Estramustine

Estramustine (, , ) is an estrogen and cytostatic antineoplastic agent which was never marketed. It is an estrogen ester – specifically, the C3 normustine ester of estradiol – and acts in part as a prodrug of estradiol in the body. Estramustine phosphate, the C17β phosphate ester of estramustine and a prodrug of estramustine, estromustine, estradiol, and estrone, is marketed and used in the treatment of prostate cancer.