High-grade gliomas are malignant (cancerous) tumors that form in your child’s brain or spinal cord. They grow quickly and spread rapidly throughout the central nervous system. There’s no cure for these tumors. Surgery, radiation and targeted therapies can slow tumor growth and help ease symptoms.
A high-grade glioma (pronounced “glee-OH-ma”) is a fast-growing cancer that affects your child’s brain or spinal cord. A glioma is a mass of cells, or a tumor, that forms when glial cells grow out of control. Glial cells support neurons, or nerves, in the central nervous system. A glioma that’s considered “high-grade” spreads quickly.
High-grade gliomas may not always be curable. They’re challenging to treat because they grow rapidly into the brain or spinal cord. The cancer cells can invade between the healthy cells. This can make it difficult to remove the cancer without damaging the healthy tissue. Healthy cells and cancer cells become quickly bound together. As a result, gliomas may be hard to remove with surgery without damaging healthy tissue.
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The World Health Organization (WHO) classifies gliomas as low grade (Grades 1 and 2) and high grade (Grades 3 and 4). High-grade gliomas grow faster than low-grade gliomas.
Adults may have gliomas that start as low grade and then progress to high grade. In contrast, high-grade gliomas in children usually start as high-grade. Low-grade gliomas in children are treatable and rarely progress to high grade.
Most high-grade gliomas form in the supratentorial compartment in the brain or in the brainstem.
The tumor’s location is important because it will shape your child’s treatment options. For instance, tumors in the brainstem often can’t be safely removed through surgery.
Infants, children, adolescents and adults can get high-grade gliomas. But high-grade gliomas in infants and young children are different from those occurring in adolescents and adults. These differences mean that treatments differ in infants and young children.
High-grade gliomas are the second most common type of malignant (cancerous) brain tumor in children. About 10% to 20% of childhood tumors affecting the central nervous system are high-grade gliomas.
Symptoms vary depending on the part of your child’s brain or spinal cord affected, their age and how quickly the tumor grows. Symptoms result from increased pressure and swelling from the tumor.
The most common symptom of a high-grade glioma is a headache, especially alongside other symptoms like nausea or vomiting. These headaches may feel particularly intense in the morning. Sometimes, they’re so severe that they wake your child from sleep.
Other symptoms include:
Infants with a high-grade glioma may become unusually fussy or irritable. You may notice changes in their eating habits. Their heads may grow larger, and the soft spots on the top of their head (one in the front and one in the back) may visibly bulge.
Researchers aren’t sure what causes high-grade gliomas. In adults, previous radiation therapy is a factor that may raise the risk of getting a high-grade glioma. These same external or environmental risk factors may exist for children. More research is needed to be sure.
Certain rare inherited genetic syndromes may increase the risk of children developing a high-grade glioma. A genetic condition involves an abnormality or error in the genes, the code that tells cells how to work correctly.
These conditions include:
Still, most children with high-grade gliomas don’t have a family history of them.
Your child’s healthcare provider will review their symptoms and medical history. A brain scan, or imaging study, can show whether a tumor may be causing symptoms. A biopsy can show if a tumor is malignant (cancerous) or benign (noncancerous).
If possible, your provider may remove the entire tumor instead of taking a sample so that treatment (surgery) happens as part of the diagnosis.
Biopsies aren’t always possible with high-grade gliomas. Depending on the tumor’s location, removing a tissue sample may risk damaging essential parts of the brain, like the brainstem. If a biopsy isn’t an option, your child’s healthcare provider will rely on imaging for a diagnosis.
It depends. Various factors play a role, including your child’s age, the type of gene changes in the cancer cells and how much of the tumor can be removed.
Treatments may involve removing the tumor, slowing its growth and helping ease symptoms.
Depending on the type of tumor, its location and other factors, many specialists may be involved in your child’s care. Their care team may include a neurosurgeon, a neuro-oncologist, a radiation oncologist, an endocrinologist, a nurse practitioner and a social worker, among others.
Treatments may include any of the following:
High-grade gliomas often return (recur) following treatment. In that case, your provider may offer targeted therapies that target the abnormal molecules (caused by the genetic mutation) found in your child’s tumor. These molecular targeted therapies may be available through clinical trials. A clinical trial is a study that tests the safety and effectiveness of new treatments.
Your physician may be able to provide targeted therapy drugs outside of a clinical trial if they’re available in the market or if past testing has shown them to be effective against the type of glioma your child has.
Talk to your provider about the potential side effects of various treatments. Your child’s provider will take care to spare healthy tissue during radiation treatment. Still, some tissue will likely be affected. Depending on which parts of the brain are impacted, radiation therapy can affect brain function, cause developmental disorders and disrupt hormone production.
Weigh the potential benefits of treatment against the risks with your child’s care team.
Your child’s prognosis depends on many factors that their healthcare provider can discuss with you. Outcomes depend on the type of cells affected, cell characteristics, how much of the tumor your child’s provider is able to remove during surgery, etc.
Ask about what your expectations should be based on your child’s unique situation.
These tumors usually return after treatment. The five-year survival rate for high-grade gliomas in children is less than 20%. Still, these tumors are highly variable. They form in different places, and they contain cells with different characteristics. These differences will shape your child’s prognosis.
A note from Cleveland Clinic
Receiving a high-grade glioma diagnosis is difficult. The cancer spreads quickly, and tumors often recur after treatment. You may have to weigh the benefits of treatment frequently against potential side effects that you’d rather not have your child experience.
Take advantage of every available resource to help you, your child and your family during this time. Talk with your healthcare provider about treatment options, including clinical trials. Connect with palliative care resources if they’re available. Reassure your child that they’ll have constant support as you face this diagnosis together.
Last reviewed by a Cleveland Clinic medical professional on 10/05/2022.
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