What causes brain tumours?
The cause of most benign brain tumours and primary malignant brain tumours is not known. Genetic factors may be a 'risk factor' in some cases - perhaps in about 5% of cases. For example, people with the hereditary diseases called neurofibromatosis type 1, Turcot syndrome, Li-Fraumeni cancer syndrome, and tuberous sclerosis have a higher than average risk of developing a glioma. In most of these cases, the glioma occurs in childhood or early adult life and do not account for most cases of glioma. Most cases of glioma occur in older adults where genetic factors are not thought to be involved.
Radiotherapy to the brain is thought to increase the risk of a brain tumour. But again, this would only account for a small minority of cases.
Secondary ('metastatic') brain tumours arise from various cancers of the body. These have various causes. See the separate leaflets about these other cancers.
What are the symptoms of a brain tumour?
General symptoms
Common early symptoms are headaches and feeling sick. These are due to increased pressure within the skull (raised intracranial pressure). These symptoms may come and go at first, and tend to be worse in the morning. Coughing, sneezing and stooping may make the headaches worse. Epileptic seizures (convulsions) sometimes occur. But note: most people who have epilepsy do not have a brain tumour. Increasing drowsiness may occur as the tumour enlarges.
Symptoms due to the location in the brain
As a tumour grows it can damage the nearby brain tissue. The functions of the different parts of the body are controlled by different parts of the brain. Therefore, the symptoms vary from case to case depending on which part of the brain is affected, and on the size of the affected area. For example, one or more of the following may develop. These symptoms tend to develop gradually.醫(yī)學(xué)全在線www.med126.com
How are brain tumours diagnosed and assessed?
A doctor will examine you if a brain tumour is suspected from the symptoms. This will include checking on the functions of the brain and nerves (movements, reflexes, vision, etc).
An MRI scan or CT scan of the head are the common tests done to confirm or rule out the presence of a brain tumour. (See separate leaflets called 'MRI Scan' and 'CT scan'). If a tumour is identified, further more detailed scans and tests may be done. For example, a PET scan or an angiogram are sometimes done to get more information about the tumour.
A biopsy may be needed to be sure of the type of tumour. A biopsy is when a small sample of tissue is removed from a part of the body. The sample is then examined under the microscope to look for abnormal cells. To obtain a biopsy from a brain tumour you need to have a small operation usually done under anaesthetic. A small hole is bored in the skull to allow a fine needle through to obtain a small sample of tissue. By examining the cells obtained by the biopsy, the exact type of tumour can be identified, and if it is malignant, to determine what grade it is (see above).
Blood tests and other tests on other parts of the body may be done if the tumour is thought to be a secondary tumour. For example, it is quite common for a lung cancer to spread to the brain. Therefore, a chest x-ray may be done if this is suspected.
Various hormone tests may be done if a pituitary tumour is suspected.
What are the treatments for brain tumours?
The main treatments used for brain tumours are surgery, chemotherapy, radiotherapy, and medication to control symptoms such as seizures. The treatment or combination of treatments advised in each case depends on various factors such as:
Surgery
Surgery is often the main treatment for benign brain tumours and primary malignant tumours. The aim of surgery is to remove the tumour whilst doing as little damage to the normal brain tissue. Your specialist will advise on whether surgery is a possible option.
Radiotherapy
Radiotherapy is a treatment which uses high energy beams of radiation which are focused on cancerous tissue. This kills cancer cells, or stops cancer cells from multiplying. (There is a separate leaflet which gives more details about radiotherapy.) Radiotherapy is sometimes used instead of surgery when an operation is not possible for a malignant brain tumour. Sometimes it is used in addition to surgery if it is not possible to remove all the tumour with surgery, or to kill cancerous cells which may be left behind following surgery.
Chemotherapy
Chemotherapy is a treatment which uses anti-cancer drugs to kill cancer cells, or to stop them from multiplying. (There is a separate leaflet which gives more details about chemotherapy.) It may be used in addition to other treatments such as surgery or radiotherapy, again, depending on various factors such as the type of tumour.
Medication to control symptoms
If you have seizures caused by the tumour then anticonvulsant medication will usually control the seizures. Painkillers may be needed to ease headache. Steroid medication is also commonly used to reduce inflammation around a brain tumour. This reduces the pressure inside the skull which helps to ease headaches, nausea and other 'pressure' symptoms.
You should have a full discussion with a specialist who knows your case. They will be able to give the pros and cons, likely success rate, possible side-effects, and other details about the possible treatment options for your type of brain tumour.
You should also discuss with your specialist the aims of treatment. For example:
What is the prognosis (outlook)?
It is difficult to give an overall outlook. Every case is different. For example, if you have a benign meningioma which is in a suitable place for surgery, the outlook is excellent. For primary malignant brain tumours, the outlook is variable, depending on the type, grade, and location in the brain. The outlook is usually poor if you have a secondary malignant brain tumour.
The treatment of cancer is a developing area of medicine. New treatments continue to be developed and the information on outlook above is very general. The specialist who knows your case can give more accurate information about your particular outlook, and how well your type and stage of cancer is likely to respond to treatment.
