Hormone Receptor Status
This is a test done to determine whether a breast cancer tumor is positive for estrogen and/or progesterone receptors, which helps to guide treatment and determine outcome.
It is done if you have been diagnosed with breast cancer and your caregiver wants to determine whether the tumor's growth is influenced by the hormones estrogen and/or progesterone.
Estrogen receptors (ER) and progesterone receptors (PR) are specialized proteins found within certain cells throughout the body. These receptors bind to estrogen and progesterone, female hormones that circulate in the blood, and promote new cell growth and division.
Many breast cancer tumors have receptors for estrogen and/or progesterone, often in large numbers. These tumors are said to be hormone-dependent, and estrogen and/or progesterone feed their growth. Breast cancer tissue can be tested to see if it is positive for these receptors.
A sample of breast cancer tissue is obtained by doing a fine needle aspiration, needle biopsy, surgical biopsy, or removal of a tumor surgically during a lumpectomy or mastectomy. Cancer cells do not "shed" the receptors, so they are not detectable in the blood. They must be evaluated in the cancer tissue itself.
MEANING OF TEST
Your caregiver will go over your test results with you and discuss the importance of this test.
In general, if a patient's cancer is ER- and PR-positive, the patient will have a better-than-average prognosis, and their cancer is likely to respond to endocrine therapy (anti-hormone treatments). The more receptors present and the more intense their reaction, the more likely the response. However, an individual's response depends on a variety of factors.
If a patient's cancer is ER-negative but PR-positive, the patient may still benefit from endocrine therapy but may have a diminished response.
If the cancer is both ER- and PR-negative, then the patient will probably not benefit from endocrine therapy.
Her-2/neu testing 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 Her-2/neu-positive.
Hormone receptor status testing is not available in every laboratory. It requires experience and special training to perform and interpret. Your doctor will probably send your sample to a reference laboratory and it may take several weeks before your results are available.
OBTAINING THE TEST RESULTS
Make sure you receive the results of your test. Ask how these results are to be obtained if you have not been informed. It is your responsibility to obtain your test results.
Your caregiver will provide further instructions or treatment options if necessary.