Breast Cancer Hormone Receptor Status
Cancer cells taken out during a biopsy or surgery will be tested to see if they have estrogen or progesterone receptors. When the hormones estrogen and progesterone attach to these receptors, they fuel the cancer growth. Cancers are called hormone receptor-positive or hormone receptor-negative based on whether or not they have these receptors. Knowing the hormone receptor status is important in deciding treatment options.
What are estrogen and progesterone receptors?
Receptors are proteins in or on cells that can attach to certain substances in the blood. Normal breast cells and some breast cancer cells have receptors that attach to estrogen and progesterone and depend on these hormones to grow.
Breast cancer cells may have neither, one, or both of these receptors.
- ER-positive: Breast cancers that have estrogen receptors are called ER-positive (or ER+) cancers.
- PR-positive: Breast cancers with progesterone receptors are called PR-positive (or PR+) cancers.
Keeping these receptors from attaching to the hormones can help keep the cancer from growing and spreading. There are drugs that can be used to do this.
Why is knowing hormone receptor status important?
Certain drugs are used to treat breast cancers that have one or both of these receptors. Most types of hormone therapy for breast cancer either lower estrogen levels or stop estrogen from acting on breast cancer cells. This kind of treatment is helpful for hormone receptor-positive breast cancers, but it doesn’t work on tumors that are hormone receptor-negative (both ER- and PR-negative).
All invasive breast cancers should be tested for both of these hormone receptors either on the biopsy sample or when the tumor is removed with surgery. About 2 of 3 breast cancers have at least one of these receptors. This percentage is higher in older women than in younger women. DCIS should be checked for estrogen receptors, too.
How are breast tumors tested for estrogen and progesterone?
A test called an immunohistochemistry or IHC is used most often to find out if cancer cells have estrogen and progesterone receptors. Special markers are used to label the hormone receptors so they can be seen under a microscope.
What do the test results mean?
The test results will help guide you and your cancer care team in making the best treatment decisions.
Test results will give you your hormone receptor status. It will say a tumor is hormone receptor-positive if at least 1% of the cells tested have estrogen and/or progesterone receptors. Otherwise the test will say the tumor is hormone receptor-negative.
Hormone receptor-positive (or hormone-positive) breast cancer cells have either estrogen (ER) or progesterone (PR) receptors. These breast cancers can be treated with hormone therapy drugs that lower estrogen levels or block estrogen receptors. This includes cancers that are ER-negative but PR-positive. Hormone receptor-positive cancers tend to grow more slowly than those that are hormone receptor-negative. Women with hormone receptor-positive cancers tend to have a better outlook in the short-term, but these cancers can sometimes come back many years after treatment. Hormone receptor-positive cancers are more common in women after menopause.
Hormone receptor-negative (or hormone-negative) breast cancers have neither estrogen nor progesterone receptors. Treatment with hormone therapy drugs is not helpful for these cancers. These cancers tend to grow faster than hormone receptor-positive cancers. If they come back after treatment, it’s often in the first few years. Hormone receptor-negative cancers are more common in women who have not yet gone through menopause.
Triple-negative breast cancer cells don’t have estrogen or progesterone receptors and also don’t have too much of the protein called HER2. These cancers tend to be more common in younger women and in women who are African-American or Hispanic/Latina. Triple-negative breast cancers grow and spread faster than most other types of breast cancer. Because the cancer cells don’t have hormone receptors, hormone therapy is not helpful in treating these cancers. And because they don’t have too much HER2, drugs that target HER2 aren’t helpful, either. Chemotherapy can still be useful.
Triple-positive cancers are ER-positive, PR-positive, and HER2-positive. These cancers can be treated with hormone drugs as well as drugs that target HER2.
Questions to ask your doctor about hormone receptors
These are some questions that would be good to have on hand when talking to your doctor about your breast cancer test results:
- Has my tumor been tested for hormone receptors?
- What’s my hormone receptor status? Positive or negative?
- How does my hormone receptor status affect my treatment plan?
American Society of Clinical Oncology. Estrogen and Progesterone Receptor Testing for Breast Cancer. April 19, 2010. Accessed at http://www.cancer.net/research-and-advocacy/asco-care-and-treatment-recommendations-patients/estrogen-and-progesterone-receptor-testing-breast-cancer on September 25, 2015.
Last Medical Review: June 1, 2016 Last Revised: August 18, 2016