Why it's done

Hormone therapy for breast cancer is only used to treat cancers that are hormone sensitive.

Some breast cancers are fueled by the natural hormones estrogen and progesterone. Doctors refer to these cancers as estrogen receptor positive (ER positive) or progesterone receptor positive (PR positive).

Your doctor determines if your cancer is ER positive or PR positive by analyzing a sample of your cancer cells.

Hormone therapy for breast cancer can help to:

  • Prevent cancer from coming back
  • Decrease the risk of cancer developing in other breast tissue
  • Slow or stop the growth of cancer that has spread
  • Reduce the size of a tumor prior to surgery
Oct. 26, 2016
References
  1. Breast cancer. Fort Washington, Pa.: National Comprehensive Cancer Network. http://www.nccn.org/professionals/physician_gls/f_guidelines.asp. Accessed May 5, 2016.
  2. Hormone therapy for breast cancer. National Cancer Institute. http://www.cancer.gov/types/breast/breast-hormone-therapy-fact-sheet. Accessed Aug. 19, 2016.
  3. Pritchard KI. Adjuvant endocrine therapy for non-metastatic, hormone receptor-positive breast cancer. http://www.uptodate.com/home. Accessed Aug. 19, 2016.
  4. Fareston (prescribing information). Bridgewater, N.J.: ProStrakan Inc.; 2012. http://www.fareston.com. Accessed Aug. 19, 2016.
  5. Arimidex (prescribing information). Wilmington, Del.: AstraZeneca; 2013. http://www.arimidex.com. Accessed Aug. 19, 2016.
  6. Aromasin (prescribing information). New York, N.Y.: Pfizer Inc.; 2016. http://www.aromasin.com. Accessed Aug. 19, 2016.
  7. Faslodex (prescribing information). Wilmington, Del.: AstraZeneca; 2016. http://www.faslodex.com. Accessed Aug. 19, 2016.
  8. Zoladex (prescribing information). Wilmington, Del.: AstraZeneca; 2016. http://www.zoladex.com. Accessed Aug. 19, 2016.
  9. Femara (prescribing information). East Hanover, N.J.: Novartis Pharmaceuticals Corporation; 2014. http://www.femara.com. Accessed Aug. 19, 2016.
  10. AskMayoExpert. Breast cancer. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015.
  11. Ellis M, et al. Mechanisms of action of selective estrogen receptor modulators. http://www.uptodate.com/home. Accessed Sept. 12, 2016.
  12. Ibrance (prescribing information). Mission, Kan.: Pfizer Inc; 2016. http://www.ibrance.com. Accessed Sept. 12, 2016.
  13. Afinitor (prescribing information). East Hanover, N.J.: Novartis Pharmaceuticals Corporation; 2016. http://www.afinitor.com. Accessed Sept. 12, 2016.