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Zeitschrif t. fur Krebsforschung, volume 47, pages 288-302, 1233 * OCCUPATIONAL CANCER IN ASBESTOS WORKERS* Martin Nordaann ' . The Pathology Institute of the Hannovar Capital City Director: Professor Martin Nords2nn Received or. March 18, 1933 ^Dedicated to the publisher of this Journal, my admired teacher Professor Albert Dietrich, or. the occasion of his o5ch birthday. Asbestosis, the occupational disease of the asbestos workers, obviously occurs in countries and cities where asbestos plants vara ' established. Somewhat more and earlier knowledge on this specific disease became available in England and in America than in our country. Nevertheless, Marchand demonstrated., an asbestos lung as early as 1906 to the German Pathology Association, admittedly without diagnosing the condition. Eight years later, Fahr showed a second case, the main. . characteristics of which ware by then correctly defined. In the course of the last ten years, the disease was thoroughly studied, principally in England, America, and Germany. We are acquainted with more extensive serial examinations performed here and in foreign, countries in asbestos workers. A case jointly observed by Eager and Scroebe at Hannover in Germany resulted in significant progress, since Beger studied asbestosis thoroughly from the viewpoint of mineralogy. This prompted corresponding studies elsewhere as well (Koppenhofer, Sundius). Many years of exposure to asbestos dust results clinically in asthmatic complaints and a painful death follows, caused by dextral heart paralysis. In a considerable number of cases, as in silicosis, the pathologic condition occurs jointly with lung tuberculosis (Egbert, ' Wood), and cases are generally reported in which asbestoses is combined with a lung carcinoma (Wood, Cloyne, 1933). The overall number of post-mortems is lew; however, tr.eer nunoer increased quits rapidly during recent years. To the best or my knowledge, nine cases were subjected to autopsy and were published un Germany sc (Marchand, Fahr, Loeschke, Stroebe-3eger, di Siasi, Kedler, Behai*, and two of my own)(*). . Carcinoma cases are occasionally mentioned in literature; however, merely three publications from American and England deal more thoroughly with the cancer problem in the asbestosis lung. Soma of these reports' should be regarded with the caution always necessary at the start, when, a causative correlation between, two diseases is at issue. The far-reaching significance of the question for our insurance' system requires a brief discussion of these studies, before describing two cases which we observed. The compilation of the six cases and of * other incidentally mentioned cancers in asbestosis cases is intended to confirm the contention that occupational cancer in asbestos workers does exist. . - Case 1. Lynch and Smith (Anar. J. Of Cancer, 24, 56 (1935)}. Lynch refers to a worker, 57 years old, who was employed for 22 years as a weaver in a cotton spinning factory; this was followed by 21 years in. an asbestos plant. The X-ray taken shortly before his death coincides- exactly with Komig's representation of our Case 5, with the difference that the deep tumor shade is located in the right lung. The pcst-sortem revealed lung fibrosis with numerous asbestos fibers and asbestos cor puscles, as well as a cornified malignant squamous epithelioma in the right anterior lobe. The author classifies the tumor as a Schneeberg lisig cancer type or ) as a type of cancer found in coal dust lungs and ether pneumoconiosis cases; he finally compares the same with cancers in workers exposed to (*> Actorcing to Prof. Sauce's report, 3 deaths, u.b. (specifically) wichouc carcinoma, occurred at Dresden v it hit. the r.r. i b-: :;:rvayed. minerals containing arsenic, in which cases a causative correlation between the occupational disease and the cancer can hardly be questioned. It is certainly true that the fibrosis developed long before the start of carcinogenesis in the lungs; available information on cancer con firms that the cancer is attributable to chronic irritant effects, in. this case to bronchial irritation. Case 2. Gloyne (Tubercle 1935, 5) reports on a woman, 35 years old, who started to work with asbestos 17 years before her death; the occupa tion lasted for eight years. Accordingly, she had not been exposed to asbestos for nine years prior to her death. The lung asbestosis was of moderate extent. The right superior lobe showed a small, walnut-sized node, microscopically diagnosed as a malignant squamous epithelioma; its ramifications extended to the lung apex and pleura. The neoplasm " obviously