Skip to content
My WebMD Sign In, Sign Up

Breast Cancer Health Center

Font Size

Breast Cancer and Endocrine Therapy

There are certain hormones that can attach to breast cancer cells and affect their ability to multiply. The purpose of endocrine therapy, formerly called hormone therapy, is to add, block, or remove hormones.

With breast cancer, the female hormones estrogen and progesterone can promote the growth of some breast cancer cells. Therefore in some patients, endocrine therapy is given to block the body's naturally occurring estrogen to slow or stop the cancer's growth.

Recommended Related to Breast Cancer

Soy and Breast Cancer: What's the Link?

To be safe, Jennifer Mukai all but eliminated soy from her diet after being told she had breast cancer in May 2009. Being of Japanese descent and also health conscious, the Seattle interior designer says she was eating a lot of soy in various forms before her diagnosis. “I drank about three-quarters of a cup of soy milk in my coffee twice a day and ate tofu and edamame [soy beans] pretty regularly,” the 44-year-old tells WebMD. “I was also probably getting quite a bit of soy in the meat-substitute...

Read the Soy and Breast Cancer: What's the Link? article > >

There are two types of hormone therapy for breast cancer.

  • Drugs that inhibit estrogen and progesterone from promoting breast cancer cell growth.
  • Drugs or surgery to turn off the production of hormones from the ovaries.

Do not confuse the term hormone therapy that is used for treating women with breast cancer with hormone replacement therapy that is typically used by postmenopausal women. Hormone therapy for cancer treatment, endocrine therapy, stops hormones from getting to breast cancer cells. Hormone therapy for postmenopausal women without cancer --  called "hormone replacement therapy" -- adds more hormones to your body to counter the effects of menopause.

Who Gets Endocrine Therapy for Breast Cancer?

As part of the diagnosis process, tests are done to determine if the breast cancer cells have estrogen or progesterone receptors. If so, that means that growth of the cancer can be stimulated with these hormones. If a cancer is found to have these receptors, endocrine therapy is recommended as part of the treatment plan.

What Hormone Therapy Drugs Are Used for Breast Cancer?

There are several common hormone therapy drugs used for breast cancer:

  • Tamoxifen
  • Fareston
  • Arimidex
  • Aromasin
  • Femara
  • Zoladex/Lupron
  • Megace
  • Halotestin

 

Breast Cancer and Tamoxifen

Tamoxifen is a pill that has been used for over 30 years to treat breast cancer. It was first used in metastatic breast cancer (cancer that spread) because it slowed or stopped the growth of cancer cells in the body. Tamoxifen also decreases the chance that some early-stage breast cancers will recur in premenopausal or post menopausal women and it can reduce the risk of cancer developing in the unaffected breast.

In addition, tamoxifen may offer an alternative to watchful waiting or prophylactic (preventative) mastectomy for women at high risk for developing breast cancer.

Tamoxifen is a type of drug called a selective estrogen-receptor modulator (SERM). At the breast, it functions as an anti-estrogen. Estrogen promotes the growth of breast cancer cells. Tamoxifen blocks estrogen from attaching to estrogen receptors on these cells. By doing this, it is believed that the growth of the breast cancer cells will be halted.

Tamoxifen is considered an option in the following cases:

  1. Treatment of ductal carcinoma in situ (DCIS) along with breast-sparing surgery or mastectomy.
  2. Adjuvant treatment of lobular carcinoma in situ (LCIS) to reduce the risk of developing more advanced breast cancer.
  3. Adjuvant treatment of breast cancer in men and women whose cancers are estrogen-receptor positive.
  4. Treatment of recurrent and metastatic breast cancer.
  5. To prevent breast cancer in women at high risk for developing the disease.

WebMD Medical Reference

Today on WebMD

Breast Cancer Overview
From self-exams and biopsies to reconstruction, we’ve got you covered.
Dealing with breast cancer
Get answers to your questions.
 
woman having mammogram
Experts don’t agree on all fronts, but you can be your own advocate.
woman undergoing breast cancer test
Many women worry. But the truth? Most abnormalities aren’t breast cancer.
 
Breast Cancer Treatments Improving
VIDEO
Resolved To Quit Smoking
SLIDESHOW
 
Woman getting mammogram
Article
Screening Tests for Women
SLIDESHOW
 
ovarian cancer overview slideshow
SLIDESHOW
serious woman
Article
 
what is your cancer risk
HEALTH CHECK
10 Ways to Revitalize Slideshow
SLIDESHOW