Document 4JZQRQ8R1wyMvLpJd2jamOd7x

FILE NAME: Neighborhood Exposures (NE) DATE: 1955 DOC#: NE004 DOCUMENT DESCRIPTION: Medical Journal Editorial - Silicosis, Asbestosis, and Cancer of the Lung American Journal of Clinical Pathology OFFICIAL PUBLICATION OF THE AMERICAN SOC IETY OF CLINICAL PATHOLOGISTS W. A. D . Anderson P. R. Beamed L awrence Berman G. R. B iskind O. A. Brines C. G. Culbertson E lbert D eCourset I srael D avidsoiin L. W. D ices Board of Editors S. E . Gould, Editor- in-Chief E. A. Gall A. S. Giordano G eorge Gomori \Y. S. H offman J. W. K ernohan H. J. Linn T. B. M agatii F. I). M ann P. J. M elnick A. R. Moritz Otto Sap|,tw Robert Schrek T. H. Seldon K urt Stern G. G. Stilwell F. IV. SUNDEKMAN V. X . T ompkins L. A. Weed J ean L. K ing, Assistant to tlu Editor Volume 25, Numbers 7*H-^ JULY-DECEMBEH iO M PK IK S-U cC/ LIB R A R Y MAR 24 1953 Cuu of vv RICHMOND. VA Baltimore The Williams & Wilkins Companv 1955 1 ' TOMPKINS MCCAW UBfcWI m edical COLLATE W V1RW 6.1 f (72 HlCHMO,ViU X. -- ----- T*-~ \y tz - EDITORIALS Silicosis, Asbestosis, axd Canceh o r the Lvxg The concept that members of .occupations especially exposed to dust, particu larly silica, have an unusual liability to cancer of the lung is an old one which is still held. Reliable epidemiologic data from various sources, however, show that pulmonary cancers are not excessively frequent among persons having occupa tional contact with coal'- * and silica dust 10- '* and affected with anthracosis, silicosis, and anthracosilicosis, such as gold and coal miners. Infact, in radioactive ore miners with severe silicofibrosis in Schneebcrg and Joachimslhal, who have a notoriously high frequency of lung cancer, the lungs are not often the site of such tumors.11Likewise, Bonser, Faulds, and Stewart5 recently reported the existence of an inverse relation between cancer of the lung and siderosilicosis in English iion-vi.i Mcrev.'2thcr,n m.ted that cn!y 99 of (<>'(* of ( 1.30 per cent) were found to have carcinoma of the lungs on postmortem examination. In a series of 383 autopsy cases of silicosis in men 47 to 75 years old, lung cancer was present in only 7, i.c., in 1.8 per cent against an expected rate of 9.9 to 12 per cent according to the age range and sex of the series.'4Sporlein suggested on the basis of this evidence that an antagonism may exist between silicosis and cancer of the lung, especially since not a single instance of lung cancer was found among ` 187 men with severe silicosis. The epidemiologic and pathologic evidence supporting a causal relationship between asbestosis and cancer of the lung, on the other hand, is quite substantial. Asbestos, a magnesium-iron silicate, mined on the North American continent and in South Africa, is incriminated in this respect.*i - *17 A total of 127 cases of asbestosis cancer of the lung arc on record (I'nited States, 21 cases; Canada, 6; iirrui ijinani. vieiinain, ,. j vn ui iik .iiniin,tii .it. v.crc recent!;, ob served by O'Domiell15 among 21 aulopsv cases of asbestosis seen bet ween 1940 and 1954 in a small community in Pennsylvania and occurring among employees of an asbest os text ile plant. The incidence reported for aslwstosis cancer of the lung in autopsy series of asbestosis ranges from 7.5 per cent *to 50 per cent .J It is 15.5 per cent for a series of 738 autopsies of asltestosic with 114 lung cancers collected from the literature. According to Mcrowethcr, the male-female ratio of asbestosis cancer of the lung is at the low level of 2.45:1. Aslestosis cancers show a diversity of histologic types. Among 50 cases, 29 were of Kiinnmmw <11type la were of the round cell-anaplastic variety. 