Dramatic improvements in survival have been achieved for children and adolescents with cancer.[1,2] Between 1975 and 2020, childhood cancer mortality decreased by more than 50%.[1-5] Between 1975 and 2020, the 5-year survival rate for patients with neuroblastoma increased, from 86% to 93% for children younger than 1 year and from 34% to 83% for children aged 1 to 14 years.[2,3]
Childhood and adolescent cancer survivors require close monitoring because cancer therapy side effects may persist or develop months or years after treatment. For specific information about the incidence, type, and monitoring of late effects in childhood and adolescent cancer survivors, see Late Effects of Treatment for Childhood Cancer.
Neuroblastoma is the most common extracranial solid tumor in childhood. More than 650 cases are diagnosed each year in the United States.[2,6-8] The prevalence is about 1 case per 7,000 live births. The incidence is 8.3 cases per 1 million per year in children younger than 15 years. The overall incidence of neuroblastoma cases in the United States has remained stable.[9] About 37% of patients are diagnosed as infants, and 90% are younger than 5 years at diagnosis, with a median age at diagnosis of 17 months.[8,10] The data on age at diagnosis show that this is a disease of infancy, with the highest rate of diagnosis in the first month of life.[6,10,11]
Population-based studies (of screening for infants with neuroblastoma) have demonstrated that spontaneous regression of neuroblastoma without clinical detection in the first year of life is at least as prevalent as clinically detected neuroblastoma.[12-14]
The United States Cancer Statistics database and the National Program of Cancer Registries survival database were used to describe epidemiological trends in incidence and outcomes in patients with neuroblastoma between 2003 and 2019. Non-Hispanic White patients have a higher risk of developing neuroblastoma than all other race and ethnicity groups. Compared with non-Hispanic White patients, the relative risks were 0.54 for Hispanic patients, 0.64 for non-Hispanic Asian or Pacific Islander patients, 0.69 for non-Hispanic American Indian and Alaska Native patients, and 0.73 for non-Hispanic Black patients.[9] The 5-year relative survival rates were higher for non-Hispanic White patients (80.7%) and Hispanic patients (80.8%), compared with non-Hispanic Black patients (72.6%).[9]
Findings from epidemiological studies have not unequivocally linked environmental or other exposures to increased or decreased incidences of neuroblastoma.[15]
Neuroblastoma originates in the adrenal medulla and paraspinal or periaortic regions where sympathetic nervous system tissue is present (see Figure 1).
Studies analyzing constitutional DNA in rare cohorts of patients with familial neuroblastoma have provided insight into the complex genetic basis for tumor initiation. About 1% to 2% of patients with neuroblastoma have a family history of the disease. These children are, on average, younger (9 months at diagnosis) than patients without a family history, and about 20% of these patients have multifocal primary neuroblastoma.
Germline variants. Several germline variants have been associated with a genetic predisposition to neuroblastoma, including the following:
Other cancer predisposition syndromes. Children with gene aberrations associated with other cancer predisposition syndromes may be at increased risk of developing neuroblastoma and other malignancies. The following syndromes primarily involve genes in the canonical RAS pathway:
In addition, neuroblastoma has been described in patients with the following syndromes:
With increased availability of sequencing techniques, the spectrum of germline alterations seen in patients with neuroblastoma is expanding. For example, one study identified a series of 11 patients with germline pathogenic variants in SMARCA4.[30] In another study of 786 patients with neuroblastoma, 13.9% had pathogenic or likely pathogenic germline variants in cancer predisposition genes. BARD1, ERCC2, CHEK2, and MSH3 were the genes in which germline pathogenic variants were most commonly observed. Germline pathogenic variants in BARD1, EZH2, ALK, PTCH1, and MSH3 were specifically enriched in patients with neuroblastoma, compared with controls. Patients with these alterations had inferior survival, compared with patients without these alterations.[31] Another study replicated the findings that germline alterations in cancer predisposition genes are associated with inferior outcomes. In addition, the researchers showed that the burden of germline functional variants beyond conventional cancer predisposition genes was also prognostic.[32] For more information about SMARCA4, visit Rhabdoid Tumor Predisposition Syndrome Type 2.
Sporadic neuroblastoma may also have an increased incidence resulting from less potent germline predispositions. Genome-wide association studies have identified several common genomic variants (single nucleotide polymorphisms) with modest effect size that are associated with increased risk of developing neuroblastoma. Most of these genomic risk variants are significantly associated with distinct neuroblastoma phenotypes (i.e., high-risk vs. low-risk disease).[33]
Screening recommendations from the American Association for Cancer Research (AACR) came from the 2016 Childhood Cancer Predisposition Workshop. The AACR recommends that the following individuals undergo biochemical and radiographic surveillance for early detection of tumors in the first 10 years of life:[27]
Surveillance consists of the following:[27]
Surveillance begins at birth or at diagnosis of neuroblastoma predisposition and continues every 3 months until age 6 years, then every 6 months until age 10 years. Patients with Costello syndrome may have elevated urinary catecholamines in the absence of a catecholamine-secreting tumor, so only high or significantly rising levels should prompt investigation beyond ultrasonography and chest x-ray.[35] Patients with Li-Fraumeni syndrome should not undergo chest x-rays.[27]
About 5% of children with Beckwith-Wiedemann syndrome have variants that cause decreased activity of CDKN1C. A review of all large studies of genetically subtyped Beckwith-Wiedemann syndrome found 70 children with the CDKN1C variant, 4.6% of whom developed neuroblastoma. There were no cases of Wilms tumor or hepatoblastoma. There is little experience with screening these children for neuroblastoma, so there are no generally accepted guidelines. However, the authors of the study suggest screening with urinary VMA/HVA every 4 to 6 months. Patients with other genetic subtypes of Beckwith-Wiedemann syndrome have a prevalence of neuroblastoma of less than 1%. No neuroblastic tumors were found among 123 children with the genotype gain of methylation at imprinting control region 1.[36]
Current data do not support neuroblastoma screening in the general public. Screening at the ages of 3 weeks, 6 months, or 1 year did not lead to a reduced incidence of advanced-stage neuroblastoma with unfavorable biological characteristics in older children, nor did it reduce overall mortality from neuroblastoma.[13,14] No public health benefits have been shown from screening infants for neuroblastoma at these ages.
