What are the other Names for this Test? (Equivalent Terms)

• ER and PR Status Test
• Estrogen and Progesterone Receptor Status Test
• Estrogen/Progesterone Receptor Status Test

What is ER and PR Hormone Receptor Status Test? (Background Information)

• In breast cancer, the ER and PR Hormone Receptor Status Test is carried out, to determine the presence of receptors to estrogen and/or progesterone in the cancer cells. Receptors are proteins found on the surface or inside of cells. These bind to specific substances, in order to exert a particular influence on the cell
• Breast cancers that test positive for hormone receptors carry a better prognosis and respond to treatment with hormone therapy. Testing maybe done on a sample of tumor tissue obtained through needle aspiration, biopsy or through post-surgical removal
• A procedure called immunohistochemistry is done on the test specimen, and it is examined for the presence of receptors to estrogen and/or progesterone

What are the Clinical Indications for performing the ER and PR Hormone Receptor Status Test?

Following are the clinical indications for performing the ER and PR Hormone Receptor Status Test:

• In all instances of invasive breast cancer, whether newly diagnosed or recurrent, as part of the initial workup
• The health practitioner may also recommend testing on non-invasive breast cancers (ductal carcinoma in situ)

How is the Specimen Collected for ER and PR Hormone Receptor Status Test?

Following is the specimen collection process for ER and PR Hormone Receptor Status Test:

Sample required: Breast tissue

Process:

• A sample of breast tissue can be obtained by inserting a needle into the site of suspected tumor and aspirating a sample of cells (fine needle aspiration cytology or FNAC), or by a surgical biopsy of breast tumor. A biopsy of metastatic breast cancer can also be used for Receptor Status Testing
• The blood sample is drawn through a needle inserted into the vein (arm)

Preparation required: The physician may recommend discontinuing any hormones (you are taking) for some time, prior to testing.

What is the Significance of ER and PR Hormone Receptor Status Test Result?

The outcomes and corresponding significance of the ER and PR Hormone Receptor Status Test are as follows:

• The cancer may test positive for both estrogen (ER) and progesterone (PR) receptors. This carries the best prognosis; 75-80% of individuals with ER and PR positive status respond to hormone therapy
• The cancer may test positive for either estrogen or progesterone receptors. Positivity  for only one receptor, carries a slightly diminished prognosis; 40-50% of ‘only ER positive’ individuals, and 25-30% of ‘only PR positive’ individuals respond to hormone therapy
• The cancer may test negative for both estrogen and progesterone receptors. This carries the worst possible outcome; only 10% or less of such cancers, respond to hormone therapy

The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.

Additional and Relevant Useful Information:

Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.