7 were adeno carcinomas, uud 5 were combination forms of squamous cell and adenocarcinoma. Asbestosis cancers follow the lopographic pattern of asbestosis by involving often the lower lobes (four-fifths, according to Isselbacher, Klaus, and Hardy5). A multicentric genesis of cancer in the diffuse asbest otic lungs is not unusual. The exposure period to asbestos preceding and accompanying the development of asbestosis and cancer of the lung ranges from G months to 42 years. The lag Itetwc-en cessation of exposure and appearance of the pulmonary tumor may be USX .tw o d to dust, particuan old one which is towcvcr, show that jns having ocrupaI with anthracosis, tfact, in radioactive insthal, who have a ftc*n the site of such ported the existence [sili-osiv in English m'> of Mlicosis (1.32 at > old. lung cancer rat of 9.9 to 12 per sin suggested on the t silicosis and cancer er was found among Jal relationship ,v-.. quite substantial, erica continent and olal of 12T cases of 21 cases: Canada. 6; cs were recently ob) !1|| |M`I VI41 1910 ng among employee? in autopsy series of 5 per cent for a scries d from the literature, sis cancer of the lung inng "cases, 29 were variety, 7 were ndenosiiil .irlenocarcinonta. sis by involving often laus, and Hardy7). A is is not unusual. The . g the development of to 42 years. The lag ~ nonary tumor may be _ as long a 20 years These tumors <M*cur on an average at a some hat earlier age than cryptogenetic cancers of tin* lung. The production of asU-stosis cancers in experimental animals has not reliably been accomplished.11 It is uncertain whether a minimum of 170,000 dust particles per liter of air is j a prerequisite for the development of asbestosis cancer jn man and whether the inhaled part ides must be above a certain size to be effective. Asbestosis cancer of the lung i? a compensable occupational disease in Germany15and is notifiable with : the Chief Inspector of Factories in England and Wales. In a Canadian case of occupational asbestosis cancer of the lung which was litigated, settlement was made in favor of the plaintiff. The available scientific evidence is adequate for | recognizing asbestosis cancer of the lung for medicolegal reasons as an oeeupaj tional disease. Since, at least in former years, industrial asbestos effluents caused 1 local environmental air pollution, the possibility exists that in the absence of a history of specific employment of the deceased individual, asbestosis might be observed at autopsy because of former residence near an asbestos plant. Since asbestosis, like berylliosis, presents a characteristic histologic lesion, there should * be no serious diriieun\ in iucuwf. I..c "r.crgbborhood" cases of asbestosis and 1 asbestosis cancer of the lung. Epidemiologic data available at present indicate that an increased liability to cancer of the lung is limited to the presence of : asbestosis of the lung and does not extend to exposure to asbestos without the ! existence of a pneumoconiosis resulting therefrom. National Cancer Institute National Institutes of Health Bethcsda, Maryland W. C. Hi eper. M.D. Chief, Environmental Cancer Section REFERENCES 1. A llen , M . 1..: B ronchiogcnir carcinom a associated w ith pneum oconiosis: report of 2 cases. J. Indiist. Hyg., 16: 346-347, 1954. 2. Bun-er, C>. M .. F.sri.ris, j . S., and Stewart, M . J.: O ccupational cancer of ib e u rin ary Iit liter in <l\-i--t nft- n n c ra iiv t--a n d of th e lung in asliestos tex tile wnrkers and iron-ore m iners. Am. ,1. f l i n . P a in ., a: >_u ..... 3. C artier. P .: Some clinical observations of asliestosis in m ine and mill w orker-. Arcii. In d iist. H e a lth . 11: 204- 207. 1055. 4 . D oll, R .: M ortality from lung cancer in asbestos worker.-. B rit. J . lu d ti-t. M ed., 12: 81- ; . 1955. 5 . H umhikckr, F .: The co-incidence of prim ary carcinom a of the lung and pulm onary a -b e -to -i- A m. J . P a th .. 19: 7tt7-S07, 1943. 6. H ceckr, W. ('.: K nvironm ciital lung cancer. Jn Proc. First Conference N ational Cancer ]n --|itu tc . C an a d a . 1954. New Y o rk : A cadem ic Pres.-, In c ., 1955. pp. ] MV-239. 7 . IssK i.m ciO K . K . J.. KlaVs, I I .. anii Uasdt. H . I..: A sbesto-is and hronchogenic carcinom a: report of one utltopsied case and review of available literature. Am. J . M ed., 16 : 721- 732. 