CHILDHOOD BRAIN TUMOURS

What is childhood brain tumour?

Childhood brain tumours are a diverse group of diseases characterized by the abnormal growth of tissue contained within the skull. Brain tumours can be benign (without cancer cells) or malignant (contains cancer cells). The brain controls vital functions such as memory and learning, the senses (hearing, sight, smell, taste, and touch), and emotion. It also controls other parts of the body, including muscles, organs, and blood vessels. Other than leukaemia and lymphoma, brain tumours are the most common type of cancer that occurs in children.

This treatment information summary refers only to tumours that originate in the brain (primary brain tumours). Metastatic brain tumours, which are secondary tumours formed by cancer cells that begin in other parts of the body and spread to the brain, are not included. Brain tumours can occur in both children and adults; however, treatment may be different for adults than for children.

If your child has symptoms that may be caused by a brain tumour, his or her doctor may order a computed tomographic (CT) scan, a diagnostic test that uses computers and x-rays to create pictures of the body. A magnetic resonance imaging (MRI) scan, a diagnostic test similar to a CT scan but which uses magnetic waves instead of x-rays, may also be performed.

Often, surgery is required to determine whether a brain tumour exists and what type of tumour it is. A small sample of tumour tissue may be surgically removed and examined under a microscope. This is called a biopsy. Sometimes a biopsy is done by making a small hole in the skull and using a needle to extract a sample of the tumour.

There are many types of brain tumours that occur in children. Treatment and chance of recovery (prognosis) depend on the type of tumour, its location within the brain, the extent to which it has spread, and your child's age and general health.

Grading of childhood brain tumour

Once childhood brain tumour is detected, additional tests will be performed to determine the type of tumour. If a biopsy specimen is taken, the tumour cells will be examined carefully under a microscope to see how different they appear from normal cells. This will determine the grade of the tumour. The grade of a tumour is determined by microscopic examination of its cells to see how similar the cells are to normal cells. Cells from higher-grade, more abnormal-looking tumours usually grow faster and are more malignant than cells from lower-grade tumours. Your child's doctor needs to know the type and grade of tumour in order to plan treatment.

There is no staging for childhood brain tumours. Brain tumours are grouped according to their location within the brain and the appearance and behaviour of the tumour tissue.

Recurrent brain tumour

Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may recur in its original location, in another part of the central nervous system, or systemically (throughout the body).

Treatment Option Overview

There are treatments for all children with brain tumours. Three kinds of treatment are used:

• Surgery (removing the tumour in an operation)
• Radiation therapy (using high-dose x-rays to kill tumour cells)
• Chemotherapy (using drugs to kill tumour cells)

More than one method of treatment may be used, depending on the needs of the patient.

Experienced doctors working together may provide the best treatment for children with brain tumours. Your child's treatment will often be coordinated by a paediatric oncologist, a doctor who specializes in cancer in children. The paediatric oncologist may refer your child to other specialists, such as a paediatric neurosurgeon (a specialist in childhood brain surgery), a paediatric neurologist, a psychologist, a radiation oncologist, and other doctors who specialize in the type of treatment your child requires.

Treatment options often depend on the type of tumour and its location within the brain. Complete or near complete removal of the tumour is often possible. If the tumour cannot be completely removed, radiation therapy and/or chemotherapy may also be given.

Radiation therapy uses high-energy radiation from x-rays and other sources to kill cancer cells and shrink tumours. Radiation therapy for childhood brain tumours usually comes from a machine outside the body (external radiation therapy). For some types of brain tumours, clinical trials are evaluating radiation therapy given in several small doses per day (hyperfractionated radiation therapy). Since radiation therapy can affect growth and brain development, other clinical trials are testing ways to decrease or delay radiation therapy, especially for younger children who have not yet achieved full growth.

Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy drugs may be taken by mouth or injected into a vein (intravenous) or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells throughout the body. Chemotherapy is being studied in clinical trials as a means of delaying, modifying or eliminating the need for radiation therapy in younger patients, as well as for use prior to or during radiation therapy.

Treatment for childhood brain tumour depends on the type and grade of the tumour, its location within the brain, and your child's age and overall health.