Low grade glioma
Low grade gliomas are benign (non-cancerous) tumours (grade I or II) that develop from brain cells called astrocytes.
In this section
Astrocytomas are the most common type of glioma. Different types include; pilocytic, pilomyxoid and fibrillary astrocytomas. In children, more than 80% of astrocytomas are low grade.
Low grade astrocytomas usually develop only where they originated and grow slowly over a period of time. These tumours can arise anywhere in the brain or spinal cord. The most common areas for them to occur are the cerebral hemispheres (frontal, parietal, temporal lobes) and the cerebellum.
They can spread (disseminate) to other areas of the brain or spinal cord in the cerebrospinal fluid, although this is rare. Tumours can be solid or part cystic (fluid filled).
Who gets a low grade glioma?
This is the most common type of brain tumour in children, representing 40% of all childhood brain and spinal cord tumours. There are about 150 cases of childhood low grade gliomas a year in the UK.
Although adults also develop low grade gliomas, they behave and are treated very differently.
Like most brain tumours the cause of low grade gliomas is unknown in most cases. However, some are associated with a genetic condition called neurofibromatosis type 1.
Signs and symptoms
The symptoms depend on where the tumour is located and also whether there is increased pressure in the head (raised intracranial pressure). Symptoms include:
- nausea and vomiting (most common)
- lethargy and irritability
- seizures (fits)
- difficulty with tasks like handwriting
- gradual decline in school work
- changes in personality and behaviour
- abnormal gait (the way the child walks).
If the tumour spreads or is located in the spinal cord, the signs and symptoms may include:
- 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.
Staging is a measure of how far the tumour has spread beyond its original site. It is most important to know whether the tumour has been removed by the neuro-surgeon or whether the tumour has spread to the cerebrospinal fluid and spine.
Treatment for low grade glioma depends on location of the tumour and the age of the child. Common treatments include:
Most children will have an operation to confirm the diagnosis, relieve pressure and to try and remove as much of the tumour as possible. However, if the tumour is deep in the brain a biopsy only may be carried out to confirm the diagnosis. This is to try and avoid further damage to the child’s brain. If the neurosurgeon can remove all or most of the tumour this may be the only treatment needed and observation with brain scans will be arranged.
Radiotherapy is commonly used after surgery to destroy any remaining tumour cells in children older than 8-10 years. Radiotherapy is usually directed locally to where the tumour is/ was. See the Children’s Unit booklet Radiotherapy treatment for more details on this type of treatment.
Chemotherapy is given together with surgery and/or radiotherapy to treat the tumour. Treatment with anti-cancer drugs is used to destroy the tumour cells. It is usually given by injections and drips into a vein (intravenous infusion).
Chemotherapy is usually outpatient based and lasts over a year but is quite well tolerated and children can usually continue to attend school.
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 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 well-being 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.
The majority of low grade gliomas are not life-threatening but some inoperable tumours (often in young children) can prove to be very difficult to treat. In up to half of cases though. initially controlled low grade gliomas can grow back and require further therapy.
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.
Temporary hair loss is common.
For details of the side effects of individual drugs please see Macmillan specific drug information leaflets.
What are the possible long-term effects of treatment?
Low grade gliomas cause long-term problems related to where they are located. Tumours can result in growth, hormonal and behavioural changes with possible learning problems and difficulties with coordination. Hearing and visual disturbances can result from both tumour and treatments. Physical disabilities and seizures can be a problem even when the tumour is controlled. These need to be monitored. Treatment can reduce fertility and there is a small risk of developing a second cancer later in life.
All children are followed up after treatment is finished in the long-term brain tumour follow-up clinic. Your child will be seen at regular intervals in this clinic, indefinitely, so that we can help with any long-term effects of the treatment.