This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cytotoxic Anticancer Drugs, Subject name: Pharmacology
Which of the following drugs is not used in prostate carcinoma? 
Select and explain. 
A. Finasteride, B. Diethylstilbesterol, C. Testosterone, D. Flutamide
C: Testosterone
Answer: C: Testosterone 
Explanation: 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.