Cancer Induction by Polyurethan and Polysilicone Plastics

Abstract

Since definite experimental evidence was obtained regarding a carcinogenic effect of parenterally implanted, fully cured and vulcanized Silastic, distinct caution should be employed in the use of this plastic in human prostheses, i.e., its use should be restricted to the management of those diseases which justify possible cancer risks. Polyurethans of different chemical composition possess properties that are carcinogenic to rats when implanted as foams and rigid plastics. The chemical nature of carcinogenesis induced by polyurethans is indicated by deterioration of these plastics when implanted into rats (the foams faster than the rigid ones) and the fact that they are capable of inducing carcinomas (intestinal mucosa, liver, peritoneum) and sarcomas (connective tissue of skin, wall of colon, and stomach). They are thus pluripotential like other chemical carcinogens. The apparent formation of peritoneal mesotheliomas resulting from the implantation of polyurethan foams has its human counterpart in the occurrence of pleural and peritoneal mesotheliomas in man following occupational and environmental exposures to asbestos dust. The definite carcinogenic action of polyurethans parenterally introduced into rats provides a warning against indiscriminate use of these plastics in human medical practice because of possible delayed carcinogenic sequelae. The observations reported furnish additional warnings against any uncontrolled and avoidable exposures of man to many of the recently developed carbon and silicon polymers that are used in the economy and in industry. Carcinomas of the intestinal mucosa may be induced by carcinogens introduced into the peritoneal cavity and penetrating the intestinal wall from the serosal surface.