Hormone Receptor Status
Oestrogen receptors and progesterone receptors are specialised proteins found within certain cells throughout the body. These receptors bind the female hormones, oestrogen and progesterone, which both circulate in the blood.
Many breast cancer tumours have receptors for oestrogen and/or progesterone, often in large numbers. When receptors are present, the tumour is said to be Oestrogen Receptor positive (ER-positive, the American spelling of Oestrogen is Estrogen) and/or Progesterone Receptor positive (PR-positive). These tumours are said to be hormone-dependent, and oestrogen and/or progesterone feed their growth. Breast cancer tissue can be tested to see if it is positive for these receptors.
How is the sample collected for testing?
A sample of breast cancer tissue is obtained (such as by doing a fine needle aspiration, needle biopsy, or surgical biopsy) or a tumour removed surgically during a lumpectomy or mastectomy and is tested.
Is any test preparation needed to ensure the quality of the sample?
How is it used?
Hormone receptor status is used as a prognostic marker. Those with ER- and PR-positive tumours tend to have a better prognosis than those with ER- or PR-negative tumours.
The hormone receptor status test is also used to help determine treatment options, including endocrine therapy (anti-hormone treatments, such as tamoxifen), when a primary tumour has been removed or to help guide treatment decisions when a tumour recurs.
When is it requested?
Hormone receptor status testing is recommended as part of an initial workup of invasive breast cancer. It is not diagnostic but helps the doctor to decide what the treatment options are and to help understand more about the tumour's characteristics.
What does the test result mean?
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 tumour is to respond to anti-hormone treatment. 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.
Is there anything else I should know?
Her-2/neu testing may be done at the same time as hormone receptor status testing. A patient with a positive oestrogen and/or progesterone receptor status may find their response to endocrine therapy diminished if they are also Her-2/neu-positive. Her-2 positive tumours can be treated with a different treatment, trastuzumab (Herceptin®).
Hormone receptor status testing is not available in every laboratory, samples may have to be sent to specialist centres for analysis and interpretation.
Is there a blood test that can be done to check my hormone receptor status?
No. The cancer cells do not "shed" the receptors, so they are not detectable in the blood. They must be looked for in the cancer tissue itself.