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.
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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 too many of these receptors are known as ER positive (+) or PR positive (+). This lets more oestrogen or progesterone enter the cell, where it stimulates cancer cell growth.
ER+ and PR+ cancers are usually treated with hormone therapy drugs (or 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 receptors (ER-), the drugs are generally not used.
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 (HER+). Tumours with low levels are called HER2 negative (HER2–).
It is often recommended that people with HER2+ breast cancer have chemotherapy and targeted therapy before they have surgery. This is known as neoadjuvant chemotherapy or neoadjuvant therapy.
You may also have chemotherapy or other therapy after surgery. This is known as adjuvant therapy.
Some breast cancers are hormone receptor negative (ER– and PR–) as well as being HER2 negative (HER2–). These are called triple negative breast cancers.
Triple negative cancers do not respond to hormone therapy or to the targeted therapy drugs used for HER2+ cancers. The current treatment options for people with triple negative breast cancer include chemotherapy before and/or after surgery and some other types of targeted therapy drugs. Triple negative breast cancers usually respond well to chemotherapy. Radiation therapy may also be given after some types of surgery.
Women who have not been through menopause and people with a BRCA1 mutation are at higher risk of having triple negative breast cancer.
What are gene activity tests?
Known as molecular assays, genomic assays, or a gene expression profile, these tests look at which genes are active in the cancer cells. The patterns they show help to predict the risk of cancer returning. This can help guide treatment plans.
These tests may be suggested for some early breast cancers (ER+ and HER–) to see whether chemotherapy is needed. For example, if the risk of cancer returning is high, chemotherapy may be needed. If the risk is low, hormone therapy, or no extra therapy, may be suggested.
The current molecular assays used include Oncotype DX, EndoPredict, Prosigna and MammaPrint. They are not usually covered by Medicare or private health funds and can cost several thousand dollars.
Ask your medical oncologist if a gene activity test is of use for you. The standard pathology tests done on all breast cancers may be all that’s needed for your treatment plan.
Podcast: Tests and Cancer
A/Prof Elisabeth Elder, Specialist Breast Surgeon, Westmead Breast Cancer Institute and The University of Sydney, NSW; Collette Butler, Clinical Nurse Consultant and McGrath Breast Care Nurse, Cancer Support Centre, Launceston, TAS; Tania Cercone, Consumer; Kate Cox, 13 11 20 Consultant, Cancer Council SA; Dr Marcus Dreosti, Radiation Oncologist and Medical Director, GenesisCare, SA; Dr Susan Fraser, Breast Physician, Cairns Hospital and Marlin Coast Surgery Cairns, QLD; Dr Hilda High, Genetic Oncologist, Sydney Cancer Genetics, NSW; Prof David W Kissane AC, Chair of Palliative Medicine Research, The University of Notre Dame Australia, and St Vincent’s Hospital Sydney, NSW; Prof Sherene Loi, Medical Oncologist, Peter MacCallum Cancer Centre, VIC; Dr W Kevin Patterson, Medical Oncologist, Adelaide Oncology and Haematology, SA; Angela Thomas, Consumer; Iwa Yeung, Physiotherapist, Princess Alexandra Hospital, QLD.
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