Endocrine Therapy


Background for patients

If you were taking hormonal replacement or birth control at the time of your breast cancer diagnosis, you may have been told by your health care team to stop.  Therefore, it may be confusing that now your physician is talking to you about “hormonal therapy” for breast cancer risk reduction and/or therapy.  

Scientific discoveries have informed us that many breast cancers may be encouraged to grow by the hormones, estrogen and/or progesterone.  These hormones “park” on breast cancer cells that will receive them and make them grow.   Therefore, medications that block the “parking places” (aka receptors) on these cells will prevent cancer cells from growing.   Alternatively, blocking the production of estrogen by a woman’s body overall will also reduce the chance of estrogen feeding the growth of breast cells.

There are several ways to block hormones from reaching and promoting the growth of breast cancer cells:

  • Tamoxifen – primarily for the management of cancer risk after other cancer treatment or prevention of breast cancer in someone at high risk but who has not been diagnosed.
  • Arimidex - for post-menopausal women or women induced to achieve early menopause
  • Ovarian oblation
  • oophorectomy – usually reserved for women positive for BRCA1/2 gene mutations

Watch the Video on this page to learn more