ANTITUMOR-ACTIVITY OF FOLLIGEN, A NOVEL GONADOTROPIN-RELEASING-HORMONE ANALOG AGAINST DMBA-INDUCED TUMORS IN THE RAT

A novel chicken gonadotropin-releasing hormone (GnRH) analogue (Folligen), which has a different mechanism of action than superactive mammalian GnRH analogues, has been developed. In this study we report that in 9,10-dimetyl-2-bezanthracene-indced mammary carcinomas in rats, Folligen caused an almost 100% tumour remission during a 3-week daily treatment, without blocking ovarian functions. It decreased oestradiol but not to castration levels. while progesterone was not decreased at all; instead, it was slightly stimulated. The histological picture of the ovaries showed no signs of the inhibition of ovarian functions, but the presence of developing follicles and corpora lutea. In comparison, super-active mammalian GnRH analogues caused similar tumour remission but with hormonal castration and a complete block of ovarian functions.