Definition: what is a neuroblastoma?

Neuroblastoma is a malignant tumor developing from the cells giving rise to the sympathetic nervous system. These cells, which should normally be present in the embryonic stage in the fetus and then develop with growth, remain in an immature state, probably because they are genetically dysregulated. Contrary to what one might think, neuroblastoma is not a brain tumor. Tumors develop in the adrenal gland, paravertebral sympathetic ganglion chains and abdominal parasympathetic ganglia.

Neuroblastoma in children

The disease is detected before the age of 5 in 90% of cases. It is much rarer beyond that. “Most common tumor in young children neuroblastoma accounts for about 8% of all childhood cancers. In high-risk forms, it is a tumor that has a poor prognosis, and which is responsible for 15% of deaths in pediatric oncologywhich makes it one of the major causes of death in children under 4 years of age.“, says Dr. Fabienne Gumy Pause, pediatric oncologist at the University Hospitals of Geneva.

Neuroblastoma in adults

Neuroblastoma is extremely rare adulthood.

What are the symptoms of neuroblastoma?

The symptoms are very variable and will depend on the location of the tumour:

• On the stomach: abdominal pain, a hard and swollen belly.
• At chest level: the tumor can compress the airways and cause breathing difficulties.
• At the neck: swelling, presence of a mass.
• In bones and bone marrow: bone pain, fever, weight loss, fatigue.
• Leg weakness, difficulty walking.

“In an uncommon but classic form of neuroblastoma, the tumor can infiltrate the foramen (passage between the vertebrae) and enter the spinal canal, which can compress the spinal cord. We then speak of hourglass tumor“which may be responsible for neurological disorders, adds the pediatric oncologist.

What causes neuroblastoma?

The origin of neuroblastoma is not clearly determined. “We know that there are genetic variants likely to promote its appearance. In 1 to 2%, it is a family form, in which we find mutations in the ALK or PHOX2B genes. These are mutations in cells throughout the patient’s body that can be passed down from generation to generation“, explains the specialist.

What are the stages?

• Stage 1: Neuroblastoma is located and can be operated easily.
• Stages 2 and 3: stage locoregional.
• Stage 4: metastatic form.
• Stage 4S : metastatic form of the small child but favorable prognosis.

How is neuroblastoma diagnosed?

Often, parents consult the doctor because the child has a big belly, discomfort, fatigue. The diagnosis is primarily based on clinical examination and imaging which will make it possible to detect the presence of a tumour. A biopsy will then be performed to confirm the diagnosis and determine the aggressiveness of the tumour.

What are the treatments for neuroblastoma?

In intermediate forms, chemotherapy is indicated.

The therapeutic strategy varies according to several criteria: the stage of the neuroblastoma, the age of the patient, the histology of the tumor and any genetic abnormalities. These elements make it possible to classify the tumor in a risk group: low risk, intermediate risk or high risk. “In the most favorable cases, an operation allows total recovery. In the intermediate forms, chemotherapy is indicated. The most unfavorable forms will require the deployment of the entire therapeutic arsenal: chemotherapy, surgery, radiotherapy and high-dose chemotherapy coupled with autologous stem cell transplantationthat is, it is a marrow transplant with the patient’s marrow. At the end of these very heavy treatments, so-called maintenance treatments are prescribed, with antibodies against neuroblasts (immunotherapy). These so-called high-risk forms generally affect children over 18 months and are immediately considered extremely aggressive. Most of the time, they are metastatic with localized metastases in bone or bone marrow. This treatment lasts about a year and a half“informs Dr. Fabienne Gumy Pause.

What is the prognosis and chances of recovery from neuroblastoma?

For neonatal and localized forms, the cure rate is 90%. About the the most severe forms, it is 50% and the risks of having sequels are many. Neuroblastoma is a disease that remains mysterious, research continues.

Thanks to Dr Fabienne Gumy Pause, pediatric oncologist at the University Hospitals of Geneva.