13/04/2026
What is breast cancer?
Breast cancer is the abnormal growth of cells in the breast. It usually starts in the lining of the breast ducts or lobules, and can grow into cancerous (malignant) tumours.
Most breast cancers are found when they are invasive. This means that the cancer has spread from the breast ducts or lobules into the surrounding breast tissue.
Invasive breast cancer can be early, locally advanced or advanced (metastatic). Advanced breast cancer is when cancer cells have spread (metastasised) outside the breast and nearby lymph nodes to other parts of the body.
About 5% of cancers are advanced when breast cancer is first diagnosed.
This information has been prepared to help you understand more about early and locally advanced breast cancer, and includes a short section on advanced (metastatic) breast cancer.
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The breasts
The lymphatic system
Your guide to best cancer care
A lot can happen in a hurry when you’re diagnosed with cancer. The guide to best cancer care for breast cancer can help you make sense of what should happen.
It will help you with what questions to ask your health professionals to make sure you receive the best care at every step.
Read the guide
Types of breast conditions
Non-invasive breast conditions
Invasive breast conditions
How common is breast cancer?
There are about 20,000 people diagnosed with breast cancer in Australia every year.
Women
In Australia, breast cancer is the most common cancer in women (apart from common skin cancers), with one in eight women diagnosed by age 85.
Young women can get breast cancer, but it is more common over the age of 40, and the risk increases with age. In rare cases, pregnant or breastfeeding women can get breast cancer.
See a doctor about any persistent lump noticed during pregnancy.
Men
About 220 men (most aged over 60) are diagnosed with breast cancer each year. It is treated in the same way as for women. Transgender, non-binary and gender-diverse people
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