Ependymomas

What is an ependymoma?

Ependymomas grow in the cells in the lining of the fluid-filled spaces (ventricles) in the brain. They are usually located in the back of the brain, in the cerebellum. Less often, they are located in the upper brain, in the supratentorial region. They may also be located in the centre of the spinal cord.

Ependymomas are more common in children under the age of 6, and particularly under the age of 2. Ependymomas are treated like cancerous (malignant) tumours because they can behave aggressively (recur and/or spread), even though some ependymomas may look benign under the microscope. They are treated with surgery, which is almost always followed by radiation therapy and sometimes chemotherapy.

What are the symptoms of an ependymoma?

The symptoms of ependymoma may be different based on the location of the tumour.

If the ependymoma is at the back of the brain in the cerebellum, there may be coordination problems or signs of too much fluid in the brain (hydrocephalus), such as headache, vomiting, and nausea. Children younger than 2 may have a larger head size due to hydrocephalus.

If the ependymoma is in the upper part of the brain, it can cause hemiparesis, which is weakness on one side of the body, as well as headaches and sometimes seizures.

Other symptoms of ependymomas can include:

• fatigue
• coordination problems
• feeding problems
• uncontrollable eye movements

What causes an ependymoma?

The causes of ependymomas are not known. There is no way to predict that a child will get a tumour. Nobody is to blame if a child develops a tumour.

Currently, there is no definite proof that environmental factors such as radiation, food or chemicals can cause brain cancer in children.

How many other children have ependymomas?

Ependymomas account for about 8% to 10% of brain tumours in children.

How are ependymomas diagnosed?

Doctors and other health-care professionals will use well-established diagnostic tests to see if a brain tumour is causing your child’s symptoms. These tests will include a physical examination, and brain scans such as magnetic resonance imaging (MRI) or computerized tomography (CT scan), which will identify the presence of a tumour. How a tumour looks on imaging can suggest what type of tumour it is, but ultimately a piece of the tumour needs to be looked at under the microscope to make the final diagnosis. This is done through a surgery where the goal is to remove as much of the tumour as possible.

A sample of tissue will be taken at the time of surgery to confirm the diagnosis. This small piece of tumour will be removed and sent to a doctor called a pathologist. They will look at the tumour under a microscope to learn the exact type of tumour and do specialized tests to learn more about the tumour characteristics (molecular testing).

Researchers and doctors used to think that how an ependymoma looked under the microscope was the best way to see how aggressive the tumour was. They now know that specialized tumour testing called molecular diagnostics is the best way to learn more about the behavior of the tumour. For example, some ependymomas have specific genetic changes that tell us that the tumour will be difficult to treat. Not all ependymomas have these changes.

Staging

In rare cases, an ependymoma can spread. Before starting any treatment, the doctor will first want to know if there are any other tumours in the brain or spine. For this reason, a number of tests are done at diagnosis to see if the cells have spread. This is called staging. These tests include an MRI of the spine, and studies of cells in cerebrospinal fluid (CSF). CSF testing is done by a short procedure called a lumbar puncture. Staging helps to determine the most effective treatment.

How is an ependymoma treated?

After your child’s surgery and once the health-care team has a clear understanding of what is causing your child’s symptoms, a meeting with the team will be set up to talk about results and the treatment plan. Remember that it is helpful to bring a paper and a pen or laptop and take notes at each meeting with this team. It is important to have the child’s primary caregivers in this meeting, for example both parents.

The treatment team may include a neurosurgeon, a neuro-oncologist, radiation oncologist, a nurse practitioner or nurse, and a social worker. During the meeting, they will explain which doctor is responsible for your child’s treatment, and the roles of everyone who is there. Other team members may be involved such as a dietitian, pharmacists, occupational therapist, and physiotherapist, depending on your child’s needs. Every team member has their role in your child’s care, and everyone works together to make your child feel better.

