Document ZopERMBedXXy1NxoRzv5qnLL

Vinyl Chloride Carcinogenicity: An Experimental Model for Carcinogenesis Studies -__ fL Maiton! Institute of OnMlogyend Tumour Center Bologne, Italy 40136 Long-term experimental bioassays of vinyl chloride (VC) carcinogenesis have supplied us with a body of knowledge concerning, on the one hand, the factors and mechanisms of carcinogenesis in general and, on the other, the value of experimental carcinogenesis bioassays in identifying oncogenic agents in the human environment, in assessing the degree of the risk, in predicting their itffects on man, and in providing the basis for adequate measures of preven tion. The achievements of these results have been favored, in our opinion, by the fact that these experimental studies have been performed by a single institution, under controlled conditions, which were kept uniform during the experiments with reference to material, type of animals and their care, methods of treatment, and the recording of biological effects. The experimental project on VC carcinogenesis started at the Experimental Unit of the Bologna Institute of Oncology and Tumour Center on July 1, 1971. It included a series of 18 correlated and integrated experiments, started in sequence. At present, part of the experiments have already ended, but several are still going on. It is foreseen that the program will end by June 1978. 7.7- This report will consider mainly the terminated or the advanced experi ments with significant results. EXPERIMENTAL PROCEDURES The experiments were planned to study the effects of VC, administered through different routes (inhalation, ingestion, and peritoneal and sub cutaneous injection), at different concentrations, for varying periods of time, by continuous or intermittent treatment, on animals of different species (rats, mice, hamsters), strains (Sprague-Dawley and Wistar rats), sex, and age (adults, newborns, embryos), r, 120 C. Maltonl The chambers of exposure are built basically of stainless steel and glass. They have been designed to deliver concentrations varying from 30,000 to 1 ppm of VC and to treat simultaneously nearly 4500 rodents. The VC con centration in the chambers is controlled by continuous gas chromatography. The VC is supplied by Montedison. Each stock is analyzed in the Montedison Research Unit. The impurities and their maximal levels in the VC employed have been as follows: HjO Acetic aldehyde Acetylene Allene Butane 1,3-Butadiene Chlorophene Diacetylene Vinyl acetylene Propine Methyl chloride 100 ppm 5 ppm 2 ppm 5 ppm 8 ppm 10 ppm 10 ppm 4 ppm 10 ppm 3 ppm 100 ppm The experiments utilize mainly Sprague-Dawley rats; Wistar rats, Swiss mice, and hamsters have also been used. All the animals, except the hamsters, have been bred in our Institute for years, and, whatever their use, all are examined at death by complete autopsy, giving us extensive information con cerning their current pathology. The animals were weaned and classified by sex when 4-5 weeks old, at which time they were numbered by ear punch and divided into groups by litter distribution. From weaning, the animals have been fed, ad libitum, an adequate commercial diet. The animals are kept in groups of 5 in makrolon cages with tops made of stainless-steel wire, except those in the inhalation experiments, which, during the treatment period, are housed in groups of 10 in stainless-steel wire cages with solid bottoms of the same metal. The animals are controlled weekly and weighed every 2 weeks during the period of treatment and monthly after the treatment is over. All the detectable gross pathological changes are recorded during the control. All the animals are kept under observation until spontaneous death. The animals, when moribund, are isolated in order to avoid cannibalism. A complete autopsy is made on each animal. Histological examinations are performed on Zymbal glands, interscapular brown fat, salivary glands, tongue, lungs, liver, kidneys, spleen, stomach, different segments of the intestine, bladder, brain, bones of the legs and feet, and any other organ with patho logical lesions. All the animals exposed to the highest doses (30,000 and 10,000 ppm for 52 weeks), with or without tumors, were examined radiologically during treatment and/or at death; moreover, radiologic examinations have also been made on several animals bearing tumors even though these animals had been exposed to the lower doses. The plan of the experiments is shown in Tables 1 to 7.1 1 All Tables have been