followed the bronchial ramifications- Giant, calls were determinable at the border of the neoplasm. Case 3. Gloyne (Tubercle 1935,5). The second case described in the same publication deals with a woman, 71 years old, with moderately severe asbestosis, ascites and left vein thrombosis. The left inferior lung lobe showed a neoplasm with numerous necroses and caverns, allegedly similar to those demonstrated in Lynch's case (Case 1). A malignant squamous epithelioma was microscopically verified in this case as well. In his summary, Gloyne does not seem'to be quite certain concerning the primary starting point, such as the bronchus, for example, despite the fact that the cancer proliferated along the bronchial ramifications; simultaneous carcinogenesis could have taken place at numerous sates. In another case (Casa 3), the tumor had obviously developed at the site where the asbestos!s was in the most advanced stage. In both cases, the author was under the impression that the tumor was not large enough to cause death; . neither did he feel that the patients asbestesis was severe enough to be acceptable as the only cause of .death. . Ke believes instead that the two pathologic conditions had a joint lethal effect. . .* The author raises the question concerning a causative correlation, but refuses to make any attempt in his publication to answer`the same.' Case 4. Egbert and Geiger [Amer. Rev. Tbc- 34, 143 (1936)].- A Hungarian sale, 41 years old. worked uninterruptedly for 18 years as a weaver in an asbestos factory. A pneuaonia which persisted for eight days was followed by coughing and shortness of breath. The sanitary condi-" tions in the factory where ha worked were isoroved to some extent only two years prior to his-death. He died within eight months with the symptoms of left superior lobe cancer of the lung- In this case, bronchial * carcinoma metastases were found in various organs, in addition to asbes-tosis adenocaminoma was microscopically diagnosed. The authors believe that asbestos possibly caussii the lung carcinomas. Within brief intervals, two cases were under observation in our Institute; both patients were workers with asbescosis and lung carcinomas. Case 5. Our own findings. A woman, 35 years old, worked for a total period of exactly seven years, from her 17th to her 2oth year of life, in an asbestos factory, with an interruption lasting for T-l/2 years. This included two years in the asbestos .cardroom; cae rest of the time was spent in the spinning ar.d weaving 'workshops. After tra i above period, she never returned to the factory; her dcnicia was at a considerable distance from the plant. Her father's death was caused by cancer of the esophagus; her . mother died after a miscarriage. Her brother and sisters ware in good health, with one exception: a sister was affected by tuberculosis. Five brothers died in the war; two died in infancy. The patient was affected by childhood diseases only. After three miscarriages, her marriage remained without issue. The Wassersann blood cast was nega tive. While employed, the patient had a bronchial catarrh, but never asked for sick leave. Four to five years before her death, she started to cough and shortness of breath developed later; this was especially severe in the spring and the fall. Three quarters of a year prior to her death, she received medical attention; sub febrile temperatures, - pleuritic grating (sounds) and sluggishness of the sinistral respire-- ' ticn was found. The X-ray taken at that time revealed a curious shadow in the left inferior lung region, extending in the shape of a wedge from * the hilus to the back. While hospitalized (see Eonig's report on this case), the previous diagnosis cf tuberculosis was corrected and asbestoses was diagnosed instead. The large , by then extremely dark shadow in the ' region of the left inferior lobe led to the assumption that a tumor, originating from the asbestosis, had developed. ' The cadaver was pale and showed poor-nutritional condition. The lungs as well as the superior abdominal organs shewed coalescent sur faces. The lungs were inflated; the section surfaces were reddish-brown, smooch and filled with a foaming fluid containing large quantities of asbestos corpuscles. The lung section had a r.et-iike pattern, vich ! brickk--rreedd,, rough webbing. The left inferior lobe was very herd, brick-red or white, a walnut-sized cavern with jegged border extended from the principal bronchus and was obviously connected with the lat ter. Skeletized vessels and bronchi infiltrated the cavern, recalling the pattern of a buttress system. . The core remote area surrounding the cavern was rough; the pleura