We do not know how to prevent the spread of breast cancer
to other parts of the body (metastasis).
Over 90% of breast cancer deaths are due to the spread of the disease to other organs of the body, including bone, lungs, liver and brain. Unfortunately, there is much that is still unknown about the causes and processes of metastasis.
Many scientists agree that decreasing mortality from breast cancer will require having a better understanding of why some breast cancers recur and become deadly by spreading to other organs in the body.