Causes and Risk Factors for Neuroblastoma
Neuroblastoma is a rare cancer that almost always affects infants and young children, developing from immature nerve cells of the sympathetic nervous system, most often in the adrenal glands. Understanding the neuroblastoma causes and risk factors covered here can help you and your child’s care team watch for early signs and ask informed questions.
Key Takeaways
- Neuroblastoma develops from immature nerve cells of the sympathetic nervous system — most often in the adrenal medulla — and it is almost entirely a cancer of infancy and early childhood.
- Most cases are sporadic, arising from random genetic changes with no known cause; according to MedlinePlus Genetics, only about 1-2% run in families, usually tied to an inherited change in the ALK or PHOX2B gene.
- According to the National Cancer Institute, age is the strongest known risk factor: about 90% of children are diagnosed before age five, with a median age around 17 months.
- No environmental exposure or lifestyle factor during pregnancy or childhood has been consistently linked to neuroblastoma risk.
- MYCN gene amplification, found in about a quarter of tumors, is identified after diagnosis and helps predict how the cancer may behave — it is not a cause parents can watch for beforehand.
What Causes Neuroblastoma?
At its core, neuroblastoma develops through a complex interplay of genetic changes that make neuroblasts — immature nerve cells of the sympathetic nervous system — grow out of control instead of maturing normally. These cells cluster most densely inside the adrenal medulla — the gland’s inner core, seated beneath its outer cortex — which is why most tumors start there, though tumors can also arise from nerve tissue along the spine in the chest, abdomen, pelvis, or neck. This nerve-tissue origin sets neuroblastoma apart from cancers that begin in the adrenal gland’s outer layer, the cortex. The exact trigger for these cellular changes is still under investigation, but genetic change is the consistently identified driver — unlike many adult cancers, neuroblastoma is rarely linked to lifestyle or outside exposures.
Neuroblastoma is fundamentally a biological error during fetal development or early childhood: specific genetic alterations within these neuroblasts start the disease process long before any symptoms appear. Because the underlying change happens this early, no choice you or your child made caused it — the cellular course is largely set before the cancer becomes noticeable.
Genetic Factors in Neuroblastoma
Genetic alterations play a pivotal role in the development of neuroblastoma. These changes fall into two categories: inherited mutations passed down from a parent, and sporadic mutations that occur spontaneously during a child’s development. Both types shape the genetic risk factors for neuroblastoma and influence how and why the disease appears.
Inherited Gene Mutations
In a small percentage of cases, neuroblastoma runs in families because of an inherited gene mutation. Familial neuroblastoma is most often tied to a mutation in the ALK (anaplastic lymphoma kinase) gene — the cause of roughly three-quarters of familial cases — or, less often, the PHOX2B gene, according to MedlinePlus Genetics. Inheriting one of these mutations raises a child’s chance of developing neuroblastoma and can mean the disease appears at a younger age or as more than one tumor, but not every child who carries the mutation goes on to develop cancer. While rare, these inherited mutations underscore why a strong family history matters when assessing your child’s risk.
Sporadic Genetic Changes
About 98% of neuroblastoma cases are sporadic, meaning they are not inherited. These cases arise from genetic changes that occur randomly in neuroblast cells — not from anything a parent did during pregnancy. Researchers have linked sporadic neuroblastoma to changes such as deletions in chromosome 1p, which can disable a tumor-suppressor gene that normally keeps cell growth in check. A related but separate finding, MYCN gene amplification, shows up in about a quarter of tumors; MedlinePlus Genetics notes this change tracks with how aggressively the disease behaves rather than with what causes it, and it is identified through tumor testing after diagnosis, not as an early warning sign. Researchers continue to study these spontaneous changes to understand neuroblastoma at a molecular level.
Identifying Risk Factors for Neuroblastoma
While the exact causes of neuroblastoma are primarily genetic, a few factors are known to raise a child’s likelihood of developing the disease. Identifying these risk factors helps medical professionals and families understand who might be more susceptible, although universal screening is not currently recommended because the disease is so rare.
