Effects of aminoglutethimide, alone and in combination with surgical castration, on pancreatic carcinogenesis in rats and hamsters.
The present 12-month study was carried out to investigate the effects of the aromatase inhibitor aminoglutethimide, alone and in combination with orchiectomy, on pancreatic carcinogenesis in azaserine-treated rats and N-nitrosobis(2-oxopropyl)-amine-treated hamsters. Treatment of the animals started 4 months after the last injection with the carcinogen. They were surgically castrated and/or treated with aminoglutethimide. Aminoglutethimide-treated rats developed less pancreatic tumours than did untreated controls. Multiplicity of (pre-)-neoplastic acinar lesions was lower in orchiectomized rats than in intact rats. Inhibition of pancreatic carcinogenesis was most pronounced in rats that were both orchiectomized and treated with aminoglutethimide. These effects were statistically significant after 8 months, but not after 4 months, of treatment. In hamsters, aminoglutethimide showed an enhancing rather than an inhibitory effect on the formation of ductular pancreatic tumours. Castration appeared to have no effect on the development of N-nitrosobis(2-oxopropyl)amine-induced ductular lesions in the pancreas, either alone, or in combination with aminoglutethimide. The present findings indicate that aminoglutethimide, alone and in combination with surgical castration, might be of value for the treatment of pancreatic acinar tumours, whereas the usefulness of aminoglutethimide for treatment of ductular adenocarcinomas of the pancreas is somewhat doubtful.