grouped at the end of this paper. RESULT! The resu (Maltoni Inhalatii Adult Sp ExPosEr gland ca cutaneot mammai In Ap 50 ppm. affects tl tion of t The c experim As fa our mat VC sho onset of Expose sharply angiosa: 6000 pi Spragut VC has pregnar 14). The angiosa treatme among served Wistar In this tions, ^ Spragu tissues Swiss 1 VC exmamm and/ot effectiv In ( ucc 022909 Vtnyl Chloride Carcinogenicity 121 RESULTS The results of our experiments have been reported in several previous papers (Maltoni 1974; Maltoni and Lefemine 1974a,b, 1975; Maltoni et al. 1974). Inhalation Studio* Adult Sprague-Dawley Rats Exposed for 52 weeks. VC produces on Sprague-Dawley rats Zymbal gland carcinomas, nephroblastomas, liver and other site angiosarcomas, sub cutaneous angiomas, skin carcinomas, hepatomas, brain neuroblastomas, and mammary carcinomas (Tables 8 and 9). In April 1974 we proved that VC was effective from 30,000 ppm down to 50 ppm. A dose-response relationship has been found. Moreover, the dose affects the prevalence of some tumors and, on the whole, the relative distribu tion of the various types of tumors (Table 10). The carcinogenic effect of VC at the concentration of 50 ppm, under our experimental conditions, is now being re-proved definitively (Table 11). As far as the doses below 50 ppm are concerned, the up-to-date review of our material, at 87 weeks from the start of the experiment, has proved that VC shows carcinogenic effects also at lower doses, namely at 25 ppm, with onset of liver angiosarcomas (Table 12). Exposed for shorter periods. The reduction of length of treatment sharply reduces the onset of several types of turnon, particularly of liveT angiosarcomas (Table 13). When treated for only 5 weeks at 10,000 and 6000 ppm (BT10), no liver angiosarcomas were observed. ' Sprague-Dawley Rats oi Different Ages--Embryos and Newborns VC has a transplacental effect. Exposure of breeders from days 12 to 18 of pregnancy is sufficient to produce VC-dependent tumors in offspring (Table 14), The effect of age, however, is striking when comparing the onset of liver angiosarcomas and hepatomas in newborn and adult animals after 5 weeks of treatment at the same concentration (Table 15). The incidence of hepatomas among newborn rats is exceptionally high when compared with what we ob served in all the other experiments of the project performed in adult animals. Wistar Rats In this strain of rats also, when exposed for 52 weeks at different concentra tions, VC appears to produce broadly the same kinds of tumors it produces in Sprague-Dawley rats; however, the relative response of different organs and tissues appears to differ in the two strains (Table 16). Swiss Mice and Golden Hamsters VC exposure for 30 weeks, at different doses, produces in mice lung tumors, mammary carcinomas, liver angiosarcomas, vascular tumors of other types and/or site, and epithelial tumors of the skin (Table 17). It has proved to be effective at doses as low as 50 ppm. In Golden hamsters, VC produces liver angiosarcomas, skin trichoepi theliomas, melanomas, and foiestomach epithelial tumors; it also anticipated the onset of lymphomas, whose latency time is 48 weeks in treated animals and 82 weeks in controls (Table 18). Ingestion Studies on Sprague-Dawley Rats VC ingested by stomach tube for 52 weeks or more produces in SpragueDawley rats a large spectrum of the tumors it produces by inhalation (Table 19). No carcinogenic effects have been detected at lower doses after 57 weeks (Table 20). Injection Studies on Sprague-Dawley Rats One nephroblastoma and one subcutaneous angiosarcoma have been found among 240 animals which received from one to four intraperitoneal injections of 4.25 mg of VC. One nephroblastoma has been observed among 75 animals which received a subcutaneous injection of 4.25 mg of VC. Morphological Observations The VC-dependent tumors are of the rare and current type. Extensive iconog raphy has been given in previous publications (Maltoni and Lefemine 1974a; Maltoni et aL 1974). Apart from tumors, other tissue changes have been observed in treated animals. We plan to review all our slides in order to record extraneoplastic lesions. However, we want to point out here a current finding, i.e., vascular changes and correlated pathological lesions. In VC-treated animals, we observed in different anatomical sites vascular or sinusoidal ectasia and endothelial cell hyperplasia, dysplasia, and atypia (which may be considered the precursors of angioblastic tumors). Furthermore, in a high percentage of animals, local or systemic perivascular edema and hemorrhages were found. Hemorrhages are unusually frequent in the brain. CONCLUSIONS From the available data provided by long-term experimental bioassays, which have been partly presented here, and from the history of VC carcinogenesis, the following conclusions can be drawn; 1. VC is a multipotential carcinogen, meaning that it may produce tumors of different types at different sites. This fact and the increasing evidence from other carcinogenic models suggest that carcinogens in general should be considered multipotential. 