EFFECTS OF AN ANDROGENIC DERIVATIVE ON THE DEVELOPMENT OF CHEMICALLY-INDUCED MAMMARY CARCINOGENESIS IN THE RAT

The effects of art androgenic derivative - danazol on the development of dimethylbenz(a)anthracene (DMBA)rat mammary carcinogenesis were stu died. Animals in the treated group received danazol (10-12 mg/kg/day) during 169 days, starting 5 days after DMBA induction. As compared wit h tumours in control animals, those treated with danazol appear later and are significantly smaller. Moreover, this treatment reduced the in cidence of animals affected by mammary cancer and the average number o f malignant tumours in each animal. In the same way, the incidence bf animals with missing nodules was significantly higher in the group tre ated with danazol. It is concluded that danazol has an inhibitory effe ct on experimental mammary tumours. This effect seems to be greater th e earlier the treatment is started and the longer time it is applied.