As with other types of cancer, cancers of the spine are a result of abnormal growth and uncontrollable multiplication of the cells. Vertebral cancers arise from the bony vertebrae of the spine, whereas cancers arising from the nervous tissue of the spinal cord are called spinal cord cancers.
Spine cancer can either be primary or secondary. Primary spine cancers originate from the cells in the spine. Secondary spinal cancer is a result of the spread (metastasis) of cancer from other organs, such as the breast, lung and prostate, to the spine. Secondary spinal cancer is more common than primary spinal cancer. Multiple myeloma is a cancer that often metastasizes to the spine.
Spinal tumours can be categorized by their location within the spine. There are 3 categorizations:
- Intradural-extramedullary – inside the dura (a thin covering of the spinal cord), but outside of the actual spinal cord
- Tumours that develop here could be from a covering of the spinal cord, called the arachnoid membrane. They could also develop from the nerve roots that extend out of the spinal cord, or at the spinal cord base
- Intramedullary – inside the spinal cord itself
- Tumours that develop here are from cells of the spinal cord itself
- Extradural – outside the dura (a thin covering of the spinal cord)
- Tumours that develop here are most commonly due to metastatic cancer. Tumours can also develop from the bony vertebrae or from cells covering the nerve roots, but this is less common.
While tumours that affect the vertebrae are mostly due to metastasis, there are some types of tumours that start within the bones of the spine itself. Some examples of these are chordoma, chondrosarcoma, osteosarcoma, plasmacytoma and Ewing’s sarcoma.
Spinal cancers are a relatively rare disease. The formation of benign, non-invasive tumours is more common. However, these benign tumours are still dangerous. They can affect the function of the nervous system by pushing on the spinal cord or nerves. This could lead to the loss of movement and sensation below the tumour, and may also affect bladder and bowel functions. If untreated, the damage could be permanent. They can also cause pain, vertebral fractures or spinal instability as they grow within the bone and disrupt its function.