Astrocytoma is the name given to a type of brain tumour deriving from a star-shaped cell called an astrocyte. They can occur in most parts of the brain and, more rarely, the spinal cord. The most common place, however, is the cerebrum (the main part of the brain). The chances of developing an astrocytoma increase with age and around 4,500 new cases are diagnosed in the UK each year.
Astrocytomas can be classified into four grades, depending on their severity; grade I being the lowest and least serious, and grade IV being the most severe. Low-grade (I and II) tumours usually have a slow growth rate and are less likely to spread than the higher grades. Many can be fully removed with a good chance of not regrowing. The higher grades of tumour, sometimes known as 'anaplastic astrocytoma' (grade III) and 'glioblastoma multiforme' (grade IV) can be more difficult to treat. There is a much higher chance of growth and spreading to other parts of the brain as well as of recurrence after removal. Astrocytomas vary in size from 1-2cm3 to over 400cm3, and size is not necessarily linked with tumour grade; even a low-grade tumour can grow to a large size if it is not treated.
Symptoms and Diagnosis
Symptoms will vary greatly from person to person due to the part of the brain affected by the tumour. For instance, a tumour in the frontal lobe of the brain may cause mood and personality changes, while a tumour in the temporal lobe may lead to difficulties with speech and co-ordination. Other more general side effects, mainly due to raised intracranial pressure caused by the tumour, include headaches, nausea/vomiting, seizures and visual problems.
A number of tests need to be performed by a specialist to make a clear diagnosis. These will often include a neurological exam to assess the effects the tumour is having on the nervous system, and a computed tomography (CT) or magnetic resonance imaging (MRI) scan to build up a picture of the brain. If the scans show that surgical removal of the tumour is not possible, a sample of the tumour ('biopsy') may be taken to help determine the best treatment. During the biopsy procedure, which is usually carried out under general anaesthetic, a small hole is drilled in the skull and a fine needle used to obtain a tiny sample of the tumour. The needle can be guided by CT so that healthy brain tissue is not damaged.
The results of the tests and investigations detailed above will help the specialist decide the best course of treatment. This will depend on factors including the patient's general health and the grade, size and position of the tumour. At this stage the specialist should also clearly explain the risks of treatment to the patient. Steroid drugs may also be given to reduce any swelling in the brain before treatment begins.
Low-grade astrocytomas are often treated by surgically removing (excising) the entire tumour, as these tumours are usually localised and can be removed without damaging healthy brain structures. If it is too difficult to remove all of the tumour, as much as possible will be removed (known as 'debulking'). For example, a tumour that has been growing for a long time may have begun to wrap around major blood vessels, making complete removal too dangerous. High-grade astrocytomas are particularly difficult to remove completely, as they are likely to have invaded nearby tissue, making it difficult for the surgeon to identify the edges of the tumour.
The surgery usually involves opening the skull under a general anaesthetic and cutting away or 'resecting' the tumour. In some cases the operation may be performed under local anaesthetic with the patient awake throughout. After-care and recovery from surgery can be quite traumatic, with long standing side effects including epilepsy and limb weakness, even partial paralysis. With modern surgical techniques, however, including guidance from CT or MRI scans, damage to healthy brain tissue and subsequent complications can be minimised.
After surgery, or as an alternative to surgery in inoperable cases, radiotherapy is usually carried out to kill any remaining tumour cells. Chemotherapy may also be provided, particularly for high-grade astrocytomas.
The outlook for patients with astrocytoma varies greatly from case to case, but sadly many are terminal, with a large percentage of patients dying in the first five years after diagnosis. Support from family, friends and professional counselling are invaluable. Much more research is needed into these, and all other types of brain tumour, as very little research has been carried out to date, mainly due to lack of funding. Organisations that are trying to raise funds for research at present, as well as offering support to families and patients, include Brain Tumour UK and Astro-Fund. In addition, The Richard Burns Foundation was set up with the aim of 'inspiring and supporting active people whose lives are affected by serious illness and injury'. This is in memory of the former World Rally Champion, who died in 2005 after being diagnosed with astrocytoma. Hopefully we will soon understand more, and be better able to treat these life-destroying afflictions.