Document 0qwZMrz3Kj3eVaQOR6nDreamm

FILE NAME Brakes BRK DATE 1970 Apr DOC BRK032 DOCUMENT DESCRIPTION Journal Article - Epidemiology of Primary Malignant Mesothelioma Tumors in Canada EPIDEMIOLOGY OF PRIMARY MALIGNANT ot t age MESOTHELIAL MESOTHELIAL TUMORS IN CANADA a MOT 1 infor D. McDONALD A. HARPER O. A. EL AFTAR AND J. C. MCDONALD of c a e termin ondar teria ! advan occuze hist is notoriously poor All fatal malignant mesothelial tumors known to pathologists in Canada between 1959 and 1968 were registered They numbered 165 1 per million population per annum two thirds were in males Occupational and residen- tial histories were obtained blind from relatives and friends of 90 of the cases and 2 matched control series An association with definite or probable occupational exposure to asbestos was clearly demonstrated but only 20 of male cases and one female case had any such contact Almost all the excess was in the manufacture and industrial application of asbestos rather than in mining or milling No association was found with lesser degrees of occupational exposure or residence in asbestosmining areas but there was a small excess of possible domestic exposures The smoking histories in the mesothelial ge wer S^ COTTO et micsoe smokin oe cer fe. eRe C+ cases A fi Cy vestig Smet and pit relativ tumor and main control groups cases of primary lung cancer were almost identical and unlike those for Adahkdiy pleten we French direct AE tory a :1 ot i" vats f| beans . ny Reet eee rns oe eo 7 ee wae se abd VIDENCE FOR AN ASSOCIATION BETWEEN MA- lignant mesothelioma and asbestos ex- posure rests mainly on the remarkable con- centra on cases reported by Wagner et al the cocidolite mining areas of South Africa the control studies of Elmes et al in Bel- fast and Newhouse and Thompson in London and the considerable considerable excess mortality due to this disease observed by Selikoff et al in American insulation workers The survey described here was undertaken to obtain a more generally representative view of the problem in one of the 2 major chrysotile chrysotile producing countries of the world Our aim has been to study and fatal cases known to have occurred in Canada 1959 METHION At the end of 1967 members of either the we wrote Canadian to the 123 123 Association PetMeet of Pathologists or the Quebec Association of om Laboratory Physicians inquiring whether they o had seen any fatal cases of primary primary malignaut au, tumors of the pleura or peritoneum diagnosed het by autopsy or biopsy since 1959. In duecourse we obtained a reply from them all and if mis | was the affirmative a personal visit was aye made is one of us to review the records and nie to exclude cases which did not meet the criteria on about which the pathologist had serious doubt In all 165 cases were found ers, 119 were pleural 15 peritoneal 3 pleural and peritonical and 1 pericardial The diagno was supported by autopsy in two thirds of 6 eb cases and by biopsy in the remainderLL at at edi, we plan to have material from as many is possible reviewed by a panel of pathologists During the visit to the pathologist 2 fani control cases one primary and one second- Rte ary lung cancer were selected from the i topsy or biopsy records matched for sex and OP was gi as poss panics of the relative volved cement a check subject followi ing ov luge h mestic proofit bling P ing bu or clute as closely as possible for age and date OL match From the Department of Epidemiolgy Epidemiology Epidemiology and Health death In 2 instances no match adequately McGill University Montreal Canada A preliminats report on these results sented at the International Conference on Se comios's at Johannesburg in April 1969 2 Supported by a grant from the Institute was prePretino- of Occurs ing case of primmy lung cancer could be found Two control series were chosen in or Tn der to examine types of question Primands to Phraidmands pational and Environmental Health of the Quebec we wished to know whether persons who ae had Asbestos Mining Association , died from malignant mesothelial tumors This surve was made possible by the guat help . ed given us is pathologists and members of provincial and differed in their past exposure to asbestos an other health departments throughout Canada We are pr also much indebted to all those who did the held work and to the friends and relatives of the deceased certain other materials from comparable sons in the general population Comparab Comparab ced for their