What is metastatic breast cancer?

Metastatic breast cancer is breast cancer that has spread beyond the breast and lymph nodes, to other parts of the body. Metastatic breast cancer is also referred to as stage IV or advanced breast cancer. Most diagnoses are made early, before the cancer has spread to the lymph nodes and other parts of the body. But it’s important to keep in mind that an estimated three in four of the women living with metastatic breast cancer were initially diagnosed with stage I-III breast cancer.