Evidence (against neuroblastoma screening):
The most frequent signs and symptoms of neuroblastoma in children are caused by tumor mass and metastases and include the following:
The clinical presentation of neuroblastoma in adolescents is similar to that in children. The only exception is that bone marrow involvement occurs less frequently in adolescents, and there is a greater frequency of metastases in unusual sites such as lung or brain.[40]
Paraneoplastic neurological findings, including cerebellar ataxia or opsoclonus/myoclonus, occur rarely in children with neuroblastoma.[41] Of young children presenting with opsoclonus/myoclonus syndrome, about one-half are found to have neuroblastoma.[42,43] The incidence in the United Kingdom is estimated at 0.18 cases per 1 million children per year. The average age at diagnosis is 1.5 to 2 years.[44]
The usual presentation is the onset of progressive neurological dysfunction over a few days before a neuroblastoma is discovered. However, on occasion, neurological symptoms arise long after removal of the primary tumor.[42,45,46] Patients with neuroblastoma who present with opsoclonus/myoclonus syndrome often have neuroblastoma with favorable biological features and have excellent survival rates, although tumor-related deaths have been reported.[42]
The opsoclonus/myoclonus syndrome appears to be caused by an immunologic mechanism that is not yet fully characterized.[42] The primary tumor is typically diffusely infiltrated with lymphocytes.[47] Cerebrospinal fluid shows an increased number of B cells, and oligoclonal immunoglobulin bands are often seen. Steroid-responsive elevations of B-cell–related cytokines are also often seen.[48]
Genomic copy number profiles were analyzed in 44 cases of neuroblastoma associated with opsoclonus/myoclonus syndrome. Because there were no tumor relapses or disease-related deaths, the overall genomic profile was not prognostically significant.[49]
Some patients may rapidly respond neurologically to immune interventions or simply to removal of the neuroblastoma, but in many cases, improvement may be slow and partial. While immunological therapy has improved acutely presenting motor deficits and ataxia, its benefit on long-term neuropsychological disability, which primarily consists of cognitive and behavioral deficits, is not clear. The long-term benefits of rapid improvement resulting from treatment, whether of symptoms or of the underlying neuroblastoma, are unclear, but rapid improvement appears to be worthwhile.[46,50]
Treatment with adrenocorticotropic hormones or corticosteroids can be effective for acute symptoms, but some patients do not respond to corticosteroids.[45,51] Other therapy with various immunomodulatory drugs, plasmapheresis, intravenous gamma globulin, and rituximab have been reported to be effective in select cases.[45,52-55] Combination immunosuppressive therapy has been explored, with improved short-term results.[56] The short-term neurological outcomes may be superior in patients treated with chemotherapy, possibly because of its immunosuppressive effects.[41]
The Children’s Oncology Group (COG) completed the first randomized, open-label, phase III study of patients with opsoclonus/myoclonus ataxia syndrome.[57] Patients with newly diagnosed neuroblastoma and opsoclonus/myoclonus ataxia syndrome who were younger than 8 years were randomly assigned to receive either intravenous immunoglobulin (IVIG) or no IVIG in addition to prednisone and risk-adapted treatment of the tumor.[57]
Diagnostic evaluation of neuroblastoma includes the following:
Metaiodobenzylguanidine (MIBG) scanning is a critical part of the standard diagnostic evaluation of neuroblastoma, for both the primary tumor and sites of metastases.[59,60] MIBG scanning is also critical to assess response to therapy.[60] About 90% of neuroblastoma cases are MIBG avid. Fluorine F 18-fludeoxyglucose positron emission tomography (PET) scans are used to evaluate extent of disease in patients with tumors that are not MIBG avid.[61] For more information about imaging of neuroblastoma, see the Evaluation of Primary Tumor and Metastatic Disease section.
In contrast to urine, serum catecholamines are not routinely used in the diagnosis of neuroblastoma except in unusual circumstances.
For patients older than 18 months with stage 4 disease, bone marrow with extensive tumor involvement combined with elevated catecholamine metabolites may be adequate for diagnosis and assigning the risk and treatment group. However, INPC cannot be determined from tumor metastatic to bone marrow. Testing for MYCN amplification may be successfully performed on involved bone marrow if there is at least 30% tumor involvement. However, every attempt should be made to obtain an adequate biopsy from the primary tumor.
For information about the use of biopsy in patients younger than 1 year, see the Observation and Spontaneous Regression of Fetal/Neonatal Neuroblastoma section.
The diagnosis of neuroblastoma requires the involvement of pathologists who are familiar with childhood tumors. Some neuroblastomas cannot be differentiated morphologically, via conventional light microscopy with hematoxylin and eosin staining alone, from other small round blue cell tumors of childhood, such as lymphomas, Ewing sarcoma, and rhabdomyosarcomas. In such cases, immunohistochemical and cytogenetic analysis may be needed to diagnose a specific small round blue cell tumor.
