Estrogen antagonists are used to treat estrogen hormone-dependent cancer, such as breast carcinoma. A wellknown estrogen antagonist used in breast cancer therapy is Tamoxifen (Nolvadex). This drug, in combination with surgery and other chemotherapeutic drugs, reduces breast cancer recurrence by 30%. Estrogen antagonists can also be administered to prevent breast cancer in women who have a strong family history of the disease. Thyroxine is a natural thyroid hormone. It does not treat thyroid cancer. ACTH is an anterior pituitary hormone that stimulates the adrenal glands to release glucocorticoids; it does not treat adrenal cancer. Glucagon is a pancreatic alpha cell hormone that stimulates glycogenolysis and gluconeogenesis; it does not treat pancreatic cancer.Pharmacological Therapies