Chordoma

Overview

Chordoma is a rare type of bone cancer that starts in the bones of the spine or the skull. Chordomas are different from other bone tumors for reasons including where they grow, how they start and who they affect.

Chordomas can grow anywhere along the spine. But they often grow in two locations. The first is in a bone called the clivus. The clivus is located where the skull sits atop the spine, also called the skull base. The second is at the bottom of the spine, called the sacrum. Chordomas also can grow in the areas in between, sometimes called the mobile spine.

Chordomas start in leftover cells that help form the spine before birth. Usually, any leftover cells go away soon after a baby is born. But sometimes a few of the cells stay. Rarely, in about 1 in 1 million people, the leftover cells eventually become cancerous.

Chordomas can happen at any age. But they most often affect adults ages 40 to 60. Chordomas usually grow slowly. Surgery is usually the main treatment. However, chordomas can be hard to remove fully. This is because they grow very close to the spinal cord, blood vessels, nerves and brain. A chordoma often comes back after treatment.

Types

Different types of chordomas include:

• Conventional chordoma, also called classic chordoma and classical chordoma. This is the most common type. Under a microscope, it looks like bubbly cells in a slimy mix, similar to soap bubbles.
• Chondroid chordoma. Up to roughly 15% of chordomas are this type. Under a microscope, chondroid chordomas look similar to classic chordomas. But they also have tissue that looks similar to cartilage tissue found in parts of the body such as the nose.
• Dedifferentiated. Up to just under 10% of chordomas are this type. Under a microscope, this type of chordoma has two parts. One part looks like classic chordoma cells that also have a special protein called brachyury. The other part looks like a different type of cancer cell.
• Poorly differentiated. This rare type of chordoma mostly affects kids and young adults and is usually found in the skull base. It's identified due to a missing gene called SMARCB1 (INI1).

Causes

It's not clear what causes most chordomas. They usually happen randomly. Rarely, they can be hereditary, meaning chordomas can run in families. This cancer most often starts in the bones in the skull or spine.

Chordoma happens when cells in the bones develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, DNA gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time. In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to grow and multiply quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells.

The cancer cells form a mass called a tumor. The tumor can grow to invade and destroy healthy body tissue. In time, cancer cells can break away and spread to other parts of the body. Cancer that spreads is called metastatic cancer.

Complications

Complications of chordomas typically are caused by the tumors growing and pressing into blood vessels, nerves and other tissues. Other complications happen if the cancer spreads to other parts of the body.

Chordoma complications of the nervous system may include:

• Cerebrospinal fluid leaks, though this is rare.
• Headaches.
• Hearing loss.
• Problems with balance, coordination and walking.
• Trouble swallowing or speaking.
• Trouble breathing.
• Vision problems.
• Water buildup on the brain, which can increase pressure inside the skull and cause headaches, nausea and vomiting.
• Weakness or numbness in the face, arms or legs.

Sometimes chordoma tumors can spread to other parts of the body. You may hear this called metastatic chordoma. Less than half of chordomas spread to other parts of the body. It's most common in chordomas that are found in areas of the spine below the neck and with the poorly differentiated type of chordoma. Sometimes metastatic chordoma may be called advanced chordoma or end-stage chordoma.

The most common place for a chordoma to spread is to the lungs. But it also can spread to the liver or other bones or soft tissues. Depending on where metastatic chordoma has spread, complications may include:

• Bone breaks.
• Extreme tiredness.
• Lumps.
• Pain.
• Swelling of the belly.
• Trouble breathing.
• Yellow skin or eyes, called jaundice.
• Weight loss.

Treatment

Chordoma treatment depends on the size and location of the cancer, as well as whether it has invaded nerves or other tissue.

• Surgery is often the first step and an important chordoma treatment. If a tumor can be taken out fully, it offers the best chance at a cure.
• Radiation therapy usually follows surgery, to kill any cancer cells that might remain. Sometimes radiation therapy is used before surgery to make a tumor smaller and easier to take out. Sometimes radiation therapy might be used by itself, if it's not possible to take out the tumor through surgery.
• Targeted therapy medicines may be used for cancer that's spread in the body, called metastases, or for cancer that returns after initial treatment, called a recurrence.

In some cases, chordoma can be cured. But chordomas can be difficult to treat. It's hard to take them out fully because they grow so near the brain and spine. And they resist conventional radiation and chemotherapy. Often, chordomas return. This is called a recurrence. When that happens, treatment can help control or manage the cancer over time instead of cure it.

Surgery

In chordoma surgery, surgeons aim to take out as much of the tumor as possible in one piece. When done in the mobile spine or sacrum, this is called en bloc resection. When a chordoma can be taken out fully in one piece, the procedure lowers the chance of cancer cells spreading and the cancer coming back.