cooperation sty demanded that the control series show's dL Received for publication April 1970 ) ~ omprise persons matched with the cases J 914 a == oe wetEsSSReapeat anras oes eemoar Ss ates ee ee ae PEUPRs SEeSeyceaRnEsoSeaaigeeAiae nSie. Pie tier isSe Fis atone Ta epee prapinnesSoL me e ee ee Tat Aas A Ps RO Fa ye eri} wt as No. 4 MALIGNANT MisOTHELLA TUMORS McDonald et al 915 age sex date and place of death and pov dustry cement industry dock or transport mortem diagnostic procedure To insure that information obtained from relatives would be industry No interviewer knew to which group the } of equal quality it was important that the case under investigation belonged and the terminal illness should also be similar Sec- information recorded in the questionnaire ondary lung cancer seemed to meet these cri- was also coded blind Questionnaires were , teria reasonably well and had the additional completed for 147 91 of the 193 cases and advantage that several primary cancer sites controls .. ? were included but none were in the lung A 2 second main question was whether primary FINDINGS mesothelial tumors were related to tobacco smoking in the same way as primary lung can cer and for this reason a matched series of cases of this disease was also selected sepd A field survey was arranged in which in vestigators doctors public health nurses \ } and public health inspectors sought out the { : relatives and friends of the deceased and com- I t pleted a detailed questionnaire in English or would would French relating to occupation residence in- would direct household exposure to dust family his- wouwloudld kiswtory kiswtory and smoking habits Special emphasis kiswtory and smoking smoking habits Special So far ciation ciation of deceased Thether they deceased malignant did ... diagnosed deceased possible all employers or employing com- panies were listed with dates and a note made of the exact nature of the work done The ; ; relative was then asked whether each job in- The distribution of cases by province and year of death is shown in Table 1 and by age sex and site in Table 2. More cases were found in 1966 and 1967 than in previous years Recent interest in these tumors may have contributed to this and as the records in some hospitals were poorer for the earlier years memory may also have been a factor With these points in mind the true rate of increase is difficult to assess During the 8 com- plete years 1960-1967 the average annual incidence was 1.0 per million of population The rate was appreciably higher in Quebec 1.5 than in Ontario 0.8 or in the rest of Canada 0.9 1966 and 1967 again accounting for much of the difference Three quar due course ; and if this volved contact with wood rubber asbestos cement copper nickel or fiber glass Finally ters of the cases were aged 50 or more at death and males predominated by 2.4 to 1 al visit was check list was used to inquire whether the Under 50 there was little difference in the records amidious details subject had ever been employed in any of the sex distribution meet these details hologist had a ' work were found pleural and ,, he diagnosis chands of the following locomotive repair shop shipbuilding overhauling or breaking installation of large boilers or steam pipes insulation of domestic heating equipment building proofing fireproofing heat retention assembling prefabricated buildings and demolish- The case and 2 control series were very similar in age distribution and in the propor tion of each for which the questionnaire was completed Table ) Table 4 shows the number of men aged 18 years or more who were occupationally exposed up to 10 years inder Later ing buildings manufacture of brake linings before death to asbestos and certain other ma- ( many thologists or clutch plates mining industry textile in- terials in dust or vapor form Whereas all 3 ogist 2 fatal one second- discuss discuss in ABLE . Distribution of Cases by Year of Death and Province from the au in for sex and Year Ontario Quebec Other Provinces Canada experience and date of iately match- 1960 1961 er could be : 1962 - 6 ... 15 t 6 3 10 4 4 5 13 chosen in or- : 1963 ... 3 7 19 i n Primarily ; sons who had : I trunors had ! asbestos and 1 1964 1965 6 S 3 17 i 7 5 19 1966 S 14 9 31 1907 6 13 6 25 1968 1st half 5 ... 