2. The neoplastic response to VC depends largely on the species and strain of the animal used. If for some tumors the influence of the agent has been prominent, as is the case of liver angiosarcomas, for other types of tumors, Vinyl Chloride Carcinogenicity 123 like Zymbai gland carcinomas and lung tumors among others, the species and strain of the animals have a determinant role. 3. The age of the animals is an extremely important factor in determining not only the general incidence of tumors, but also their relative distribu tion. 4. The dose affects, at least in given ranges, the incidence of tumors and their own relative distribution. 5. VC administered by inhalation has been found to produce angiosarcomas of the liver in rats at concentrations as low as 25 ppm. 6. The carcinogenicity of VC in man, as well as the most important target organs, have been predicted by experimental bioassays. All human tumors which at present have been correlated to the exposure to VC bad been predicted by experimental evidence (Table 21). To our knowledge, 63 liver angiosarcomas in workers in the VC-PVC industry have been documented throughout the world (Table 22). Epi demiologic data had exposed a high incidence of brain tumors, large-cell carcinomas of the lung, lymphomas, and leukemias. Early cases of hepa tomas are also being found among exposed workers. A cytological ex amination of sputa from nearly 4000 Italian workers in the VC-PVC industry has shown a high incidence of changes in bronchial epithelia, including squamous dysplasia and atypical adenomatous proliferation. 7. Finally, experimental bioassays have provided indications on the level of the risk that have led to the adoption of new rules and measures of pre vention. We wish, as we did in the past, that proper experimental bioassays would be performed, following a list of priorities, on all the agents already produced, used, and widespread in the human environment, and on the new ones destined for production. In our Institute, we now have under study several compounds that are widely produced and used. REFERENCES Maltoni, C. 1974. Occupational carcinogenesis. II. International symposium on cancer detection and prevention, Bologna 1973. In Advances in tumour pre vention, detection and characterization (ed. C. Maltoni), vol. 2, p. 19. Excerpta Medica, Amsterdam. Maltoni, C. and G. Lefemine. 1974a. Carcinogenicity bioassays of vinyl chloride. I. Research plan and early results. Environ. Res. 7:387. -----------. 1974b. Le potenzialiti dei saggi sperimentaii nella predizione dei rischi oncogeni ambientali. Un esempio: il cloruro di vinile. Accademia Nationale dei Lincei, Rendicontl della Classe di Science Fisiche, Matematiche e Naturali, vol. LVI, serie VIII, fasc. 3, p. 412. ----------- . 1975. Carcinogenicity bioassays of vinyl chloride: Current results. In Toxicity of vinyl chloride-polyvinyl chloride (ed. I.J. Selikoff and E.C. Ham mond), p. 195. New York Academy of Sciences, New York. Maltoni, C., G. Lefemine, P. Chieco and D. Carretti. 1974. La cancerogenesi ambientale e professionale: Nuove prospettive alia luce della cancerogenesi da cloruro di vinile. Cli Ospedali della Vita, vol. 1, fasc. 5-6, p. 4. Table 1 Plan of the Experiments on Vinyl Chloride Oncogenesis: Effects of Inhalation of Different Doses for 1 Year Animals: Sprague-Dawley rats no. Exp. no. BTl BT2 BT6 BT9 BT15 Treatment doses VC age (weeks) 8 10,000, 6000, 2500, 500, 250, 50 ppm; untreated controls; treated con* trols: VA 2500 ppm 200,150,100 ppm; un treated controls 30,000 ppm 50 ppm; untreated controls 25,10, 5,1 ppm; untreated controls 13 13 17 11 13 268 280 30 200 300 i total 309 577 265 545 30 60 200 400 300 600 per group 64-96 120-185 60 100-300 120 1 The duration of treatment in each case was 4 hr daily, 5 days weekly. Table 2 Plan of the Experiments on Vinyl Chloride Oncogenesis: Effects of Length of Exposure by Inhalation Animals: Sprague-Dawley rats Exp. no. Treatment doses VC duration - age (weeks) 8 no. S total per group BT3 BT10 10.000, 6000, 2S00, 4 hr daily, 5 days 21 262 288 550 500, 250, 50 weekly, 17 ppm; untreated weeks controls 10.000.6000 ppm; 4 hr daily, 5 days 11 420 420 840 untreated con* weekly, 5 trols weeks; 4 hr daily, 1 day weekly, 25 weeks; 1 hr daily, 4 days weekly, 25 weeks 60-190 120 124 UCC Table 4 Plan of the Experiment* on Vinyl Chloride Oncogenesis: Effects of Strain Animals: Wistar rats no. Exp. no. Treatment.