Medulloblastoma Treatment

Medulloblastoma is an aggressive brain tumor. It is one of the most common cancerous brain tumors in childhood. Medulloblastoma accounts for about 20% of all childhood malignant brain tumors. The tumor can spread to other parts of the central nervous system (brain and the spinal cord).

The brain tumor program at St. Jude Children’s Research Hospital specializes in treatments for medulloblastoma. We are a world leader in the management of this disease.

Find out more about medulloblastoma on the Together by St. Jude™ online resource.
 

Medulloblastoma types

Studies from St. Jude and other institutions have found that medulloblastoma can be divided into molecular groups and subgroups. This is important because knowing the grouping allows us to determine the best treatment for your child.

So, molecular testing must be done to get the correct diagnosis and determine the best treatment.

Molecular groups

The molecular groups of medulloblastoma are:

• Medulloblastoma, WNT activated
• Medulloblastoma, Sonic Hedgehog (SHH) activated
• Medulloblastoma, non-WNT/non-SHH
  • Medulloblastoma group 3
  • Medulloblastoma, group 4

Histologic groups

You may also find in pathology reports that medulloblastoma is described histologically (by how the tumor looks under the microscope). While this grouping may be helpful, it is incomplete without molecular testing.

The following are the histologic groups and how they associate with the molecular groups:

• Medulloblastoma classic: Medulloblastomas with classic histology mostly belong to WNT and group 4 categories, but some group 3 and SHH tumors may have classic histology.
• Medulloblastoma large cell anaplastic: Medulloblastomas with large cell or anaplastic histology mostly belong to the group 3 and SHH activated tumors.
• Medulloblastoma desmoplastic nodular: Medulloblastomas with true desmoplastic nodular histology are almost always SHH activated.
• Medulloblastoma with extensive nodularity: Medulloblastomas with true extensive nodularity histology are almost always SHH activated.

Recently, these types have been further divided into the following subgroups:

• Medulloblastoma, WNT activated
  • (no subgroups)
• Medulloblastoma, SHH activated
  • SHH-1
  • SHH-2
  • SHH-3
  • SHH-4
• Medulloblastoma, non-WNT/non-SHH
  • G3/G4- I
  • G3/G4-II
  • G3/G4-III
  • G3/G4-IV
  • G3/G4-V
  • G3/G4-VI
  • G3/G4-VII
  • G3/G4-VIII

Treatment of medulloblastoma

Treatment of medulloblastoma includes surgery, chemotherapy, and in most cases radiation therapy.

• Surgery removes part or all of the tumor tissue. This takes out cancerous tissue and helps determine the type of tumor.
• Chemotherapy (chemo) is important in the treatment of these tumors. The exact type of chemotherapy and the length of treatment will depend on your child’s age and type of tumor.
• Radiation: The dose, location, and timing of radiation will depend on many factors. These include your child’s age, type of tumor, and if it has spread to other parts of the brain or spine.

At St. Jude, the treatment of medulloblastoma differs by the:

• Molecular group and subgroup
• Extent of its spread at the time of diagnosis (metastatic state)
• Age at diagnosis

Our goal is to give each child the most effective therapy to cure their tumor while sparing them unnecessary treatment to improve their long-term quality of life. As a result, our treatments use less chemotherapy and radiation therapy than most other treatment centers. We also use the latest technology, such as advanced molecular testing and proton therapy.

Infants and young children

Infants with medulloblastoma are a special group. They are defined as any child who is younger than 3 years old when diagnosed.

Most medulloblastomas in this age group belong to 2 molecular groups: SHH-activated (75%) and group 3 (20%), with the remaining 5% being group 4.

Because the brains of infants are still developing, radiation to the brain may cause long-term problems with thinking and learning skills. Our strategy is to avoid or minimize radiation in these children when possible. So, infants with SHH-activated medulloblastoma (SHH-1 and SHH-2) do not receive radiation to the brain.

The remaining 25%, who have group 3 (G3) and group 4 (G4) medulloblastoma, have a more aggressive disease. We have found this disease to be incurable without radiation.

Children with G3 or G4 get a radiation-delaying strategy. It uses chemotherapy to reduce and control the disease until they are older than 3 years. These patients are reassessed at age 3 for proton-beam treatment to their brain and spine. Children with minimal to no visible disease get reduced doses of radiation. In this way, we give as little radiation as possible to children who need it.

Children older than 36 months (3 years)

Most medulloblastomas are diagnosed in children older than 3 into adulthood. Like the infants, these patients are treated at St. Jude based on their molecular group and how far the disease has spread.

All patients receive surgery, radiation to the brain and spine, and chemotherapy. But the doses of radiation and the number of chemotherapy courses depend on the molecular group of medulloblastoma.

St. Jude is a leader in the treatment of certain molecular groups, such as WNT-activated medulloblastoma. We reduce the dose of therapy to these tumors because they have a better prognosis and are more likely to be cured without a lot of side effects.

For other more aggressive molecular groups, such as group 3, we also lead the way in adding new therapies to help improve prognosis.

All medulloblastoma patients get supportive care that includes physical therapy, speech therapy, occupational therapy, and neurocognitive therapy. Our goal is to maximize their recovery and minimize the side effects of therapy.

Medulloblastoma clinical trials

St. Jude clinical trials were the first to introduce treatment of medulloblastoma by the tumor’s molecular type. This continues today.

We offer clinical trials and research studies for children, teens, and young adults with medulloblastoma. Learn more about clinical research at St. Jude.

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