Document g2BwwMoDpXvRGz7vNNOm85Vj9

*. Brief Report %Q >; ft' C> r`- i- Lung Cancer Cell Type and Asbestos Exposure Andrew Churg, MO It Is often claimed that adenocarcinoma le the moat frequent type of five series that have internal controls. lung cancer seen in workers exposed to asbestos. Careful review of the The report by Whitwell et al* is the published data, however, falls to support this claim. Rather, it seems that all one most frequentlycited as showing types of lung cancers occur In asbestos workers, and the presence or the preponderance of adenocarcino absence of a specific cell type cannot be used to prove or disprove an mas (35% of the total number of lung association of carcinoma and asbestos exposure. carcinomas). Using the comparison (JAMA 1985;253:2984-2985) data provided in the same article, however, there is actually no statisti cal difference between the asbestos- VIRTUALLY every review article or lung cancers from the Veterans exposed and control patients. None of textbook dealing with the area of Administration11 to serve as controls; the other studies have a preponder occupational lung disease includes the even casual observation indicates ance of adenocarcinomas, and, in fact, statement that adenocarcinoma is the that, overall, the asbestos-exposed the series of Martischnig et al* and most common type of lung cancer group has fewer adenocarcinomas Blot (cited in Ives et al10) are rather found in those with asbestos expo and mora small-cell and squamous heavily skewed toward squamous car sure.1'1 This notion is so widespread carcinomas than do the controls. cinomas. and often repeated that the presence Because it can be argued that the These data demonstrate that squa or absence of this specific type of chosen control group was not an mous carcinomas accounted for 43% tumor has become a frequent legal appropriate match. Table 2 details of the total 410 tumors, small-cell argument when a worker claims that exposure to asbestos caused his lung cancer. Table 1.--Lung Cancer Cad Type in Bgfn Seriee It is instructive to assemble the of Patients Wftft Aabesto* Exposure data on which this statement is based. Table 1 gives the results of , S't-TVCed Typ.ae, No. (%). eight reports providing information on lung cancer cell type in 471 patients with asbestos exposure. The . LarpwCa* -^T^^^Sortoo.'W(,^'^T^r5<--Cireiwoiea-'irew6inBiea:?'vearelnoma.. Caretnowo*' AsOMtowSxoOMd first three reports*4 specifically deal with patients with asbestosis, and the WtWwWIatat.* 93 21 (23) 26 (28) 33 (35) (> 13 (u) ora others seem to have some proportion KiiwntW andChute.* 36 11 (30) 11 (30) it (30) 6 (10) of patients with asbestosis mixed in. ^s^v^gac-ts) . t.cBv.- . o<o>r. For comparison, I have arbitrarily picked a large series of patients with AMMM.' 23 aif Auartach et at." 193 9 (38) ^ ':T2i (57) 96 (90) 7 (30) r (ion 46 (29) 6 (26) '* 29 (16) 1 (4) < ' 20 (10) ;. .i9e {42)';i-;i i2a''(27)^' - 42 <g>-v: From mo Oaportmant of Pathology. Udwrady at Srfdaft Cofunttt. Vcncouwr. RaprM raquotta to Oopartmant of Pathology. Univoratty of BrttMi Columbia. 2311 WMbreofc Mol. VtneouMr. Srtdah ColumOio. Canada VST 1WS (Dr CJxjry). Cox 406 Yaanar** (1968*1977). 400 Nonaxpaaad W) ^-.las'.aaki^risavtss^-v^/ios-tiT) 123 (31) 82 (21) 129 (32) 66 (17) Beporta that do not use latpa-cad cardnoma haw had dda cataeoiy eeuntad aa zaro. tBaaad on daath eartMcataa. 