Which of the following drugs is not used in prostate carcinoma

Ref-KDT 6/e p291 Prostatic carcinoma results due to excessive testosterone. Testosterone is cnveed to dihydrotestosterone (DfT) by 5-alpha reductase. DfI is responsible for prostatic growth Flutamide is an androgen rereptor antagonist whereas finasteride is reductase inhibitor. Both of these drugs can be used in pros tatic cancer. Diethylstilbesterol is an estrogen. It will cause feedback inhibition of pituitary and hypothalamus. Decreased secretion of GnRH (LH and PSH) results in the decrease in testosterone. It was also used previously for orostatic carcinoma.