Neuroblastoma

Medical Experts

Contributor

Bayrak-Toydemir

Pinar Bayrak-Toydemir, MD, PhD, FACMG

Professor of Pathology (Clinical), University of Utah

Medical Director, Molecular Genetics and Genomics, ARUP Laboratories

Contributor

Frank

Elizabeth L. Frank, PhD, DABCC

Professor of Pathology (Clinical), University of Utah

Medical Director, Analytic Biochemistry, Calculi and Manual Chemistry; Co-Medical Director, Mass Spectrometry, ARUP Laboratories

Contributor

Nelson H

Heather Nelson, PhD, DABCC

Assistant Professor (Clinical), University of Utah

Medical Director, Clinical Chemistry and Mass Spectrometry, ARUP Laboratories

Neuroblastomas are solid tumors of the neuroendocrine system and the most common extracranial tumors in infants and children.^,^, Outcomes range from spontaneous regression to aggressive metastatic tumors and potential death.^, Because prompt, appropriate intervention can be lifesaving, accurate diagnosis and prognosis are essential. Measurement of urinary catecholamine metabolites may aid in the diagnosis of neuroblastoma. In addition, genetic testing can be useful to identify relevant pathogenic variants, stratify risk, inform prognosis, and guide treatment.

Quick Answers for Clinicians

When is neuroblastoma suspected?

Neuroblastoma may be suspected in young children or infants who exhibit tumors or masses in the abdomen, chest, spine, pelvis, or neck. There may be associated bladder dysfunction, constipation, pain or weakness in the lower extremities, or symptoms of spinal cord compression. These symptoms can be a result of organ compression. Coagulopathy, anemia, and thrombocytopenia may be noted, as well as dysfunction of the kidneys and lungs from abdominal distention. Metastasis in the skin, which is more common in infants, can cause painless subcutaneous nodules with a blue cast anywhere on the body, and bone lesions in the skull may lead to the characteristic “raccoon eyes” or proptosis with or without periorbital bruising.

Systemic symptoms that may be seen in neuroblastoma include fever and weight loss, flushing, hypertension, and/or tachycardia. Children with opsoclonus myoclonus syndrome (OMS) should be evaluated for neuroblastoma because the condition is diagnosed in a high percentage of these patients.

Which biochemical testing should be ordered to investigate for neuroblastoma, and when should it be performed?

Biochemical testing in children with suspected neuroblastoma includes initial workup with CBC and electrolytes, creatinine, and liver and renal function tests. Tests that are also helpful in specific select cases include prothrombin time/international normalized ratio (INR), ferritin, and lactate dehydrogenase (LDH), which is a marker for cell turnover. Neuron-specific enolase has been shown to correlate with prognosis in late-stage disease. Tests for the urine catecholamine metabolites, homovanillic acid (HVA) and vanillylmandelic acid (VMA), are highly sensitive and specific for neuroblastoma.^,^,

How is biochemical testing used to monitor neuroblastoma?

For intermediate-risk disease, surveillance for recurrence following initial diagnosis and treatment of neuroblastoma includes a CBC with differential (if bone marrow was involved) followed by creatinine and thyroid studies, annually through 3 years posttreatment. High-risk disease should be monitored after completion of initial therapy with CBC, electrolytes, creatinine, alanine aminotransferase (ALT), and bilirubin tests, as well as thyroid studies, at designated intervals for the first 5 years. As well, hemoglobin A1C, ferritin, and reproductive health studies (follicle-stimulating hormone, luteinizing hormone, and anti-Müllerian hormone) should be ordered as clinically indicated. Although urinary catecholamine testing (e.g., homovanillic acid [HVA] and vanillylmandelic acid [VMA]) may provide useful information during posttreatment surveillance, it is no longer included in the standard surveillance recommendations outlined in the National Comprehensive Cancer Network’s (NCCN’s) guidelines for neuroblastoma, which prioritize imaging and clinical assessment.

Which syndromes are associated with neuroblastoma, and how do predisposing syndromic diseases affect testing recommendations?

Several cancer predisposition syndromes have been associated with an increased risk of developing neuroblastomas. These include Costello, Noonan, Li-Fraumeni, ROHHAD (rapid-onset obesity, hypothalamic disfunction, hypoventilation, and autonomic dysfunction), and Beckwith-Wiedemann syndromes; hereditary pheochromocytoma syndrome; hereditary paraganglioma syndrome; and neurofibromatosis type 1. In addition, hereditary neuroblastoma may occur in individuals with germline loss-of-function variants in PHOX2B, a gene also implicated in central hypoventilation syndrome (i.e., Ondine curse). Surveillance testing for neuroblastoma is recommended for select subsets of patients with syndromic or genetic predisposition, based on their specific risk profiles. This may include evaluation of urinary catecholamine metabolites (e.g., homovanillic acid [HVA] and vanillylmandelic acid [VMA]), particularly in syndromes in which these markers are reliable indicators of disease. However, the utility of catecholamine testing varies by syndrome, and alternative or additional imaging-based surveillance may be preferred depending on the underlying genetic mutation.