* doses VC age (weeks) 9 per $ total group BT7 10,000, 6000, 2500, 500, 11 220 220 250, 50, ppm; untreated controls BT17 1 ppm; untreated controls 13 120 120 240 30-40 120 The route in both cases was by inhalation, and the duration of treatment was 4 hr daily, J days weekly, 52 weeks. Table 5 Plan of the Experiments on Vinyl Chloride Oncogenesis: Effects of Species Animals no. Exp. no. Treatment.* doses VC species age strain {weeks) 9 per S total group BT4 BT8 10,000, 6000, 2500, 500, 250,50 ppm; untreated controls 10,000, 6000, 2500, 500, 250, 50 ppm; untreated control* mouse Swiss hamster Golden u 250 260 510 60-150 n 268 268 32-70 > The route in both cases was by inhalation, and the duration of treatment was 4 hr daily, 5 days weekly, 30 weeks. Table 6 Plan of the Experiments on Vinyl Chloride Oncogenesis: Experiments by Ingestion Animals: Sprague-Dawley rats Exp. no. Treatment doses VC duration (weeks) 9 no. per i total group BTll BT27 50 mg, 16.65 mg, 3.33 mg/kg body weight in olive oil; controls: olive oil 1 mg, 0.3 mg, 0.03 mg/kg body weight in olive oil; controls: olive oil 5 times weekly, 52 weeks 5 times weekly, 52 weeks or more 13 160 160 320 80 10 300 300 600 150 126 UCC 022915 Table 7 Plan of the Experiments on Vinyl Chloride Oncogenesis: Experiments by Injection Exp. no. BT12 BT13 route endoperitoneal subcutaneous Treatment doses VC 4.2S mg in 1.0 ml olive oil; con trols: 1.0 ml olive oil 4.2S mg in 1.0 ml dive oil; con trols: 1.0 ml olive oil duration (weeks) 4, 3, 2 times by two months and once 13 1 injection 21 Animals: Sprague-Dawtey rats no. 9 t total ISO ISO 300 80 70 150 per group 60 75 Table 8 Experiment DTI: Results after 135 Weeks (End of Experiment) Animals with tumors Group, treatment Animals (S-D rats) total correeled no.* Zymbal gland carcinoma^* av. latency no. % (weeks) nrphroblastomas* ----- av. latency no. % (weeks) no. angiosarcomas livera sub- mam- other ----------------------------------- cuta-skin brain mary type av. neous car- neuro- car- and/ la- other an- cino- hrpa- biasto- cino- or tency sites giomas mas tomas mas mas site* % (weeks) no. no. no. no. no. no. no. total* no. I VA 2500 ppm H VC 10,000 ppm III VC 6000 ppm IV VC 2500 ppm V VC 500 ppm VI VC 250 ppm VII VC 50 ppm VIII No treatment Total 96 49 69 61 72 60 74 59 67 59 67 59 64 59 68 58 577 464 16 26 50 7 12 62 2 3 33 4 7 79 ------ ------ 29 ... _ 5 8 59 4 7 65 6 10 74 4 7 83 6 to 80 1 2 135 26 -- -- 9 15 64 13 22 70 13 22 78 7 12 81 4 7 79 1 2 135 47 -- -- 3* 4 3 1 7 3 4' 38 3* 3 1 1 3 -- 8- 31 3* 3 1 2 5 1 3* 32 2* 1 1 4-- 1 3* 22 2' -- 4 -- -- 1 2p 16 II 1 1 -- -- 2 7' to 10* 6 14 12 11 8 15 8 37 155 ucc 022917 $ nrtrt rnnn 'tcnsi enn i<n mrl nnm A hr rlailv S rlnv* wcrklv. for SI Wtckl Exposure by inhalation to VC in air at 10,000, 6000, 2500, 500, 250, and 50 ppm, 4 hr daily, 5 days weekly, for 52 weeks. Animals alive after 26 weeks, when the first tumor {a Zymbal gland carcinoma) was observed. The percentages refer to the corrected number. > Mclaslascs to lung. ' Mctaslases lo liver, lung, spleen, and brain. <* Metaslases lo lung. * One intra-abdominal angiosarcoma (next to liver); I angiosarcoma of the lips; 1 angiosarcoma of the nose. t One angiosarcoma in subcutaneous fibrosing angioma; I ossifying parauricular angiosarcoma; 1 intra-abdominal angiosarcoma (next to liver). (One ossifying angiosarcoma of neck; 2 intra-abdominal angiosarcomas (I next to spleen and 1 next lo ovary). 1 One angiosarcoma of uterus; 1 lung angiosarcoma. 1 One intra-abdominal angiosarcoma (next to spleen); I inlralhoracic ossifying angiosarcoma. 1 One intra-abdominal diffused angiosarcoma. a Several cases of breast fibroadenomas; adrenal and pituitary tumors (generally adenomas) have not been considered since their distribution in the different groups does not vary significantly. 