above the sane showed nodular thickening to 10 nm; the section surface was dry, partitioned into'fields and whits (sea Figure 1). ` . Figure 1. Left lung, in Case 5 (cy posc-sorten report, pags 1247/37). Malignant squacous epithelioma of the left inferior loba and pleura, with central decomposition cavern. Lung asbestosis. . . i --C " Mecastases were detected in che kidneys, partially in "he shape of full nodes, partially in the shapa of a rough, white network. The cancer-free sections of the lung showed the known ashestosis pattern under the microscope. It should be pointad out in this con text that the cornifications caused by asoestosis ware partially quite significant, truth in excess of the -condition defined as diffusa lung fibrosis, as known, in cases of lung congestion. The large number of . giant cells surrounding the asbestos corpuscles was espacialiy note worthy, also as compared with che available data on cases reported by Fahr, di Biasi, Loeschke and Stroeba-Bager. The tumor itself was a coraified, malignant squamous epithelioma; its epithelial cones and stroma contained entire bunches of asbestos fibers and asbestos cor puscles (Figure 2). The matastases showed the same structure, but with out asbestos. ' Case 6. Mala, 55 years old. Ke was employed from his 35 eh to his 43rd year of life in the workshop of an asbestos factory, where the substance was prepared for spinning. Ha worked there for seven years; eight months of unemployment followed, during which he was ill with pneumonia. He was then active in a wool laundry up to four aonths before he died. The patient was enlisted for military duty and served during the three war years only. Previous diseases: diphtheria, scarlet fever and malaria. His weight never exceeded 65 kg. He complained about dry ness in the throat, which had persisted since approjdmately 1919. He was later treated for a bronchial catarrh and acidosis. Considerable weight loss occurred three months before death; and his sputum was bloody. Tuberculosis was suspected. The patient discontinued his work four months before he died. Shortness of breath and coughing persisted. The respiration showed sinistral sluggishness.. Breathing was subdued and weaker in that region. The sputum contained masses of asbestos corpuscles Figure 3. X-ray, Case 6 (2 months before death). Deep shading of the left inferior region. vf V > c-. 7 ( ** X I f. A*' ' > The X-ray showed a deep shade in the left inferior lobe region (Figure 3)- The attending physicians, Drs. Schulte and Eeicheic (Hannover) diagnosed--or. the basis of these s yep toss--lung.asbestoses and carcinoma in the left inferior lobe, with metastasis into the. diaphragm, resulting from the radiologically determinable narrowing of the esophagus. The post-mortem revealed significant adhesions in the lung, with expanded alveoli and a finely articulated, steel- gray, rough pattern. The color of the section surface from the. rest of the area was reddish-brown. A dotted black and white tumor was . detected in the region of the inferior lobe; the tutor had infiltrated nearby organs such as: the pericardium, the left chamber of the heart, the diaphragm, the peritoneum in the left superior abdominal area, the retroperitoneal tissues in the rear of the spleen, the lymph node group * at that location, the inferior thoracic and superior lumbar sectors of the spinal column (Figure 4). A walnuc-sized decomposition cavern with inflamed borders was found in the center of the tumor, forming ar. exten sion of the primary bronchus. . Figure 4. Left lung. Case 6 (Post-mortem report, page 1335/37). Malignant squamous epithelioma of the left inferior lobe and of the pleura, vich central decomposition cavern. Lung asbestosis. . .\ / - ;I , .- ' . j*v.v*, . J S... .-'A ./ 1 \. LIs xV I *. r.o - v r\ >- Li.. . ^ .I - i >: ? r*\ %'V.-.v* ' **' . I T y: / D Atypical bronchial epithelium growth fro- the right anterior lobe in Case 6. (Post-screen retort, page 1335/37). ` ' The microscopic examination of cancer-free sections showed asbestosis; its severity and extent was comparable to findings in cases when the lethal outcome was not a sequela of complication. The left inferior lobe contained a significantly decomposed, cornified, malignant squamous epithelioma, in which asbestos fibers and asbestos corpuscles were determinable. The right anterior lobe showed an area with considerable hardening (Figure 5). The micro scopic examination revealed significant bronchial epithelium growth which infiltrated delimited areas in the form of a true carcinoma. The marcrophage and giant cell count in the lungs, within the area of the comificacions and in the alveolar spaces, was as high as in Case 5. w'e compiled the cited cases as well as those observed by us, diagnosed as asbestosis and carcinoma cases, or.