A chordoma is a rare cancerous primary bone tumor that usually occurs along the spine. It occurs in approximately only one person per million each year. This malignant cancer usually occurs in the base of the spine (sacrum) or in the base of the skull. It can sometimes occur in the tailbone area. These tumors form from small remains of the notochord (a coil of cells in the embryo) that develops into the spinal cord. As the tumor grows, it puts pressure on the nearby areas of the brain or spinal cord. Although chordoma is most common in adults, it can affect patients of any age.

Chordomas grow slowly, but they are difficult to treat because they’re located very close to the spinal cord, brainstem, nerves and arteries. They often recur after treatment, and the cancer spreads (metastasizes) to other areas of the body, such as the lungs, in about 40 percent of cases. There are three subtypes of chordoma: conventional (sometimes called classic), chondroid and dedifferentiated. Chondroid chordomas tend to be less aggressive than conventional chordomas. Dedifferentiated chordomas are more aggressive, faster growing and more likely to spread to other parts of the body.

Chordomas typically occur in adults, ages 40 to 70. About 5 percent of chordomas are diagnosed in children. Males are affected about twice as often as females.

How is it diagnosed?

A chordoma anywhere along the spine may cause pain, weakness or numbness in the back, arms or legs. A chordoma at the base of the skull (occipital chordoma) may lead to double vision (diplopia), neck pain and headaches. A chordoma in the tailbone (coccygeal chordoma) may result in a lump large enough to be felt through the skin and may create problems with bladder or bowel function.

What are the treatment options?

Surgery is the main treatment for chordoma. The goal is to remove as much of the cancerous tumor as possible without causing unacceptable harm. Removal of the entire tumor (complete resection) during the first surgery offers the best chances for control and long-term survival. Radiation therapy can also reduce the risk of recurrence after the surgery and prolong survival for the patient. Even after surgery and/or radiation, chordomas often return in the same location or in the areas around the original tumor. Many patients undergo multiple surgeries over several years to treat these recurrences. Chemotherapy may slow or temporarily stop the progress of the tumor for the patients with advanced or inoperable disease. Since chordomas are slow growing, standard cytotoxic chemotherapy agents that kill fast-growing cells are usually ineffective. Some chordomas have been reported to respond to molecularly targeted cancer drugs; however, no drugs are currently approved for the treatment of chordoma.