Can Brain Stem Glioma Be Cured?

A brain stem glioma, tumors which usually affect children, is not curable. Treatment can send this cancer into remission, however, meaning tests show no evidence of the disease. It’s nearly impossible to tell if a few cancer cells remain after treatment, so the potential for a second bout with the disease is always present, even after successful treatment.

A glioma is a type of tumor that occurs when cells in the glia, the supportive tissue of the brain, grow out of control. The glia helps keep neurons in place and functioning properly. Brain stem glioma usually refers to gliomas located in the brainstem. 

There are three types of glial cells that can produce tumors: 

• Astrocytes
• Oligodendrocytes
• Ependymal cells
• Mixed gliomas display a mixture of these cells 

Most brain stem gliomas tend to be astrocytomas, which can act differently depending on the part of the brainstem in which they occur. Gliomas that develop in the midbrain and medulla (the top and bottom segments of the brainstem) are usually low grade (grade I) tumors while those that occur in the pons (the mid-portion of the brainstem) are usually high grade (grade IV) tumors that grow much faster and progress more rapidly. 

Brain stem gliomas usually occur in children, accounting for 11% of primary brain tumors in children and adolescents. 

Symptoms of brain stem glioma can develop quickly, over the course of days or weeks because the tumors grow so rapidly. Normal brainstem function can be affected and can result in symptoms such as:

• Abnormal eye movements
• Weakness of one side of the face
• Numbness or weakness of the extremities
• Balance problems
• Headaches
• Nausea

The cause of brain stem glioma is unknown. 

A risk factor for developing brain stem glioma includes a rare genetic condition called neurofibromatosis type 1 (NF1).

Brain stem glioma is diagnosed with a physical exam and patient history. Other exams and tests used to diagnose brain stem glioma include: 

• Neurological exam
  • Mental status
  • Coordination
  • Ability to walk normally
  • How well the muscles, senses, and reflexes work
• Magnetic resonance imaging (MRI) with gadolinium
• Computerized tomography (CT) scan
• Biopsy 

Treatments for brain stem gliomas include one or more of the following: 

• Surgery
  • Grade I brain stem gliomas are usually treated with surgery, or surgery plus radiation therapy
  • If the tumor can be completely removed, brain stem glioma may be cured at this stage in some cases
  • However, most of the time, brain stem gliomas are grade II-IV and grow rapidly, and they cannot be cured. The rapid growth of these tumors can impact critical brainstem functions and often surgery to remove the tumor is not possible. 
• Radiation therapy
  • The most effective and most common first-line treatment
  • May also be combined with chemotherapy
• Chemotherapy
  • Usually used to treat tumor re-growth, either using standard agents or experimental drugs
  • Participation in a clinical research study that includes new experimental drugs may be suggested