The minimum criterion for a diagnosis of neuroblastoma, as established by international agreement, is that diagnosis must be based on one of the following:[64]
The phenomenon of spontaneous regression has been well described in infants with neuroblastoma, especially in infants with the INSS 4S/INRG MS pattern of metastatic spread.[65] In rare cases, fetal ultrasonography can show suspected neuroblastoma prenatally.[66] Management recommendations are evolving regarding the need for immediate diagnostic biopsy in infants aged 6 months and younger with suspected neuroblastoma tumors that are likely to spontaneously regress. For more information about INSS 4S/INRG MS disease, see the Evaluation of Primary Tumor and Metastatic Disease section.
Spontaneous regression generally occurs in tumors with the following features:[67-69]
Additional features associated with spontaneous regression include the lack of telomerase expression,[67,70] the expression of the H-Ras protein,[71] and the expression of the neurotrophin receptor TrkA, a nerve growth factor receptor.[72]
Studies have suggested that selected infants who appear to have asymptomatic, small, low-stage adrenal neuroblastoma (detected by screening or during prenatal or incidental ultrasonography) often have tumors that spontaneously regress. These patients may be observed safely without surgical intervention or tissue diagnosis.[73-75]
Evidence (observation [spontaneous regression]):
The prognosis for patients with neuroblastoma is related to the following:
Some of these prognostic factors have been combined to create risk groups to help define treatment. For more information, see the sections on International Neuroblastoma Risk Group Staging System (INRGSS) and Children’s Oncology Group (COG) Neuroblastoma Risk Grouping.
The effect of age at diagnosis on 5-year survival is profound. In the COG ANBL00B1 (NCT00904241) study of 4,832 patients with newly diagnosed neuroblastoma, those younger than 18 months had a 5-year EFS rate of 82% and an OS rate of 91%. In comparison, patients aged 18 months or older had a 5-year EFS rate of 64% and an OS rate of 74%.[78]
According to the National Childhood Cancer Registry (NCCR), the 5-year relative survival rates from 2014 to 2020 were as follows:[2]
The effect of patient age on prognosis is strongly influenced by clinical and pathobiological factors, as evidenced by the following:
Adolescents and adults rarely develop neuroblastoma, accounting for less than 5% of all cases. When neuroblastoma occurs in this age range, it shows a more indolent clinical course than neuroblastoma in younger patients, and it often shows de novo chemotherapy resistance.[81] Neuroblastoma in adolescents and young adults may also exhibit unusual clinicopathological characteristics such as large tumors, bilateral adrenal disease, and pheochromocytoma-like features.[82][Level of evidence C1] Neuroblastoma has a worse long-term prognosis in adolescents older than 10 years or in adults, regardless of stage or site.
Although adolescent and young adult patients have infrequent MYCN amplification (9% in patients aged 10–21 years), older children with advanced disease have a poor rate of survival. Tumors from the adolescent and young adult population commonly have segmental chromosomal aberrations, and ALK and ATRX variants are much more frequent.[83-85] In adolescents, approximately 40% of the tumors have loss-of-function variants in ATRX, compared with less than 20% in younger children and 0% in infants younger than 1 year.[81] Complex DNA microarray findings and novel variants have been reported in some patients.[82][Level of evidence C1]
The 5-year OS rate for adolescent and young adult patients (aged 15–39 years) is 38%.[86][Level of evidence C1] The 5-year EFS rate is 32% for patients between the ages of 10 years and 21 years, and the OS rate is 46%. For patients with stage 4 disease, the 10-year EFS rate is 3%, and the OS rate is 5%.[87] Aggressive chemotherapy and surgery have been shown to achieve a minimal disease state in more than 50% of these patients.[40,88] Other modalities, such as local radiation therapy, autologous stem cell transplant, and the use of agents with confirmed activity, may improve the poor prognosis for adolescents and adults.[87,88]
The biology of adult-onset neuroblastoma appears to differ from the biology of pediatric or adolescent neuroblastoma based on a single-institution series of 44 patients (aged 18–71 years).[89]
As noted above, adult-onset neuroblastoma is enriched for activating ALK variants. In a single-institution retrospective study, 13 adults (median age, 34 years; range, 16–71 years) with relapsed, ALK-altered neuroblastoma were treated with lorlatinib. Nine patients (69%) had a complete or partial response, five of whom were previously treated with other ALK inhibitors. Lorlatinib was associated with significant adverse events requiring dose reduction. However, responses were seen using doses below the recommended adult dose.[90] In another multicenter trial, 15 adults (aged 18 years or older; median age, 24 years) with relapsed or refractory ALK-altered neuroblastoma were treated with lorlatinib. The response rate (complete, partial, and minor response) was 67%.[91]
Several image-based and surgery-based systems were used for assigning disease stage of neuroblastoma before the 1990s. In an effort to compare results obtained throughout the world, a surgical pathological staging system, termed the International Neuroblastoma Staging System (INSS), was developed.[64] The INSS predicted outcome based on stage at diagnosis, although important interactions with biological variables were also found.[3,4,11,64,79,80,92-94] However, because surgical approaches differ from one institution to another, INSS stage for patients with locoregional disease may also vary considerably. To define extent of disease at diagnosis in a uniform manner, a presurgical International Neuroblastoma Risk Group staging system (INRGSS) was developed for the International Neuroblastoma Risk Group Classification System.[95,96] The INRGSS is currently used in North American and European cooperative group studies. This staging system is not affected by locoregional lymph node involvement.
For the patients with newly diagnosed neuroblastoma enrolled in the ANBL00B1 (NCT00904241) study, the 5-year EFS and OS rates, according to INRGSS stage, were the following:[78]
For more information, see the following sections:
Neuroblastoma tumor histology has a significant impact on prognosis and risk group assignment. For more information, see the Histological Classification of Neuroblastic Tumors section and Table 2.
