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.
Indications
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.
Biological Functions
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.
Mechanism of action
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.
