17,730 new cases of breast cancer are estimated to be diagnosed in Australia this year.
Breast cancer occurs when abnormal cells in the breast grow in an uncontrolled way, and can start in the ducts or the lobules (milk sacks) of the breast. Cancer which remains in the ducts or lobules is called non-invasive breast cancer. If the cancer spreads, it becomes invasive cancer.
Breast cancer can occur in both males and females, but is far more common in females. It is estimated that in 2017, 17,730 new cases of breast cancer (144 males and 17,586 females) will be diagnosed, making it the most commonly diagnosed cancer in Australia.