Indications for Testing

Laboratory testing for neuroblastoma is indicated to:

Aid in the diagnosis of children with abdominal masses, a neuroblastoma-associated syndrome, or other suggestive findings^,
Stratify tumor risk, inform prognosis, and guide treatment^,
Screen individuals with genetic factors that increase the risk of neuroblastoma

Criteria for Diagnosis

A diagnosis of neuroblastoma requires one of the following^,:

Unequivocal pathology results from tumor tissue examination (via light microscopy, with or without immunohistochemistry or electron microscopy)
Bone marrow aspirate or trephine biopsy with unequivocal evidence of tumor cells, as well as elevated concentrations of urinary catecholamine metabolites

Laboratory Testing

Screening and Diagnosis

Although universal screening for neuroblastoma is not recommended, screening may be considered in patients with known genetic predisposition or increased risk for neuroblastoma (e.g., an ALK or PHOX2B variant, a predisposing syndrome, or a strong family history of the condition). When indicated, surveillance typically includes imaging and urinary catecholamine testing every 3 months until 6 years of age, then every 6 months until 10 years of age.

Diagnosis and staging of neuroblastoma require a biopsy and histologic examination. Laboratory testing can be used to support diagnosis when tumor cells are observed and can identify pathogenic variants and genetic aberrations that inform risk stratification and prognosis. Imaging may also play a role in diagnosis and staging.

Biochemical Testing

Testing for neuroblastoma may include measurement of urinary catecholamine metabolites, specifically homovanillic acid (HVA, a dopamine metabolite) and vanillylmandelic acid (VMA, an epinephrine/norepinephrine metabolite).

HVA and VMA, which are sensitive and specific markers for neuroendocrine tumors, are elevated at presentation in most patients with neuroblastoma. Persistent elevations may suggest residual or recurrent disease. Notably, in individuals with Costello syndrome, HVA and VMA concentrations may be independently elevated; further investigation is suggested in the presence of very high or sharply increasing HVA and VMA concentrations.

If bone marrow is the only tissue specimen obtained for testing, measurement of elevated urinary HVA and VMA are required for diagnosis. A random urine collection normalized for urinary creatinine or a 24-hour urine collection may be used for testing. Plasma catecholamine testing is not routinely performed but may be considered in patients for whom urine collection is not possible. Testing may be performed using high-performance liquid chromatography (HPLC) with electrochemical or mass spectrometry detection. Tandem mass spectrometry enables rapid measurement of multiple metabolites at once and calculation of the HVA/VMA ratio, which may have prognostic significance.

Detection of Genetic Variants for Inherited Risk

Several genetic variants are associated with an increased risk of neuroblastoma. A substantial number of familial cases involve variants in the ALK gene. Germline variants in PHOX2B, a gene implicated in congenital central hypoventilation syndrome and Hirschsprung disease, have also been linked to neuroblastoma.^, In very rare cases, deletions at 1p36 or 11q14-23 have been identified in patients with neuroblastoma. Additional syndromes associated with neuroblastoma include Costello, Noonan, Li-Fraumeni, ROHHAD (rapid-onset obesity, hypothalamic dysfunction, hypoventilation, and autonomic dysfunction), and Beckwith-Wiedemann syndromes; hereditary paraganglioma syndrome; and neurofibromatosis type 1.

Single nucleotide polymorphisms (SNPs) in the following genes have been shown to increase the risk of developing neuroblastoma: BARD1, CASC-15, CDKN1B, CPZ, DDX4, DUSP12, HACE1, HSD17B12, IL31RA, KIF15, LIN28B, LMO1, MLF1, MMP20, NBAT-1, NEFL, SPAG16, and TP53.

Both targeted testing for a known familial variant and panel testing are generally available and may be used to confirm hereditary neuroblastoma.

Additional Testing

Additional recommended testing for patients with suspected neuroendocrine tumors includes a CBC with differential and a comprehensive metabolic panel to assess liver and kidney function.^,^, In patients with liver involvement or increased risk of bleeding, a prothrombin time/international normalized ratio (PT/INR) test may be considered. Finally, neuron-specific enolase (a neuroendocrine tumor marker), lactate dehydrogenase (LDH, a marker of cellular turnover),^,^, and ferritin are commonly measured at diagnosis and may have prognostic value.^,^,

Risk Assessment and Prognosis

In patients with neuroblastoma, risk stratification informs prognosis and treatment. High-risk tumors require aggressive intervention, whereas some low-risk tumors may spontaneously regress without treatment.

Risk is stratified according to age, tumor stage (per the International Neuroblastoma Risk Group), histopathologic findings, MYCN status, tumor ploidy, and the presence of segmental chromosomal aberrations (SCAs). Neurotrophin receptor kinase expression, MYC/MYCN protein expression, and sequence variants in ALK and other genes have also been found to correlate with prognosis.

Next Generation Sequencing of Tumor Tissue

Next generation sequencing (NGS) is recommended to simultaneously assess for MYCN amplification, sequence variants in ALK and other relevant genes, and detect SCAs (i.e., cytogenetic abnormalities including losses in 1p, 11q, 3p, or 4p and gains in 17q, 1q, or 2p). NGS may also be used to estimate tumor ploidy.

Alternate Genetic Testing Methods

Testing for prognostic markers can also be performed via fluorescence in situ hybridization (FISH), microarray, and flow cytometry. However, these methods are not suitable to identify sequence variants in ALK and other relevant genes.

Immunohistochemistry

Neurotrophin receptor kinase expression and MYC/MYCN protein expression can be assessed by immunohistochemistry. Neurotrophin receptor kinase expression may be useful in differentiating low- and high-risk tumors. MYC/MYCN protein expression has implications for overall survival rates; high-level expression is reported to have prognostic value independent of other markers.