Document ZnDdq0qea73o4nENLx9wXNrLp

R&S 108976 aiMEDICAL PDSTA3CH DDCLb-ZNT UDSCB.IPTIOH , 'OP.H 63 63 69 76 Duplicate in all ca cs r ---7* /fj'd year as-196i- OOQflaOO Pile lumber [Bight justify [feeric only] Author (s), as Last Kane PS (Ko Punctuation) and coden for journal as JAKA preceeded-by. one blank space /najTc n! d. ' 20 -21 40 41 77* 73 ~ t/c- ""] Sub-lncEi: Cods 60 '61 62 n_ 12 13 Title of Report; end vith space--hyphen-hyphan-space. ToLlcv vith Index Ter--?, s4 ep` aratet d* t ironr each other vith -coma-space. qo not aoorevnate. Avoid other punctuation*^ 61 '62 21 22 23 24 Source (Journal, Vol*, Number, rages,Date ) /Cje^j y(,^i. 4^.^ 7/ UV -TKTb TS-/V, Z`7'7^ v/ 61 62. 3T 32 rief S-.u--- -- 2 10 TTL'Vi'SV* 61 62 ________________________________________________________________________ __ - 61 62 63 64 PRECURSOR LESIONS IN EXPOSED POPULATIONS AS t'-l INDICATORS OF OCCUPATIONAL CANCER RISK Cesarc Maltoni ) i Institute of Oncology and Tumour Centre Bologna, Italy f j j Nowadays, one more and more must face the problem of working popula tion groups who are exposed to a carcinogenic risk, namely, workers exposed to agents known to be carcinogenic both on the basis of experimental bioassays and on the basis of epidemiologic investigations; workers exposed to agents known to be carcinogens on experimental systems, though not yet epidemiologically proven to have an effect on humans; and workers exposed to agents of recent production, about which there is no valid experimental study or epidemiologic research yet available. We all agree that exposed occupational populations should undergo careful periodical medical examinations that must be as specific as possible and whose results should be correlated to occupational exposure. The aim of medical control, in the field of occupational oncogenesis, is chiefly to detect and to characterize, early and precisely, any precancerous or cancerous changes or any other change correlated directly or indirectly to exposure to a carcinogen. The data obtained from such examinations are important from several points of view: They may provide information for epidemiologic investigations that are aimed at detecting possible oncogenic factors in the occupational environment. They may add weight to the results of experimental carcinogenicity bioassays on agents already produced and/or used in industry. They may provide information on the degree of the risk in the factory as a whole and in each section of it. They may be used to very directly verify whether planned or claimed measures of protection are valid and sufficient. The early detection of precancerous lesions presents the possibility of intro ducing protective measures, which, in turn, may lower the incidence or delay the appearance of occupational tumors. The methods used in these examinations should be as specific as possible, sensitive, precise, easily repeatable, and harmless for the workers examined. They will vary, of course, depending on the type of carcinogens and on the organs more likely to be affected, that is, the target organs. At the same time, it must be noted that the value of early detection of already established occupational tumors has been and is overemphasized. In fact, it is now known that, often in an exposed population, occupational tumors may arise simultaneously in different organs, and in the same organs they are often multicentric. Well-established examples of multicentric tumors are, for instanee, liver angiosarcomas in vinyl chloride workers, occupational pulmonary tumors, asbestos-induced mesotheliomas, and tumors of the urinary tract caused 444 ; i ! i 1 ' eoa <soz O >e. 7O<. z uo, ep 33 ji o st. > I w. F z I wuz (J .uo-l (o1. " lUu7WL/OJ?l. X V) &<ZQ CO ao to --N4| MW*? ill Mm?, yy-ti-sr*r*MwaM, 446 Annals New York Academy of Sciences by aromatic amines. Investigations performed in .our'Institute on the last kind of occupational cancer have shown that in dyestuff workers with bladder tumors dysplastic and cancerous foci may be detected from the renal pelvis to the Frequency of Cel Exposed to Aroma urethra. In such a situation, very little, of course, can be done to cure these individuals. Our position, therefore, is in sharp contrast to those who claim to "protect" (!) workers exposed to carcinogenic risk by early detection,of tumors. With the aim of contributing to the identification of onco'genic factors, to the epidemiologic investigation of occupational cancer risk, to monitoring the No. of Wor Factory Under Con It efficacy of protective measures, and to the detection of early tumor precursors, we are, conducting at our Institute several projects of periodic