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How is breast cancer diagnosed?

If you have any breast changes or a mammogram shows something suspicious, your GP will ask about your medical history, including your family history of breast cancer. They will also perform a physical examination, checking both your breasts as well as the lymph nodes under your arms and above your collarbone.

To find out if the changes have been caused by cancer, your GP may arrange some tests, such as a mammogram, ultrasound, breast MRI and possibly a biopsy. They may refer you to a specialist for these and other tests.

A mammogram is a low-dose x-ray of the breast tissue. It can check a lump or other change found by the physical examination. It can also show changes that can’t be felt during a physical examination.

Your breast is placed between two x-ray plates. The plates press together firmly for a few moments to spread the breast tissue out so that clear pictures can be taken. You will feel some pressure, which can be uncomfortable. Both breasts will be checked. If you have breast implants, let staff know before you have the mammogram.

Tomosynthesis – Also known as three-dimensional mammography or digital breast tomosynthesis (DBT), tomosynthesis takes x-rays of the breast from many angles and uses a computer to combine them into a three-dimensional image. This form of breast imaging may be more accurate in some situations such as finding small breast cancers, particularly in dense breast tissue.

An ultrasound uses soundwaves to create a picture of breast tissue. It will often be done if a mammogram picks up breast changes, or if you or your GP can feel a lump.

The person performing the ultrasound will spread a gel on your breast, and then move a small device called a transducer over the area and the lymph nodes in your armpit. This sends out soundwaves that echo when they meet something dense, like an organ or a tumour. A computer creates a picture from these echoes. The scan is painless and takes about 15–20 minutes.

A magnetic resonance imaging (MRI) scan uses a large magnet and radio waves to create pictures of the breast tissue on a computer. Breast MRI is mainly used for people who are at high risk of breast cancer or who have very dense breast tissue or implants. It may also be used if imaging tests results are not clear and to help plan breast surgery.

Before a breast MRI, you will have an injection of a contrast dye to make any cancerous breast tissue easier to see. You will lie face down on a table with cushioned openings for your breasts. The table slides into the machine, which is large and shaped like a cylinder. The scan may take 30–40 minutes. It is painless but can be noisy. You will usually be offered earplugs or headphones to listen to music. Some people feel anxious or claustrophobic in the cylinder. If you think you may become distressed, mention it beforehand to your medical team. You may be given a mild sedative to help you relax.

If breast cancer is suspected, a small sample of cells or tissue is taken from the lump or area of concern. A specialist doctor called a pathologist examines the sample and checks it for cancer cells under a microscope.

There are different ways of taking a biopsy and you may need more than one type. The biopsy may be done in a specialist’s rooms, at a radiology practice, in hospital or at a breast clinic. Bruising to your breast is common after any type of biopsy.

Core biopsy – The piece of tissue (a core) is removed with a needle. Local anaesthetic is used to numb the area, and a mammogram, ultrasound or MRI scan is used to guide the needle into place.

Vacuum-assisted core biopsy – A needle attached to a suction-type instrument is inserted into a small cut in the breast. A larger amount of tissue is removed with a vacuum biopsy, making it more accurate in some situations. The needle is usually guided into place with a mammogram, ultrasound or MRI. This biopsy is done under a local anaesthetic, but you may feel some discomfort.

Fine needle aspiration (FNA) – A thin needle is inserted into an abnormal lymph node or other tissue, often with an ultrasound to help guide the needle into place. A local anaesthetic may be used to numb the area where the needle is inserted.

Surgical biopsy – If a needle biopsy is not possible, or if the biopsy result doesn’t provide a clear diagnosis, you may have a surgical biopsy to remove all or part of a lump found on a screening mammogram or other imaging technique. A wire or other device is inserted to act as a guide during the surgery, and then the tissue is removed under general anaesthetic. This is usually done as day surgery.

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

Hormone receptor status – ER+ and/or PR+ = 70-80% of all breast cancers

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+ = 15-20% of all breast cancers

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 – ER– PR– and HER2- = 10-20% of all breast cancers

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. They are currently 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.

If the tests show that you have breast cancer, you may have further tests to check whether the cancer has spread to other parts of your body.

Blood tests – Samples may be taken to check your general health, and to look at your bone marrow and liver function for signs of cancer.

Bone scan – A bone scan may be done to see if the breast cancer has spread to your bones. A small amount of radioactive material is injected into a vein, usually in your arm. This material is attracted to areas of bone where there is cancer. After a few hours, the bones are viewed with a scanning machine, which sends pictures to a computer. A bone scan is painless and the radioactive material is not harmful. You should drink plenty of fluids on the day of the test and the day after.

CT scan – A CT (computerised tomography) scan uses x-ray beams to take pictures of the inside of the body. It is used to look for signs that the cancer has spread. Before the scan, you will be given an injection of dye into a vein in your arm. This dye, known as contrast, makes the pictures clearer. For the scan, you will lie flat on a table while the CT scanner, which is large and shaped like a doughnut, takes pictures. This painless test takes 30–40 minutes.

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This information is reviewed by

This information was last reviewed July 2020 by the following expert content reviewers: Prof Bruce Mann, Professor of Surgery, The University of Melbourne, and Director, Breast Tumour Stream, Victorian Comprehensive Cancer Centre, VIC; Dr Marie Burke, Radiation Oncologist, and Medical Director GenesisCare Oncology, QLD; Dr Susan Fraser, Breast Physician, Cairns Hospital and Marlin Coast Surgery Cairns, QLD; Ruth Groom, Consumer; Julie McGirr, 13 11 20 Consultant, Cancer Council Victoria; A/Prof Catriona McNeil, Medical Oncologist, Chris O’Brien Lifehouse, NSW; Dr Roya Merie, Staff Specialist, Radiation Oncology, Liverpool Cancer Therapy Centre, Liverpool Hospital, NSW; Dr Eva Nagy, Oncoplastic Breast Surgeon, Sydney Oncoplastic Surgery, NSW; Gay Refeld, Clinical Nurse Consultant – Breast Care, St John of God Subiaco Hospital, WA; Genny Springham, Consumer.