The doctor will explain the type of tumour that your child has, based on what the team has learned through diagnostic testing and staging. You will learn the expected effect this tumour will have on your child in the upcoming months and years, based on what is known about the tumour. This is called the prognosis.

The team may talk about placing your child on a protocol, which is a treatment plan ependymomas. You will need to consent (agree) to the plan for the treatment to begin. Teenaged patients may be asked for their consent as well.

Your team will also talk to you about placing an IV line called a central line. This will help doctors give the treatments in a safer way and avoid multiple pokes for blood tests. You will get more information about the line insertion in details during the meeting.

Surgery and radiation therapy

The first course of treatment is surgery. The goal is to remove as much of the tumour as possible. Surgeons consider surgery so important that they will sometimes accept that surgery may cause some damage to the brain when trying to remove the tumour completely. After surgery, children may have problems with swallowing, speech, balance, or coordination. They may experience double vision. If the tumour was in the section of the brain called the posterior fossa, they may experience a mutism called posterior fossa mutism, where they cannot speak for a period of time after the surgery.

Surgery is generally followed by radiation therapy, which is the use of high-energy X-rays, gamma rays, or electrons to destroy tumour cells.

In cases where the tumour was not removed completely, going back for a second surgery (second-look surgery) may be used before radiation is given. Second-look surgery is done to see the effect of treatment and try and remove more tumour if possible. It can be done soon after the first surgery or after chemotherapy.

Chemotherapy

The role of chemotherapy in the treatment of ependymoma is still uncertain. Clinical trials in Europe and North America are currently evaluating the role of chemotherapy in children who have had a complete resection of their ependymoma. There are data suggesting that chemotherapy may be beneficial for the treatment of ependymoma. However, there is no evidence that chemotherapy can replace radiation in the treatment of ependymoma.

If a child is younger than 1 year old, chemotherapy may be given rather than radiotherapy, because of radiation’s long-term effect on the developing brain. The chemotherapy is given to prevent the tumour from getting bigger. Some doctors will use radiotherapy when the child is older than 1 year old.

Currently, children with ependymoma who are older than 1 year old and who have had an incomplete resection are given 2 cycles of chemotherapy within 7 weeks. This chemotherapy is administered as follows:

• Oral: This means that a pill or capsule is swallowed by mouth.
• Intravenous (IV): This is the most common way to give chemotherapy. The drugs are delivered through a needle directly into a vein. A port or central line may be used.

If a child has hydrocephalus and the flow of cerebrospinal fluid (CSF) is blocked, a shunt may be needed.

What is the outcome for a child with an ependymoma?

The outcome for a child with a brain tumour depends on many factors. These factors include the child’s age, the location of the tumour, whether it has spread, how much has been removed in surgery, and the molecular characteristics of the tumour.

For ependymomas, the outcome is better if the tumour is supratentorial (in the cerebrum), and if it can be completely removed during surgery. Five years after treatment, 50% to 70% of children with an ependymoma will survive.

Recurrence of ependymomas

Surgery is the treatment of choice if an ependymoma recurs (grows back). It appears to offer the most benefit in improving the quality of life and the chance of success.

If radiation therapy was not done, then radiation at the site of the tumour is recommended.

If a child has had radiation therapy, re-irradiation may be considered. It involves giving one high dose of radiation and it often occurs after a repeat surgery. Depending on the type of recurrence, the doctor may choose to give a focal irradiation which focuses on the tumour itself, or craniospinal radiation which is given to the brain and spinal cord.

In some cases, surgery using radiation (radiosurgery) may be considered.

The role of chemotherapy in treating a recurrent ependymoma is not clear. Many chemotherapy drugs are currently being studied, but no protocols have yet been developed that would improve results. Chemotherapy may be offered as an experimental treatment if the tumour cannot be removed by surgery, or if the tumour has spread (metastasized).

Overall, the results of treating a recurrence are better if the tumour is smaller and if it was detected in an MRI scan (subclinical recurrence). For that reason, a child with an ependymoma will have regular scans and follow up.