In the ANBL00B1 (NCT00904241) study of 4,832 patients with newly diagnosed neuroblastoma, 52% of tumors were classified as favorable and 48% as unfavorable, according to the International Neuroblastoma Pathology Classification (INPC). For patients with tumors classified as favorable, the 5-year EFS rate was 88%, and the 5-year OS rate was 96%. For patients with tumors classified as unfavorable, the 5-year EFS rate was 55%, and the 5-year OS rate was 66% (P < .0001).[78]
Histological characteristics considered prognostically favorable include the following:
High mitosis/karyorrhexis index and undifferentiated tumor cells are considered prognostically unfavorable histological characteristics, but the prognostic value is age dependent.[100,101]
A COG study (P9641 [NCT00003119]) investigated the effect of histology, among other factors, on outcome. Of 915 children with stage 1 and stage 2 neuroblastoma without MYCN amplification, 87% were treated with initial surgery and observation. Patients (13%) who had or were at risk of developing symptomatic disease, or who had less than 50% tumor resection at diagnosis, or who had unresectable progressive disease after surgery alone, were treated with chemotherapy and surgery. Those with favorable histological features reported a 5-year EFS rate of 90% to 94% and an OS rate of 99% to 100%. Those with unfavorable histology had an EFS rate of 80% to 86% and an OS rate of 89% to 93%.[79]
In the COG ANBL0531 (NCT00499616) study for intermediate-risk patients with neuroblastoma, treatment was assigned using a biology-based and response-based algorithm, which included allelic status of 1p36 and 11q23. Patients with MYCN-amplified tumors were excluded.[102]
A study using data from the INRG Data Commons evaluated the prognostic strength of the underlying INPC histological criteria. The independent prognostic ability of age, histological category, mitosis-karyorrhexis index (MKI), and grade was demonstrated. Four age-related, histological prognostic groups were identified (aged <18 months with low vs. high MKI, and aged ≥18 months with differentiated vs. undifferentiated/poorly differentiated tumors). Compared with survival trees generated with established COG risk criteria, an additional prognostic subgroup was identified and validated when individual histological features were analyzed in lieu of INPC.[104] The INPC is described in the Histological Classification of Neuroblastic Tumors section.
For more information, see the Genomic and Biological Features of Neuroblastoma section.
Clinical and biological features of neuroblastoma differ by primary tumor site. In a study of data on 8,389 patients in clinical trials and compiled by the International Risk Group Project, the following results were observed, confirming the results from much smaller, previous studies with less complete clinical and biological data:[105]
Using the Therapeutically Applicable Research to Generate Effect Treatments (TARGET) and genome-wide association study data sets, a study compared the genomic and epigenomic data of primary diagnostic neuroblastomas originating in the adrenal gland (n = 646) with that of neuroblastomas originating in the thoracic sympathetic ganglia (n = 118). Neuroblastomas arising in the adrenal gland were more likely to harbor structural DNA aberrations such as MYCN amplification, whereas thoracic tumors showed defects in mitotic checkpoints resulting in hyperdiploidy. Thoracic tumors were more likely to harbor gain-of-function ALK aberrations than were adrenal tumors among all cases (OR, 1.89; P = .04), and among cases without MYCN amplification (OR, 2.86; P = .003). Because 16% of thoracic tumors harbor ALK variants, routine sequencing for these variants in this setting should be considered.[106]
In the TARGET cohort, 70% of patients with adrenal primary tumors and 51% of patients with thoracic primary tumors had stage 4 disease. In the genome-wide association study without MYCN amplification, 43% of patients with adrenal primary tumors and 17% of patients with thoracic primary tumors had stage 4 disease. By multivariate analysis, adrenal site was an independent predictor of worse outcome in the genome-wide association study cohort but not in the TARGET cohort after adjusting for MYCN amplification status, disease stage, and age of at least 18 months. Adrenal neuroblastoma was not an independent predictor of worse EFS by similar multivariable analysis for either the genome-wide association study or TARGET cohorts.[106]
It is not clear whether the effect of primary neuroblastoma tumor site on prognosis is entirely dependent on the differences in tumor biology associated with tumor site.
Multifocal neuroblastoma occurs rarely, usually in infants, and generally has a good prognosis.[107] Familial neuroblastoma and germline ALK gene pathogenic variants should be considered in patients with multiple primary neuroblastomas.
Response to treatment has been associated with outcome. In patients with intermediate-risk disease who had a poor response to initial therapy in the COG ANBL0531 (NCT00499616) study, 6 of 20 patients subsequently developed progressive or recurrent disease, and one patient died.[102]
In patients with high-risk disease, the persistence of neuroblastoma cells in bone marrow after induction chemotherapy is associated with a poor prognosis. Sensitive techniques that detect minimal residual disease may be used to assess prognosis.[108-110] For example, detection of RNA transcripts expressed by neuroblastoma cells (in the bone marrow) after initial induction chemotherapy in children with high-risk neuroblastoma has been associated with significantly inferior EFS and OS.[111]
Similarly, the persistence of MIBG-avid tumor, measured as Curie score greater than 2 after completion of induction therapy, predicts a poor prognosis for patients with MYCN-nonamplified high-risk tumors. A Curie score greater than 0 after induction therapy is associated with a worse outcome for high-risk patients with MYCN-amplified disease.[112,113] An analysis of North American patients who went on to receive tandem transplants showed that patients with Curie scores greater than 0 at the end of induction therapy had inferior EFS rates.[114] For more information about Curie scoring, see the Curie and SIOPEN scoring methods section.