1 Two Zymbal gland adenomas; I ovarian cysloadenocardnoma; 1 neurilemmoma. Four Zymbal gland adenomas; 2 hepatic angiomas; 1 peritoneal angioma; 1 salivary gland adenocarcinoma. One Zymbal gland adenoma; 2 ependymomas. * One pulmonary fibrosarcoma; 2 lymphomas, p One Zymbal gland adenoma; 1 lymphoma. (Three Zymbal gland adenomas; 1 subcutaneous angiopertctloma; 3 uterine adenocarcinomas (f with sarcomatous component). 'One invasive acanthoma of Zymbal gland; 1 subcutaneous fibrosarcoma; 2 peritoneal fibroangiomas; 2 uterine adenocarcinomas (I with sarcomatous com ponent); 1 uterine leiomyosarcoma; 1 ovarian fibrosarcoma; 1 pulmonary rhabdomyosarcoma; 1 lymphoma. * Several animals with two or more tumors. ucc 022918 1 Tabl* 9 Experiment BT2: Results after 143 Weeks (End of Experiment) No. of animals with tumors Group, treatment Zymbal angiosarcomas gland Animals car* nephro- other (S-D rats) cinomas blastomas liver sites other type and! or site total> I VC 200 ppm II VC 150 ppm III VC 100 ppm IV No treatment Total 120 1 3 12 120 2 7 5 120 1 10 1 185 1 -- 545 5 20 18 1* 23" 30 3" 17* 29 -- 12' 20 1* 20s 21 5 72 100 Exposure by inhalation to VC in air at 200, 150, and 100 ppm, 4 hr daily, 5 days weekly, for 52 weeks. * One intra-abdominal angiosarcoma. t> Two subcutaneous angiosarcomas; 1 intra-abdominal angiosarcoma. * One subcutaneous angiosarcoma. a Five skin carcinomas; 1 subcutaneous fibroangtoma; 4 mammary carcinomas; 2 liver fibroangiomas; 3 liver angiomas; 3 liver hepatomas; 1 liver colangioma; 1 intra-abdominal fibroangioma; 1 leimyosarcoma of uterus; 1 neurilemmoma; 1 orbital fibrosarcoma. * Three skin carcinomas; 5 mammary carcinomas; 1 thymus angioma; 1 nasal osteo sarcoma; 1 cranial osteosarcoma; 1 liver colangioma; 2 adenocarcinomas of uterus; 1 fibromixosarcoma of uterus; 1 fibrosarcoma of lung; 1 lymphoma. 1 One skin carcinoma; 1 subcutaneous fibrosarcoma; 3 mammary carcinomas; 1 intraabdominal angioma; 3 forestomach papillomas; 1 adenocarcinoma of uterus; 1 intraabdominal rabdomyosarcoma; 1 kidney adenoma. i One Zymbal gland adenoma; 1 skin adenocarcinoma; 1 skin sebaceous adenoma; 1 subcutaneous fibrosarcoma; 2 subcutaneous fibromixosarcoma*; 1 mammary carcinoma; 1 intrathoracic rabdomyosarcoma; 3 forestomach papillomas; 1 adrenal carcinoma; 3 adenocarcinomas of uterus; 1 fibrosarcoma of uterus; 1 fibrosarcoma of scrotum; 3 lymphoma*. k Several animals with two or more tumors. Tabl Exp< t VC E: weel ft ' obse b ; mar ovaj d 130 ucc 022919 Table 10 Experiment BT6: Results after 63 Weeks (End of Experiment) Animals with tumors Croup, Treatment Animals (S-D rats) cor rected total no.* Zymbal gland carcinomas ongio* other sarcomas type and/ la- blasto- other Or tency mas liver sties site no. % {weeks) no. no. no. no. total* no. i VC 30,000 ppm 60 60 31 52 43 -- 17 1> 27* 51 Exposure by inhalation to VC in air at 30,000 ppm, 4 hr daily, 5 days weekly, for 52 weeks. * Animals alive after 24 weeks, when the first tumor (a Zymbal gland carcinoma) was observed. The percentages refer to the corrected number. *> One lung angiosarcoma. c Seven Zymbal gland adenomas; 1 skin carcinoma; 1 subcutaneous fibroangioma; 2 mammary carcinomas; 1 liver angioma; 1 hepatoma; 11 forestomach papillomas; 1 ovarian angioma; 1 brain neuroblastoma; 1 Harderian gland carcinoma. Several animals with two or more tumors. 131 Table 11 Experiment DT9: Results after 100 Weeks No. of animals with tumors Groups, treatment Animals (SrD rats) total survivors Zymbal gland nephrocar- blastercinomas mas angiosarcomas liver other sites total mammary tumors his- other tological malig- examine- car- nant tion cinomas tumors fibroadenomas other type and/ or site 1 VC 30 ppm 11 No treatment Total 300 55 6* 1 6 7* 111 90 43 2* 45 28* 128 100 28 --1 -- -- 20 8 3 2* 3 7* 24 400 83 62 6 7 131 98 46 4 48 35 152 Exposure by inhalation to VC in air at 30 ppm, 4 hr daily, 3 days weekly, for 32 weeks. * One with sarcomatous component. fcTwo subcutaneous angiosarcomas; 1 mammary angiosarcoma; 1 heart angiosarcoma; I thymus angiosarcoma; 1 abdominal angiosarcoma (next to spleen); I ovarian angiosarcoma. x Two carcinosarcomas. * Two carcinosarcomas. *TWo skin carcinomas; 3 subcutaneous fibrosarcomas; 3 subcutaneous rabdomyosarcomas; 1 subcutaneous leiomyosarcoma; 1 subcutaneous mixed sarcoma; I subcutaneous fibroangionia; I liver angioma; 1 thymus fibroangioma; 1 mediastinal fibroangioma; I spleen fibroangioma; I uterine fibroangioma; 2 uterine adenocarcinomas; 2 hypophysis adenomas in malignant deviation; I Leydig cells tumor; I ovarian fibroma; I retroperitoneal liposarcoma; 1 osteosarcoma; 4 leukemias. * One subcutaneous