mass examina tions of occupational groups at risk. Two examples of monitoring occupational risk by the detection- of precursor lesions are reported here. The method used is cytologic examination. The first example is of occupational groups who are known or suspected of being at risk of developing pulmonary cancer. Many of the steps in the histogenesis of pulmonary cancers are now known. The possible sequence of local changes in lung carcinogenesis with reference to cancer histotypes is shown in Table 1. The distribution of the various cytologic indices determined by sputum examination has been studied among workers of the chemical industry. Three different groups have been examined: workers in the chromium industry exposed to bichromates and chromium pigments, workers of the vinyl chloridepolyvinyl chloride (VC-PVC) industry exposed to the monomer, and workers of different chemical factories not directly involved in the production or use of known carcinogens. Heavy smokers (20 or more cigarettes per day for more than 10 years, or 15-20 cigarettes per day for morb than 15 years) not working in chemical industries were chosen as controls. The results are reported in Table 2. The incidence of the abnormal classes II-III, III, and III-IV among chromium and VC-PVC workers is much higher than expected, even when compared with populations of heavy smokers. Of particular importance is the increased incidence of the more advanced classes among chromium and VC-PVC workers, and also among workers of the chemical industry in general. The 116 workers to a group of 2QQ, a the past few years, involved was closed c The second exan group of 472 worke amines and therefore The incidence of of class III or more, the last result may l secutive cytologic ex on symptomless peo class 111 and over th; It should be poii among whom in the upper urinary tract \ The two examp sented, indicate bot network of prevent! deal with past or pr Table 2 to be carinogens or Frequency of Cellular Changes in the Respiratory Tract among Workers assessed. of Chromium, VC-PVC, and the General Chemical Industry, Detected by Sputum Cytology Workers Occupation Chromium industry VC-PVC industry Chemical industry (in general) Control (heavy smokers) No. 116 (100%) 267 (100%) 371 (100%) 1000 (100%) Cytologic Classes(Papanicolaou) I -- 75 (28.1%) 112 (30.2%) 335 (33.5%) II 62 (53.4%) 138 (51.7%) 196 (52.8%) 556 (55.6%) II-1I1 24 (20.7%) 38 (14.2%) 57 (15.4%) 103 (10.3%) III and III-IV IV V 30 (25.9%) 16 (6%) 6 (1.6%) 6 (0.6%) ---- ---- ---- ---- r >-SM7-1i. st kind umors, to the : these aim to amors, ors, to ng the ursors, imina- cursoi 3D (/) ted o nown ace t< O 00 CO 00 o ! mtur Thre iustry | orideirkers | ir use y for ) not lasses izher , Of | asses the AKERS Maltoni: Precursor Lesions Table 3 Frequency of Cellular Atypias in the'Urinary Tract among Workers Exposed to Aromatic Amines in Four North Italian Dyestuff Factories, Detected by Urine Cytology No. of Workers Factory Under Control A B C D Total 232 159 40 41 472 Cytologic Classes (Papanicolaou) I X-II II II-III III III-IV IV V 48 46 114 14 7 1 1 1 58 20 49 25 5 1 1 ____ It 8 7 3 8 1 '2 ____ 16 15 9 1-- -- -- _ 133 89 179 43 20 3 4 1 The 116 workers exposed to chromium compounds examined by us belong to a group of 200, among whom 21 cases of lung carcinomas were detected in the past few years. Incidently, following our finding, the section of the factory involved was closed down. The second example is the cytologic examination of urinary sediments in a group of 472 workers from four Italian dyestuff factories exposed to aromatic amines and therefore at risk for tumors of the urinary tract. The incidence of classes 11*111 and over was surprisingly high, with 28 cases of class III or more, equivalent to about 60'/r (Table 3). The significance of the last result may be appreciated when it is realized that among 60,000 con secutive cytologic examinations of urinary sediments performed in our Institute on symptomless people from the general population, we found an incidence of class III and over that approached 1 It should be pointed out that these 472 workers belong to a group of 1449, among whom in the past years 189 cases of tumors of the bladder and of the upper urinary tract were detected. The two examples reported, among the many that could have been pre sented, indicate both the value and-the need for such examinations in the network of preventive measures to be undertaken when, unfortunately, we must deal with past or present occupational exposures to agents known or suspected to be carinogens or to agents whose effects on man have not yet been properly assessed. ' saBvis**'*