Cytestrol acetate explained

Cytestrol acetate is a steroidal antiestrogen and a cytostatic antineoplastic agent (i.e., chemotherapeutic) which was developed for the treatment of breast cancer but was never marketed.^{[1] [2] [3] [4]}

It is an 11α-hydroxylated derivative of ethinylestradiol in which a bis(2-chloroethyl)amine nitrogen mustard moiety has been attached as an ester at the C3 position and acetate esters have been attached at the C11α and C17β positions. The mechanism of action of cytestrol acetate in breast cancer is two-fold: (1) acting as an antiestrogen similarly to fulvestrant or ICI-164384; and (2) having cytostatic actions via the carbamate–nitrogen mustard moiety analogously to estramustine phosphate. The drug shows potent efficacy against breast cancer superior to that of tamoxifen in in vitro models.

See also

• List of hormonal cytostatic antineoplastic agents

Notes and References

1. Oborotov AV, Smirnova ZS, Osetrova IP, Polozkova AP, Rzheznikov VM . Antitumor activity of various medicinal forms of the new estrogenocytostatic drug cytestrol acetate. Pharmaceutical Chemistry Journal. 33. 10. 1999. 526–527. 0091-150X. 10.1007/BF02508372. 5550495.
2. Smirnova ZS, Rzheznikov VM, Tolkachev VN, Borisova LM, Kiseleva MP, Semeĭkin AV, Fedotcheva TA, Shirokikh KE, Banin VV, Shimanovskiĭ NL . 6 . [Antitumor and antiproliferative action of the steroidal cytostatic antiestrogen cytestrol acetate on hormone-dependent tumor models] . ru . Eksperimental'naia i Klinicheskaia Farmakologiia . 77 . 10 . 31–35 . 2014 . 25518525 .
3. Smirnova ZS . 2003 . [Experimental Study of Hormonocytostatics for Treatment of Breast Cancer.] . Российский биотерапевтический журнал . Russian biotherapeutic journal . Russian . 2 . 2 .
4. Smirnova ZS, Rzheznikov VM, Tolkachev VN, Borisova LM, Kiseleva MP, Semeykin AV, Fedocheva TA, Shirokikh KE, Banin VV, Shimanovsky NL . Противоопухолевое и антипролиферативное действие стероидного антиэстрогена цитэстрола ацетата на моделях гормонозависимых опухолей. . Antitumor and antiproliferative effects of the steroid antiestrogen citestrol acetate in models of hormone-dependent tumors. . Russian . Экспериментальная и клиническая фармакология . Experimental and clinical pharmacology. . November 2014 . 77 . 10 . 31–35 .