2 16 parable per- i Comparabil series should ; ; the cases for ry Incidence 1960-1967 a= . ~ 46 70 .S we ee 1.5 ee: 49 0.9 165 1.0 - $ Ate 4 i x ui Ty =oR r, I?PSTSoEmR. eee GR Ms Se vw ?i bea 7 "2 in 7a) , Gax ir October 1970 Vol 26 ~ -ne Age TAB 2 oe ee Pleura - Distribution of Mesothelial Tumors by Age Sex and Site ee eee ee se Peritoneum Pleura and peritoneum Pericardium Pericardium Pericardium Total Total ee ee years M F M F M F M F M F ~ oY 0 _ _ 1 10- 2 I _ - _ 2 1 20- - _ ~ 4 30- 7 40- ) 50- 18 4 I 7 4 3 ti H _ - _ { _ -- _- 4 { - | I 8 6 1 13 9 ! 31 8 60- 26 5 2 5 _ 2 28 12 70- 15 5 7 6 _ _ _ 22 tt _ 80- 4 I 1 -- _ - 4 S AHE 80 33 26 10 t 2 4 3 108 57 113 45 3 4 165 num groups were equally exposed to wood dust relatively more men in the mesothelial tumor group were exposed to all the other materials the greatest excess being for asbestos Men who were exposed to asbestos tended also to be exposed to other materials especially rement and fiber glass Table 4 but these were only responsible for part of the excess exposure to the other materials The excess of definite or probable exposure to asbestos Table 5 in the mesothelial tumor group compared with both control groups was substantial < .001 But there was vir- tually no difference in the frequency of jobs in which exposure was classified as possible In 60 of the cases however occupational exposure to asbestos was considered un- likely Only 2 women in all had any occupa- tional exposure to asbestos there was R definite exposure in the mesothelial tumor group and a possible exposure in the secondary lung cancer group The occupations involving definite or prob- able exposure to asbestos are listed in Table 6. Men employed in asbestos textile manu- facture the installation of brake linings or as insulators were responsible for most of the excess of cases over controls Mine or mill workers made little contribution to the differ- ence man ucts and only one person a hardware store- had worked with asbestos prod- The time between first exposure and death for the 21 cases in the definite or probable class ranged from 16 to 50 years 4 men and one woman who worked on the job for less than 4 years had intervals of 18 26 26 29. and 33 years Materials other than asbestos also deserve further consideration since several men had worked with more than one of them Exclud ing diff to ber were to I in ! 20 An Tal app tact > 9 seciite - best in th copp TABLE 3 Distribution by Age and Sex Males of Cases and Controls i Females ice Mesothelial tumors Secondary lung cancer Primary lung cancer Mesothelial tumors Secondary lung cancer Primary lung cancer n1020 30 4050fin- in80- ML Mean SD . 22 8 13 10 31 31 27 25 23 22 3 10S 101 58.7 13 11 22 66 1F 26 22 35 32 20 19 + 108 97 59.1 13.3 ( 22 24 20 24 23 35 33 17 15 + 107 95 59.1 12 ( 1 3 66 ...8 $ 12 11 11 10 54 57 51 - 55 19.3 1 2 65 10 7 14 13 11 3 57 53 37 4 17 1 2 toge 14 13 met. 8 7 12 | 15 15 nenE ens 3 2 Meee 56 47 58 S 15 5 Re No. of questionnaires completed shown in parenthesesparentheses ATR NF Vow.Un second or prob 1 Table mamu Ings or of the or mill diller e store uw prod and r prob men job for 26 26 deserve Cu had Exclud Hary eee 1 No. 1 MALIGNANT MESOTHELIAL OL tvors McDonald et al 917 . Tante 4. ~ -- Occupational Exposure it Men to Certain Materials wee Asbestos Cement Copper Fiber glass Nickel Rubber Work Mesothelial tumors 100 men 20 17 3 62 63 52 31 18 1 Secondary Secondary lung cancer 96 men 3 0 10 0 0 0 19 0 Primary lung cancer , 97 inen t . ; 0 10 ) ( ) 16 0 Total exposures ' recorded 75 131 32 0 29 0 * Definite or probable exposure to the substances substances named in dust or form in number of men who were also definitely or probably exposed to asbestosvaips ogriven in pam reennthaegseeds 18 or more The ore S ing wood for which there was evidently no facture brass foundry nickel lathe ey difference between the 3 groups 37 exposures operator 2 mine worker rubber tire manufacture to cement copper fiber glass nickel or rub- plantation work fiber glass municipal main- e her were recorded for the cases of which 12 tenance work caulking ship tar were in men definitely or probably exposed Residential histories indicated that of to asbestos The 25 15 REE in 19 remaining exposures were male cases and %% of female cases had spent men and the comparable figures for the their childhood entirely in a rural area com- Eee 2 control groups were 10 and 9 respectively pared with 10 of males and 38 of females An analysis of these exposures is shown in with secondary lung cancer but the primary Table 7 where it may be seen that the excess lung cancers were less often reared in rural appeared to be in occupations involving con- areas males 31 