This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Drug useful in breast cancer is ? 
Select and explain. 
A. Tamoxifen, B. Cyproterone, C. Testosterone, D. Chlorambucil
A: Tamoxifen
Answer: A: Tamoxifen 
Explanation: Ans. is 'a' i.e., Tamoxifen Pharmacotherapv of breast cancer Many breast carcinomas possess estrogen receptors Estrogen promotes their growth. Drugs which decrease the action of estrogen on breast CA by one or other mechanisms, can be used in breast CA. Drugs used in Breast cancer Selective estrogen receptor modulators (SERMs) - Tamoxifen, Tromifene. Selective estrogen receptor down regulators (SERDs) - Fulvestrant Aromatase inhibitors - Letrozole, anastrozole, exemestone LHRH (GnRh) analogues Aminoglutethemide High doses progesterones - Megastrol acetate.