Chordoma

Chordoma is a rare tumor that usually occurs in the spine and base of the skull. It is a malignant tumor that grows fairly slowly. It can spread to other organs, usually the lungs. It represents only about 1 percent of all malignant bone tumors.

Description

Chordomas develop in a structure called the notochord. The notochord forms the early spine in the beginning stages of fetal development. Most of the notochord is replaced by the spine during the first six months of development. Small areas can remain, and chordomas can form in these areas.

Most chordomas occur at the base of the spine (sacrum), in the tailbone (coccyx) or at the base of the skull (40 percent), but they can occur other places in the spine.

Most patients with chordomas are between 40 and 70 years of age. Occasionally this tumor can occur in younger patients, even children. The average age of people affected is about 55 years.

Chordomas are life-threatening. They can cause death by direct growth or by spreading to other organs. They spread to the lungs about 20 to 30 percent of the time.

Cause

Chordomas occur spontaneously. They are not known to be caused by trauma, environmental factors, or diet. Chordomas are not inherited. Chordomas are not associated with any medical conditions or use of any medications or supplements.

Symptoms

Chordomas grow slowly. Patients often have symptoms for a long time (more than a year) before they seek medical attention.

Symptoms depend on the location of the tumor:

• Tumors in the skull can cause headache or problems with vision.
• Tumors in the spine can cause pain in the area of tumor (neck, back, or tailbone). A tumor pressing on nearby nerves can cause symptoms similar to a "slipped" (herniated) disk. These symptoms include arm or leg pain, weakness, or numbness.
• Tumors in the tailbone area can cause a noticeable mass, numbness in the crotch area, and problems with the bowel and bladder.

Tests

Several imaging tests may be required to identify a chordoma, including x-rays, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans.

Chordomas themselves do not show up well, but the bone damage may be seen on the x-rays. X-rays of the sacrum are often difficult for doctors to interpret.


Typical sacral chordomas.


Computed tomography (CT) scans of the same sacral chordomas.


Corresponding magnetic resonance (MRI) scans.


Treatment

Treatment of chordomas is very difficult. This is mainly because these tumors are near the brain and spinal cord.

Traditional chemotherapy has not been very effective, and radiation alone rarely cures the tumor.

Surgery is the preferred treatment option, where possible. Surgery in combination with radiation is often used to treat chordomas. When tumors cannot be surgically removed, sometimes radiation therapy can stop the growth of the tumor.

Although it is the best treatment for chordomas, in many cases surgery can be difficult to perform because of important structures near the tumor. The surgeon must remove the tumor and a margin of normal tissue around it. This often results in a loss of neurologic function. For example, surgical removal of tumors in the sacrum can result in loss of control of bowel and bladder function (incontinence).

Fifty to 75% of patients treated with surgery will be alive after 5 years.

Research on the Horizon

Advances in radiation therapy are allowing higher doses of radiation to be applied with less damage to surrounding normal tissues, such as the brain and spinal cord. Different types of radiation therapy (including proton beam therapy, intraoperative radiation, and brachytherapy) may offer better treatment of these tumors. These therapies may be combined with more limited surgery in the future.

New drug treatments, including use of a drug called imatinib mseylate are being investigated which may help slow the growth of tumors that cannot be removed.