Estrogen Receptor/Progesterone Receptor (ER/PR) Tests

Why this test may be ordered

• To guide treatment for people diagnosed with breast cancer by determining hormone receptor status.
• preparationInstructions:
• Your provider will give specific instructions. If you take blood thinners (including aspirin), you may need to stop before the biopsy. Tell your provider about all medicines and supplements. If you receive general anesthesia, you will likely need to fast for several hours before the procedure and arrange for someone to drive you home.

Preparation and collection

Your provider will give specific instructions. If you take blood thinners (including aspirin), you may need to stop before the biopsy. Tell your provider about all medicines and supplements. If you receive general anesthesia, you will likely need to fast for several hours before the procedure and arrange for someone to drive you home.

A breast biopsy is performed to obtain a tissue sample. Common methods include fine needle aspiration, core needle biopsy, or surgical biopsy. The procedure is usually done on an outpatient basis.

Common risks after breast biopsy include bruising, temporary discomfort, infection (treatable with antibiotics), and bleeding. If general anesthesia is used, it is very safe for most people. Talk to your provider about any concerns.

Understanding results

Results show whether your breast cancer is hormone receptor-positive or hormone receptor-negative. Your provider will interpret the results and discuss what they mean for your treatment options.

• Hormone receptor-positive (HR+): At least 1% of the cancer cells have estrogen and/or progesterone receptors. The cancer may use these hormones to grow. Hormone therapy medicines that lower hormone levels or block their effects can be very effective. The higher the receptor levels, the more likely these medicines will help. Limitation: This result does not guarantee that hormone therapy will work; it indicates a higher likelihood of benefit. Other tests (e.g., HER2) may also be needed to guide treatment. Next step: Your provider will discuss treatment options that may include hormone therapy. Additional testing may be recommended.
• Hormone receptor-negative (HR-): Less than 1% of the cancer cells have estrogen or progesterone receptors. Hormone therapy medicines will not be effective for this type of cancer. Limitation: This result does not rule out other treatment options; it simply indicates that hormone therapy is unlikely to help. Next step: Your provider will discuss other treatment approaches, such as chemotherapy, targeted therapy, or immunotherapy, depending on the cancer's characteristics.

• 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.
• False-positive or false-negative results are possible but uncommon; your provider may recommend additional testing if results are unclear.

What to do next

Your provider will use the hormone receptor status along with other test results (such as HER2 status) to create a personalized treatment plan. Ask your provider any questions you have about your results and what they mean for your care.

• 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

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