Medulloblastoma is a fast-growing, high-grade tumor. The various types of medulloblastoma include:
- classic medulloblastoma
- desmoplastic nodular medulloblastoma
- large-cell or anaplastic medulloblastoma
- medulloblastoma with neuroblastic or neuronal differentiation
- medulloblastoma with glial differentiation
- melanotic medulloblastoma
Medulloblastoma is always located in the cerebellum—the lower, rear portion of the brain. It is unusual for medulloblastomas to spread outside the brain and spinal cord.
Medulloblastoma is a fast-growing, high-grade tumor. It is the most common of the embryonal tumors—tumors that arise from “emybryonal” or “immature” cells at the earliest stage of their development.
The most common symptoms of medulloblastoma include behavioral changes, changes in appetite, symptoms of increased pressure on the brain (eg, headache, nausea, vomiting, and drowsiness, as well as problems with coordination). Unusual eye movements may also occur.
Medulloblastoma is relatively rare, accounting for less than 2% of all primary brain tumors and 18% of all pediatric brain tumors. More than 70% of all pediatric medulloblastomas are diagnosed in children under age 10. Very few occur in children up to age 1.
Medulloblastoma in adults is less common, but it does occur. About one-third of all medulloblastomas diagnosed in the United States are found in adults between the ages of 20-44. The incidence in adults sharply decreases in frequency after age 45, with very few older adults having this tumor. Medulloblastoma occurs more often in men than in women.
Like many tumor types, the exact cause of medulloblastoma is not known. However, scientists are making significant strides in understanding its biology. Changes have been identified in genes and chromosomes (the cell’s DNA blueprints) that may play a role in the development of this tumor. There are also a few rare, genetic health syndromes that are associated with increased risk for developing this tumor.
Treatment consists of surgical removal of as much tumor as possible, radiation, and then chemotherapy (in older children and adults).
New approaches to treatment are currently in development. These new therapies are offered in organized research studies called clinical trials via TrialConnect®, the ABTA's clinical trial match service.
How well a patient responds to treatment is affected by the age they are at the time of diagnosis, the size and extent of the tumor, the amount of mass that can be removed safely, and the level of metastatic disease.
Overall, the Central Brain Tumor Registry of the United States reports about 57%-60% of adults (age 20+) with medulloblastoma are alive at five years following diagnosis, and 44% at 10 years. It is important to realize these statistics do not reflect the differences in outcome between low risk and high risk groups (since high risk groups may not do as well), differences in patient characteristics, nor differences in patient responses to treatment. And "10 year survival" means the patients were followed for only 10 years; we do not know how well they did beyond that length of time.
With current therapies, 70% - 80% of children with average-risk medulloblastoma can be expected to be alive and free of disease five years from diagnosis. Even in those children with high-risk disease, effective therapy is possible and results in long-term disease control in as high as 60% - 65% of patients. Outcome for infants is poorer, but for those infants with localized disease at the time of diagnosis, survival rates in the 30% - 50% range are being seen.
Take time to speak with your healthcare team to learn how these statistics apply to your individual situation.