​​​Some women diagnosed with breast cancer do not have any signs or symptoms of the disease. However, there are sometimes changes in the breast that a woman may notice¹. Any change should be brought to the attention of your GP. Changes to look out for include:¹

• A new lump or lumpiness, especially if it's only in one breast
• A change in the size or shape of one or both breasts
• Changes to the skin of the breasts, such as dimpling (looking like an orange peel), rash, or redness
• Pain in the breast or nipple
• Discomfort or swelling in either armpit
• A retracted (turned in) nipple or discharge from the nipple (other than breast milk)

​​​​​​Your GP will usually order one or more diagnostic tests if:

• You notice a lump in your breast during a self-examination
• They find a lump or other breast changes during a physical examination
• A screening mammogram shows a finding that requires more evaluation

Finding breast cancer at an early stage means that a doctor can begin treatment earlier in the course of the disease. Screening mammograms are an important diagnostic tool for early detection and have been shown to help reduce the number of deaths from breast cancer among women 40 to 74 years old².

Breast Screen Australia and Breast Screen Aotearoa are national screening programs that offer free mammograms every 2 years for women aged between 50-74 years in Australia³ and between 45-69 years in New Zealand.⁴

If breast cancer is suspected, it is likely your GP will refer you to a cancer specialist, such as a breast surgeon or an oncologist, who will perform one or more tests to make a diagnosis and/or to see if the cancer has spread to other parts of the body.

Imaging tests can be used which enable the doctor to see the structure of a person’s breast, including:⁵

• A mammogram is a low dose X-ray of the breast. It may be done even if you have already had a routine screening through BreastScreen Australia or Health New Zealand
• Ultrasound uses sound waves and can help determine if a breast lump is solid or filled with fluid. It may be done alone or together with a mammogram to provide more information
• Magnetic Resonance Imaging (MRI) scans use a magnetic field and radio waves to produce detailed pictures of soft tissue that may not show up in an X-ray

Imaging tests are useful for suggesting if cancer is present, but only a biopsy can provide a definite diagnosis. During a biopsy, small pieces of breast tissue are taken so that it can be examined under a microscope by a pathologist for the presence of cancer cells.⁵

If cancer is detected in your breast, you may have additional scans to see if the cancer has spread to other parts of the body, such as:⁶

• A CT scan (Computerised Tomography) provides a more-detailed x-ray of the body, usually in order to see if cancer has spread to the organs such as the lungs or liver⁶
• Bone scans, also called bone scintigraphy, can be used to help identify cancer in the bone, which appear as one or multiple ‘hot spots’⁷
• A PET scan (Positron Emission Tomography) uses a radioactive substance (called a tracer) to look for the potential spread of breast cancer. This tracer can help identify areas of cancer that an MRI or CT scan may not show.⁸

Your care team will take a number of factors into account when deciding on a treatment plan. These include:⁹

• If the cancer has spread and if so, how far
• If the cancer cells have certain hormone receptors, that is if the cancer is estrogen receptor (ER) positive and/or progesterone receptor (PR) positive
• The amount of a protein called HER2 on the cancer cells
• Your overall health and personal preferences for treatment
• Whether you have gone through menopause

The most common treatments for breast cancer include:¹⁰

• Surgery: Surgeons remove a portion of the breast containing the cancer or the entire breast
• Chemotherapy: Medicines that are given to shrink or destroy cancer cells
• Radiation therapy: High-energy rays are used to kill cancer cells
• Hormonal therapy: Medicines which are given to prevent cancer cells from getting the hormones they need to grow
• Targeted therapy: Medicines that attack specific targets inside or on the cancer cells
• Immunotherapy: Medicines that work with the body’s own immune system to help it fight cancer cells

Talk to your GP or specialist if you have any questions about breast cancer, screening, treatment, or steps you can take to reduce your risk. If you think you have any of the signs or symptoms of breast cancer, make an appointment to see your GP right away.

1. Cancer Council. Types of Cancer. www.cancer.org.au/cancer-information/types-of-cancer/breast-cancer Accessed Nov 2025.
2. 2. US Preventive Services Task Force. Screening for Breast Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2024;331(22):1918–1930. doi:10.1001/jama.2024.5534 Accessed Nov 2025
3. BreastScreen Australia Program. www.health.gov.au/our-work/breastscreen-australia-program/about-the-breastscreen-australia-program Accessed Nov, 2025.
4. Health New Zealand – Breast Screening https://info.health.nz/keeping-healthy/cancer-screening/breast-screening Accessed Nov 2025.
5. Breast Cancer Network Australia. Tests to Diagnose Early Breast Cancer. https://www.bcna.org.au/resource-hub/articles/tests-to-diagnose-early-breast-cancer/. Accessed Nov 2025.
6. Breast Cancer Now. Secondary breast cancer tests. https://breastcancernow.org/about-breast-cancer/secondary-breast-cancer/secondary-breast-cancer-tests/ Accessed Nov 2025.
7. BreastCancer.org - Bone Scans: Has Breast Cancer Spread to Your Bones? https://www.breastcancer.org/screening-testing/bone-scans Accessed Nov 2025
8. Medline Plus. PET scan for breast cancer. https://medlineplus.gov/ency/article/007469.htm Accessed Nov 2025.
9. American Cancer Society – Treatment of Breast Cancer by Stage https://www.cancer.org/cancer/types/breast-cancer/treatment/treatment-of-breast-cancer-by-stage.html
10. American Cancer Society – Treating Breast Cancer https://www.cancer.org/cancer/types/breast-cancer/treatment.html Accessed Nov 2025.