In an analysis of patients from four consecutive COG high-risk trials, an end-induction response of partial response (PR) or better, according to the 1993 International Neuroblastoma Response Criteria,[64] was significantly associated with higher EFS and OS. On multivariable analysis (n = 407), the absence of 11q loss of heterozygosity (LOH) was the only factor that remained significantly associated with PR or better (OR, 1.962 vs. 11q LOH; 95% CI, 1.104–3.487; P = .0216).[115]
A treatment-associated decrease in mitosis and an increase in histological differentiation of the primary tumor are also prognostic of response.[116]
The accuracy of prognostication based on decrease in primary tumor size is less clear. In a study conducted by seven large international centers, 229 high-risk patients were treated in a variety of ways. Treatment included chemotherapy, surgical removal of the primary tumor, radiation to the tumor bed, high-dose myeloablative therapy plus stem cell transplant, and, in most cases, isotretinoin and anti-GD2 antibody immunotherapy enhanced by cytokines. Primary tumor response was measured after induction chemotherapy in three ways: as 30% or greater reduction in the longest dimension, 50% or greater reduction in tumor volume, or 65% or greater reduction in tumor volume (calculated from three tumor dimensions, a conventional radiological technique). The measurements were performed at diagnosis and after induction chemotherapy before primary tumor resection. None of the methods of measuring primary tumor response at end of induction chemotherapy predicted survival.[117]
Higher serum LDH and ferritin values conferred worse 5-year EFS and OS rates in a large international cohort of patients diagnosed with neuroblastoma (n > 8,575) from 1990 to 2016. Higher serum values for LDH and ferritin also conferred worse 3-year EFS and OS rates in patients with high-risk neuroblastoma after 2009. In a multivariate analysis that adjusted for age at diagnosis, MYCN status, and INSS stage 4 disease, LDH and ferritin maintained independent prognostic ability (P < .0001).[118][Level of evidence C1]
Although not critically evaluated in the original INRG classification system, subsequent analysis of the INRG Data Commons has clearly demonstrated independent statistical significance of the levels of serum ferritin and LDH on prognosis in all patients and in high-risk patients, including in the time period between 2010 and 2016. Therefore, it was suggested that these two easily obtainable lab values be incorporated into the prognostic classification system of the INRG.[118]
Between 1975 and 2020, the 5-year survival rate for neuroblastoma in the United States increased from 86% to 93% for children younger than 1 year and from 34% to 83% for children aged 1 to 14 years.[2,3] The 5-year relative survival rate for all infants and children with neuroblastoma increased from 46% when diagnosed between 1974 and 1989 to 71% when diagnosed between 1999 and 2005.[119] More recent estimates from 2014 to 2020 show an even higher 5-year relative survival rate of approximately 85% for infants and children younger than 15 years.[2] These statistics can be misleading because of the extremely heterogeneous prognosis based on the patient's age, stage, and biology. However, studies demonstrate a significant improvement in survival for high-risk patients diagnosed and treated between 2000 and 2019, compared with patients diagnosed from 1990 to 1999.[120,121] For more information, see Table 1. Similarly, the COG ANBL0531 (NCT00499616) study found equivalent outcomes for many subsets of intermediate-risk children who were treated with substantially reduced chemotherapy, compared with the earlier COG-A3961 (NCT00003093) study.[102]
Neuroblastomas are classified as one of the small round blue cell tumors of childhood. They are a heterogenous group of tumors composed of cellular aggregates with varying degrees of differentiation, from mature ganglioneuromas to less-mature ganglioneuroblastomas to immature neuroblastomas. These differences reflect the varying malignant potential of these tumors.[1]
The INPC system was derived from the experience with the original Shimada classification, and the two systems are compared in Table 1. The INPC involves histological evaluation of tumor specimens obtained before therapy for the following morphological features:[2-6]
Favorable and unfavorable prognoses are defined based on these histological parameters and patient age. The prognostic significance of this classification system, and of related systems using similar criteria, has been confirmed in several studies (see Table 1).[2-4,6]
International Neuroblastoma Pathology Classification | Original Shimada Classification | Prognostic Group | |||
---|---|---|---|---|---|
MKI = mitosis-karyorrhexis index. | |||||
aReprinted with permission. Copyright © 1999 American Cancer Society. All rights reserved.[2] Hiroyuki Shimada, Inge M. Ambros, Louis P. Dehner, Jun-ichi Hata, Vijay V. Joshi, Borghild Roald, Daniel O. Stram, Robert B. Gerbing, John N. Lukens, Katherine K. Matthay, Robert P. Castleberry, The International Neuroblastoma Pathology Classification (the Shimada System), Cancer, volume 86, issue 2, pages 364–72. | |||||
bSubtypes of neuroblastoma are described in detail elsewhere.[7] | |||||
cRare subtype, especially diagnosed in this age group. Further investigation and analysis required. | |||||
dPrognostic grouping for these tumor categories is not related to patient age. | |||||
Neuroblastoma: | (Schwannian stroma-poor)b | Stroma-poor | |||
Favorable: | Favorable | Favorable | |||
<1.5 y | Poorly differentiated or differentiating & low or intermediate MKI tumor | ||||
1.5–5 y | Differentiating & low MKI tumor | ||||
Unfavorable: | Unfavorable | Unfavorable | |||
<1.5 y | a) undifferentiated tumorc | ||||
b) high MKI tumor | |||||
1.5–5 y | a) undifferentiated or poorly differentiated tumor | ||||
b) intermediate or high MKI tumor | |||||
≥5 y | All tumors | ||||
Ganglioneuroblastoma, intermixed | (Schwannian stroma-rich) | Stroma-rich intermixed (favorable) | Favorabled | ||
