What is metastatic breast cancer?
You might have heard the term metastatic breast cancer but not be totally sure what it is. Simply put, metastatic breast cancer is the most advanced form of breast cancer (stage four or IV) — if cancer has metastasized, then it means that it has spread to other parts of the body.
Metastatic breast cancer occurs when breast cancer cells break away from the tumor in your breast and pass through to your bloodstream or your lymphatic system (the network of thin tubes that carry fluid around your body). Once the cells have spread, they can then settle in other organs and form new tumors.