2984 JAMA, May 24/31, 1985--Vol 253. NO. 20 Lung Cancer and Asbestos--Churg carcinomas for 28%, adenocarcino mas for 19%, and large-cell carcino mas for 10%. There is no significant difference between the asbestosexposed and control patients for ade nocarcinomas or large-cell carcino mas, but squamous carcinomas are statistically less frequent and small cell carcinomas statistically more fre quent in the asbestos-exposed group. There are some cautions that should be exercised in interpreting the data just cited. Uncertainty arises from the arbitrary fashion in which pathologists subclassify lung can cers.l4,,`*4 Also, most of the series are quite small, so that only a few changed diagnoses could alter the proportion of the tumor types. There is also a mix of surgical and autopsy cases, a factor that definitely influ ences the apparent proportion of cell types.1414 Nonetheless, it appears that there is no real evidence for a prepon derance of adenocarcinomas in those with asbestos exposure; rather one can conclude that all histological types of lung cancer occur in these workers and that cell type cannot be used as an argument for or against Table 2.--Lung Cancer Can Type in Reports With Asbestos-Exposed Workers and Internal Controls '**7; . * 1 - Reported 9arise.' ~ ' ' ---j-:9au--owe .- ffmed Cad ---- Ad--a v-Large Cad. . - ^Cardeeae-t.-^.CawSaoear^^ caramaae-. " - Carcineea* ' :______ n,` L>^osed.aascaitf*j.. j iConeoLAV - ,.... -.Vfrtair .^..^,8 Whitweil et ai* 'Exposed^ 9*."'^.--^ 13 (14r '-v- w<40***' -29' 00 :^'^*12 (W Martischnig et el* ..Control, tig-. .. * &-<&"*' Auerbach et el" Exposed, 183 ' jj;aW8ar*: Cone*,'848. ia*.(l9> m Slot (chad by tvee et al')t **'*** *'**' '* ' cont&;i8V^v* Totat expotsd.410 . Control. 143*0 ...... 84* 208- (20) . 78 (19> (TOt^:-* 198 (191 ^T' i08 (10T :` ' 'Reports that do not wee large-cod carcinoma have had this category counted aa zero. fSasad on doeth certificates. the involvement of asbestos in a given case. Reference* I. Becklake MR: Asbestos-related diseases of the lung and other organs: Their epidemiology and implications for clinical practice. Am Rev Revpir Die 1976;114:187-227. Z Parket WIfc Occupational Lung Disorder*. ed Z London. Butterworths, 1982. 3. Medical Advisory Panel to the Aabestoa International Association: Criteria for the disgnoais of aabestosia and considerations in the attribution of lung cancer and mesothelioma to asbestos exposure, let Arch Occup Environ Health 1982:49:357-361. 4. Hourihane DO'B, MeCaughey WTE: Patho logical aspects of asbestosia. Postgrad Med J l966;426I3-622. 5. Whitweil P, Newhouse ML, Bennett OR: A study of the histological types of lung cancer in workers suffering from asbestosia in the United Kingdom. BrJlnd Med 1974:31:298-303. 6. Hasan FM, Nash' G. Kaxemi H: Asbestos exposure and related neoplasia. Am J Med 1973.-65:649454. 7. Kannenteia M, Churg J: Pathology of car cinoma of tho tuag associated with asbestos exposure. Cancer 197230:14-21. 8. Martischnig KM, Newell DJ, Barnsley WC, et si: Unsuspected exposure to asbestos and bronchogenic carcinoma. Br Med J 1977;1:74& 749. 9. Finkeisteio MM: Aabestosia in long-term employees of an Ontario asbestos-csment fac tory. Am Rev Respir Die 1982325:498-501. 10. Ives JC, Buffier PA, Greenberg D: Envi ronmental associations and histopathologic pat terns of carcinoma of the lung. Am Rev Respir Die 1983328395-209. II. Auerbach O, Garhakei L, Parks VR, et ah Histologic type of lung cancer and asbestos exposure. Cancer 1984543017-3021. 12. Cox JD, Yesner RA: Adenocarcinoma of the lung: Recent results from the Veterans Administration Lung Group. Am Rev Respir Die 19793203025-1029. 13. Feinstein AR, Gelfman NA, Yesner R, et ah Observer variability in the diagnosis of lung cancer. Am Rev Respir Die 1970:101.-671-878. 14. Yesner R: Observer variability and reli ability in lung caaeer diagnosis. Cancer Chemotker Rep 1973;4(pt 3):55-57. JAMA, May 24/31. 1985--Vol 253, No. 20 Lung Cancer and Asbestos--Churg 2985