe*0 suggested that the carcinogenicity areas, he found no variation in the intensity or of asbestos may be related to the presence of nat length of production of these fields or in the extent ural and contaminated oils associated with the as of the environmental pollution and incidence of pul bestos fiber or to certain carcinogenic metals or monary asbestosis. In bWrtHsA^nerica, chrysotile is metal complexes in the fibers. They found that the main fiber mined although crocidolite and amo* crocidolite and amosite contained appreciable site are present in lesser amounts. Both pleura and amounts of natural oils. Furthermore, all the as peritoneal mesothelioma have be$ir"foncd in work bestos fibers, including chrysotile, may contain sec ers exposed to these fibe: ondary oils as a result of an addition of oil to the Wagner" in 1962 induced me&theliom^by inocu asbestos during the processing or as a result of con lating various dusts into the pleural cawty pf rats. tamination. Furthermore, almost universally, the Pleural tumors developed in thosfe-mdtul^Ced with asbestos is transported and stored in jute bags and crocidolite, chrysotile, and a finely divided silicon' the oil from the jute fiber is absorbed to a great ex- powder (99.9% silicon dioxide). Recently Skidmore //vtnt by all three types of asbestos fiber. . and Wagner'* showed that crocidolite, chrysotile/ 'Both chrysotile and amosite have a significant silica powder, and to a lesser extent, amosite, all X ferrous content, particularly of certain macromolec- induced pleural mesotheliomata in guinea pigs alter ular complexes of iron, such as iron-dextran which interpleural injection. Peacock and Peacock'* in- is known tb.be highly carcinogenic in animals. The dn-'ed malignant tumors in fowls with crocidolite ''iron content of .chrysotile is much lower than the rnosite. A number of hypotheses to explain other two fiberi. is proposed by Harington and ithogenesis of this disease have been proposed, Roe"l^2th3a4t 5th6e7 c8a*rS1n0o1g1enic agent or agents may out none of them have been widely accepted. The not be the "fiber^themsdves but either Ihu natural first theory was that of physical irritation due to oil or secondary' oils which are present on the fiber the presence of asbestos fibers deposited .in the ter and or possibly the iron cpmpjex. The authors are minal lymphatics of the serosal surfaces* or due to currently performing biologic for the carcino the migration of the asbestos fiber from"'the .lung genicity of these matayrals. Htfwe&er, these studies following inhalation or from the gut as^a result'd were in a preliminary form *p'tbe ti/tfe of the report. ingestion. Fibers have been demonstxated'k^a'npm-'/ ber of COM tissues, including parietal pleura, and spleen, but there have been gnaostfrice/fpeoy-r'.^'.'VT'/vV*^ Au Centric and Trade Name JSB,Aure0loU.J9t, Aureotope.*fl of fibers m the pentoneal surfaces. *///.s'p> y rfHm&^mtptfaoild cCoolllooiiddal aAuu i1s9s$., Aure**oulo,np* brto*ca*19$. %\Referei 1. Rokitenjky. C. Von: Menu*) of Path. Anst Sydenham Soc. an Aralyai* oLTKair Aasociation With Asbestos Trims.. London p 265, 1854. 19268-278 <Ma>764. S 2. Brown, WJ_ end Johnson, LC~- Pott Inflammatory "Tu* 12. Enticlmap. J.B_ and Smither, W'.PJj Peritoneal Tumors more" of Pleura: 3 cases of Pleural Fibroma of Interlobar Fiature. in Asbestosis, Brit J Jnduttr Med 2130-31 (Jan) 1964. Milii Surt 109:415-425 (Oct) 1951. 13. Selikoff. Chur*. J.; and Hammond. F.C-: Relatiota 3. Wjllit, JLA.: Pathology of Turnon, Washington, DC: Butter- Between Exposure to Asbestos end Mesothelioma, Ntw Eng J worth Inc, I960, P 185. Med 272:560-565 (March) 1965. 4. Ackerman. XV.: Allot of Tumor Pathology, Washington, 14. Ncwhouse, MX, and Thompson, -H.: Epidemiology et DC: Armed Force* Isiiitut* of Palhology, section 6, part 23,1956, Mesothelial Tumors in the London Area, Ann MY Acad Sri 132: P 100. ,, 579-588 (Dec 31) 1965. 5. Godwin. M.C: Diffusa Meaothaliomaa With Comment in 15. Wagner, J.C.: Munday, DEL: and Harmflon. JS.X Histo- Their Relation to Localized Flbrou* Mesothelioma*, Cancer 10: ebamica) Demonstration of Hyaluronic Arid in PIaura) Meso 298-319 (March-April) 1957. - theliomas. J Path Beet 64:73-78 (July) 1962. 6. Window, DJ-. and Taylor, H.B-: Malignant Peritoneal 16. Sluis-Cremer. G.K.: Asbestotis in South Africa. Certain Mesotheliomas. Cancer 13:127-136 (Jan-Feb) 1960. Geographical and Environmental Consider*tjona, Ann NY Acmd 7. Wagner, J.C.: Sleggs. GA.; and Marthand, P_: Diffuse Pico- Sci 132315-234 (Dec 31) 19G5. raj Mesothelioma and Asbestosis Exposure in North Western 17. Wagner. J.C.: Experimental Production of Meaolhelial Tu Cape Province. Brit J Jnduttr Med 17:260-271 (Oct) I960. mours of the Pleura by ImplanUiioo of Dusts in Laboratory 8. Wagner, J.C.: Epidemiology of Diffuse Meaothelial Tumors: Animals. Nature 196:180.181 (Oct 13) 1962. E*" ' *e of an Association From Studies in South Africa and 18. Wagner. J.C, and Skidmore. J.Wj Asbestos Dust Deposi 1 Gngdero. Ann MY Acad Sci 132:575-578 (Dec 31) 1965. tion and Retention is Rats, Ann NY Acad Sci 132:77-36 (Dec 31) - iter. GM.t Faulda, JB.i and Stewart, MJ.: Occupational 1965. , cf Urinary Bladder in Dyestuffs Operatives and of Lung in 19. Peacock. A, end Peacock, PA: Aibettoe Induced Tumor* btnos Textile Workers and Iron Ore Minas, Amtr J Clin Path F116-134 (Feb) 1955. in FotcU. abstracts. Fifth Annual Meeting British Association tor Cancer. Scotland: R. S. Edinburgh, 1964. 10. Mincuso. T.F, and Coulter, J.: Methodology in Industrial 20. .Harinrton. JS- and Roe, F-J.G: Studies of Carrinogmcsis Health Studies. Arch Environ Health 6-210-226 (Feb) 1963. of Asbestos Fiber* and Their Netvuml Oils, Ann NY Acad Sri 12it 11. Hourihane. D.O.: The Pathology i Mesotheliomata and 439-450 (Dee 31) 1965. ---- ------- -------------------- L V -if l__BB 0007573*7 JAMA, Aug 21, 1967 Vol 201. No 8 r;*)