fibrosarcoma; I subcutaneous angiopencilosarcoma; 2 uterine fibrosarcomas; 3 leukemias. Several animats with two or more tumors. ucc 022921 5I <<<< | i E? = Tibi* 12 Experiment BT15: Results after 87 Weeks No. o] animals with tumors Croup, treatment Animals other (S-D rats) Zymbal angiosarcomas mam- type gland phro- mary anil car* blasto- other car* or total vivors e (nomas mas liver sites cinomas site total I VC 25 ppm 120 45 3 3 10 7 20 II VC 10 ppm 120 51 1 -- -- -- 11 5 16 ni VC 5 ppm 120 62 -- -- -- -- 13 5 17 IV VC 1 ppm 120 49 -- -- -- -- 8 4 12 V No treatment 120 49 -- -- _ -- 2 4 6 Total 600 256 4-- 3 -- 44 25 71 Exposure by inhalation to VC in air at 25, 10, 5, and 1 ppm, 4 tar daily, 5 days weekly, for 52 weeks. Table 13 Experiment BT3: Result* after 155 Weeks (End of Experiment) Group, treatment I VC 10,000 ppm II VC 6000 ppm HI VC 2500 ppm IV VC 500 ppm v VC 250 ppm VI VC 50 ppm VII No treatment Total Animals (S-D rats) ----------------------- surtotal vlvors 60 60 60 60 60 60 190 550 -- -- -- -- -- -- 2 2 Zymbal gland car- cinomas 7 (16) 6 (7) 3 (2) 1 (4) 1 -- I 19 (29) nephrobtastomas 1 (5) 1 (4) 2 (6) -- (4) 2 (6) 1 (1) -- 7 (26) No. of animals with tumors angiosarcomas liver other sites brain neurobtastomas other type and/or site - (9) 1 (13) 1 (13) 1 (7) -- (4) -- (1) -- 3 (47) 1* (3) 1* (3) 2* (3) I* (2) ____ (2) V (1) 1* 8 (14) 6 (7) 2 (3) 2 (5) -- _ -- _ 10 (15) 7h (18) ll> 03) 6t (ID 3* (10) 5' (8) 5- (13) 12* (10) 49 (83) total 21 (38) 17 (3D 13 (32) 6 (22) 7 (16) 8 (10) 12 (6) 84 (155) Ucc 022923 Exposure by inhalation to VC in air at 10,000, 6000, 2500, 500, 250, and 50 ppm^ hr (laily, 5 days weekly, for 17 weeks. Exposure by inhalation to VC in air at 10,000, 6000, 2300, 300, 250, and 50 ppm, 4 hr daily, 5 days weekly, for 17 weeks. * The number of tumors found in experiment BTI after 135 weeks is shown in parentheses. h One subcutaneous angiosarcoma. One intra-abdominal angiosarcoma. t One subcutaneous angiosarcoma; 1 intra-abdominal angiosarcoma. One intra-abdominal angiosarcoma. 1 One subcutaneous ossifying angiosarcoma; 1 orbital angiosarcoma. One ovarian angiosarcoma. Three skin carcinomas; 1 skin papilloma (nose); 1 renal adenoma; 1 lung angioma; 1 parauricular fibrosarcoma. `One Zymbal gland fibroangioma; 5 skin carcinomas; 1 subcutaneous angioma; 1 mammary carcinoma; 1 forestomach papilloma; 1 adenocarcinoma of uterus; 1 cranial osteoma. J Two skin carcinomas; 1 subcutaneous angioma; 1 mammary carcinoma; 1 hepatoma; 1 adenocarcinoma of uterus. k One ovarian carcinoma; 2 lymphomas. < One Zymbal gland adenoma; I mammary carcinoma; 1 adenocarcinoma of uterus; 1 Leydig cells tumor; 1 retrobulbar fibroma. One skin papilloma (nose); 1 mammary carcinoma; 3 adenocarcinomas of uterus. One Zymbal gland adenoma; 1 skin carcinoma; 3 subcutaneous fibrosarcomas; 1 subcutaneous leiomyosarcoma; I mammary carcinoma; I ovarian gyn- androblasloma; I fibrosarcoma of uterus; 1 salivary adenocarcinoma; 2 lymphomas. Several animals with two or more tumors. 135 Table 14 Experiment BTS: Results after 143 Weeks (End of Experiment) No. of animals with tumors Group, treatment Animals (S-D rats) total rteted no. Zymbal ntgland car blaste cinomas mas angio sarcomas liver other sites other type or sit* total I VC 10,000 ppm breeders n VC 6000 ppm breeders HI VC 10,000 ppm offspring IV VC 6000 ppm offspring Total 30 30 i -- 1" 2* 3* 30 30 54 51 3 i -- 2* 2* 8 32 32 1 -- 2* 4* 6 146 143 5 i -- 5 8 17 Exposure by inhalation to VC in air at 10,000 and 6000 ppm of breeders, 4 hr daily, for 1 week (from 12th to 18th day of pregnancy). Animals alive after 22 weeks, when the first tumor (a subcutaneous angiosarcoma) arose in an offspring. b One intra-abdominal angiosarcoma. One subcutaneous angiosarcoma; 1 angiosarcoma of the leg. > One subcutaneous angiosarcoma; 1 intra-abdominal angiosarcoma. * One liver fibroangioma; 1 liver angioma. f One Zymbal gland fibrosarcoma; 1 ovarian leiomyosarcoma. sOne Zymbal gland adenoma; 1 skin carcinoma; 1 subcutaneous fibroangioma; 1 mammary carcinoma. a One animal with two tumors. Tabl Incit Rest Ex/ no BTl BT1 E diffe 136 ucc 022925 Table 15 Incidence of Hepatic Tumor* among Sprague-Dawley Rats Exposed to VC; Results after 104 Weeks Liver turnon Exp, no. Group No. of animals total sur* angio vivors sarcomas hepa* tomas total animals with liver tumors BT10 I VC 10,000 ppm 120 16 -- i II VC 6000 ppm 120 15 -- -- m no treatment 249 55 -- -- BT14 I VC 10,000 ppm II VC 6000 ppm 46 8 10 15 19 43 5 10 13 17 