If tests on the biopsy sample confirm you have breast cancer, extra tests on the biopsy sample will be done to understand more about the breast cancer and help plan treatment. The results will be included in the pathology report.
Learn more about:
Hormone receptor status
The hormones oestrogen and progesterone are produced naturally in the body. A receptor is a protein on the surface of the cell. Normal breast cells have oestrogen receptors (ER) and progesterone receptors (PR). Breast cancers that have these receptors are known as ER positive (ER+) or PR positive (PR+). This means that oestrogen or progesterone enters the cell, where it may stimulate cancer cells to grow.
ER+ and PR+ cancers are usually treated with hormone therapy drugs (also known as endocrine therapy) that block the receptor, or drugs that reduce the amount of hormones that the body makes (aromatase inhibitors).
If the cancer has low levels of oestrogen receptors, hormone therapy drugs are sometimes used. These drugs are not used for cancers with no oestrogen receptors.
HER2 status
HER2 (human epidermal growth factor receptor 2) is a protein that is found on the surface of some cells and controls how cells grow and divide. HER2 levels are worked out with an initial test of the protein, and then can be confirmed with an in-situ hybridisation (ISH) test, which is done before giving targeted therapy.
Tumours with high levels of these receptors are called HER2 positive (HER2+). Tumours with low levels are called HER2 negative (HER2– or HER2 low).
It is often recommended that people with HER2+ breast cancer have chemotherapy and targeted therapy before they have surgery (neoadjuvant treatment). Depending on how the cancer responds to the neoadjuvant treatment and surgery, you may also have chemotherapy or targeted therapy after surgery (adjuvant treatment).
Triple negative breast cancer
Some breast cancers do not have oestrogen (ER–), progesterone (PR–) or HER2 (HER2–) receptors. These are called triple negative breast cancers.
Triple negative breast cancers do not respond to hormone therapy or to the targeted therapy drugs used for HER2+ cancers in early breast cancers.
These types of cancer usually respond well to chemotherapy, so this may be used before and/or after surgery (neoadjuvant/ adjuvant treatment).
Some other types of targeted therapy may be used for triple negative breast cancer.
Recently, various types of immunotherapy have been shown to work well for some triple negative cancers. These may be used before surgery for larger cancers or for cancers that also affect lymph nodes.
What are gene expression profile tests?
Gene expression profile tests may be done on the biopsy sample. These tests look at which genes are active in the cancer cells. The results provide information about the risk of cancer returning.
These tests may also be called genomic tests or molecular assays. They are different to genetic tests, which are used to look for inherited gene faults.
The gene expression profile tests available in Australia are Oncotype DX, EndoPredict, PAM50, and MammaPrint.
The test results will help the doctor work out if chemotherapy will be helpful after surgery. It can take 14 days for the results to come back, so it’s important to order these tests as soon as possible. It may be helpful for your surgeon to order these tests before you see your oncologist.
Ask your doctor if a gene expression profile test is an option for you. The standard pathology tests done on all breast cancers may be all that is needed for your treatment plan.
Gene expression profile tests may not be covered by Medicare; check what you may have to pay.
→ READ MORE: Staging and prognosis for breast cancer
Podcast: Tests and Cancer
Listen to more of our podcast for people affected by cancer
More resources
Dr Diana Adams, Medical Oncologist, Macarthur Cancer Therapy Centre, NSW; Prof Bruce Mann, Specialist Breast Surgeon and Director, Breast Cancer Services, The Royal Melbourne and The Royal Women’s Hospitals, VIC; Dr Shagun Aggarwal, Specialist Plastic and Reconstructive Surgeon, Prince of Wales, Sydney Children’s and Royal Hospital for Women, NSW; Andrea Concannon, consumer; Jenny Gilchrist, Nurse Practitioner Breast Oncology, Macquarie University Hospital, NSW; Monica Graham, 13 11 20 Consultant, Cancer Council WA; Natasha Keir, Nurse Practitioner Breast Oncology, GenesisCare, QLD; Dr Bronwyn Kennedy, Breast Physician, Chris O’Brien Lifehouse and Westmead Breast Cancer Institute, NSW; Lisa Montgomery, consumer; A/Prof Sanjay Warrier, Specialist Breast Surgeon, Chris O’Brien Lifehouse, NSW; Dr Janice Yeh, Radiation Oncologist, Peter MacCallum Cancer Centre, VIC.
View the Cancer Council NSW editorial policy.
