Chordoma

What is chordoma?

Chordoma is a rare malignant (cancerous) bone tumor that forms in your spine or the base of your skull. It’s a type of sarcoma.

Chordomas can occur at any point along your spine:

• About 35% develop in the base of your spine (sacrum).
• About 35% develop where your spine meets your skull (skull base). These are called clival chordomas because the bone in the skull base that’s most often involved is the clivus.
• About 30% develop in the vertebrae of your mobile spine — most commonly the second cervical vertebrae (in your neck) followed by your lumbar spine and then thoracic spine.

Chordomas typically grow slowly, but they can be difficult to treat due to how they invade nearby nervous system tissue.

They also tend to recur (come back) after treatment — usually in the same place. Chordomas spread to other parts of your body (metastasize) in 30% to 40% of cases.

If an advanced chordoma does metastasize, it most commonly spreads to your:

• Lungs.
• Nearby lymph nodes.
• Other bones.
• Liver.
• Skin.

What are the types of chordomas?

The World Health Organization (WHO) recognizes three distinct types of chordoma based on what the cells look like under a microscope (their histology):

• Classic/conventional chordoma: This is the most common type (80% to 90% of all cases). It’s made up of a unique type of cell that looks “bubbly.” Chondroid chordoma is a variant of this type. It makes up 5% to 15% of all chordoma cases. Chondroid chordoma often forms in the base of your skull.
• Dedifferentiated chordoma: This is a rare type of chordoma (less than 5% of cases) that appears as a mix of abnormal cells. It’s more aggressive, faster growing and more likely to metastasize than conventional chordoma.
• Poorly differentiated chordoma: This type is very rare. There have been fewer than 60 cases recorded in medical literature. Poorly differentiated chordoma is characterized by the deletion of a gene called SMARCB1, or INI1. These chordomas most commonly affect children and young adults.

Who do chordomas affect?

Chordomas can develop in anyone at any age, but they’re most likely to occur in adults aged 50 to 80. About 5% of cases affect children.

Men and people assigned male at birth are approximately 1.5 times as likely to have a chordoma as women and people assigned female at birth.

How common are chordomas?

Chordomas are rare. They affect about 1 person for every 1 million people per year. That means that about 300 people receive a chordoma diagnosis each year in the United States.

About 1% to 4% of all primary bone tumors are chordomas.

What are the symptoms of chordoma?

As a chordoma grows, it puts pressure on nearby areas of your spinal cord or brain. This pressure causes the symptoms of chordoma. Symptoms can also vary based on where the tumor is along your spine.

General chordoma symptoms include pain, weakness and/or numbness in your back, arms or legs.

Symptoms of a chordoma at the base of your skull may include:

• Double vision (diplopia).
• Blurry vision.
• Headaches.
• Facial numbness/pain.

Symptoms of a chordoma in your tailbone may include:

• A lump that you can feel through your skin.
• Issues with bladder or bowel function.
• Low back or tailbone pain.

What is the cause of chordoma?

Researchers don’t know exactly why chordomas form. But they think changes (mutations) in the TBXT gene are likely involved.

A few families have had multiple members who’ve developed a chordoma. Studies revealed that these people inherited a duplication of the TBXT gene. Researchers have also identified changes in the TBXT gene in people with chordoma who have no family history of the condition.

A chordoma develops from cells of the notochord. This is a structure that’s present in a developing embryo and is important for the future development of its spine. The notochord usually disappears by the time the fetus is eight weeks old. But in a small percentage of people, a few notochord cells can remain embedded in the bones of the spine or the base of the skull.

A change in the TBXT gene may trigger the growth of these cells, leading to a chordoma.

People with a genetic condition called tuberous sclerosis are at higher risk of developing chordoma. This condition causes a variety of medical issues, including epilepsy, developmental delay and tumors throughout your body. Tuberous sclerosis is caused by mutations in two genes: TSC1 and TSC2.

How are chordomas diagnosed?

Your healthcare provider will ask about your symptoms and medical history. They’ll likely perform a physical exam and a neurological exam.

If they suspect a tumor, they’ll order an imaging test, such as an X-ray, computed tomography (CT) scan or MRI scan.

Your provider will likely refer you to a bone cancer specialist for a second opinion and confirmation of the diagnosis. You may need additional imaging tests to better determine the location of the chordoma and see if it’s spread to other areas of your body.

The only way healthcare providers can definitively diagnose chordoma is with a biopsy — usually a needle biopsy. This involves taking a small sample of the tumor so a specialist can examine it under a microscope.

How is chordoma treated?

The go-to treatment option for chordoma is surgery. Total surgical removal of the tumor (en bloc resection) has the best chance of prolonging survival. However, this is often difficult due to the location of the tumors. Specifically, this isn’t possible for chordomas in the base of your skull.

A chordoma in your spine can invade your spinal cord and nearby important nerves and arteries, which could cause lasting issues or death if they’re damaged during surgery. A chordoma at the base of your skull is often difficult to completely remove because it’s close to essential structures such as your brainstem, cranial nerves and spinal cord. Neurosurgeons aim to remove as much of the chordoma as they safely can.

Chordomas are generally resistant to radiation therapy and chemotherapy as primary treatments. But your healthcare team might recommend radiation therapy after surgery to lower the chance that the tumor will grow back.

Researchers are currently studying experimental therapies for chordomas, such as targeted therapy and immunotherapy. There may be clinical trials available that you can participate in.

How can I prevent developing chordoma?

There’s nothing you can do to prevent developing chordoma. Most cases happen randomly.

If you have a family history of chordoma or tuberous sclerosis, be sure to see your healthcare team regularly so they can monitor you for signs of chordoma. The earlier they can catch it, the better.

What is the prognosis of chordoma?

The prognosis (outlook) of chordoma varies depending on a few factors:

• The tumor’s location and how much of it can be surgically removed: Total removal of the tumor is associated with a better prognosis. Nonsurgical treatment only is associated with a worse prognosis.
• If it has spread (metastasized): Distant metastasis is associated with a decrease in survival rate.
• Your age at diagnosis: People over 60 years old generally have a decreased survival rate.
• If the tumor has dedifferentiation or not: Poorly differentiated chordoma has a worse prognosis than conventional chordoma.

Your healthcare team will be able to give you more accurate information about what you can expect. Don’t be afraid to ask them questions.

Can chordoma be fatal?

Yes, chordoma can cause death — typically due to tissue destruction in your spinal cord, brain or brainstem after it has recurred (come back).

A study of 357 people with chordoma revealed that the survival rates were:

• After three years: 80.5%.
• After five years: 68.4%.
• After 10 years: 39.2%.

It’s important to remember that these are just averages. Your healthcare team can provide more detailed information about survival rates based on your unique situation.

When should I see my healthcare provider about chordoma?

Chordomas often come back (recur), even many years after treatment. Because of this, long-term follow-up with your healthcare team is important.

If you have any new or worsening symptoms, talk to your healthcare provider.

What kind of cancer is chordoma?

Chordoma is a type of bone cancer. More specifically, it’s a type of sarcoma, which is a broad group of cancers that begin in your bones and your soft (connective) tissues.

Can chordoma be noncancerous?

No. All subtypes of chordoma are considered malignant (cancerous).

A note from Cleveland Clinic

Learning you have a rare type of bone cancer can be scary and stressful. Chordomas can be difficult to treat because of their location. But know that your healthcare team will develop an individualized and thorough treatment plan to help treat the chordoma and improve your quality of life.