Which of the following drugs is not used in prostate carcinoma?

Prostatic carcinoma results due to excessive testosterone. Testosterone is conveed to dihydrotestosterone (DHT) by 5-a-reductase. DHT is responsible for prostatic growth. Flutamide is an androgen receptor antagonist whereas finasteride is 5-a-reductase inhibitor. Diethylstilbestrol is an estrogen. It will cause feedback inhibition of pituitary and hypothalamus.It was also used previously for prostatic carcinoma.