The goal of hormone therapy is to prevent estrogen from stimulating breast cancer cells. It is recommended for women whose breast cancers are hormone-receptor positive (either estrogen or progesterone), regardless of the size of the tumor and whether or not it has spread to the lymph nodes. Like chemotherapy, hormone therapy works systemically.
Hormone therapy works by blocking estrogen that causes cell proliferation. It is used only for patients with hormone receptor-positive ("hormone sensitive") tumors. Different types of hormone therapy work in different ways by:
- Blocking estrogen receptors in cancer cells (Tamoxifen)
- Suppressing estrogen production in the body (Aromatase inhibitors)
- Destroying ovaries, which produce estrogen (Ovarian ablation)
Tamoxifen was the first widely used hormonal therapy drug, but today it is mainly used as adjuvant therapy for premenopausal and perimenopausal women with hormone-sensitive breast cancer. Postmenopausal women are now usually prescribed aromatase inhibitors.
Tamoxifen and Selective Estrogen Receptor Modulators (SERMs)
Review Date: 11/08/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.