|
What is childhood visual pathway glioma?
Childhood visual pathway glioma is a type of brain tumor in which cancer
(malignant) cells begin to grow in the tissues of the brain. The brain controls
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 leukemia or lymphoma, brain tumors are the most
common type of cancer that occurs in children.
Gliomas are a type of astrocytoma, tumors that start in brain cells called
astrocytes. A visual pathway glioma occurs along the nerve that sends messages
from the eye to the brain (the optic nerve). Visual pathway gliomas are visual
pathway tumors. They may grow rapidly or slowly, depending on the grade of the
tumor.
This PDQ summary covers tumors that start in the brain (primary brain
tumors). Often cancer found in the brain has started somewhere else in the body
and has spread (metastasized) to the brain. This is called brain metastasis
(refer to the PDQ summary on Adult Brain Tumor Treatment for more informaiton).
Like most cancer, childhood brain tumor is best treated when it is found
(diagnosed) early. If your child has symptoms, the doctor may order a computed
tomographic (CT) scan, a special x-ray that uses a computer to make a picture of
your child's brain. A magnetic resonance imaging (MRI) scan, which uses magnetic
waves to make a picture of your child's brain, may also be done.
Often, surgery is required to see whether there is a brain tumor and to tell
what type of tumor it is. The doctor may cut out a piece of tissue from the
brain and look at it under a microscope. This is called a biopsy.
There are many types of brain tumors in children and the chance of recovery
(prognosis) depends on the type of tumor, where it is located within the brain,
and your child's age and general health.
Stage information
Once childhood visual pathway glioma is found, more tests will be done to
find out the type of tumor. If a biopsy specimen is taken, the cancer cells will
be looked at carefully under a microscope to see how different they are from the
normal cells. This will determine the histologic grade of the tumor. Your
child's doctor needs to know the type and grade of tumor in order to plan
treatment.
There is no staging for childhood visual pathway glioma. The treatment
depends on whether or not your child has received treatment.
Untreated childhood visual pathway glioma
Untreated childhood visual pathway glioma means that no treatment has been given
except to treat symptoms.
Recurrent visual pathway glioma
Recurrent disease means that the cancer has come back (recurred) after it has
been treated. It may come back in the brain or in the head or spinal area.
Treatment option overview
There are treatments for all children with visual pathway gliomas. Three
kinds of treatment are used:
- surgery (taking out the cancer in an operation)
- radiation therapy (using high-dose x-rays to kill cancer cells)
- chemotherapy (using drugs to kill cancer cells).
Experienced doctors working together can often give the best treatment for
children with visual pathway glioma. Your child's treatment will often be
coordinated by a pediatric oncologist, a doctor who specializes in cancer in
children. The pediatric oncologist may refer you to other doctors, such as a
pediatric neurosurgeon (a specialist in childhood brain surgery), a pediatric
neurologist, a psychologist, a radiation oncologist, and other doctors who
specialize in the type of treatment your child requires.
Surgery is one treatment for visual pathway glioma. Depending on where the
cancer is and the type of cancer, your child's doctor may remove as much of the
tumor as possible. If the tumor cannot be totally removed, radiation therapy and
chemotherapy may also be given. If the cancer is in a place where it cannot be
removed, surgery may be limited to a biopsy of the cancer.
Radiation therapy uses high-energy x-rays to kill cancer cells and shrink
tumors. Radiation therapy for childhood brain tumors usually comes from a
machine outside the body (external radiation therapy). The use of radiation put
into the brain through thin plastic tubes (internal radiation therapy) is under
study. For some types of brain tumors, clinical trials are evaluating radiation
therapy given in several small doses per day (hyperfractionated radiation
therapy). Radiation therapy can affect growth and brain development, so clinical
trials are testing ways to decrease or delay radiation therapy, especially for
younger children.
Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by
pill, or it may be put into the body by a needle in a vein 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 to delay the use of radiation therapy in
some patients. Clinical trials are studying different chemotherapy drugs for
visual pathway gliomas.
Treatment by type
Treatment for childhood visual pathway glioma depends on the type and stage of
the disease and your child's age and overall health.
Your child may receive treatment that is considered standard based on its
effectiveness in a number of patients in past studies, or you may choose to have
your child go into a clinical trial. Not all patients are cured with standard
therapy and some standard treatments may have more side effects than are
desired. For these reasons, clinical trials are designed to test new treatments
and to find better ways to treat cancer patients. Clinical trials are going on
in most parts of the country for childhood visual pathway glioma. If you want
more information, call the Cancer Information Service at 1-800-4-CANCER
(1-800-422-6237); TTY at 1-800-332-8615.
Untreated childhood visual pathway glioma
Your child's treatment may be one of the following:
For patients without symptoms or progression, observation without
treatment.
Surgery.
Radiation therapy.
Chemotherapy.
Clinical trials evaluating chemotherapy to shrink the tumor and delay
radiation therapy.
Recurrent childhood visual pathway glioma
Treatment for recurrent disease depends on the type of tumor, whether the
tumor comes back in the same place or in another part of the brain, and the
treatment that was given before.
If possible, the tumor may be removed during surgery. Radiation therapy may
be given, especially if it was not given before. Chemotherapy may be used, and
clinical trials are evaluating new chemotherapy drugs. You may wish to consider
having your child treated with new methods on a clinical trial.
Source: National Institutes of Health; National
Cancer Institute
|