females 28 No diller tact with copper nickel fiber glass or rubber ence was found between cases and both con- endawe 9 rather than with cement only and trol groups after the age of 15 Exclud- seemed unrelated to possible exposure to as- years ing 5 cases 3 mine or mill workers and 2 bestos The relevant occupations of the 9 men textile workers and one mine and mill in the mesothelial group were as follows worker in each control who lived in + copper lathe operator 2 munition manu- mining towns only 3 megnroaundp 2 women had TABLE 5. Males Distribution of Cases and Controls According to Their Occupational Exposure to Asbestos Mesothelial tumors Secondary lung cancer Primary lung cancer Exposure to asbestos No. / No. % No. % Definite Probable Possible Unlikely Hn) 20 o 20 20 0 60 60 1 3.1 | 22 22.9 71 74 ty " al 16 77 + 16.5 79.4 79.4 All 100 100.0 06 1000 1000 07 100.0 < Mal0.e0s01 Distribution of definite and probable groups compared with possible and unlikely x 1 21.5 2 d.f. Females Exposure to asbestos Definite Probable Possible Unlikely Mesothelial tumors No. H Ca 2.0 10 08 0 Secondary lung cancer No. 1 ; _ 1 1.0 51 98 1 IE 50 1000 1000 52 100 0 One child in each group dying under the age of 18 has been excluderi excluderi Primary lung cancer No. on -- 46 16 100.0 100 0 Wc 2 chs Man veka ee =. bu ah a FREER > PEI Be 2 918 CANCER October 1970 Table 6. Distribution of Oceny Expo tions Classified Under Delinite or Probable are to Asbestos Mesothelial Mesothelial tumors Secondary Jung cancer Primary lung cancer Asbestos mine or mill Asbestos textile manufacture Brakelining installation Insulation 3 1 1 r , 0 2 0 ( 5 0 U Other occupations involving contact with insulation materials S 2 3 Hardware store thandling asbestos sheet and pipe 1 - 0 Filled gas masks with asbestos textile \ 01 ... TOTAL 21 " * Includes one person who worked in brakelining manufacture Vol 26 ever lived within 20 miles of an asbestos mine One of the 5 was a case 3 had second- The frequency of cancer reported in close relatives did not differ from that in the con- ary lung cancer and one had primary lung cancer . trol groups An analysis of cigarette smoking habits is shown in Table S. In both males The possibility of contact as result of some other member of the family bringing home dusty clothes from occupations involv ing the use of asbestos was also examined Excluding 7 persons 5 cases and one in each control group who were occupationally exposed themselves definitely or probably there was one case in female with definite and females persons in the primary lung cancer group had smoked considerably more than those in either the case or secondary lung cancer groups The latter 2 groups hau > almost an identical distribution of smoking habits The 20 men with definite or probable occupational exposure to asbestos showed no great difference in smoking habits from cases home exposure and one male with probable without occupational exposure home exposure In addition to 5 persons one case and f with primary lung cancer who DISCUSSION were possibly occupationally exposed to as bestos themselves there were 26 persons with Though our study is not directly compa a possible home exposure 14 cases 6 with secondary lung cancer and 6 with primary lung cancer The category of possible home rable with those of Elmes et al in Belfast and Newhouse and Thompson in London it seems fairly clear that the difference between exposure was given in households where a person possibly exposed at work to asbestos brought home dusty clothes Thus excluding cases and controls regarding asbestos exposure was less in our findings than in theirs There are several possible explanations for this dgarn those persons with definite or probable occu- The first is that our study was based on a na- pational exposure there were 15 persons with tional sample of cases derived from all parts mesothelial tumors 8 with secondary lung of a very large country whereas theirs were or cancer and 10 with primary lung cancer who had had at least possible home exposure to asbestos dust from 2 specific industrial areas one a shipbuilding city and the other from a hospital close to a large asbestos factory A second TABLE 7. Occupational Exposure to Certain Materials of Men without Definite or Probable ExpExposuore sure to Asbestos Mesothelial tumors Secondary lung cancer Primary lung cancer Cement only Copper nickel rubber or tiber glass 10 6 02 19 1 10 82 0 92 * Including three men also exposed to cement The number