This information is about a specific type of tumour called an astrocytic tumour. It should ideally be read with our general information about brain or spinal cord tumours.

The central nervous system (CNS) is made up of the brain and spinal cord. Cells within the CNS normally grow in an orderly and controlled way. However, if this order is disrupted, the cells continue to divide and form a lump or tumour.

A tumour is either benign or malignant. A benign tumour may continue to grow, but the cells do not spread from the original site. In a malignant tumour, the cells can invade and destroy surrounding tissue and may spread to other parts of the brain.

Tumours affecting the CNS are fairly rare. About 4500 new tumours are diagnosed each year in the UK. Many of these are malignant.

Within the brain and spinal cord there are nerve cells and also cells that support and protect the nerve cells. The supporting cells are called glial cells. A tumour of these cells is known as a glioma.

Astrocytic tumours are the most common type of glioma and develop from a type of star-shaped cell called an astrocyte. They can occur in most parts of the brain and occasionally in the spinal cord. However, they most commonly grow in the main part of the brain, the cerebrum (the white area on the diagram below).

People of any age can develop an astrocytic tumour, but those in the cerebrum are more common in adults, and the chance of developing one increases as people get older. Astrocytic tumours in the cerebellum are more common in children or young people.

Grading refers to the appearance of the tumour cells under the microscope. The grade gives an idea of how quickly the tumour may grow. There are four grades: grades 1 and 2 (low-grade), grade 3 and 4 (high-grade).

Low-grade astrocytic tumours are usually slow‑growing and are not likely to spread. Many low-grade astrocytic tumours can be removed with surgery, and are unlikely to come back if they have been completely removed.

High-grade astrocytic tumours can be difficult to treat. Their cells look more abnormal than the ones in low-grade tumours. They are more likely to grow faster and to spread to other parts of the brain. It is common for the tumour to come back after initial treatment. This is known as a recurrence. Further treatment will probably then be necessary.

The four grades of astrocytic tumour are also sometimes known by names:

Low-grade astrocytic tumours

• Grade 1 - pilocytic astrocytoma
• Grade 2 - low-grade (diffuse) astrocytoma

High-grade astrocytic tumours

• Grade 3 - anaplastic astrocytoma
• Grade 4 - glioblastoma multiforme (GBM).

As with most brain tumours, the cause is unknown. Research is being carried out into possible causes.

Symptoms can occur due to increased pressure within the skull known as raised intracranial pressure (or ICP). The pressure can increase because of a blockage in the ventricles (fluid-filled spaces in the brain), which leads to a build-up of cerebrospinal fluid (CSF). CSF is the fluid that surrounds and protects the brain and spinal cord. The increased pressure may also be caused by swelling around the tumour itself.

Raised intracranial pressure can cause headaches, sickness (vomiting) and visual problems.

Other symptoms, such as fits (seizures) and changes in behaviour and personality can occur because of the position of the tumour in the brain.

A tumour of the frontal lobe of the brain (see the diagram above) may cause gradual changes in mood and personality. There may also be paralysis on one side of the body. A tumour in the temporal lobe of the brain may cause problems with coordination and speech, and may affect memory. If the parietal lobe of the brain is affected, it may be difficult to write and do other similar tasks. An astrocytoma in the cerebellum may lead to problems with co-ordination and balance.

So that your doctors can plan your treatment, they need to find out as much as possible about the type, position and size of the tumour, by doing a number of tests and investigations.

Neurological examination (nerve tests) The first test you have will be a neurological examination to assess any effect of the tumour on your nervous system. A CT scan or MRI scan will be done to find the exact position and size of the tumour.

CT (computerised tomography) scan A CT scan takes a series of x-rays which build up a three-dimensional picture of the inside of the body. The scan is painless but takes from 10–30 minutes. CT scans use a small amount of radiation, which will be very unlikely to harm you and will not harm anyone you come into contact with. You will be asked not to eat or drink for at least four hours before the scan.

Most people who have a CT scan are given a drink or injection to allow particular areas to be seen more clearly. This may make you feel hot all over. Before having the injection or drink, it is important to tell the person doing this test if you are allergic to iodine or have asthma.

MRI (magnetic resonance imaging) scan This test is similar to a CT scan, but uses magnetism instead of x-rays to build up a detailed picture of areas of your body. During the scan you will be asked to lie very still on the couch inside a long tube for about 30 minutes. It is painless but can be uncomfortable, and some people feel a bit claustrophobic during the scan. It is also noisy, but you will be given earplugs or headphones.

Some people are given an injection of dye into a vein in the arm, but this usually does not cause any discomfort.