- the following table U. CO I o 0 o o u 4-' Q o H p- "3 3 o -- 3 -- 3o w Ul 3 4-1 4_) c rj a _j r3 tS j-, ui . 3 -a --' c c. ^ o o; 3 33 rz Ui 3O " -H tc Ui 3 u> e. C3 O V) c cC u> f! ,2 r-I C O --1 * o 3S 3 3 2> O 3 ci 2 22 O cu 2o O' cn a 4-1 r* r: c 2 3 4-1 H -- oS ^4 -- 4-1 --4 3 2 o Ua .3 -3 O 3 cn b C3 3 o 2 C5 2 3 w 4-1 u cn Ul u C3 R 3 -H 3 Oe 3 a U-l "3 C <o o --' tz z 3 4J 3 CO --4 a 3. O to 3 i-H K 4-1 CO <2 CO C C CO o 3 4J >N 33 o --C 3u "wJ 3* o CO T-t 4J Ul 4J c c c 3 Vi-I 2 > W "3f-- ra cc Ui w 3 3 U| V. > crz 3 T^ t**n U o c 3 c 4-1 3 *H -D UJ c. O R 3 ^ t-J 4-1 CO 0 r-{ 3 C *H O 3 t4 H c R rt 3u 3 3 to 3 C o^ CO *r4 4-1 3 Ul -^1 O 4_ 3 5 H 2ra Ch4 C -3 Ui 2 fH R c 3 U3 *-{ U-1 CO 3 R3R z i--( O Ul ( Table 1. tfhe occupational diseases o f asbestos workers. G erm any: 12 s e c t io n s , in c lu d in g 2 c a rc in o m a s ................................... n p p ro x . 17% England (H ood): 12 cases o f d e a th , in c lu d in g 2 (3?) w i t h c a rc in o m a s . . . ...............................................a p p r o x . 20% "V--...... As Che data show, lung cancer occurred in numerous cases jointly with asbestcsis. .This could be accidental (Gloyne, vrood) . However, the six cases subjected to intensive observation show several identical characteristics. Accordingly, a cause-effect correlation is presys&blv present between the asbestosis lung and the occupational disease in question. . . The snail number of cases is explained as follows: the number of workers exposed to the risk in asbestos plants is significantly lower * than the overall number of persons active in such plants. For example: the estimated number of persons exposed to the asbestos risk in. Germany merely anounts to a few thousand. Moreover, the wcrk force includes numerous women who, jointly with some men, are frequently employed by ' the plants for a brief period only. According to- British, American, and Germah"`auth6rs, noticeable symptoms or objective signs of dust inhalation become evident after several years of exposure. Therefore, no large number of case histories related to our problem was available. Also, attention focused on the occupational hazard of abestosis only-a short while ago. The bulk of scientific studies completed in Fngland originates from the years 1327/29 (see Literature). Apart frea the earlier work of Marchand (1906) and Fahr (1914), lung asbestosis was more thoroughly discussed in Germany starting from 1931/32 only; the same applies to America. Our Table definitely shows that the publications dealing with our problem in particular originate from the l3st three years. As a matter of course, the decisive evaluation of a new patho logic pattern is undertaken when the basic characteristics of the disease at issue are already knovrn. Since the available statistical material is limited, the question whether the cancer of asbestos workers is an occupational disease car. be settled merely on the basis of cases with lethal outcome. In Ger many, 12 post-mortems, including two cases of cancer, ware performed,' i.e., 17% of the cases shoved 'cancer. In three cases, the post-mortem took place at Hannover; two showed cancer. The prognosis of another patient (the fourth case) is unfavorable. The latter is treated by ` occupational disease specialists; it is believed that no carcinoma is present. Accordingly, carcinomas were found in 50% of the cases- The number of cases subjected to post-mortems in Germany is probably much higher; many of them were not reported. So survey of the 100 cases observed by Wood in England is available. In 30% of the latter asbestosis combined with tuberculosis, was diagnosed; the diagnosis of 17 cases has not yet been confirmed; in the remaining 53 cases, lung asbestosis was definitely diagnosed. Twelve patients died, two of them had lung cancer and one had "a few deposits of growth in the pleura." Disregarding the last-mentioned, questionable case, two out of twelve asbestosis patients, i.e., 17%, had cancer. The small number of cancer cases should not be used as an argument against a causative correlation; it corresponds to the present status of the problem's scientific study. The percentages mentioned by me, calculated according to a small number of cases, do not claim to represent the actual percentage; they are, nevertheless, defi nitely useful for the further study of the problem at issue. We trust chat efforts made by factories and occupational disease specialists to improve sanitary conditions in plants will prevent any rapid