But it can be difficult to take out the whole chordoma. This is because chordomas grow around important structures, including the brain, spinal cord, nerves and blood vessels. Surgeons try to remove the cancer without damaging healthy structures. It's also challenging to safely reach parts of the skull base.

When a chordoma can't be taken out completely, surgeons try to take out as much as possible.

Types of surgery may differ depending on where the tumor is located:

• Skull base chordoma surgery. Sometimes surgeons can go through the nose to get to a skull base chordoma. This kind of surgery is called endoscopic skull base surgery. It uses a long, thin tube called an endoscope. The endoscope is inserted through the nose to access the cancer. Special tools can be passed through the endoscope to take out the cancer. Sometimes a traditional open surgery is needed. During open surgery, a surgeon uses surgical instruments inserted through a large cut, also called an incision, at the back of the head or neck. Other approaches also may be used.
• Mobile spine and sacral chordoma surgery. The goal of chordoma surgery in areas of the spine below the skull base is to take out as much of the tumor as possible. Other surrounding bone and tissues also may be taken out. If the tumor is in the sacrum, at the bottom of the spine, the whole sacrum may be taken out. This is called a sacrectomy. This surgery may be done through an incision in the belly or in the back.

Rarely, surgeons might suggest another surgery to stabilize the area where the cancer once was.

Complications of chordoma surgery include risks of any surgery, such as infection, blood clots and bleeding. Complications also can happen if nerves are damaged during surgery. Possible complications include:

• Double vision.
• Bowel or bladder changes.
• Loss of sexual function.
• Numbness or loss of feeling.
• Trouble walking or sitting.
• Leaking of the fluid that surrounds the brain and spinal cord, called cerebrospinal fluid.

Radiation

Radiation therapy treats cancer with powerful energy beams. The energy can come from X-rays, photons, protons or other sources.

During radiation therapy, you lie on a table while a machine moves around you. The machine directs radiation to precise points on your body.

In the past, chordomas have resisted standard radiation that needed to be given at a dose low enough not to damage any nearby spinal cord or brain tissue. Newer radiation treatments may help by delivering a higher dose of radiation more directly to the tumor while protecting the surrounding brain, spinal cord and nerves. Examples of radiation options include:

• Proton therapy.
• Intensity-modulated radiation therapy (IMRT).
• Stereotactic radiosurgery.
• Stereotactic body radiotherapy.
• Carbon ion therapy.

The type of radiation therapy used can vary depending on where the cancer is located and what options the surgical center has.

Side effects of radiation therapy may include:

• Tiredness.
• Skin swelling, irritation or other changes.
• Headache.
• Hormone changes, such as hypopituitarism.
• Brain changes or damage.
• Hearing and vision changes.
• Trouble swallowing.

There's also a slight risk that radiation therapy might cause a different cancer later on. This is called a secondary cancer.

Targeted therapy medicines

Chordoma usually does not shrink with standard chemotherapy. But targeted therapy for cancer is a treatment that uses medicines to attack specific chemicals in cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die.

Targeted therapy is sometimes used as part of a clinical trial. Or it's used off-label to treat chordoma that spreads to other areas of the body, called metastatic chordoma. Off-label means the drug has been approved by the Food and Drug Administration to treat a different condition. Targeted therapy also may be used to treat chordoma that comes back after treatment, called a recurrence.

Some examples of targeted therapy that might be used first for chordoma include:

• Imatinib.
• Dasatinib.
• Sunitinib.

Sometimes, other drugs might be used. These could include:

• Imatinib given with a chemotherapy drug or with sirolimus.
• Erlotinib.
• Lapatinib
• Sorafenib.

Side effects of targeted therapy may include:

• Tiredness.
• Upset stomach.
• Rash.
• Diarrhea.
• Swelling.
• Thyroid and kidney changes.

Treatments being studied

Scientists continue to research possible new treatments for chordoma. Some of those include:

• Checkpoint inhibitors. These are a type of drug that helps the immune system find and attack cancer cells.
• Brachyury-targeted therapies. Chordomas almost always make brachyury protein. So vaccines and new drugs that target brachyury are being tested.

Preparing for an appointment

Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you. If your healthcare professional thinks you might have a chordoma, you may be referred to a specialist.

Because appointments can be brief, it's a good idea to be prepared. Here's some information to help you get ready.

What you can do

• Be aware of anything you need to do ahead of time. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet.
• Write down symptoms you have, including any that may not seem related to the reason for which you scheduled the appointment.
• Write down important personal information, including major stresses or recent life changes.
• Make a list of all medicines, vitamins and supplements you're taking and the doses.
• Take a family member or friend along. It can be hard to remember all the information provided during an appointment. Someone who goes with you may remember something that you missed or forgot.
• Write down questions to ask your healthcare team.

