Metastatic breast cancer describes a type of breast cancer in which the cells have broken away from their original location to form a new tumor in different tissue or a different organ. The spread of cancer cells from their original location is called metastasis. Breast cancer is considered metastatic if it has spread beyond the breast and nearby lymph nodes to other parts of the body, such as the bones, liver, lungs, brain, or other organs. Metastases, the plural of metastasis, means more than one area of cancer spread.
Metastatic breast cancer is not considered curable, but it’s possible to experience periods when tests show no evidence of disease, often called NED. And while reaching NED may not always be possible, it’s likely that there will be periods when the cancer does not grow. This is called stable disease. Metastatic breast cancer is also known as
- stage IV breast cancer
- advanced breast cancer; this term is used often outside the U.S. to describe stage IV breast cancer
You may see or hear those terms being used interchangeably. Advanced breast cancer is not the same as locally advanced breast cancer. Locally advanced breast cancer includes
- tumors that are larger than 5 centimeters across
- breast cancer that has spread to breast skin or chest muscles
- breast cancer that has spread to multiple lymph nodes in the armpit or tissue surrounding the collarbone, or both
- inflammatory breast cancer
Advanced (metastatic, stage IV) breast cancer means the cells have traveled beyond these local areas. Talk with your care team if you are confused by or uncertain about these terms.