increase of cases under observation by eliminating the risk demon strated by us here. , c J The next objection raised agair.se the cause-effect correlation, is the generally large number of lung carcinoma cases, and, in particular, its incidence in those of tha 50 to 70 age groups. The Table indicates in this context that one-half of the cancer patients were young; two ' were 35 years old and one man was 41 years old. The fact that a regular period of 15 to 21 years passed in all cancer cases from the stare of asbestos work until death occurred is even more significant chan the high incidence of cancer in young patients. The average duration of the period is IS years--a fact which is correct in half of the cases. The oldest patient in the series survived for the briefest period, i.e., for 15 years. However, older workers became exposed to asbestos much, later in life. Therefore, the age when an old patient dies does not indicate a specific age-related susceptibility to cancer; instead, it seems to be a function of carcinogenesis in asbestosis cases. Four out of six cancer patients ware exposed to asbestos dust during part of said period and only in its initial stage. They had inhaled asbestos into' their lungs; carcinogenesis was not inhibited by the fact that these per sons later avoided exposure to dust inhalation. The periods of work \ lasted for at least seven to eight years; a woman, 71 years old, worked for 1-1/2 years only. She, nevertheless, developed severe asbestosis. The investigation of the sputum while the patient was alive as well as > the anatomic examination of the lung definitely proved chat leaving the plant does not mean chat asbestos is eliminated from the lung; nor does it prevent the development of lung fibrosis and cardiac muscle hyper plasia with corresponding, even if possibly tolerable, symptoms. Tcia t i , ) r ) above pathologic pattern strikingly recalls the development of experi mental tar cancer: as known, the period following the discontinuation of cutaneous tar application can no longer prevent the development cf the carcinoma. Ws, therefore, believe that the small number of findings is amply compensated by the regularity of the phenomena revealed by them. Inde pendently from the patient's age, cancer occurs in young persons with, lung asbestosis after approximately 13 years, whenever the patient in ' question worked in asbestos dust for several years- A comparison of the cases reveals additional coincidences. The cancer localised in the lung is definitely a so-called primary cancer. . Moreover, a malignant squamous epithelioma was found in 5/6 of the cases., aijd in 5/6 of i-h* ^fl^iaflwa was localized in the inferior ' lobe. As known, lung cancer usually develops in the bronchial mucous membranes as adenocarcinoma or a small-call, rather indifferent tumor. From the viewpoint of incidence, the malignant squamous epithelioma shows the third highest incidence. In most cases, the real causes of lung carcinomas are unknown. . However, scars and bronchiectasis neoplasms could be precursors of lung carcinomas. In such cases, a slow restructuring of the lung tissues is believed to precede carcinogenesis, since numerous cancers develop at the sites where prolonged tissue regeneration took place. Gloyne defines the cancers diagnosed by him as small; he .contends chat vital tissues were never excessively involved. He is, nevertheless, unable to exclude the possibility chat lung tumors could be of multiple origin. A confirmed -15- and Geiger. As the figures show, ic is nainly localized in the bron chus., in the shape of a round node. On the other hand, Lynch and Smith diagnosed the tumor detected by then at first as a case of tuberculosis. We believe to have detected the smallest tumor in the right anterior lobe of our Case 2. The cancerous bronchial epithelium growth in the non-cornified layers of the epithelial cells (Figure 5) showed a regular developaent pattern within a larger area, and was con-* nected with bronchial epithelium ramifications, also known to occur in cases of lung necrosis. We, therefore, believe that the multiple, oetaplastic squamous epithelioma of the bronchial system is character istic for asbestosis; another known form, the adenocarcinoma, occurs in exceptional cases only and, therefore, confirms the rule. Findings and diagnosis are similar in case of cancer originating from cirrhosis of zne iivsr, a phenomenon which is no longer doubted by anyone. . The objection could be voiced in this context that tissue restruc turing in the lung is by nc means sufficient for cancer etiolcgy, since ic would presumably result in a much.higher lung cancer incidence, for