Brain stem glioma

Brain stem glioma is a type of brain tumour in children that starts in the brain stem. They often grow in the middle of the brain stem and are hard to remove with surgery. Most brain stem gliomas are pontine gliomas, which start in the part of the brain stem called the pons.

There are 2 main types of gliomas that occur in children.

Diffuse brain stem glioma is the most common. It often spreads throughout the brain stem. These tumours often start in the pons and are called diffuse intrinsic pontine glioma (DIPG). They tend to be high-grade tumours and are very aggressive. DIPG is hard to treat and has a poor prognosis. If this tumour comes back after treatment, it is called recurrent diffuse brain stem glioma.

Focal brain stem glioma occurs in one area or is contained within a small part of the brain stem. It is usually benign or low grade, and it is less aggressive than diffuse brain stem glioma. Focal brain stem glioma is easier to treat and has a better prognosis than DIPG. If this tumour comes back after treatment, it is called recurrent focal brain stem glioma.

The healthcare team will suggest treatments based on your child's needs and work with you to develop a treatment plan. Treatments for brain stem gliomas depend on:

• the type of glioma
• the grade of the tumour
• the location of the tumour
• how far the tumour has grown or spread
• if the tumour can be surgically removed (is resectable)
• your child's age, neurological condition and general health

Diffuse brain stem gliomas are most commonly treated with radiation therapy because most of these tumours cannot be removed with surgery. In some cases, targeted therapy will be offered after radiation therapy. Diffuse intrinsic pontine glioma (DIPG) is not a single tumour and it spreads throughout the brain stem. Surgery is not usually recommended for most DIPGs because it would be too dangerous and would likely do more harm than good. To help plan treatment, a biopsy is often done to test for gene mutations that are sensitive to certain targeted therapy drugs.

Recurrent diffuse brain stem glioma has no standard treatment. Doctors suggest enrolling your child in a clinical trial.

Focal brain stem glioma that is growing slowly may not need treatment right away unless the tumour causes problems. If treatment is needed, doctors will try to remove as much of the tumour as possible. Radiation therapy, chemotherapy, targeted therapy or combination of may be used after surgery. If surgery is not possible, radiation therapy, chemotherapy, targeted therapy, or a combination of may be used to treat the tumour.

Recurrent focal brain stem glioma may be treated with surgery, radiation therapy or chemotherapy. A combination of these treatments may also be used.

Radiation therapy uses high-energy rays or particles to destroy cancer cells.

External radiation therapy is the most common treatment used for diffuse brain stem gliomas because most of these tumours can't be removed with surgery. Radiation is directed to the area immediately surrounding the tumour and sometimes to the whole brain.

For focal brain stem gliomas, radiation therapy is usually given after surgery. It may also be given as the main treatment, with or without chemotherapy, if surgery cannot be done. External or internal radiation therapy may be used for focal brain stem gliomas.

In children younger than 3 years of age, radiation can damage developing brain cells. In these cases, doctors will try to delay giving radiation until the child is older. Radiation therapy is also generally not used to treat children with neurofibromatosis type 1 (NF1) as their tumours respond better to other treatments.

Find out more about radiation therapy for childhood brain and spinal cord tumours.

Chemotherapy uses drugs to destroy cancer cells. Chemotherapy may be given as part of the treatment for both focal and diffuse brain stem gliomas. It may be given along with radiation therapy to make radiation therapy more effective. Children younger than 3 years of age may be treated with chemotherapy to delay giving radiation therapy until they are older.

The chemotherapy drugs that are usually used first to treat brain stem gliomas include:

• temozolomide (Temodal)
• lomustine (CeeNU, CCNU)
• carboplatin
• vincristine

Find out more about chemotherapy for childhood brain and spinal cord tumours.

Targeted therapy uses drugs to target specific molecules (such as proteins) on cancer cells or inside them to stop the growth and spread of cancer. Targeted therapy is sometimes used to treat brain stem gliomas.

Targeted therapy drugs that may be used to treat brain stem gliomas include:

• bevacizumab (Avastin and biosimilars)
• dabrafenib (Tafinlar)
• trametinib (Mekinist)

Find out more about targeted therapy for childhood brain and spinal cord tumours.

Surgery is usually not possible for diffuse brain stem gliomas because they are hard to remove.

Surgery may be used for focal brain stem gliomas that can be easily reached. The goal is to remove as much of the tumour as possible. If the doctor can remove all of the tumour, no further treatment may be needed. Radiation therapy, chemotherapy or both may be used after surgery. If surgery is not possible, radiation therapy, chemotherapy or both may be used to treat the tumour. Surgery may also be used to place a shunt to drain extra fluid from the brain.

Find out more about surgery for childhood brain and spinal cord tumours.

Children with cancer may be treated in a clinical trial. Clinical trials look at new ways to prevent, find and treat cancer. Find out more about clinical trials.