Behind the Tumor: Medulloblastoma

April 10, 2024

Medulloblastoma is a cancerous brain tumor that starts near the brainstem in the cerebellum. The tumor is fast growing and can spread to other areas of your brain and spinal cord. Medulloblastoma is more common in children than adults. 

Population

While medulloblastoma is rare, it is the most common pediatric malignant (cancerous) brain tumor. Approximately 20% of childhood brain tumors are medulloblastomas. According to the American Cancer Society, about 500 children are diagnosed with medulloblastoma each year in the United States. There are four known subtypes of childhood medulloblastoma. The exact subtype can impact a patient’s treatment plan in some situations.

In adults, medulloblastoma represents only 1% of all malignant brain tumors. It typically affects younger adults (between 20 and 40 years of age). Only about 200 adults are diagnosed with medulloblastoma each year in the United States. Doctors have identified three subtypes of adult medulloblastoma. As with childhood medulloblastoma, different subtypes may call for different treatment plans.

Symptoms

Medulloblastoma symptoms can vary depending on several factors, including a person’s age, the size of the tumor and the stage of development. These symptoms may be due to the location of the tumor or because of pressure buildup inside their brain. Warning signs may include:

  • Headaches
  • Dizziness
  • Nausea and vomiting
  • Tiredness
  • Balance problems
  • Changes in vision
  • Difficulty walking
  • Back pain
  • Urinary or bowel incontinence

Causes

The exact cause of medulloblastoma is unknown. But there are certain genetic conditions that could increase your or your child’s risk for developing the condition, including:

  • BRCA1 gene mutations. BRCA1 (breast cancer gene 1) and BRCA2 (breast cancer gene 2) produce proteins to help repair damaged DNA. People who inherit certain variants of these genes have increased risks for many different types of cancer. These individuals are also more likely to develop cancer at a younger age.
  • Nevoid basal cell carcinoma syndrome (NBCCS). Also called Gorlin syndrome, this hereditary condition is characterized by several basal cell skin cancers. People with NBCCS have about a 5% chance of developing medulloblastoma.
  • Turcot syndrome. This hereditary condition is described as colorectal (colon) cancer with primary brain tumors. It’s caused by gene mutations. People with Turcot syndrome have colorectal cancer along with a tumor in their central nervous system, such as a medulloblastoma or pituitary adenoma.

Treatments

  • Surgery to remove the astrocytoma. A brain surgeon, also called a neurosurgeon, works to remove as much of the astrocytoma as possible. The goal is to remove all of the tumor. Sometimes the tumor is in a spot that is hard to reach. It may be too risky to remove it all. Even so, removing some of the astrocytoma may lower your symptoms. For some people, surgery may be the only treatment needed. For others, more treatments may be recommended to kill any remaining tumor cells and lower the risk of the tumor coming back.
  • Radiation therapy. Radiation therapy uses powerful energy beams to kill tumor cells. The energy can come from X-rays, protons and other sources. During radiation therapy, you lie on a table while a machine moves around you. The machine sends beams to exact points in your brain. The treatment only takes a few minutes. Radiation therapy might be used after surgery. It can be used if the cancer wasn’t removed completely or if there’s a higher risk the cancer will return. Radiation may be used with chemotherapy for cancers that grow quickly. For people who can’t have surgery, radiation therapy and chemotherapy may be used as the main treatment.
  • Chemotherapy. Chemotherapy uses strong medicines to kill tumor cells. Chemotherapy medicines can be taken in pill form or injected into a vein. Sometimes, a circular wafer of chemotherapy medicine can be put in your brain after surgery. There, it slowly dissolves and releases the medicine. Chemotherapy is often used after surgery to kill any tumor cells that might remain. It can be used with radiation therapy for tumors that grow quickly.
  • Clinical trials. Clinical trials are studies of new treatments. These studies offer a chance to try the latest treatment options. The risk of side effects may not be known. Ask a member of your health care team whether you can participate in a clinical trials.
  • Supportive care. Supportive care, also called palliative care, focuses on providing relief from pain and other symptoms of a serious illness. Palliative care specialists work with you, your family and your other health care team members to provide extra support. Palliative care can be used at the same time as other treatments, such as surgery, chemotherapy or radiation therapy. Often, palliative care begins as you start your astrocytoma treatments. You may not need to wait for complications to happen in order to receive palliative care

What questions should I ask my healthcare provider?

A full understanding of your or your child’s diagnosis can help you make an informed decision regarding treatment. Here are some questions to ask your healthcare provider if you or your child has been diagnosed with medulloblastoma:

  • Where is the tumor located?
  • Has the medulloblastoma spread?
  • What treatment do you recommend?
  • Are there clinical studies of new treatments that might improve treatment?
  • Who’ll be leading my medical team?
  • Do you have any literature I can read about medulloblastoma?
  • Who can I talk to if I’m worried about managing the cost of treatment?
  • Is there a local support group I can join?

Sources: Mayo Clinic, Cleveland Clinic, MD Anderson Cancer Center, NCI Connect

A Note from Brains for the Cure:

Discovering a brain tumor can be unsettling and overwhelming. Your healthcare team will create a personalized and comprehensive treatment strategy and enhance your quality of life. For specific questions, consult your healthcare provider.