Endocrine therapy

Endocrine therapy, or hormone therapy, is a type of treatment that slows or stops the growth of hormone-sensitive breast tumors. It does so by preventing the body from producing estrogen and progesterone—hormones that promote the growth of some breast cancers—or interfering with the effects these hormones have on cancer cells. Endocrine therapy may be used to treat breast cancers that rely on hormones to grow, such as estrogen receptor (ER)–positive breast cancer.