of men possibly exposed to asbestos is given in parentheses pos casc thir surv we of 1 was pos- The not gati selc on I best Seve ex risk Our to ; and cor Icss wor asbe lung in canc T dica O. L asbest 2 lioma asbest 22:20 3 ae * reanae seats oe 8 +2 2 f peeSATS ot Rept y E~ I ee Lege noes Jace aka New de MALIGNANT MrsonviAL TUMORS 6 McDonald McDonald et al 919 TABLE 8. Average Daily Number of Vigarettes Sinoked ' Madle Female _ Cigarettes A Cigarettes . per day N or less 11-20 30 or more , TOTAL Mesothelial 11.mors 21 22 17 18 40 10 20 97 100 1 Secondary lung cancer 19 20 21 22 37 30 18 19 95 100 . Primary lung cancer Mesoth iai tumors with asbestos | exposure i 2 10 TT 17 + 20 13 05 34 36 Lt F eee 95 100 20 100 Mesothelial Mesothelial tumors Secondary lung cancer Primary Primary lung cancer 20 SV " 18 36 71 S 10 47 " 20 10 20 i 44 12 27 2 4 3.6 3. 7 eee woe 100 100 15 100 Excluding 6 persons under 15 years of age and 6 men and 2 women whose smoking history was not recorded possibility is that our series was diluted by cases which they would not have accepted \ third point is that we took great care to in- mors are rare in Canada and it is somewhat doubtful whether there has been a true increase in incidence since 1959. An association sure that the histories of case and control between these tumors and definite or prob- were collected and coded without knowledge able occupational exposure to asbestos was of the group to which they belonged This clearly demonstrated but only a minority of . ; was not so stated in the Belfast survey and not male cases 20 and one female case had - $ possible in the study of Newhouse and any such exposure No difference was found tet Thompson The findings of Sclikoff et al arc not comparable with ours since their investi- between cases and the 2 control groups re- garding lesser degrees of occupational expo- we gation was based on an occupational group sure or residence in mining areas : selected for its exposure to asbestos and not but in 107 of the mesothelial tumors com on population sample pared with % of the secondary lung caucer : It was not our aim to assess the role of as- group there was at least a possible domestic bestos in the etiology of primary lung cancer contact with asbestos dust , Several studies have shown that occupational Probably our most noteworthy finding exposure may be associated with increased was that almost all the excess in occupational risk of this tumor especially in smokers Since exposure was in the manufacture and indus- our series of primary lung cancer was selected to match the mesothelial cases in age sex and geographical distribution it cannot be considered representative in itself Nevertheless it was probably sufficiently so for it to be trial application of asbestos rather than in mining or milling Taken in conjunction with the results of other epidemiologic studies this suggests either that chrysotile is less associated with mesothelial tumors than other worth noting that the history of exposure to asbestos was very similar to that for secondary forms of asbestos or that something in addi- tion to asbestos is necessery If there is an : lung cancer Any contribution from asbestos additional factor our findings imply that it in the causation of this series of primary lung is not cigarette smoking cancers was therefore not apparent Nine men with mesothelial tumors had worked in occupations unrelated to asbestos i CONCLUSION but involving contact with copper nickel The findings from this national survey indicate that primary malignant niesothelial tu- rubber or fiber glass compared with one in each of the control groups The interpretation of this finding is doubtful REFERENCES 1. Elmes C. McCaughey W. T. E. and Wade Relation between exposure to asbestos and mesotheli- 0. .: Diffuse mesothelioma of the pleura and oma New Eng J. Med 360-565 1965 asbestos Brit Med 1. 350-353 1965 4. Selikoff I. J. Hammond E. C. and Churg J. JAM.I . 2. Newhouse M. .. and Thompson H Mesothie- Asbestos exposure smoking and neoplasia 106-112 1968 lionia of pleura and peritoneum following exposure to asbestos in the London area Brit J. Industr Med 5. Wagner J. C Sleggs C. A. and Marchand P 22.261-260 1965 Diffuse plemal mesothelioma and asbestos exposure in the north western Cape Province Brit J. Industr 3. Seliko I. J. Churg , and Hammond E. C Med 260-271 260-271 1960 Le + ae Resslis \f ghaidahe he qr Sg ye ae * ee _v cae Se aes PAM ace * SE ye R3t2 E at ice pled SUE Yee Sh Se Ayes