Low-grade glioma

What is a low-grade glioma?

Gliomas are a type of brain or spine tumor formed from glial cells. Glial cells are non-neuronal cells or non-nerve cells in the central nervous system (CNS). There are four different types of glial cells: astrocytes, oligodendrocytes, microglia and ependymal cells. These function to support and protect the neurons or “nerves” in the brain. They support the nerves by providing structure (like scaffolding) to grow on, supply food and oxygen, and remove dead cells and cellular debris. Rarely, these cells can go wrong and grow into gliomas.

Once diagnosed, a glioma is graded based on how abnormal the cells appear and how quickly they are growing or dividing. Grade I or grade II gliomas are considered low-grade gliomas. These tumors are typically slow growing and less likely to spread (metastasize) but can cause many problems and need medical treatment.

Just as there are different types of glial cells, there are different types of low-grade gliomas. The name of the tumor generally refers to the type of glial cell it originates from. For example, the most common pediatric low-grade glioma is an astrocytoma, which comes from astrocytes.

Gliomas can form in several different areas of the brain and spine including:

• Cerebellum – area that coordinates movement, balance and posture
• Cerebrum – area that controls thinking, speech, emotions, reading, writing, problem-solving and movement
• Brainstem – area that controls breathing, heart rate, facial movements, eye movements, swallowing and many other functions
• Hypothalamus – area that controls body temperature, thirst and hunger
• Visual pathway – area that controls a group of nerves that connects the eyes to the brain
• Optic nerve – nerve that controls vision
• Spinal cord – cluster of nerves and glial cells that connects the nerves of the body with the brain.

How common is low-grade glioma?

Pediatric low-grade gliomas are the most common central nervous system (CNS) tumor in children. They make up 30% of all childhood CNS tumors.

What are the symptoms of a low-grade glioma?

The symptoms related to low-grade gliomas can vary based on the size of the tumor as well as where it is in the brain. The child’s age and how fast the tumor grows can also dictate the symptoms experienced. Symptoms may include:

• Vision, hearing or speech problems
• Headaches, especially in the early morning
• Loss of balance or trouble walking
• Weakness, tingling or changes of feeling on one side
• Nausea and vomiting
• Unexplained weight gain or loss
• Seizures
• Changes in personality or behavior
• Increased head size (in infants)

How is low-grade glioma treated?

•   Surgery – is used to both treat and diagnose low-grade gliomas.
  • A biopsy is a surgery performed to get a piece of the tumor in order to diagnose the tumor by type and grade.
  • A resection is a surgery performed to get most or all the tumor removed.
  • For many low-grade gliomas, surgery is curative if the tumor is completely removed.
  • If very little tumor remains after surgery, the patient can be closely followed with an MRI.

• Chemotherapy (“chemo”) – is a medicine given after surgery to kill cancer cells or stop them from growing and dividing. This treatment is given by mouth or as an injection into the blood stream. If more than one type of chemo is given at a time, it is known as combination therapy. Examples of chemotherapy commonly used in low grade gliomas are vincristine, carboplatin, vinblastine and lomustine.

• Targeted Therapy – is a more specialized kind of chemotherapy that is designed to “target” or attack a specific marker in the tumor. This marker is the change in the cancer cell that makes it unique from healthy cells. This therapy can keep cancer cells from growing or repairing and can tell the cancer cell to destroy itself. Targeted therapy is usually given by mouth.  Examples of targeted therapy for low-grade gliomas are selumetinib, trametinib, mirdametinib and everolimus. 
• Radiation Therapy – uses high-energy X-rays or other types of radiation, such as proton beam, to kill cancer cells or stop them from growing. The way the radiation is given depends on the type of tumor, disease risk and where the tumor is in the brain or spinal cord.

Your medical team, often made up of an oncologist, surgeon and radiation oncologist, can discuss the types of therapy with you and decide on the best option for your child.

What are the survival rates for low-grade glioma?

Survival rates for low-grade gliomas in children are very good, with 10-year survival rate exceeding 85. Individual results vary widely based on the following factors:

• The specific type, location and grade of the glioma
• If the tumor has been totally resected
• If the tumor is localized to one area or has spread
• The age of the child when diagnosed
• Whether the tumor is newly diagnosed or has returned (recurred)

Why choose St. Jude for your child’s low-grade glioma treatment?

• St. Jude is the only National Cancer Institute-designated Comprehensive Cancer Center devoted solely to children.
• St. Jude has created more clinical trials for cancer than any other children’s hospital in the United States.
• The St. Jude Brain Tumor Program is one of the largest in the country filled with expert doctors from many medical fields. These include pediatric neurosurgeons from Le Bonheur Children’s Hospital who operate on the brain, skull and spinal cord; pediatric neuro-oncologists who study and treat cancer in the brain and nervous system; and radiation oncologists, who are experienced in using state of the art proton beam radiation therapy. This diverse knowledge is vital to the complete care of children with brain tumors.
• In addition, our brain tumor program is supported by specialized staff in nursing, rehabilitation services, neuropathology, pharmacy, neuroradiology, neuropsychology, ophthalmology, clinical nutrition, child life and social work, along with many others. All staff members have been specially trained to care for children with brain tumors.
• St. Jude is committed to not only finding cures but also helping children with their quality of life. Children are not just small people. Their bodies and systems are unique, along with the disorders that affect them. For the best care, they need a specialized team. This is what you get from the St. Jude Brain Tumor Program.
• St. Jude practices patient family-centered care. Patient family-centered care focuses on the family as a child’s primary source of strength, support and well being.
• St. Jude is the only institution in the country to offer in-house clinical genomic testing, including whole genome sequencing of tumors, as a part of routine clinical care for patients. The results are used by our doctors to identify personalized treatment plans for each of our patients.