What Are High Grade Gliomas?

High-grade gliomas are tumors of the glial cells, cells found in the brain and spinal cord. They are called “high-grade” because the tumors are fast-growing and they spread quickly through brain tissue, which makes them hard to treat. The tumors occur in children of all ages, from infants to adults.

High-grade gliomas are rare and account for 8-12% of all childhood brain tumors. They occur equally in boys and girls.

High-grade gliomas are classified by their location and by how they appear when examined under a microscope. Classifying the tumor helps determine how the disease will progress and helps identify the best treatment for it. Although the outlook for high-grade gliomas is generally poor, some children can be cured.

Causes

Sometimes, high doses of radiation therapy can cause high-grade gliomas, but the reason for most high-grade gliomas in children is not known. Although doctors continue their research to understand what causes the tumors to occur, so far there have been few reliable findings. Genetic causes are rare, and these tumors are not believed to be linked to anything in the environment.

Symptoms

The symptoms of a brain tumor often depend on where it is located. One of the most common signs of high-grade gliomas is headaches, particularly headaches that wake children up in the morning and are associated with vomiting. High-grade gliomas can also cause seizures or cause young children to miss developmental milestones. Sometimes, tumors can cause problems with vision, hearing, or speech, or troubles with balance.

These symptoms can also be related to other health conditions, so if your child displays any of these, it is important to have a thorough medical exam.

Diagnosis

The first step in diagnosing a brain tumor is usually to take an image of the brain and / or spine using an MRI or CT scan. These tests can help show that a tumor is present. But, to definitely diagnose a high-grade glioma, a biopsy is required. In a biopsy, doctors examine a small sample of the tumor tissue. This helps determine the specific type of tumor and can help detect the presence of certain biological “markers” in the tumor. These markers may be used to help determine treatment.

Treatment

The primary treatment for high-grade gliomas is to perform surgery to remove the tumor. Surgery is performed only when it can be done safely, without causing additional damage to the brain. Some types of tumors, such as diffuse midline gliomas, cannot be removed due to their location in delicate and crucial areas of the brain.

In addition to surgery, most children will also receive radiation therapy and / or chemotherapy, depending on their age and type of tumor. When tumors continue to grow even after chemotherapy and radiation, clinical trials may be considered.

Outlook

Current treatments for high-grade gliomas will cure some children, but many tumors continue to grow despite our best therapies.

Research is underway to better understand these tumors in order to develop more effective therapies. At Cincinnati Children’s, our researchers have also been able to develop laboratory models of high-grade glioma tumors in order to study their biology. They use these models to design and test different ways to treat the tumors. The goal is to move new treatments as rapidly and safely as possible from the laboratory into clinical studies that will help patients.