Biopsy To give an exact diagnosis, a sample of cells is sometimes taken from the tumour and looked at under a microscope. The biopsy involves an operation and you may have to stay in hospital for a few days. There are different ways of doing the biopsy depending upon the position of the tumour in the brain. Your doctor will discuss with you whether this is necessary in your case, and exactly what the operation involves.

The treatment for astrocytoma depends on a number of things, including your general health and the size, grade and position of the tumour. The results of your tests will enable your doctor to decide on the best type of treatment for you. There are some risks associated with treatment to the brain and your doctor will discuss these with you.

Your treatment will usually be planned by a team of specialists known as a multidisciplinary team (MDT). The team will usually include a doctor who operates on the brain (neurosurgeon), a doctor who specialises in treating illnesses of the brain (neurologist), a doctor who specialises in treating cancer (an oncologist), a specialist nurse and possibly other health professionals, such as a physiotherapist or a dietitian.

If the pressure in the skull is raised, it is important to reduce it before any treatment is given for brain tumours. Steroid drugs may be used to reduce swelling around the tumour. If raised intracranial pressure is due to a build-up of CSF, a tube (shunt) may have to be inserted to drain off the excess fluid.

Consent

Before you have any treatment, your doctor will give you full information about what the treatment involves and explain the aims of the treatment to you. They will usually ask you to sign a form saying that you give your permission (consent) for the hospital staff to give you the treatment. No medical treatment can be given without your consent.

Benefits and disadvantages of treatment

Treatment can be given for different reasons and the potential benefits will vary depending upon the individual situation. If you have been offered treatment that aims to cure your cancer, deciding whether to have the treatment may not be difficult. However, if a cure is not possible and the treatment is to control the cancer for a period of time, it may be more difficult to decide whether to go ahead.

If you feel that you can’t make a decision about the treatment when it is first explained to you, you can always ask for more time to decide.

You are free to choose not to have the treatment and the staff can explain what may happen if you do not have it. You don't have to give a reason for not wanting to have treatment, but it can be helpful to let the staff know your concerns so that they can give you the best advice.

Surgery

Where possible, surgery is the first type of treatment for an astrocytoma. The aim of surgery is to remove as much of the tumour as possible without damaging the surrounding brain tissue. Depending on the size, position and spread of the tumour, it may not be possible to remove it completely and further treatment may be given as a follow-up to surgery.

Low-grade astrocytic tumours in the cerebellum (see diagram on page 2) can generally be removed completely by surgery. High-grade tumours, because of their tendency to spread, are more difficult to treat, and surgery is usually followed by radiotherapy and/or chemotherapy.

Some tumours cannot be reached by surgery, or it may be that the risk of damage to the surrounding brain cells is too high. If surgery is not possible, your doctor will discuss other forms of treatment with you.

Radiotherapy

Radiotherapy treatment uses high-energy rays to destroy the cancer cells. It is often used after surgery to destroy any remaining tumour cells. It may be used alone, or with chemotherapy, to treat astrocytoma if surgery is not possible. Radiotherapy is usually given as an external treatment.

Chemotherapy

Chemotherapy is the use of anti-cancer (cytotoxic) drugs, which destroy cancer cells. It may be given alone or together with surgery and radiotherapy to treat an astrocytic tumour.

You may find the idea of a tumour affecting your brain extremely frightening. The brain controls the body, and not being in control is something that can be very worrying. You may have many different emotions, including anxiety and fear. These are all normal reactions, and are part of the process many people go through in trying to come to terms with their condition.

Many people find it helpful to talk things over with their doctor or nurse, or one of our support service nurses. Close friends and family members can also offer support.

Driving

In some circumstances, you may not be allowed to drive for a period of time. If you had an epileptic fit before treatment, the Drivers and Vehicle Licensing Association (DVLA) will not allow you to drive for a year after your last fit. You can then drive again provided you remain well.

After treatment, you will not be able to drive for at least one to two years, depending on the grade of your tumour. However, if the tumour comes back this period will be extended.

You may not be allowed to drive some vehicles, such as a LGV (large goods vehicle) or a PCV (passenger carrying vehicle).

The hospital will not contact the DVLA, but it is your responsibility to do so and your doctor will advise you how on to do this.

This section has been compiled using information from a number of reliable sources, including:

• Oxford Textbook of Oncology (2nd edition). Souhami et al. Oxford University Press, 2002.
• Cancer and Its Management (4th edition). Souhami and Tobias. Oxford Blackwell Scientific Publications, 2003.
• Cancer in the Nervous System (2nd edition). Levin. Oxford University Press, 2002.

For further references, please see the general bibliography.