Posted Date: Jul 3, 2008
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.
The risk of developing visual pathway gliomas is increased in children with a genetic disorder called neurofibromatosis type 1 (NF-1). NF-1 is a rare genetic condition that causes brown spots and tumors on the skin, freckling in skin areas not exposed to the sun, tumors on the nerves, and developmental changes in the nervous system, muscles, bone, and skin. Children with NF-1 who develop visual pathway gliomas may have a good chance of recovery and may not require treatment until symptoms appear or change.
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 Tumors Treatment for more information).
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. See the PDQ® summary on Childhood Brain and Spinal Cord Tumors Treatment Overview for more information about the types of childhood brain tumors.
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.
There is no staging for childhood visual pathway glioma. The treatment depends on:
Different types of treatment are available for children with visual pathway glioma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.
Because cancer in children is rare, taking part in a clinical trial should be considered. Some clinical trials are open only to patients who have not started treatment
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). Because radiation therapy can affect growth and brain development, clinical trials are testing ways to decrease or delay radiation therapy, especially for younger children. These include internal radiation therapy, in which radiation is put into the brain through thin plastic tubes, and hyperfractionated radiation therapy, in which radiation therapy is given in several small doses per day instead of all at once. Conformal radiation therapy uses a computer to create a 3-D picture of the tumor and the radiation beams are shaped to fit the tumor; this helps to keep the radiation away from healthy tissue as much as possible.
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.
Some brain tumors and cancer treatments cause side effects that continue or appear years after cancer treatment has ended. These are called late effects. Late effects of cancer treatment may include physical problems; changes in mood, feelings, thinking, learning or memory; and having second cancers (new types of cancer). Some late effects may be treated or controlled. It is important to talk with your child's doctors about the possible late effects caused by some treatments. Refer to the PDQ® summary on Late Effects of Treatment for Childhood Cancer for more information.
For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.
Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.
Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.
Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.
Clinical trials are taking place in many parts of the country. In the following lists of treatments for the different stages, a link to search results for current clinical trials is included for each section. These have been retrieved from NCI's clinical trials database. For some types or stages of cancer, there may not be any trials listed. Check with your child's doctor for clinical trials that are not listed here but may be right for your child.
Check for U.S. clinical trials from NCI's PDQ® Cancer Clinical Trials Registry that are now accepting patients with untreated childhood visual pathway glioma. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.
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.
Check for U.S. clinical trials from NCI's PDQ® Cancer Clinical Trials Registry that are now accepting patients with recurrent childhood visual pathway glioma. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.
For more information from the National Cancer Institute about childhood brain tumors, see the following:
For more childhood cancer information and other general cancer resources from the National Cancer Institute, see the following:
For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 a.m. to 4:30 p.m. A trained Cancer Information Specialist is available to answer your questions.
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Editorial changes were made to this summary.
PDQ® is a comprehensive cancer database available on NCI's Web site.
PDQ® is the National Cancer Institute's (NCI's) comprehensive cancer information database. Most of the information contained in PDQ® is available online at NCI's Web site. PDQ® is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research.
PDQ® contains cancer information summaries.
The PDQ® database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries are available in two versions. The health professional versions provide detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions provide current and accurate cancer information.
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PDQ® also contains information on clinical trials.
A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." In the United States, about two-thirds of children with cancer are treated in a clinical trial at some point in their illness.
Listings of clinical trials are included in PDQ® and are available online at NCI's Web site. Descriptions of the trials are available in health professional and patient versions. For additional help in locating a childhood cancer clinical trial, call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).
The PDQ® database contains listings of groups specializing in clinical trials.
The Children's Oncology Group (COG) is the major group that organizes clinical trials for childhood cancers in the United States. Information about contacting COG is available on the NCI Web site or from the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).