What is neuroblastoma?

Neuroblastoma is a form of cancer that develops from embryonic nerve cells originating in the neural crest, known as neuroblasts. The neural crest is an embryonic structure that contributes to the formation of the peripheral sympathetic nervous system. This system includes the sympathetic ganglia—clusters of nerve cells aligned along the spinal column—as well as part of the adrenal gland. The sympathetic nervous system regulates automatic functions such as sweating and stress responses.

During embryonic development, the normal maturation process of neuroblasts can sometimes be interrupted. When this occurs, immature neuroblasts may multiply uncontrollably, giving rise to a tumor called neuroblastoma. 
It is the second most common solid tumor in children¹, with 130 to 150 new cases diagnosed each year in France (Neuroblastoma, InCA 2021). It primarily affects very young children: the average age at diagnosis is approximatively 18 months, and 90% of cases occur before the age of five.
Neuroblastomas are classified into low-, intermediate-, and high-risk groups, based on age at diagnosis (around 18 months), extent of disease (localized, metastatic...), or molecular features of the tumor.

Risk factors for neuroblastoma

For most patients, no risk factors have been formally identified. However, rare cases are linked to a familial predisposition or the pre-existence of another disease. One to 2% of neuroblastomas develop in the context of family history, known from data collected on the occurrence of a cancer in the immediate family.

Neuroblastoma can sometimes be associated with other disorders, such as Hirschsprung's disease (congenital disorder of the terminal part of the intestine), neurofibromatosis type 1 (neurocutaneous disease of the peripheral nerves and skin), Ondine syndrome (characterized by insufficient shallow breathing), Beckwith-Wiedemann syndrome (associated with fetal overgrowth and congenital malformations), DiGeorge syndrome (causing facial and cardiac malformations).

[1] Neuroblastomas InCA, 2021.