What is metastatic breast cancer?
Metastatic breast cancer, also known as secondary breast cancer, advanced breast cancer or stage 4 breast cancer, occurs when the tumour spreads beyond the primary site of the breast.
Breast cancer originates in the breast, and can be treated with surgery, radiation, chemotherapy and targeted treatments to eliminate cancer cells from the body.
However, sometimes not every cancer cell is eradicated. They may also survive treatment or escape into the blood stream before treatment starts. It only takes a single cancer cell in the body for it to grow into a tumour and spread to other parts of the body.
Who is at risk of metastatic breast cancer?
Many women diagnosed with secondary breast cancer have already been diagnosed and successfully treated for breast cancer, but for others being diagnosed with metastatic breast cancer may be the first time they’ve known about it.
In developed countries like Australia, around 20-30% of women who have been diagnosed with early stage breast cancer will go on to develop metastatic breast cancer.^ This can sometimes occur more than 10-15 years after the original diagnosis.^
The survival rate of women that have metastatic breast cancer at first diagnosis is alarmingly low, with only 1 in 4 women still alive 5 years after diagnosis.