Your time with your healthcare team is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For chordoma, some basic questions to ask include:

• Do I have a chordoma?
• What is the stage of my chordoma?
• Has my chordoma spread to other parts of my body?
• Will I need more tests?
• What are the treatment options?
• How much does each treatment increase my chances of a cure or prolong my life?
• What are the potential side effects of each treatment?
• How will each treatment affect my daily life?
• Is there one treatment option you believe is the best?
• What would you recommend to a friend or family member in my situation?
• Should I see a specialist?
• Are there any brochures or other printed material that I can take with me? What websites do you recommend?
• What will determine whether I should plan for a follow-up visit?

Don't hesitate to ask other questions.

What to expect from your doctor

Be prepared to answer questions, such as:

• When did your symptoms begin?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?

Chordoma stages

After a chordoma diagnosis, the next step often is to find out the cancer's extent. This also is called the cancer's stage. Staging is the process health professionals use to describe how much cancer is in the body and where it is. Imaging tests can help measure the tumor. Biopsies may be done to look at the cancer cells. Your healthcare team uses the cancer stage to help create your treatment plan.

Chordoma staging might be done using different staging systems. Examples of systems include the:

• Enneking system, which has three stages.
• American Joint Committee on Cancer (AJCC) system, which has four stages.

Staging terms

For chordoma, staging usually looks at a few factors. The AJCC system refers to these as T, N and M.:

• T. The size of the tumor.
• N. Whether the tumor has spread to nearby tissues or lymph nodes.
• M. Whether the cancer has spread to other parts of the body.

A lower stage number, no matter which staging system is used, means the cancer is less advanced. This means it's smaller, growing slowly and has not spread from the original tumor area. A higher stage number means the cancer is larger, growing more quickly or has spread.

Health professionals also look at how aggressive tumor cells look under a microscope. This is known as the tumor's grade (G).

A lower grade number, no matter which staging system is used, means a less aggressive, slower growing cancer. A higher grade number means a more aggressive, faster growing cancer.

• The Enneking system has two grades.
• The AJCC system has four grades.

Staging also might include the type of chordoma because it can relate to how aggressive it may be. Dedifferentiated and poorly differentiated chordomas tend to be more aggressive than conventional, also called classic and classical chordomas or chondroid chordomas. And chondroid chordomas tend to be more aggressive than conventional chordomas.

You may hear the term "end-stage chordoma." This refers to a chordoma that cannot be cured or managed with treatment. End-stage cancer treatment focuses on controlling pain and other symptoms to improve comfort.

Chordoma prognosis

A cancer prognosis tells you how likely it is that the cancer can be cured. Your healthcare team can get a general sense of your prognosis from staging. But the stage can't tell your future. Your personal prognosis may depend on:

• Biopsy results.
• How much of the tumor can be taken out during surgery.
• The cancer's stage and grade.

Talk with your healthcare team about your prognosis if you want to know what to expect. Your healthcare team members can explain what they consider when thinking about your prognosis.

Cancer survival rates or survival statistics tell you the percentage of people who survive a certain type of cancer for a specific amount of time, such as 5 or 10 years. These numbers can help you and your healthcare team to understand the chance your cancer will be cured, called your prognosis, and decide on a treatment plan.

Cancer survival rates are usually based on research gathered on many people with a specific cancer. Because so few people have chordoma, survival rates may not be very accurate.

Also keep in mind that survival statistics take 5 or 10 years to collect. The most recent survival rates include people who had chordoma treatment more than five or 10 years ago. Those people did not have access to the latest treatments.

Keeping these things in mind, statistics suggest that average survival for chordoma has been about 10 years after diagnosis. This means about half of people diagnosed with chordoma have lived less than 10 years and half have lived longer than 10 years.

With modern, aggressive surgery and newer treatment approaches, chordoma survival rates may be increasing. Your healthcare professional may be able to give you more-specific survival statistics based on your stage of cancer and other factors personal to you.

Factors that affect survival rates

Most of the factors that affect chordoma survival rates are out of your control. Examples include:

• How much of the tumor can be taken out. This is the biggest predictor of outcomes for chordoma. If the tumor can be totally taken out in one piece, including some of the surrounding healthy tissue, it gives the best chance of a cure.
• The type of tumor. Conventional and chondroid chordomas have a better prognosis than poorly differentiated and differentiated chordomas.
• Whether the cancer has returned or spread. If the chordoma recurs after initial treatment or metastasizes it has a worse prognosis.

After your initial recovery from treatment, try to make healthy lifestyle choices to help your overall health. If possible, try to exercise, eat a balanced diet, maintain a healthy weight, get good sleep, reduce stress, skip tobacco and limit the amount of alcohol you drink. These can help improve your quality of life.