Dr Leigh Martens

General Practitioner

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Release Version: Beta

Blood-tests Explained


Disclaimer:

This website is intended to assist with patient education and should not be used as a diagnostic, treatment or prescription service, forum or platform. Always consult your own healthcare practitioner for a more personalised and detailed opinion

Estrogen/Progesterone Receptors


At a Glance

Why Get Tested?

The hormone receptor test determines if a breast cancer tumor is positive for estrogen and progesterone receptors, helping to guide treatment and determine prognosis

When to Get Tested?

When you have been diagnosed with invasive breast cancer or when your cancer has recurred

Sample Required?

A sample of breast cancer tissue obtained during a biopsy or a tumor removed surgically during a lumpectomy or mastectomy

Test Preparation Needed?

Your health practitioner may have you discontinue taking hormones for a time period before your sample is collected.

The Test Sample

What is being tested?

Receptors are specialized proteins on the surface of or within cells that recognize and bind to other substances. The binding typically has a specific effect on the cells. Many, but not all, breast cancer cells have receptors that bind to the hormones estrogen and progesterone. Breast cancer tumors with estrogen receptors (ER) and progesterone receptors (PR) depend on the hormones to grow and divide. ER and PR testing of breast tumor tissue determines if one or both types of receptors are present.

Knowing if a tumor depends on hormones to grow helps a health practitioner determine a person's risk of breast cancer recurrence and whether it can be treated with hormone therapy to block estrogen and progesterone. About two-thirds of breast cancer tissues are positive for both ER and PR.

In 2010, the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) jointly published guidelines that recommend that all tumors from individuals with newly diagnosed invasive breast cancer be evaluated for estrogen and progesterone receptors. The guidelines also state that all recurrent breast cancers should be tested and that the option of testing should be provided for patients who have non-invasive breast cancer.

How is the sample collected for testing?

A sample of breast cancer tissue is obtained by doing a fine needle aspiration, needle biopsy, or surgical biopsy, or a tumor is removed surgically during a lumpectomy or mastectomy.

Is any test preparation needed to ensure the quality of the sample?

Your health practitioner may have you discontinue taking hormones for a time period before your sample is collected.

The Test

How is it used?

Estrogen and progesterone hormone receptor (ER and PR) status tests are standard tests for all invasive breast cancers, and on recurring cancers, as recommended by guidelines published in 2010 by the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP). Hormone receptor status is used to predict an individual's cancer outcome (as a prognostic marker) and to determine if hormone therapy will be an effective treatment.

Those who have ER-positive and PR-positive tumors tend to have a better prognosis for disease-free survival and overall survival than those with ER-negative or PR-negative tumors. They are also much more likely to respond to endocrine therapy, such as the anti-hormone treatment tamoxifen.

When is it ordered?

Hormone receptor status testing is recommended as part of an initial workup when a person has been diagnosed with invasive breast cancer. Typically, testing is also performed on breast cancer that has returned after successful treatment (recurred). Patients with non-invasive breast cancer (ductal carcinoma in situ, DCIS) may discuss the option with their health practitioners and decide to undergo testing as part of their workup.

What does the test result mean?

In general, if a person's cancer is ER-positive and PR-positive, the individual will have a better than average prognosis, and their cancer is likely to respond to endocrine therapy such as tamoxifen. The more receptors present and the more intense their reaction, the more likely the response.

If a person's cancer is ER-negative but PR-positive, or ER-positive but PR-negative, then she may still benefit from endocrine therapy but may have a diminished response.

If the cancer is both ER-negative and PR-negative, then the person is not likely to benefit from endocrine therapy.

An individual's response to endocrine therapy will depend on a variety of factors, but typical response rates include:

  • ER-positive, PR-positive: 75-80%
  • ER-positive, PR-negative: 40-50%
  • ER-negative, PR-positive: 25-30%
  • ER-negative, PR-negative: 10% or less

Is there anything else I should know?

testingHER2/neu may be done at the same time as hormone receptor status testing. A patient with a positive estrogen and/or progesterone receptor status may find their response to endocrine therapy diminished if they are also HER2/neu-positive.

Hormone receptor status testing is not available in every laboratory. It requires experience and special training to perform and interpret. A health practitioner will probably send a patient's sample to a reference laboratory and it may take several days to weeks before the results are available.

It takes a small amount of cancer tissue to perform hormone receptor status testing. If a sufficient sample is not available, a health practitioner may make an assumption that a patient's cancer is ER-positive and PR-positive in order to broaden the treatment options.