Metastatic cancer of the spine is a cancer that starts in one part of the body and spreads to the spine, explains Spine-health. This occurs when the cancer cells break away from the primary tumor and travel through the bloodstream or lymph nodes to the spine's bone marrow.
Cancers of the breast, prostate or lung are the most common cancers to metastasize to the spine, states Spine-health. The cytokines that bone marrow produces attract more cancer cells, says WebMD. Bone cancer cells often remain inactive for extended periods before they begin to multiply, allowing them to evade treatment. The metastatic cancer of the spine makes the spine weak enough to fracture, states the American Cancer Society.