Age as a Primary Risk Factor
No other factor shapes neuroblastoma risk as much as age. It is diagnosed in the first year of life more often than any other childhood cancer, and how common it is at each age compared with other childhood cancers is covered on this cancer’s dedicated global-statistics page. About 90% of children are diagnosed before age five, and the median age at diagnosis is 17 months, according to the National Cancer Institute. This strong age pattern suggests the disease often originates from developmental errors early in life, when neuroblasts are most abundant and still actively maturing. For your child, age is the factor that matters most when weighing risk.
Family History Considerations
Although most cases are sporadic, a family history of neuroblastoma is a recognized, though rare, risk factor. As noted above, an inherited change in the ALK or PHOX2B gene can predispose a child to the disease. If your child has a sibling or parent who had neuroblastoma — especially if it was diagnosed unusually early or involved tumors in more than one site — genetic counseling can help clarify their risk. Still, according to MedlinePlus Genetics, familial cases are uncommon, representing only about 1-2% of all neuroblastoma diagnoses; for the vast majority of children, there is no family history of the disease, reinforcing that sporadic genetic changes remain the main driver.
Environmental and Lifestyle Connections
The role environment might play in neuroblastoma has been studied, but no definitive link has been established. Unlike many adult cancers, where exposure to certain chemicals, radiation, or habits such as smoking are clear risk factors, neuroblastoma does not appear to be strongly influenced by outside environmental or lifestyle factors. Researchers have looked at parental occupational exposures, maternal diet, infections during pregnancy, and exposure to certain chemicals or pesticides, but the evidence for any of these remains inconclusive.
Large epidemiological studies have not established a clear connection between any specific environmental or outside exposure and a child’s odds of developing neuroblastoma, according to the National Cancer Institute. This doesn’t rule out an environmental contribution entirely, but current evidence points to neuroblastoma arising mainly from intrinsic genetic and developmental errors rather than from something in a child’s surroundings. For parents, this distinction matters: it means there is usually nothing you could have done differently to prevent it, and no specific exposure to search for or blame.
Current Research and Future Insights
Ongoing research continues to deepen understanding of what drives neuroblastoma and its complex origins. Scientists are using advanced genomic sequencing to identify new genetic changes and pathways involved in tumor development, aiming for more accurate diagnostic tools and more personalized treatment strategies. Research into the ALK gene, for example, has already led to targeted therapies now being studied in children and adults with ALK-altered neuroblastoma, showing how genetic research can translate directly into clinical care.
Other studies are exploring how the tissue surrounding a tumor influences its growth, and immunotherapy — harnessing the body’s own immune system against cancer — is a promising area of research for high-risk neuroblastoma. As this knowledge expands, the goal is to improve outcomes while minimizing the long-term effects of treatment, so children affected by this disease can go on to live full lives.
Frequently Asked Questions
What is the primary cause of neuroblastoma?
The primary cause of neuroblastoma is a genetic change within immature nerve cells (neuroblasts) that leads to uncontrolled growth and tumor formation. Most cases involve sporadic, non-inherited changes, while a small percentage are linked to an inherited mutation in the ALK or PHOX2B gene. No environmental factor has been established as a cause, making genetic change — whether sporadic or inherited — the main driver.
Can neuroblastoma be inherited?
Yes, but this is rare — according to MedlinePlus Genetics, inherited (familial) neuroblastoma accounts for only about 1-2% of all cases. In these instances, a child inherits a mutated ALK or PHOX2B gene from a parent, which raises the chance of developing the disease but does not guarantee it. For the vast majority of children with neuroblastoma, the genetic changes happen spontaneously and are not passed down, meaning there is no family history involved.
What age group is most affected by neuroblastoma?
Neuroblastoma predominantly affects infants and young children: according to the National Cancer Institute, about 90% are diagnosed by age five, and the typical age at diagnosis is 17 months. Among babies under one year old, no other cancer type occurs as often. This strong age pattern reflects that the disease usually originates from developmental errors in neuroblasts during early growth.
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