1953. R. J amk-. W. H - P rim a ry lung can cer in S o u th tVules eoal-w orkcr- w ith pncunioruiii- sis. H nt J . ln d u - t. M ill., 12 : 87- 91, 1955. 9. J.vnch. , K. M ..anii C'a<xm nin.t.fatV. M .: A sb esto sis. V I. A n alysis of 40 necrop-icd ea-c-. 10. Mehkwether. E . R .: Annual R eport ol the t. luci jn.pccmi of F... :..r.: ?> .i,,. Year 1947. M edical S ectio n . L ondon: 11. M. S ta tio n e ry Oflice, 1948. pp. 14 17. 11. N orkmann, M .. ani> Sorge A .: l.ungenkrchs durch Aslic.-tsiauii tnt Tiervcr.-uch. Zt.-chr K rcb.-forsch.. 61: 169-1S2. 1941. 12. O 'D on n ell. tV. M . (L an caster. P a .): Personal co m m u n icatio n , 1955. 13. Rostoski. ().. aso Sauce, E.: Gewcrbchygicnische und kltiii-ch-rbiitgonologische L ntprsuchungen an den Errbergieuien dcs Johanngeorgcnstudicr G rubcnliciirkes in S achsen. A rch. f. G ew erbepalh. u . G ew erbchyg., 1: 731-734. 1931. i i:i*o F.M TOIALS Vol. B 14. Si".)kLtl\, S.: Schtzt die Silikose vor Luiigciikreli.'.-' Zcntrallil. allg. Path., 89: 1973*), 1H52. 15. T aUkhsHaw, ]. It.: Hcpuri on industrial hygiene in the Western Zone of Germany. Arch. Indusi. Hvg., 3: 20S-3J5. 3!*5I. 16. Vorwalu, A. J .. a m K arr, J . \V.: Pneumoconiosis an d pulm onary carcinoma. Am J. Path.. 14: 4U-5S. l!s 17. WVehs, H .. Ashestosis. Postgrad. M. J . 26: 631-63;.. IWi. M edical Genetics The science of genetics has made rapid strides during the past half century. Among the many applications of the recent advances in this field are those relat ing to human health and disease. That these applications are recognized as im portant is testified to by the results of a recent survey by Herndon* in which he reported that instruction in genetics is now given in 55 per cent of the medical schools of the American Association of Medical Colleges. The instruction varies from full-fledged courses to material included in didactic lectures. Several thousand deviations from normality- in man have been investigated from the genetic standpoint, and for several hundred of them a simple genetic basis has been reasonably well established. It is not a simple matter to confirm the genetic basis of a suspect trait, and precise technics are required for its es tablishment. A recent book by Neel and Schull7 is particularly valuable for its discussion and evaluation of many of these technics. Snyder, in his recent presentation to the medical section of the American Life Convention,10 pointed out that not only are hereditary factors, or genes, being identified in man, but that much is known of how they act. The basic function of a gene is the development of a specific substance which determines the effect of the gene on the individual. This substance is, as a rule, an enzyme, and is re sponsible for tin- catalysis of a particular step in synthesis or degradation. A mutation, which may derive from an inexact copying of the gene during its usual process of constructing a duplicate of itself in cell division, generally leads to a diminution or loss of activity in catalyzing the specific reaction that the unmutated gene accomplished. Thus, the mutated gne, which henceforth dupli cates itself in its altered chemical form just as faithfully as the unmutated gene previously copied its original form, produces an enzyme dysfunction, and hence a physiologic or morphologic aberration. The aberration may lie striking and readily recognizable, as in phenylketonuria, in which the mutant gene fails to develop the enzyme which converts phenyl alanine to tyrosine; in Tay-Sarhs* disease, in which the mutant gene does not p rovide ihe enzyme icquucu iu o x id ize spiiiiiguumim. ui in di.-v---C, in which the phosphorylasc needed to convert glycogen to glucose is not de veloped. On the other hand, the aberration resulting from the changed activity of the mutant gene may be only a slight deviation in physiologic activity under lying susceptibility, resistance, growth, or some other quantitative characteristic. In such instances the aberration may le appreciable only when several genes of this nature (polygenes) act cumulatively.