Neuroblastoma

Other Names: NB

Neuroblastoma is a tumor that develops from neuroblasts (immature nerve tissue) in an infant or child, usually before the age of 5. It most often develops in infancy and may be diagnosed in the first month of life. The tumor most often develops in the adrenal gland, but may develop in the neck, chest, or spinal cord. It is considered an aggressive tumor because it often spreads to other parts of the body (metastasizes).

Microscopic view of stroma-rich ganglioneuroblastoma

Cause

The cause of most neuroblastomas is not known. Rarely, a neuroblastoma is caused by an inherited mutation in a gene, such as the ALK gene or PHOX2B gene. Sporadic neuroblastoma: Somatic mutations are present only in certain cells and are not inherited. When neuroblastoma is associated with somatic mutations, it is called sporadic neuroblastoma.

Familial neuroblastoma: Less commonly, gene mutations that increase the risk of developing cancer can be inherited from a parent. When the mutation associated with neuroblastoma is inherited, the condition is called familial neuroblastoma.Mutations in the ALK and PHOX2B genes have been shown to increase the risk of developing sporadic and familial neuroblastoma. It is likely that there are other genes involved in the formation of neuroblastoma. The ALK gene provides instructions for making a protein called ALK receptor tyrosine kinase. Although the specific function of this protein is unknown, it appears to play an important role in cell proliferation. Mutations in the ALK gene result in an abnormal version of ALK receptor tyrosine kinase that is constantly turned on (constitutively activated). Constitutively active ALK receptor tyrosine kinase may induce abnormal proliferation of immature nerve cells and lead to neuroblastoma.

Several mutations in the PHOX2B gene have been identified in sporadic and familial neuroblastoma. The PHOX2B gene is important for the formation and differentiation of nerve cells. Mutations in this gene are believed to interfere with the PHOX2B protein's role in promoting nerve cell differentiation. This disruption of differentiation results in an excess of immature nerve cells and leads to neuroblastoma.

Deletion of certain regions of chromosome 1 and chromosome 11 are associated with neuroblastoma.

Another genetic change found in neuroblastoma is associated with the severity of the disease but not thought to cause it. About 25 percent of people with neuroblastoma have extra copies of the MYCN gene, a phenomenon called gene amplification. It is unknown how amplification of this gene contributes to the aggressive nature of neuroblastoma.

Inheritance

Most people with neuroblastoma have sporadic neuroblastoma, meaning the condition arose from somatic mutations in the body's cells and was not inherited.

About 1 to 2 percent of affected individuals have familial neuroblastoma. This form of the condition has an autosomal dominant inheritance pattern, which means one copy of the altered gene in each cell increases the risk of developing the disorder. However, the inheritance is considered to have incomplete penetrance because not everyone who inherits the altered gene from a parent develops neuroblastoma.

Epidemiology

Neuroblastoma is the most common cancer in infants younger than 1 year. It occurs in 1 in 100,000 children and is diagnosed in about 650 children each year in the United States.

Diagnosis

Diagnosing a neuroblastoma may rely on a physical examination, blood tests, imaging tests (such as MRI or CT scan) and ultimately, a biopsy.

Treatment

Treatment depends on the size and location of the tumor within the body, as well as the child’s age. Surgery is often the first step of treatment, and may be followed by chemotherapy, radiation therapy, or a stem cell transplant in more severe cases. In some children the tumor goes away without treatment. The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition.

• Iobenguane I 123 (Brand name: Adreview™)To be used in the detection of primary or metastatic pheochromocytomas or neuroblastomas as an adjunct to other diagnostic tests
• dinutuximab (Brand name: Unituxin) For use in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-2 (IL-2) and 13-cis-retinoic acid (RA), for the treatment of pediatric patients with high-risk neuroblastoma who achieve at least a partial response to prior first-line multiagent, multimodality therapy.

Prognosis

While the long-term outlook and chance of survival depends on many factors, the 5-year survival rate ranges from 40-50% in some, to over 95% in others. The child's doctor is in the best position to provide personalized information about the outlook in each case.

NIH genetic and rare disease info

• NIH info on Neuroblastoma

Neuroblastoma is a rare disease.

Neuroblastoma Resources
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