What is Metastatic Breast Cancer?
Metastatic breast cancer is the most advanced stage (stage IV) of breast cancer. The term metastatic describes a cancer that has spread from its original location to different parts of the body or distant organs. Breast cancer may present as metastatic at the time of diagnosis (though the great majority are not), or after completing adjuvant systemic and local treatment. The malignant cells usually invade surrounding breast tissue and the underarm lymph nodes first (stage II-III), and then spread to other body parts through the blood stream or lymphatic system (Stage IV). Breast cancer most commonly metastasizes to the bones, lungs, liver, lymph nodes, skin, chest wall, or brain, but can spread to pretty much any part of the body. Treatment of metastatic breast cancer mainly focuses on relieving symptoms, controlling the cancer, and extending the patient’s life as long as possible.
How Metastasis Occurs
1. Cancer invades and grows through a capillary wall near the primary tumor.
2. Cancer gets into the bloodstream or lymphatic channels after growing through the capillary wall.
3. Once in the bloodstream or lymphatic channels, the cancer cells can travel to other parts of the body.
4. The cancer may grow through a capillary wall in another part of the body and form new tumors in distant organs.