example: in cases of silicosis or tuberculosis. Ic seems, therefore, chat lung asbescosis has specific characteristics. In our opinion, such characteristics are, in fact, present. Tuberculosis and silicosis show a certain similarity, due to the restructuring of the lung which occurs in these diseases- Finally, the lung tissues are substituted by a cell-rich and later connective tissue- rich scar in both diseases. These nodif.icaticns involve massive accumu lations of tubercle bacilli or mineral dust nereides at certain, location ! It is correct to assume that these accumulations of particles occur through the lymphatic system. Accordingly, practically intact tis sues, besides decomposing sectors, are found in silicosis and tuber culosis. .. Figure 6. Giant cells surrounding asbestos corpuscles in Case 6 . (Pcsc-aortea report, page 1335/37), right lung. At variance fron the above, lung altera tions in asbestosis . . cases were initially defined as diffuse fibrosis. Our own findings in asbestosis cases coincide with the above. We fully agree with d 3aisi who states that larger scars in asbestosis are not unusual; they were present in our cases as wall. The diffuse fibrosis of the lung in asbestosis is not similar to the regular fibrosis in the congested lung. The tern "diffuse fibrosis'* is probably acceptable because the nodules and nodes characteristic for common fibrosis are not present in ashes-- tosis cases. These nodules have a fibrous, concentrically formed nucleus; frequently more recent granulation tissues adhere concentri cally to the sate. The scars in asbestosis, on the other hand, are triangular; all consist of fibers and ceils. Due to the shape and size c the asbestos fibers, accumulations of the sane occur in asbestosis as veil. CnV* minor cunr.titles reach the lymph nodes of the mediastinum. Our careful invescigacions revealed r.o asbestos corpuscles or fibers, except in the lymph node groups. ' Accordingly, the inhaled asbestos needles were distributed in the entire organism through the lymphatic system. The above becomes even more obvious when not only the asbestos corpuscles, but also the large quantities of asbestos fibers are taken into consideration. The diffuse distribution of the asbestos fibers, therefore, pre supposes a likewise diffuse, chronic irritation, which triggers the - proliferation, of the lung tissues. According to Beger's investigations at Hannover, a silicate is allegedly, at issue here which is released when the asbestos fibers are dissolved. The aorphologue di Bias! adopts the idea, at least insofar as the pointed asbestos fibers cause mechani cal irritation. Morphologically, the fiber-rich connective tissue pro liferates; a series of cellular elements is involved as well, such as Che formation of foreign body giant cells, as well as cell proliferations directly attributable to the asbestos fibers and asbestos corpuscles. The histologic preparations in our two cases seem to indicate especially extensive proliferations of such giant cells, determinable in the entire lung. Macrophage groups and other granulations were present jointly with the giant cells in the area of the cornificacicn. Lymphocytes and plasma cell infiltrations were likewise present. Accordingly, asbestosis goes hand in hand with growth and restruc turing phenomena, regularily distributed over the entire lung. This growth stimulus persists--as evident from the above statistical evalua tions--even when asbestos dust is no longer introduced, due to a 'work assignment change. - M$pn\> .t. j-wc-.-dW<4rVlBnt'|A^>'T- - . ..- . - ....... .. . -. \ ' .''`l ' / : -/' .'.'-" * '.... Under such preconditions, a diffuse cancerous growth could be a:-:p-cc In our case, in Case 1 (Lynch and Smith) and in. Case 3 (Gloyne), which show similarities according co the figures and descriptions, the grower, o the malignant squamous epithelioma is. macroscopically much more uniform i. directions, in particular within the pleura, than the growth of a nodular bronchial carcinoma,- a representative of which is listed on our Table .0 as well. Therefore, the diffuse growth stimulus involving the. entire lung in asbestosis results in a subsequent diffusa proliferation of the carcinoma. According to other opinions, the malignant squamous lung epithelioma originates directly-from the alveolar epithelium. The fol lowing question will be discussed laterr how far does the growth potenti of the covering bronchial...epithelium approximate the-growth of the scirrhous organs in the alveolar epithelium during proliferation? If _ we adopt the aforamention line of thought, the conclusion is reached that an immediate link exists between