Exposure in air at 10,000 and 6000 ppm, 4 hr daily, 5 days weekly, for 5 weeks, at different ages; 13 weeks (BT10) and 1 day (BT14). Table 16 Experiment BT7: Results after 136 Weeks Group, treatment i VC 10,000 ppm II VC 6000 ppm III VC 2500 ppm IV VC 500 ppm V VC 250 ppm VI VC 50 ppm VII No treatment Total Animals (Wistar rots) total sttrvivori Zymbal gtand car- cinomas nephroblastomas 30 1 (10) 30 -- -- (3) 1 (3) 3 (3) 30 -- -- 0) -- (5) 30 -- -- (3) 1 (2) 30 -- -- * - (2) 30 -- -- -- 40 3 -- -- 220 3 1 07) 5 (15) No. of animals with tumors angiosarcomas liver other sites brain neuroblastomas other type andf or site 8 (4) 2 (3) 3 (6) 4 1 (2) -- -- 18 (15) - (2) 1* (1) 1* (2) -- 1 (1) -- (1) -- 3 (7) 1 (2) 1 (2) -- (2) -- -- -- -- 2 (6) 2* (7) 5* (4) 2* (2) 2k 4' (3) U (1) 4* 19 (17) total1 11 (20) 8 (13) 4 (16) 7 (6) 4 (6) 1 (2) 4 39 (63) ucc 022927 Fiivnnrc Hv inhalation In VC in air at 10.000. 6000,2300, 300, 230, and 30 ppm, 4 hr daily, 5 days weekly, for 32 weeks. Exposure by inhalation lo VC in-air at 10,000, 6000,2500, 500, 250, and 50 ppm, 4 hr daily, 5 days weekly, lor 52 weeks. Tlie number of tumors found in experiment BT1 after 135 weeks is shown in parentheses. hOne intra-abdominal angiosarcoma (next to spleen). * One angiosarcoma of the intcrscapular fat pad. d One scrotal angiosarcoma. 'Two Zymbal gland adenomas. f Two liver angiomas; 1 hepatoma; 1 testicular mesothelioma; 1 thymus fibroangioma. s One skin sebaceous adenoma (eye); 1 Leydig cells tumor. * One liver fibroangioma; I intra-abdominal fibromixosarcoma. 1 One skin carcinoma; 1 skin acanthoma; I angioma of the caecum; I lymphoma. 1 One lymphoma. 1 One pericitosarcoma; t Leydig cells tumor; 2 lymphomas. Several cases with two or more tumor*. ij Table 17 Experiment BT4: Results after 81 Weeks (End of Experiment) Group. treatment I VC 10,000 ppm II VC 6000 ppm HI VC 2500 ppm IV . VC 500 ppm V VC 250 ppm VI VC 50 ppm VII No treatment Total Animals {Swiss mice) total corrected number* 3 9 S9 3 9 39 30 30 60 22 28 50 30 30 60 26 28 54 30 30 60 23 30 53 30 30 60 29 29 58 30 30 60 29 29 58 30 30 60 27 30 57 80 70 150 74 67 141 260 250 510 230 241 471 A nimah with tumors lung tumorsa mammary carcinomas6 no. % ay. la tency (weeks) no. fly. angio other la sar vascu tency comas lar % (weeks) no. no. epi thelial tumors of the skin no. other type and/ or site total" no. no. 35 70 38 70 30 57 38 66 33 57 2 3.5 86 184 -- 36 13 47 31 8 38 8 28 33 5 43 9 30 35 11 41 7 24 37 11 45 11 32 39 11 51 12 33 43 1 64 _ _ _ -- 60 -- -- 47 9* 9* 12 18* 22" 13* 1J 84 3* 6* 3* I* 2* -- __ 15 2* 36 4* 39 2r 31 1* 43 3* 40 1" 18 7* 13 20 220 ucc 022929 Exposure by inhalation to VC in air at 10,000, 6000, 2500, 500, 250, and 50 ppm, 4 hr daily, 5 days weekly, for 30 weeks. * t.iimk *iiv afi,r IK weeks when the first tumor (a mammary carcinoma) was observed. The percentages refer to the corrected number. Exposure by inhalation to VC in air at 10,000, 6000, 2500, 500, 250, and 50 ppm, 4 hr daily, 5 days weekly, for 30 weeks. * Animnls alive after 16 weeks, when the first lumor (a mammary carcinoma) was observed. The percentages refer to the corrected number. b Adenomas, some of which undergoing malignant transformation. r In females. < Three subcutaneous angiomas; 4 liver fibroangiomas; 1 heart fibroangtoma; t ossifying intcrscapular angioma. * One subcutaneous angiosarcoma; 2 liver fibroangiomas; 4 liver angiomas; I renal fibroangtoma; I thymus angioma. 1 Three subcutaneous angiosarcomas; I subcutaneous angioma; 3 liver angiomas; 2 iniru-abdominal angiosarcomas; 2 renal angiosarcomas; I lung angioma. * Two subcutaneous angiosarcomas; 1 subcutaneous fibroangioma; I subcutaneous angioma; 4 liver fibroangiomas; 1 liver angioma; 3 intra-abdominal angio sarcomas; I intra-abdominal fibroangioma; 1 renal angiosarcoma; 1 testicular fibroangioma; I angioma of the caecum; 1 lung fibroangioma; 1 lung angioma. t One subcutaneous angioma; 6 liver fibroangiomas; 10 liver angiomas; 2 intra-abdominal angiosarcomas; I ovarian angioma; I scrotal angioma; 1 lung angioma. 1 One subcutaneous angiosarcoma; t subcutaneous fibroangioma; 2 subcutaneous angiomas; 2 liver fibroangiomas; 3 liver angiomas; 1 intra-abdominal angioma; I ovarian angioma; 1 inlrathoracic fibroangioma; I angioma of the interscapular fat pad. 1 One angiosarcoma of uterus. k Two squamous carcinomas; I invasive acanthoma. 