Ganglioneuroma: | (Schwannian stroma-dominant) | ||||
Maturing | Well differentiated (favorable) | Favorabled | |||
Mature | Ganglioneuroma | ||||
Ganglioneuroblastoma, nodular | (composite Schwannian stroma-rich/stroma-dominate and stroma-poor) | Stroma-rich nodular (unfavorable) | Unfavorabled |
Most neuroblastomas with MYCN amplification have unfavorable INPC histology, but about 7% of tumors have favorable histology. The tumors generally do not express MYCN, even with the gene being amplified, and these patients have a more favorable prognosis than patients whose tumors are MYCN amplified and overexpress MYCN.[8]
The individual components of INPC data from the INRG Data Commons (18,865 patients) were analyzed, and the analysis validated the independent prognostic ability of age at diagnosis, histological category, MKI, and grade of differentiation. Four histological prognostic groups of patients were identified (aged <18 months with low vs. high MKI; aged >18 months with differentiating vs. undifferentiating/poorly differentiating tumors). Also, by using a risk schema devoid of the confounding of age and INPC, this analysis identified a novel and unfavorable subgroup of patients older than 547 days with stage 1 or 2, MYCN-nonamplified, intermediate or high MKI diploid tumors who had a very poor event-free survival (EFS) rate of 46%.[9][Level of evidence C1]
In some cases, biopsy may not be fully representative of the type of neuroblastic tumor present. For example, in one study of 125 patients with a biopsy diagnosis of ganglioneuroma or ganglioneuroblastoma, intermixed went on to undergo surgical resections. The pathological diagnosis changed in 39% of the cases, including 14 cases (12%) in which pathology changed to neuroblastoma or ganglioneuroblastoma, nodular.[10]
The INSS was developed and adopted by the Children's Oncology Group (COG) in 1986 and by cooperative groups in Europe and Japan in 1993. The INSS is a postsurgical staging system that uses tumor location with respect to midline structures, lymph node status, and, importantly, extent of upfront surgical resection to determine whether a locoregional tumor is INSS stage 1, 2A, 2B, or 3.[1,2] This system represented the first step in harmonizing disease staging and risk stratification worldwide. As a result of further advances in the understanding of neuroblastoma biology and genetics, a risk classification system was developed that incorporates clinical and biological factors in addition to INSS stage to facilitate risk group and treatment assignment for COG studies.[1-4] The final use of the INSS by the COG was for the intermediate-risk ANBL0531 (NCT00499616) study, which was closed in 2014.
To create a staging system independent of surgical resection extent, the INRGSS was developed in 2005 using image-defined risk factors (IDRFs) to categorize locoregional tumors as L1 (IDRFs absent), L2 (IDRFs present), M (metastatic), or MS (the equivalent of 4S in the INSS). For example, in the case of spinal cord compression, an IDRF is present when more than one-third of the spinal canal in the axial plane is invaded, when the leptomeningeal spaces are not visible, or when the spinal cord magnetic resonance signal intensity is abnormal. For more information about the INRGSS, see Table 2 and the lists of IDRFs (original IDRFs and COG IDRFs).
Presence of IDRFs has been associated with an increase in intraoperative complications, incomplete tumor resection, and worse survival in numerous studies.[5-7] Since 2014, COG and International Society of Paediatric Oncology Europe Neuroblastoma (SIOPEN) clinical trials have used the INRGSS, a preoperative staging system that was developed specifically for the International Neuroblastoma Risk Group (INRG) classification system (see Table 2), in place of the INSS.
Stage | Description |
---|---|
IDRFs = image-defined risk factors; INSS = International Neuroblastoma Staging System. | |
aAdapted from Monclair et al.[5]; [6] | |
L1 | Localized tumor not involving vital structures as defined by the list of IDRFsa and confined to one body compartment. |
L2 | Locoregional tumor with presence of one or more IDRFs.a |
M | Distant metastatic disease (except stage MS). |
MS | Metastatic disease in children younger than 18 months with metastases confined to skin, liver, and/or bone marrow. The primary tumor can be INSS stage 1, 2, or 3. |
IDRFs, as defined in the original literature, include the following:[5,7]
COG IDRFs, using an anatomical localization approach, include the following:[6,8]; [7][Level of evidence C1]
Assessment of surgical resectability must include IDRFs. The more IDRFs present, the higher the morbidity of the operation and the lower the chance of complete resection. The presence of two or more IDRFs should prompt a discussion regarding up-front chemotherapy rather than surgical resection at diagnosis. To decrease morbidity, it is critical to avoid up-front surgical resection with invasive tumors. An international analysis demonstrated that specific IDRFs present at diagnosis or before surgery may be associated with a lower likelihood of achieving a greater than 90% resection of the primary tumor.[9] Concordance in assessing IDRFs between local investigators and central reviewers was assessed in the context of a COG intermediate-risk trial and showed agreement in only 51.9% of cases.[10]
Neoadjuvant chemotherapy is not always effective in eliminating IDRFs. A retrospective study in the European Unresectable Neuroblastoma trial from 2001 to 2006 examined data from 143 patients with INSS stage 3 neuroblastoma who were older than 1 year without MYCN amplification. All patients had surgical risk factors that deemed the tumors unresectable. In a centrally reviewed subset, unfavorable histology by International Neuroblastoma Pathology Classification was found in 53% of patients. At diagnosis, 228 IDRFs were identified.[8]; [11][Level of evidence C1]
The INRGSS staging system is one of the prognostic markers included in the INRG Classification System.[12] For more information, see Table 4.