the carcinooa and the alveolar epithalia, proliferating in the fora or macrophages end giant cells. No additional conclusions can be reached on the basis of the diagnoses with modern morphologic methods in favor or a cause-effect correlation between asbestos and cancer. No complete solution of the cancer problem can result from the first report on an occupational cancer; the report serves only as another example. We can merely stipulate chat no inconsistency exists between these findings and the laws of carcinogenesis, as known today. Findings in cases of similar occupational cancers agree with our results. Malignant squamous epitheliomas .are quite frequently detected in such cancers as well. The occupations.! disease ac issue is statistically far core important chan ocher conicsis cases, due co che high inci dence of death caused by lung cancer. This prompts us to conclude chat che CHEMICAL r.acure of che minerals is che nose significanc and decisive facCor in lung cancer. The effecc of arsenic and radio-- accivicy in minerals was considered earlier as a contributing faccor in such cases. The possibility exists that asbestos likewise contains so-called carcinogenic substances. . We summarize below the results of our investigations, obtained on the basis of our statistical data: - In lung asbestosis, cancer develops regardless of age, i.e., in young persons as well, after approximately 18 years, affecting workers, who were exposed to asbestos dust for several years. In the cases known1 so far, the cancer was detected in most patients (5/6 of all cases) in the inferior lung lobe; it was diagnosed as a malignant squamous epi thelioma with comificacion. Lungs exposed for man years to the irritan effecc of asbestos fibers show the morphologic symptoms of a growth .. stimulus, in the fora of diffuse fibrosis, with desquamative alveolar epithelium and with foreign body cells around che asbestos corpuscles. The above restructuring of che lung tissue provides a pachogenetically well-known basis for cancer. It is not known so far which properties of asbestos are responsible in final analysis for the development of the neoplasm. Evidence chat a cancer of this type could actually exist according to facts known today is not the principal recondition for including the * v - cancer in question ar.ont the occupational diseases of asbestos workers; instead, evidence is needed to show that the incidence of the cancer in its characteristic form is sufficiently high to warrant its qualifica tion as such. I would have concluded that a cause-effect correlation muse be present here, even if I had been the only observer; with refer ence to earlier findings, X am able to confirm that ve are indeed facing an occupational cancer which affects asbestos workers. BIBLIOGRAPHY ' Alwens, W., Munch, aed. Wschr. 1935, 45. Frankf. Kasuist. Beobacht. S. 532. . *' Alwens and Jonas. Gewerbepathologie. . 3eger, Med. Klin. 1934, 1222 anid 1258. Arch. Gewerbepath- 6, 1 (1338) . Beger and Stroebe, Virchows Arch. 299. Beintker, Arch. Gewerbepath. 1931 II, 345. Virchows Arch. 293, 527. di 3iasi. Arch. Gewerbepath. 8, 136 (1937). Bohne, Dtsch. ned. Wschr. 23 (1936). Buresch, Dtsch. cad. Wschr. 1931, 1100. Butcner, Worbst u. Trillitzsch, Tuberkulose 1931. Cooke, Brit. msd. J. 1927 11,1024; 1928 II, 585; 1929a II, 204; 1929 II, 578. rahr and Feigel, Dtsch. med. Wschr. 1914 II, 1543. Gardener and Cucsrings. J. Med. Kyg. 1931. Gerbis and Ucko, Dtsch. r.ed. Wschr. 1932, Mo. 8, 2So. Cloyne, Tubercle 14,. 445, 493, 550 (1933); 1935. t Kcelsch and Lecerer, Arch. Gevarbepath. 1931 (2), R. 3. Koppenhofer, G. F., Arch. Gaverbepach. 6, H. 1, 33. Kruger, Rostock! and Saupe, Arch. Geverbapath. 1931 II, 55S. Lanza, A. J., J. anar. ned. Assoc. 106, No. 5, 368 (1936). ' Loeschke (Buresch), Dtsch. ned. Wschr. 1931 1. 1100. Verb dtsch. path Ges. (27. Tag.) 1934,.291. *. Lyle Cannings, Brie, ned. J. 8, 17 (1935), * . Lynch and Sairh, J. of Cane. 24, 1, 56, 1935. J. amar. ned. Assoc- 95, No. 9 (1930). ' .- Marchand and Risel, Verb, dtsch. path. Ges. 1906, 223. . Maxtz, L., Z. Tbk. 72 (1935). `' McDonald, Brit. sad. J. 1927 II, 1025. . Merewether, E. R. A., Tubercle 15, 69, 109-152 (1933/34). Oliver, Brit. med. J. 1927 II. 1026. ` Page, R. C- A., Acer. J. ned. Sci. 1935, No. 144, 189). Saupe, Z. inn..Med. 1933, H. 37, 825. Lung cancer and lung coinosis cases. Beziehungen. Schuster, J. of Path. 34, 751 (1931). . Sinson, Brit. ned. J. 1928 I, 885. ' Sinson and Strachau, J. of Path. 34, 1 (1931). Stewart, Bucher, Colnann, Arch, of Path. 12, 903 (1931). Sundius and Bruce, 3er. Dtsch. keras. Cas. .17, 73 (1936). Sundius and A. Bygden, Arch. Gewerbeoath. 