Metastatic breast cancer

Metastatic breast cancer is cancer that has spread from the first (primary) tumour in your breast to another part of your body. It is also known as secondary breast cancer, advanced breast cancer or stage 4 breast cancer.

Your cancer may be advanced when it is first diagnosed, or your cancer may have come back or spread sometime after your first diagnosis (recurrent cancer).

Metastatic breast cancer treatments are to keep the cancer under control, rather than to cure it. There are many treatments that can keep the cancer under control, sometimes for many years.

Most people diagnosed with metastatic breast cancer were diagnosed with primary breast cancer previously. They have been through tests, treatments and side effects. They are familiar with their healthcare team in the hospital and have learned how to cope with the disease.

Some people are diagnosed with metastatic breast cancer as their first cancer diagnosis – they have not had a previous diagnosis of breast cancer. ‘De novo’ means the breast cancer is metastatic ‘from the start’.  

Being diagnosed with metastatic breast cancer as your first cancer diagnosis is not common, but it can be incredibly overwhelming.

Your healthcare team will guide you through your diagnosis and treatment, and we are here to help too. Our Support Line nurses can help and support you, and give you information on counselling and other services. 

Cancer cells can spread via the lymphatic or blood system from your breast to other parts of the body. 

If you have had treatment for breast cancer, some cancer cells that have been inactive for many years and undetectable by scans may start to grow. 

The most common places for breast cancer to spread to are the bones, lungs, liver, brain, skin or lymph nodes. Less commonly it can spread to other parts of the body, such as the bone marrow, ovaries or lining of the abdomen (peritoneum).

The metastatic cancer is still breast cancer, even if it is found in other parts of your body. It will be treated with breast cancer treatments.

Finding out your cancer has spread can be very difficult to deal with emotionally, but in time most people find a way to cope and feel better. We have information about coping with a diagnosis of metastatic cancer.

Medical content updated from our 'Metastatic (secondary) breast cancer' booklet (2023), reviewed by Dr Megan Greally, Consultant Medical Oncologist, Alexandra Stanley, Medical Oncology Clinical Nurse Specialist and Mary O'Kelly, Daffodil Centre Nurse.