The INRGSS includes four disease stages: L1, L2, M, or MS. Localized tumors are classified as stage L1 or L2 disease based on whether one or more of the 20 IDRFs are present.[5]
The INRG Task Force has also reported consensus techniques for detecting and quantifying neuroblastoma in bone marrow, both at diagnosis and after treatment. Quantification of bone marrow metastatic disease may result in more accurate assessment of response to treatment,[13] and it is now incorporated into the International Neuroblastoma Response Criteria, which assess response to therapy.[14]
The decision by the INRG Task Force to define MS disease differently from 4S disease was based on reports in which small numbers of infants with L2 primary tumors and 4S metastatic patterns, including those aged 12 to 18 months, had favorable outcomes.[5,15] A subsequent study analyzing INRG data demonstrated that a number of biological characteristics predicted poor outcome for patients with MS disease who were aged 12 to 18 months at diagnosis. However, long-term outcomes of toddlers, aged 12 to 18 months, with favorable-biology MS disease were similar to those of infants younger than 12 months with INSS stage 4S neuroblastoma.[15]
By combining the INRGSS, age, and biological factors, each patient is assigned an INRG risk group that is prognostic of outcome and guides the appropriate risk-based treatment approach. The validity of the INRGSS was explored in the following retrospective studies of localized neuroblastoma with previously defined INSS stage without MYCN amplification:
Most international protocols have begun to incorporate the collection and use of IDRFs to define INRG stage, which is used in risk stratification and assignment of therapy.[17,18] The COG has been collecting and evaluating INRGSS data since 2006. A COG trial that opened in 2014 uses the INRGSS along with input from the surgeon to determine therapy for subsets of patients not at high risk, including those with L1, L2, and MS disease (ANBL1232 [NCT02176967], closed to accrual). Note that the INSS allows patients up to age 12 months to be classified as stage 4S, while the INRGSS allows patients up to age 18 months to be staged as MS. The primary tumor in INSS stage 4S must be INSS stage 1 or 2, while the primary tumor in MS can be L1 or L2, which includes INSS stages 1, 2, or 3. The INRGSS is used in ongoing COG studies and does not depend on a resection variable, but rather on pretreatment imaging combined with age and biological variables. It is anticipated that the use of standardized nomenclature will contribute substantially to more uniform staging and facilitate comparisons of clinical trials conducted in different parts of the world.
The COG ANBL00B1 (NCT00904241) biology study served as the infrastructure for rapid and reliable acquisition of the clinical and biological prognostic markers used for risk classification and clinical trial eligibility between 2000 and 2023. The APEC14B1 trial is currently used to facilitate risk group. For more information about the COG risk categories, see Table 3.
Based on data from 4,832 patients who were enrolled from 2007 to 2017 in the ANBL00B1 study, the COG has updated the risk classification.[19] Patients are defined as having low-, intermediate-, or high-risk disease based on clinical and biological factors (see Table 3).
High-Risk Disease | 1. Stage M, aged ≥18 months, regardless of other features | |
2. Stage M, aged <18 months with MYCN-amplified disease | ||
3. Stage MS or L2 with MYCN-amplified disease | ||
4. Stage L2 with unfavorable histology, aged ≥18 months | ||
5. Stage M or MS 12–18 months with at least one unfavorable feature: | ||
—Unfavorable histology | ||
— Segmental chromosomal aberrations | ||
—Diploid tumor | ||
6. Stage L1 incompletely resected tumor with MYCN amplification | ||
Low-Risk Disease | 1. Stage L1 with MYCN-nonamplified disease regardless of other features | |
2. Stage L1 completely resected with MYCN-amplified disease | ||
3. Stage MS, aged <12 months with all favorable features: | ||
—Asymptomatic | ||
—Favorable histology | ||
—No segmental chromosomal aberrations | ||
—Hyperdiploid tumor | ||
Intermediate-Risk Disease | All other groups not meeting the definition of high-risk or low-risk disease.a | |
aFor complete classification, see Irwin MS et al.[19] |
Combinations of prognostic factors (clinical and biological features) have been used for decades to risk-stratify patients and inform treatment assignment.[12] Schema differ across international cooperative groups. The INRG Task Force has led efforts to develop uniform approaches for staging and pretreatment risk classification, as outlined below.[20] The algorithms that use these factors to determine risk are complex and change slightly based on new knowledge. The INRG Classification System was designed based on survival-tree analyses of 35 prognostic factors in more than 8,800 patients with neuroblastoma from a variety of clinical trials. The underlying histological features in the INPC (Shimada system) were included in the analysis:[20,21]
The INRG classification schema assigns neuroblastoma patients to one of 16 pretreatment risk groups based on INRG stage, age, histological category, grade of tumor differentiation, MYCN amplification, 11q aberration (the only segmental chromosomal aberration studied), and ploidy. Four levels of risk were defined according to outcomes among 8,800 patients with high-quality data, as they had been entered in clinical trials (see Table 4).
