What is breast cancer?

Breast cancer happens when abnormal cells grow uncontrollably in the breast tissue.  

Although both men and women can develop breast cancer, it’s more common in women. Transgender and gender-diverse people can also get breast cancer.  

There are several types of breast cancer, depending on where the cancer is within the breast. It can be categorised as:  

• Non-invasive: Cancer cells are contained within the ducts or lobules of the breast and have not spread into the surrounding tissue. These are sometimes called pre-cancers.  

• Invasive: Cancer cells have spread into the surrounding tissue or other parts of the body. 

Breast cancer can develop at any age – but the risk increases as you get older. It’s estimated that 1 in 7 females in Australia are diagnosed with breast cancer in their lifetime.  

Read more about breast cancer on the Cancer Australia website 

The exact cause of breast cancer is unknown. But some factors that increase your risk of breast cancer include:  

• Female hormones (both natural and administered) 

• Getting older 

• Family history  

• Starting your period before the age of 12 

• A previous breast cancer diagnosis 

• A history of certain benign breast conditions 

Read about benign breast conditions that may increase your risk 

Other lifestyle factors that may increase your risk include:  

• Being overweight 

• Lack of physical activity 

• Drinking alcohol 

Learn more about reducing your risk of breast cancer 

The best way to detect breast cancer early is through screening.  

At BreastScreen Victoria, our free breast screening program uses 2D mammography – a low dose x-ray that provides a two-view digital image of each breast.  

It can detect cancer even when it’s too small to feel and you have no other signs or symptoms.  

If you notice unusual changes or pain in your breasts such as a lump, changes to your skin, or discharge from your nipple, see your doctor as an immediate first step. 

Learn about breast cancer signs and symptoms

What is the best test for you if you have breast symptoms?

Even if you have breast screens every 2 years, it’s important to be breast aware because breast cancer can develop at any time.  

Get to know the normal look and feel of your breasts – and see your doctor immediately if you notice any unusual changes such as lumps, pain or nipple discharge.  

Breast cancer can also be detected and diagnosed through:  

• Clinical examination, where a healthcare professional physically examines the breasts. 

• Diagnostic mammography, which is used to investigate clinical breast symptoms and to screen women with increased risk of breast cancer. You’ll need a doctor’s referral.  

• Ultrasound, which is usually used to further investigate breast symptoms or possible abnormalities that were detected in a screening or diagnostic mammogram.  

• Tomosynthesis – also known as 3D mammography – is available at some of our assessment services and other diagnostic imaging services. It is not part of our free screening program.   

• MRI scan is a non-standard test mainly used in specialist breast or imaging centres to screen those at a high risk of breast cancer. To get an MRI, you’ll need a referral by a doctor specialising in breasts, not a GP. 

• Needle biopsy, where a small sample of tissue or cells is removed from your breast and examined under a microscope. 

• Thermography, which is also known as thermal breast imaging. This technique produces ‘heat pictures’ of the breast. As it can only detect large tumours, thermography is not recommended for the early detection of breast cancer.