2998-57-4

Antineoplastic.

Estradiol 3-[N,N-Bis(2-chloroethyl)carbamate] is used treatment of breast cancer. Also used in the treatment of prostate cancer.

ChEBI: A carbamate ester obtained by the formal condensation of the hydroxy group of 17beta-estradiol with the carboxy group of bis(2-chloroethyl)carbamic acid.

Estramustine phosphate sodium (Emcyt) is a hybrid structure combining estradiol and a nitrogen mustard in a single molecule. The drug has been approved for use in prostatic carcinomas and will produce clinical remissions in one-third of patients who have failed to respond to previous estrogen therapy. The mechanism of action of estramustine is not well defined, but it does not appear to require either alkylation of DNA or the presence of estrogen receptors in tumor cells. Nonetheless, the toxicities of the drug are similar to those of estrogen therapy: breast tenderness and enlargement (gynecomastia), fluid retention, mild nausea, and an increased risk of thrombophlebitis and pulmonary embolism.The drug is not myelosuppressive.

Estramustine has a low affinity for the βm tubulin isotype, which often is overexpressed in estramustineresistant prostatic neoplasms as one defense against this therapeutic intervention.

Because this anticancer agent contains a carbamylated nitrogen mustard moiety, it is most commonly classified as a DNA alkylator; however, it is now known that its primary mechanism of antineoplastic action is inhibition of mitosis.