Frequently Asked Questions
Find answers to the most common questions about medulloblastoma
What is medulloblastoma?
Medulloblastoma is a malignant brain tumor that primarily affects children, accounting for approximately 20% of brain tumors in this age group. It develops in the cerebellum, the part of the brain responsible for balance, movement, and coordination. This tumor grows rapidly and can spread through the central nervous system, although it rarely affects other parts of the body. It is usually diagnosed within the first five years of life.
Medulloblastoma is a rare cancer, with about 5 cases per million annually in children, mostly between 1 and 9 years old. About 75% of cases occur before the age of 10. Due to its rarity, funding for research is often more challenging compared to more common diseases.
What are the symptoms of medulloblastoma?
Symptoms of medulloblastoma arise as the tumor grows or increases pressure in the brain and may include:
- Difficulty walking, maintaining balance, or performing precise movements.
- Headache, nausea, vomiting, blurred or double vision, drowsiness, confusion, seizures, and fainting.
- Weakness or numbness in arms and legs, bladder or bowel problems, and back pain.
- Rarely, when the tumor spreads to other parts of the body, symptoms like cough, chest pain, shortness of breath, swollen lymph nodes, and bone pain may occur.
Symptoms vary depending on the tumor's location.
What are the types of medulloblastoma?
Medulloblastomas are classified into four main groups based on molecular and genetic characteristics, which help define prognosis and treatment:
WNT Group: The least common (11% of cases) and with the best prognosis, achieving a 90% survival rate at 5 years. Usually affects children aged 6-10 years.
SHH Group: Accounts for 25% of cases, commonly seen in children under 3 years and adolescents aged 16 or older. It is associated with mutations in the Sonic Hedgehog pathway.
Group 3: The most aggressive, with a 50% survival rate, occurs in 25% of cases and often affects children aged 3-5 years.
Group 4: The most frequent (35% of cases) with a good prognosis, though recurrences are severe. Affects boys more commonly.
This classification is critical for guiding research and personalized treatments.
How is medulloblastoma diagnosed?
Diagnosing medulloblastoma involves medical evaluation and specific tests to identify the tumor:
Neurological exam: Tests vision, hearing, balance, coordination, and reflexes to identify affected brain areas.
Imaging tests: MRI and CT scans reveal the tumor's size, location, and possible blockages in cerebrospinal fluid.
Lumbar puncture: Collects spinal fluid to detect tumor cells (performed after controlling intracranial pressure).
Tissue sampling: Rarely used, involves taking a tumor sample for laboratory analysis.
These tests confirm the diagnosis and help plan treatment.
What is the prognosis (chance of recovery) for medulloblastoma?
The prognosis of medulloblastoma depends on factors such as tumor type, stage, extent of removal, patient age, and treatment response:
- The cure rate can reach 70-80% in children and 50-60% in adults.
- Five-year survival is approximately 80%, though recurrences reduce this to below 40%.
- Tumors of the WNT type have the best prognosis, while Groups 3 and 4 are more challenging.
Early diagnosis and appropriate treatments improve prognosis.
What are the treatments for medulloblastoma?
Medulloblastoma treatment typically combines surgery, radiation therapy, and chemotherapy, tailored to tumor type and stage:
Surgery: Removes the tumor and may involve procedures to relieve brain pressure caused by fluid accumulation.
Radiation therapy: Uses X-rays or proton beams to destroy cancer cells, with proton therapy offering precision to minimize damage to healthy tissues.
Chemotherapy: Medications administered intravenously to eliminate tumor cells, often combined with radiation or following surgery.
Can treatments for medulloblastoma cause long-term effects?
Medulloblastoma treatments, including surgery, radiation, and chemotherapy, can lead to long-term side effects such as cognitive difficulties, hormonal imbalances, and social challenges, particularly in children. These may require ongoing support.
Are there advances in treating pediatric medulloblastoma?
Yes, clinical trials with new drugs offer potential treatment options for medulloblastoma. These trials recruit eligible participants to study novel therapies like immunotherapy or alternative combinations and durations of radiation and chemotherapy. While these trials provide access to cutting-edge treatments, the risks of side effects are not fully understood.
What does the future of pediatric medulloblastoma treatment look like?
The future includes advancements in clinical trials, novel therapies, and intensive research:
Clinical trials: Explore new treatments like immunotherapy, innovative chemo-radiotherapy combinations, and personalized approaches.
Group 4 research: Led by the MBI, global efforts are underway to cure Group 4 medulloblastomas, supported by 14 international laboratories. Recent discoveries have unveiled tumor development mechanisms.
FDA-approved treatments:
- MATCHPOINT: Combines immunotherapy with drugs to overcome tumor defenses.
- mRNA vaccine: Personalized using patient cells and nanotechnology to trigger an immune response against the tumor.
More clinical trials are planned for 2024-2025, expanding cure possibilities and less aggressive treatments.