1 Five squamous carcinomas; 1 acanthoma. * One squamous carcinoma; 2 acanthomas. * One acanthoma. * One skin adenocarcinoma; 1 basalioma. p One Zymbal gland adenoma; 1 forestomach papilloma. < One subcutaneous leiomyosarcoma; t forestomach papilloma; 1 Harderian gland adenoma; l lymphoma. ' One forestomach papilloma; I parotid gland mixed tumor. * One Zymbal gland adenoma. 1 One Zymbal gland adenoma; I Leydig cells tumor; 1 lymphoma. * One parotid gland adenocarcinoma. ' One subcutaneous leiomyosarcoma; 1 adenoma of colon; 1 ovarian carcinoma; 1 leiomyosarcoma of uterus; 3 lymphomas. * Several cases with two or more tumors. Table 18 Experiment BT8: Results after 109 Weeks (End of Experiment) So. of animate with tumor* Group, treatment A nimals (Golden hamiters) liver angio- sarco** mas skin trichoepi- theliomas and ba- lym salio- melano pho ma.s* mas mas fore sto mach epi the lial* tumors other type and/ or site total* 1 VC 10,000 ppm II VC 6000 ppm III VC 2500 ppm IV VC 500 ppm V VC 250 ppm VI VC 50 ppm vn No treatment Total 35 32 33 33 32 33 70 268 6 1 -- 4 2* 10 1 2 2 2 7 7 10 -- 1 1 1 11 3* 13 2 4 -- 1 7 2* 12 -- 3~ 1 2-- 6 -- 6 I 1 4 -- 10 -- 2-- 3 24 5 2 2-- 7 8 37 14 68 Exposure by inhalation to VC in air at 10,000, 6000, 2500, 500, 250, and 50 ppm, 4 hr daily, 5 days weekly, for 30 weeks. I Several cases with acanthosis and some undergoing malignant transformation, fc Papillomas, acanthomas, some of which undergoing malignant transformation. c One subcutaneous angioma; 1 gall bladder adenocarcinoma. II Two hepatomas; 2 liver libroangtomas; 2 liver angiomas; 1 biliducts adenocar cinoma. * One hepatoma; 1 liver Abroangioma; 1 liver angioma. f One subcutaneous angioma; 1 bronchial carcinoma, t Several animals with two or more tumort. Table 19 142 UCC 022931 Table 19 Experiment BT11: Results after 120 Weeks No. of animals with tumors Group, treatment A nimats (S-D rats) total sur vivors Zymbal gland car nephro cinomas blastomas angiosarcomas liver other sites mam- car cinomas VC 50.00 mg/kg 1 II VC 16.65 mg/kg III VC 3.33 mg/kg IV Control: olive oil Total 80 2 i 2 16 2* 5 80 2 2 3 9 -- 6 80 4 -- -- -- 2 4 80 4 320 12 1 ---- 4 5 25 -- 4 4 19 other type and! or site 7* 34 3* 5' 18 totalt 29 21 9 9 68 Exposure by ingestion (stomach tube) to VC in olive oil, at 30.00, 16.65, and 3.33 mg/kg body weight, once daily, 4-5 days weekly, for 32 weeks. * One thymus angiosarcoma; I intra-abdominal angiosarcoma (next to spleen). b One iung angiosarcoma; I inIra-abdominal angiosarcoma (next to kidney). 'One skin sebaceous carcinoma; 1 hepatoma; 1 liver angioma; 2 forestomach papillomas; 1 intestinal adenocar cinoma; I lymphoma. 4 One liver angioma; I adrenal carcinoma; I lymphoma. * One subcutaneous sarcoma with angioblastk component; 1 intra-abdominal ossifying sarcoma with angiobiasiic com ponent; 1 bladder papilloma. 1 One skin carcinoma; I papilloma of the auditory duct; 1 bladder carcinoma; I adrenal carcinoma; 1 reticulosarcoma. s Several animals with two turnon.  Table 20 Experiment BT27: Results after 57 Weeks Tumors mammary tumors I II HI IV Total Treatment length {weeks} going 1 mg 57 + 0.3 mg 0.03 mg controls: olive oil 57 57 57 + + + 81 82 78 82 323 Animats* no. at start 0 total survivors 9 total present age (weeks) histologically examined corfthrotolal adenomas mas 77 158 48 67 115 67 11 ____ -- 77 159 51 48 99 67 6 ---- 85 163 48 58 106 67 14 1 2 77 159 38 57 95 67 6 -- -- 316 639 185 230 415 37 1 2 others 1 subcutaneous fibrosaxcoma 1 renal pelvis carcinoma 1 malignant histiocitosis I forestomach papilloma; 1 stomach adenomatous polypus; 2 lymphomas 7 Exposure by ingestion (stomach tube) to VC in olive oil at 1, 0.3, and 0.03 mg/kg body weight, once daily, 4-5 days weekly, for 104 weeks. * Sprague-Dawley rats, 10 weeks old at start. ucc 022933 Table 21 Turnon Presently Correlated to VC Exposure (by Inhalation) on Experimental Rodents and Man Species Angio sarcomas of liver Tumors of brain Tumors of lung Lym phomas and leu kemias Hepa tomas Angio sarcomas Seba ceous cuta neous Nephro car blastomas cinomas Other cuta neous epi thelial tumors Fore stomach Mam papillomas mary and car acan cinomas thomas Rat Mouse Hamster Man ++ ++ + (+) + (+> (+) ++ + + (+> (+) (+) + + + (+) + ++ + (+) ++ 14S Tabla 22 Reported Cases of Angiosarcoma of the Liver among Worker* Exposed to Vinyl Chloride Country Belgium Canada Czechoslovakia Federal Republic of Germany France Great Britain Italy Japan Norway Rumania Sweden Switzerland U.S.A. Yugoslavia Total Polymeritation Other , occupa tion 1 10 _ 2 8i 5 2i 2i 1 1 1 2i 1 19 2 2 57 6 Total 1 10 2 9 5 3 3 1 1 1 3 i 21 2 63 14 UCC 022935