Pontine glioma

Pontine gliomas are malignant (cancerous) tumours that originate from the part of the brain known as the brain stem (pons). They develop from cells called astrocytes.

In this section

In children, 80% of brain stem tumours are pontine gliomas.

If a biopsy is carried out they are usually found to be high grade gliomas and are classified according to the grade of aggressiveness (how quickly they grow), as either anaplastic astrocytomas (grade III) or glioblastoma multiforme (GBM). These tumours grow amongst the normal nerve cells of the brain stem, making them impossible to remove surgically as the brain stem is a vital area of the brain that controls many body functions.

Who gets pontine glioma?

Less than 40 children a year develop pontine glioma in the UK. This is around 10-15% of all childhood brain tumours. They rarely occur in adults. Like most brain tumours, the cause of pontine gliomas is unknown.

Signs and symptoms

The symptoms are related to the internal pressure that the tumour applies on the brain stem. Occasionally they can cause increased pressure in the head (raised intracranial pressure). Rarely they spread into the spine. Symptoms include:

  • squints
  • swallowing problems
  • slurred speech
  • facial weakness
  • abnormal gait (the way the child walks)
  • difficulty with tasks like handwriting
  • gradual decline in school work
  • changes in personality and behaviour.

If there is increased pressure in the head:

  • headaches
  • nausea and vomiting.

If the tumour spreads to the spine:

  • back pain
  • difficulty walking
  • problems with bowel and bladder control.

Tests / investigations

We will need to carry out some tests to find out as much as possible about the type, position and size of the tumour. This will help us to decide on the best treatment for your child. These tests include:

  • CT scan – it is likely a CT scan of your child’s brain was the first specific test carried out at your local hospital. Although MRI scans are usually the best way of seeing the tumour and the effects of treatment, sometimes CT scans are also useful.
  • MRI scan – this scan allows us to see the brain and spine in great detail and is used regularly to diagnose and follow the effect treatment is having on your child’s tumour.

Treatment of pontine glioma

Unfortunately, very few children are cured from pontine glioma. The only proven treatment is radiotherapy, which can improve a child’s symptoms in up to 75% of cases. However, the benefit is usually short-lived and the tumour starts to grow again after a few months.

Surgery is not possible due to the tumour’s position in the brain stem, growing amongst vital nerve cells. Chemotherapy has had little effect on this tumour but new agents are being investigated in clinical trials.

Surgery

Is limited to biopsy to take a small piece of tissue to confirm the diagnosis if necessary and also for research purposes as part of some clinical trials.

Radiotherapy

Radiotherapy is routinely used to try and destroy the cancer cells. See the Children’s Unit booklet called ‘Radiotherapy treatment’ for more details on this type of treatment.

Chemotherapy

Chemotherapy is usually only used as part of a clinical trial in pontine glioma. Treatment with anti-cancer drugs is used to try and destroy the tumour cells. It may be given by injections or by mouth.

If your child takes part in a clinical trial, the treatment is explained in more detail in the specific trial information sheet. You will be given an outline of the treatment in the form of a ‘road map’.

Clinical trials

Clinical trials are medical research trials involving patients that are carried out to try and find new and better treatments. In cancer, clinical trials are most commonly used to try and improve different forms of treatment such as surgery, radiotherapy or chemotherapy.

The treatment being tested may be aimed at:

  • improving the number of people cured (for example, trying new types of surgery or chemotherapy)
  • improving survival
  • relieving the symptoms of the cancer
  • relieving the side effects of treatment
  • improving the quality of life or sense of wellbeing for people with cancer.

Clinical trials may also involve research aimed at understanding more about the tumour’s biology. You may be asked to allow us to do research on the tumour sample removed at surgery, or on blood samples.

Well-run clinical trials have led to a significant improvement in the treatment of children with cancer. If you are asked to consider entering your child into a clinical trial you will be given specific information about the trial before deciding whether to take part.

Effects of treatment

General side effects of chemotherapy

Bone marrow suppression (myelosuppression)

Chemotherapy drugs decrease the production of blood cells by the bone marrow for a variable period of time. This results in low red blood cells (anaemia), low white blood cells (neutropenia) and platelets (thrombocytopenia). Your child may need blood or platelet transfusions and will be at increased risk of infections. The doctors and nurses caring for your child will tell you more about these side effects.

Nausea and vomiting

Some of the chemotherapy drugs used may make your child feel sick or vomit. We will give anti-sickness drugs at the same time to stop nausea and vomiting. These are usually very effective.

Sore mouth (mucositis)

Some of the chemotherapy drugs make the lining of the mouth and throat very sore and ulcerated. We will give your child painkillers for this, and explain how to care for your child’s mouth during treatment.

Hair loss

Temporary hair loss is common.

Specific drugs

For details of the side effects of individual drugs please see Macmillan specific drug information leaflets.