Central nervous system (CNS) tumours are abnormal growths of tissue in the brain and spine. This type of cancer occurs when the growth of cells gets out of control, developing a lump known as a tumour.
Cancerous tumours that start in the brain and spine do not often spread to other parts of the body, but can increase in size and take over surrounding tissue.
The brain and central nervous system
The brain is the control centre of the body: responsible for thoughts, feelings and actions. It is part of the central nervous system, along with the spinal cord. Different areas of the brain control different parts of the body, as well as thoughts, memories and feelings. Brain tumours can develop anywhere in the brain.
There are more than 200 different types of brain tumours. They are often named after the type of cell or the region of the brain where they begin. Most brain tumours start in the glial cells that bind the nerve cells of the brain together. These tumours are called ‘gliomas’. There are a number of different sub-types of gliomas.
The ones that are most common in young people are astrocytomas and ependymomas. Medulloblastomas are tumours that develop in the cerebellum at the back of the brain but may spread to other parts of the brain and, occasionally to other parts of the body.
There are also a number of rarer types of brain tumours. Talk to your specialist for more information about your child's particular diagnosis.
You also may have been told about the grade of your child's tumour. This refers to how fast the tumour is growing. Those classified with a higher grade generally grow faster than those classified with a lower grade.
People can get brain tumours at any age. They are the most common solid tumour for under 15s. About 5% of brain tumours are related to genetic conditions; if your child has a parent or sibling diagnosed with a tumour of the nervous system, their risk is higher than other people's.
The first symptoms of a central nervous system tumour may be headaches and sickness that are usually worse in the morning. Depending on where the tumour is located, other symptoms could include loss of vision or hearing, irritability, changes in your child's behaviour and fits, unsteadiness when walking, weakness in your child's arms or legs, and difficulty going to the toilet.
Central nervous system tumours are diagnosed using a number of tests. Specialists use MRI scans and CT scans to let them look inside the brain and identify where your child's tumour is located. They will also examine your child's eyes for any increased pressure in their brain, take blood tests, and possibly also test your child's hearing and reflexes. Doing these tests and getting the results may take some time, but it is important for your specialist to identify the particular type of tumour your child has so that they can determine the best form of treatment.
Your child's treatment plan will depend on the type of tumour they have, its size and location. Different treatments may also be used at different ages. If your child is very young, their brain will be growing quickly, so the specialists may recommend a different treatment plan than one they would use for an older child.
Surgery is the most common treatment for central nervous system tumours. The surgeons will aim to remove the tumour, or as much of it as possible. However, sometimes surgery is not a treatment option because the tumour has no clear edges and is located next to or within a delicate part of the brain.
Radiotherapy may be used in addition to surgery if it is has not been possible to remove the entire tumour surgically, or if surgery is not possible because of the location of the tumour. Radiotherapy will also usually be given to those affected by high grade tumours, whether or not these have been removed by surgery.
If your child is under three years old, radiotherapy will be avoided if possible, due to the fact that long-term side-effects are more common and often more significant in children who have had radiotherapy at a young age.
Proton Beam Therapy
If your child is under 16 and has a particular type brain tumour, your specialist may recommend that they travel abroad to have a specialised form of radiotherapy called proton beam therapy. See our proton beam therapy section for more information.
Chemotherapy can also be used, especially when treating high grade gliomas and medulloblastoma. Steroid drugs are given to reduce the swelling around brain tumours. They don’t treat the tumour itself but help relieve some of the symptoms that the tumour causes. Your child may also be given drugs to prevent fits.
If your child is undergoing chemotherapy, they may experience side-effects such as tiredness, sickness, diarrhoea and temporary hair loss. They may also be at greater risk of infections.
Radiotherapy can also make them feel tired and sick. They might experience skin irritation similar to sun burn and hair loss in the area that is being treated. The use of steroids can produce temporary side-effects, including a rounded-looking face, weight gain and mood swings.
Talk to your specialist or nurses about how you can manage these side-effects, or see the side-effects section of our website for more information.
After your child's treatment is complete they will still need to be seen regularly at an outpatient clinic. At this clinic, your specialist will be looking for any signs that your child's cancer has returned (this is known as a relapse). They will also check that their major organs, such as their heart and lungs, are still functioning correctly and haven’t been affected by the cancer treatment.
Long-term follow up
Once your child's risk of relapse has reduced, the focus of on-going follow up changes to looking out for potential long term side effects of treatment. The risk of long term side effects depends on the type of cancer your child had and the treatment they received. A personalised surveillance plan is usually created that outlines the specific long term follow up and on-going investigations that they require.
Many people are at low risk of future health problems but some will have significant on-going health needs. Talk to your specialist about the potential long-term side-effects of your child's treatment.
The long-term side-effects that your child experiences following on from their brain cancer treatment will depend on where their cancer was originally located, the treatment they received, their age when they received the treatment and a number of other factors.
They may continue to have shaking or fits, weakness on one side or in one part of their body, or difficulty in walking, speaking or understanding. These side-effects may be overcome through therapy (for example speech therapy or physiotherapy). Talk to your specialist about the options available to your child.
Updated January 2015, next planned review 2017.