Lack of Effect of Norethynodrel (enovid) on Methylcholanthrene-induced Mammary Carcinogenesis in Female Rats.

Oral progestogens for contraception (8) have become a feature of our culture, exposing a significant proportion of the female population to exogenous hormonal agents for protracted periods. Despite their importance, there is a paucity of published data on the effects of these agents on carcinogenesis in laboratory animals. For this reason, we are recording the results of an in vestigation of Enovid®1in female Wistar rats. The carcinogenic stimulus was 3-methylcholanthrene, given by gastric instillation, which produces mammary adenocarcinomas in these animals (1).