Estrogen Receptor/Progesterone Receptor (ER/PR) Tests

Why this test may be ordered

• To find out whether breast cancer cells have estrogen and/or progesterone receptors (hormone receptor status).
• To help plan the best treatment for breast cancer.

Preparation and collection

Your provider will give you instructions for how to prepare for your biopsy. If you take any blood thinners, including aspirin, you may need to stop taking them before your biopsy. Tell your provider about all the medicines and supplements you take. Don't stop or start taking anything without talking with your provider first. If you're having general anesthesia, you will probably need to fast (not eat or drink) for several hours before surgery. If you have general anesthesia or medicine to relax, you may be groggy after the procedure, so plan to have someone take you home.

Your provider will need to take a sample of your breast tissue in a procedure called a breast biopsy. There are three main types of breast biopsy procedures. They are usually done on an outpatient basis, which means you go home the same day.

It's common to have some bruising and temporary discomfort after a breast biopsy. Possible risks include: Infection, which can be treated with antibiotics, Bleeding. Your provider will give you instructions for how to care for biopsy area and manage any discomfort. General anesthesia is very safe even for most people with other health conditions.

Understanding results

The results will show whether you have a hormone receptor-positive or negative type of cancer.

• Hormone receptor-positive (HR-positive): At least 1% of the cells in your sample have estrogen and/or progesterone receptors. The cancer is using either estrogen or progesterone to grow. Limitation: The higher the levels of receptors, the more effective certain medicines may be in treating your cancer. Next step: They may want to do other tests before making a diagnosis and planning the best treatment for you.
• Hormone receptor-negative (HR-negative): Less than 1% of the cells in your sample have receptors. Limitation: These results may also be called hormone insensitive, receptor-negative, or HR-negative. Next step: HER2 testing is often done at the same time as ER/PR testing to help guide treatment.

• The test is performed on tissue from a breast biopsy; the accuracy depends on the quality and representativeness of the sample.
• Results are interpreted by a pathologist and should be discussed with your healthcare provider, who will consider the full clinical picture.

What to do next

If you have questions about your results, talk to your provider. They may want to do other tests before making a diagnosis and planning the best treatment for you.

• What is my hormone receptor status?
• What does this result mean for my treatment options?
• Will I need additional tests, such as HER2 testing?
• What are the benefits and risks of hormone therapy if I am HR+?
• What treatment options are available if I am HR-?

Evidence source

Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.

U.S. National Library of Medicine: Estrogen Receptor/Progesterone Receptor (ER/PR) Tests

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