Tests on breast tissue

If tests on the biopsy sample show that it is breast cancer, extra tests will be done to work out the features shown here and help plan treatment. The results will be included in the pathology report.

Learn more about:

• Hormone receptor status
• HER2 status
• Triple negative breast cancer
• Gene activity tests

Hormone receptor status

Hormones are chemicals in the body that transfer information. The hormones oestrogen (ER) and progesterone (PR) are produced naturally in the body.

A hormone receptor is a molecule in a cell. Most breast cancers have cells that receive signals from oestrogen or progesterone receptors, so these hormones may help the cancers grow. These cancers are called hormone receptor positive (ER+ and/or PR+) or hormone-sensitive cancers. They are likely to respond to hormone therapy that blocks oestrogen.

Breast cancers without receptor cells are called hormone receptor negative (ER– and PR–) cancers and hormone therapy is generally not used.

HER2 status

HER2 (human epidermal growth factor receptor 2) is a protein that is found on the surface of all cells and controls how cells grow and divide.

Tumours that have high levels of these receptors are called HER2 positive (HER2+). Tumours with low levels are called HER2 negative (HER2–). HER2+ cancers tend to be more aggressive than HER2– cancers. It is often recommended that people with HER2+ breast cancer have chemotherapy and targeted therapy before surgery. This is known as neoadjuvant chemotherapy.

Triple negative breast cancer

Some breast cancers are hormone receptor negative (ER– and PR–) and HER2 negative (HER2–). These are called triple negative breast cancers.

Triple negative cancers do not respond to hormone therapy or to targeted therapy drugs used for HER2 positive cancers.

The current treatment options for people with triple negative breast cancer include chemotherapy before or after surgery and some other types of targeted therapy drugs.

Gene activity tests

Also known as genomic assays or molecular assays, these tests look at the patterns of certain genes within the cancer cells. These patterns may help predict the risk of the cancer coming back, and this information helps guide treatment. For example, if there is a high risk of the cancer coming back, you may need chemotherapy.

Many tests have been developed and research around the use and effectiveness of gene activity tests is ongoing. The genomic assays that are currently available are only for breast cancer that is ER+ and HER2–. They include the Oncotype DX, EndoPredict, Prosigna and MammaPrint assays.

These tests are not recommended for everyone, and can cost up to several thousand dollars. At the time this information was posted they are not covered by Medicare or private health funds.

For more information about these tests, talk with your medical oncologist. Keep in mind that the standard pathology tests that are done on all breast cancers often provide enough information to guide treatment plans.