8, 26 (1937). Sweeny, Henry', J. aner. ned. Assoc. 106, 23 (1936). Tarreil, C. v., Labdonir.aises d. se. da l*ac. das sc. Paris 100 251 (IS85). ` Tissaraann,Zbl. Gevarbehyg. 18 (M.r. 8), 230 (1931). Williaas, E., Lancet 1934 IX, 10, 541. Wood, B-, and S. R. zloyna, Lancet 1934 II, 25 1383 and 5808. 7_ i ABSTRACT OF THE LITERATURE OF INDUSTRIAL HYGIENE i SUPPLEMENTARY TO THE JOURNAL OF INDUSTRIAL HYGIENE AND TOXICOLOGY * VOLUME 20 JANUARY, i93*-`DECEMBER, I PUBLISHED BY THE WILLIAMS & WILKINS COMPANY Baltimore, Md. 184 JOURNAL OF INDUSTRIAL HYGIENE AND TOXICOLOGY [pot. JO, m. Anaesthetised cat! were given .iotratracheal insufflations ol fine bismuth car bonate, biaiauth subnitrate aad lead glass powders by means of a powder blower in serted through a bronchoscope. Fluoro scopy aad roentgenograms demonstrated that in the dry state these radio-opaque minerals were not carried into the terminal air spaces but remained adherent to the walls of bronchi lined with ciliated epithe lium. The process of removal could be readily followed. The column of dust on the mucosal surface moved upward with a spiral motion. Neutral bismuth carbonate was usually completely eliminated in 1 to 4 days, the acid subnitrate was excreted slightly more rapidly and the lead glass had disappeared in from 7 hrs. to 2 days. The reaction of the mineral did not affect the rate of elimination, a result at variance with those of other observers. If the par ticles were suspended in fluid either saline or thin syrup, they were carried into the terminal alveoli from which they ware lowly excreted by the bronehial route over periods of week*. No svidtace of drainage to lymph nodes could be discovered. The authors suggest that inhalation of dust in the dry state might be lass dangerous than ifjj were moist. The presence of sufficient amounts of water might permit the mineral particles to penetrate beyond the protec tive ciliary epithelium and allow gradual accumulation in the lungs.--L. C. Gardaer. Occupational cuccsa in asbcsto* wotsill. Jf. Aforrfmoan. Zltchr. /. Krtbt*. fortch^ sol. 47, pp. 888-809 (1938). , The anther reports oa 2 caeae of lung cancer of which he mads the pathological- anatomical examination. Ha reports like wise on the clinical aspects of Hornig's case (aae following abstract) aad on a 55 yr. old man who had worked in asbestos from hie 25th to 43rd years. Autopsy showed aabestosis aad in the left upper lobe a markedly necrotic, eornified squamous celled epithelioma. The author mentions 4 additional cases of cancer with aebeatosifl in the literature and one must agree with him that, in view of tbs small number observed and the very few cases of asbeeto- sis autopsisd (12 esses in Germany), the number of eeacera found is a very high one. Of these 5 cases, the site of the cancer in 5 esses was the lower lobes, in five there was a squsmoua-ceUsd epithelioma. Three of the victims wsre lees than 43 yn. old; in all, work with ssbeetos had begun 15-21 yrs. before. After all, the author seems quite right in seeing s causal relation b^ tween aabestosis and lung cancer.--L Ttkky. Clinical cowswuatxoms on txi qossnoN od inpustsial CAMcnm or assbstos X'woassas. P. Horn#. Zltchr. f. Knht/orach., toi. 47, pp. 881-897 (1988). A 35 year old woman who worked in an asbestos factory from 1919-1928 fall ill of ssbastosis; in 1837 a sharply defined shadow was seen roeatgenologicaily in the upper left lobe. This shadow wea considered by the author to be a eareiaoma aad in the derision oa the ease, a causal relation between the presence of aabestosis sad the development of carcinoma was accepted. Confirmation at autopsy of the diagnosis of lung car cinoma is presented in a paper by Nordaaa (presiding abstract).--!. Tetchy. Einmmmt urvasnoanow or ran aesransto Ltrwo eaxesa quasnow. S. B. DhhmrU Zltchr. /. Krthtfonck, m!47, pp. 809-888 (1988). Ia a very exact manaar, with regard to the pertinent literature, aad with careful con sideration of all factors, the author reports on tbs turnon found ia mice kept ia tbs Scbaseberg mines. In the experiment wsre 45 aaimals of whom 28 died. Of these, 28 were given careful pathological and ana tomical examination; the other two were sent to another Institute for examination of their radioactivity. Ia 7 animals, tumors were found; ia two of them, multiple tumors ia various organs. Sines theexperi mental animals earns from almost tumorfree stock, the number of turnon found is a high ooe. In two caeae there were true epithelial lung turnon, in two, ulcers of the mediastinum, ia the other 3 cases there were tumor-like, more or less generalised changes of tbs lymphatic system. After careful consideration, the author blames tbs re-