Hormone receptor status test

The hormone receptor test is done on breast cancer cells to see if hormones cause them to grow. This test is used for anyone diagnosed with breast cancer.

Estrogen and progesterone are hormones made in all human bodies, but in different amounts. They cause the growth of some cells, including breast cancer cells. Normal breast cells and some types of breast cancer cells have estrogen receptors (ER) and progesterone receptors (PR) in the nucleus of the cell. These receptors are where the hormones attach to the cells. Once they are attached, the hormones can affect the behaviour or growth of the cells.

These hormones can cause breast cancer cells with estrogen and progesterone receptors to grow and divide.

Knowing the hormone receptor status of the tumour helps your healthcare team predict how well hormone therapy and other treatments will work.

Hormone receptor testing is done at the time of diagnosis for breast cancer. It may also be done if the cancer comes back after treatment (recurs), because sometimes the hormone receptor status can change. It is often done at the same time as the HER2 status test.

A hormone receptor status test is done on a tissue sample taken with a biopsy. The tissue is examined using an immunohistochemistry test to check for hormone receptors in the breast cancer cells.

Results of the test depend on the percentage of tumour cells that have the hormone receptors. The results are reported as positive or negative.

• Positive (or +) means that there are hormone receptors in the breast cancer cells.
• Negative (or –) means that there are no, or very few, hormone receptors in the breast cancer cells.

A breast cancer tumour may have both positive (+) and negative (–) receptors.

Hormone receptor–positive breast cancer means that the cancer cells have receptors for estrogen, progesterone, or both. In about two-thirds of all cases of breast cancer, the tumour has receptors for estrogen (ER) and progesterone (PR). Some tumours are ER positive and PR negative. Breast cancer that is ER negative and PR positive is very rare and more testing may be needed to be sure about the hormone receptor status.

Hormone receptor–negative breast cancer means that the cancer cells do not have receptors for either estrogen or progesterone.

The hormone status tells your healthcare team if hormone therapy is likely to slow or stop the breast cancer cells from growing. It also helps them decide other treatments to offer.

• HR-positive tumours that are both ER positive and PR positive are treated with hormone therapy.
• HR-positive tumours that are ER negative but PR positive are sometimes treated with hormone therapy.
• Hormone receptor negative (ER– and PR–) tumours are not treated with hormone therapy as there are no receptors for the hormone therapy to block.

Breast cancer may recur after it has been treated. If this happens, a biopsy of tissue from the tumour may be done to confirm the diagnosis of breast cancer recurrence. Sometimes a new primary breast cancer that isn't related to the first cancer is found. Hormone receptor status testing will be done again at this time.

People whose first tumours were ER positive may have ER-negative tumours when cancer recurs. This is an important prognostic factor because more hormone therapy may not work as well for these recurrent tumours.