Incidence of cancer among workers exposed to vinyl chloride in polyvinyl chloride manufacture

Abstract

Based on results from two previous studies where an excess of melanomas was found in a cohort of workers exposed to vinyl chloride (VCM), a follow up of the incidence of cancer in the same cohort of 428 workers was carried out to scrutinise whether or not the excess could be confirmed by new cases. The total number of deaths in the study group from 1953 to the end of 1993 was 132 v 141 expected, and the total number of incident cancer cases was 56 v 57 expected. There were 11 cases of lung cancer v eight expected, seven cases of melanomas v 2.07 expected, and two cases of thyroid cancer v 0.34 expected. Five of the seven melanoma cases had occurred in the group that had been most heavily exposed to VCM v 0.7 expected. In the present follow up we also found five cases of the spinocellular cancer of the skin v 1.7 expected. Out of these five cases four were diagnosed after 1984. Two of the five cases v 0.7 expected had occurred in the most heavily exposed group. The total number of skin cancers (melanomas and spinocellular cancers) were 12 v 3.7 expected. There was one new case of melanoma between 1985 and 1993 v 0.7 expected. Hence, the strength of the relation between the observed and expected number of cases was reduced compared with the last follow up, and does not strengthen the previously indicated causal relation between exposure to VCM and development of malignant melanoma. There was no excess of testicular cancers in this study. The present results may indicate that occurrence of spinocellular skin cancer could bear some relation to work in the manufacture of polyvinyl chloride (PVC). Confirmation is needed from studies on other cohorts exposed to VCM. (Occup Environ Med 2000;57:65-68)

Nonsolar occupational risk factors for cutaneous melanoma

“…Another five studies showed that PVC workers (exposed to PVC) may have an increased cutaneous melanoma risk 28,31–34 . In a case–control study, increased risk was found for workers exposed to PVC and vinyl chloride (VCM) 28 .…”

“…In a case–control study, increased risk was found for workers exposed to PVC and vinyl chloride (VCM) 28 . An excess of melanoma was observed in PVC workers in four different cohort studies 31–34 (Table 2).…”

Adolescent and adult risk factors for testicular cancer

“…In contrast to the Swedish studies, a Norwegian occupational cohort study of 428 vinyl chloride workers followed-up for 23 years, recorded only one case of testicular cancer. 113 However, the small size of the cohort might have hampered detection of an association. Although the data are limited, the available studies do suggest that an increased risk of testicular cancer is associated with occupational exposure to PVCs.…”

Meta-analysis of studies of occupational exposure to vinyl chloride in relation to cancer mortality

“…The European multicenter study (5,14) included most of the persons previously studied in the United Kingdom (15,16), Norway (17,18), Italy (19,20), and Sweden (21-23), but the populations described in national reports did not completely overlap with those in the large multicenter study, due to different entry criteria (table 2). Therefore, the results of the individual studies could not be included in a meta-analysis.…”