In the overall risk grouping, histological category is an important risk determinant for all stage L1 and L2 tumors, and grade of differentiation is prognostic in neuroblastomas and nodular ganglioneuroblastomas in patients older than 18 months. The goals of the INRG are to increase international collaboration and classify patients uniformly so that the results of clinical trials conducted around the world can be compared.[20]
INRG Stage | Histological Category | Grade of Tumor Differentiation | MYCN | 11q Aberration | Ploidy | Pretreatment Risk Group | |
---|---|---|---|---|---|---|---|
GN = ganglioneuroma; GNB = ganglioneuroblastoma; NA = not amplified. | |||||||
aReprinted with permission. © (2015) American Society of Clinical Oncology. All rights reserved. Pinto N et al.: Advances in Risk Classification and Treatment Strategies for Neuroblastoma, J Clin Oncol 33 (27), 2015: 3008–3017.[12] | |||||||
L1/L2 | GN maturing, GNB intermixed | A (very low) | |||||
L1 | Any, except GN maturing or GNB intermixed | NA | B (very low) | ||||
Amplified | K (high) | ||||||
L2 | |||||||
Aged <18 mo | Any, except GN maturing or GNB intermixed | NA | No | D (low) | |||
Yes | G (intermediate) | ||||||
Aged ≥18 mo | GNB nodular neuroblastoma | Differentiating | NA | No | E (low) | ||
Yes | H (intermediate) | ||||||
Poorly differentiated or undifferentiated | NA | H (intermediate) | |||||
Amplified | N (high) | ||||||
M | |||||||
Aged <18 mo | NA | Hyperdiploid | F (low) | ||||
Aged <12 mo | NA | Diploid | I (intermediate) | ||||
Aged 12 to <18 mo | NA | Diploid | J (intermediate) | ||||
Aged <18 mo | Amplified | O (high) | |||||
Aged ≥18 mo | P (high) | ||||||
MS | |||||||
Aged <18 mo | NA | No | C (very low) | ||||
Yes | Q (high) | ||||||
Amplified | R (high) |
Because patient age is used in all risk stratification systems, a cellular classification system that did not employ patient age was desirable, and underlying histological criteria, rather than INPC or Shimada Classification, was used in the survival-tree analyses to select prognostic criteria for the INRG Classification System. Histological findings discriminated prognostic groups most clearly in two subsets of patients, as shown in Table 5.
INSS Stage/Histological Subtype | Number of Cases | EFS (%) | OS (%) | |
---|---|---|---|---|
EFS = event-free survival; GN = ganglioneuroma; GNB = ganglioneuroblastoma; INSS = International Neuroblastoma Staging System; NB = neuroblastoma; OS = overall survival. | ||||
aAdapted from Cohn et al.[20] | ||||
INSS stage 1, 2, 3, 4S | 5,131 | 83 ± 1 | 91 ± 1 | |
GN, maturing | 162 | 97 ± 2 | 98 ± 2 | |
GNB, intermixed | ||||
NB | 4,970 | 83 ± 1 | 90 ± 1 | |
GNB, nodular | ||||
INSS stage 2, 3; age >547 d | 260 | 69 ± 3 | 81 ± 2 | |
11q normal and differentiating | 16 | 80 ± 16 | 100 | |
11q aberration or undifferentiated | 49 | 61 ± 11 | 73 ± 11 |
The INRG histological subsets are incorporated into the INRG Risk Classification Schema.
Approximately 70% of patients with neuroblastoma have metastatic disease at diagnosis. A thorough evaluation for metastatic disease is performed before therapy initiation. The studies described below are typically performed.[1]
The extent of metastatic disease is assessed by MIBG scan, which is applicable to all sites of disease, including soft tissue, bone marrow, and cortical bone. Approximately 90% of neuroblastomas will be MIBG avid. The MIBG scan has a sensitivity and specificity of 90% to 99%, and MIBG avidity is equally distributed between primary and metastatic sites.[23] Although iodine I 123 (123I) has a shorter half-life, it is preferred over 131I because of its lower radiation dose, better quality images, reduced thyroid toxicity, and lower cost.
Imaging with 123I-MIBG is optimal for identifying soft tissue and bony metastases. It was shown to be superior to positron emission tomography–computed tomography (PET-CT) in one prospective comparison.[24] In a retrospective review of 132 children with neuroblastoma, technetium Tc 99m-methylene diphosphonate (99mTc-MDP) bone scintigraphy failed to identify unique sites of metastatic disease that would change the disease stage or clinical management determined using 123I-MIBG or PET scanning. Bone scans are not used as part of standard staging for neuroblastoma.[25]
Baseline MIBG scans performed at diagnosis are excellent for monitoring disease response and performing posttherapy surveillance.[26] A retrospective analysis of paired 123I-MIBG and PET scans in 60 patients with newly diagnosed neuroblastoma demonstrated that for patients with INSS stage 1 and stage disease, PET was superior at determining the extent of primary disease and more sensitive in detecting residual masses. In contrast, for stage 4 disease, 123I-MIBG imaging was superior in detecting bone marrow and bony metastases.[27]
Multiple groups have investigated a semiquantitative scoring method to evaluate disease extent and prognostic value. The most common scoring methods in use for evaluation of disease extent and response are the Curie and the SIOPEN methods.
The prognostic significance of postinduction Curie scores has been validated in an independent cohort of patients.[29] A retrospective study of Curie scoring was performed on 123I-MIBG scans obtained from high-risk patients who had been prospectively enrolled in the SIOPEN/HR-NBL1 (NCT00030719) trial. Scans of nine anatomical regions were evaluated for bone metastases and a tenth region for all sites of soft tissue disease. Each region was scored 0 to 3 based on disease extent, and a cumulative Curie score was generated. The optimal prognostic cut point for Curie score at diagnosis was 12 in the SIOPEN/HR-NBL1 trial, with a significant outcome difference by Curie score noted (5-year EFS rate, 43.0% ± 5.7% [Curie score ≤12] vs. 21.4% ± 3.6% [Curie score >12], P < .0001). The optimal Curie score cut point after induction chemotherapy was 2 in the SIOPEN/HR-NBL1 trial, with a postinduction Curie score of greater than 2 being associated with an inferior outcome (5-year EFS rate, 39.2% ± 4.7% [Curie score ≤2] vs. 16.4% ± 4.2% [Curie score >2], P < .0001). The postinduction Curie score maintained independent statistical significance in Cox models when adjusted for the covariates of age and MYCN gene copy number.[29]
The German Pediatric Oncology Group compared the prognostic value of the Curie and SIOPEN scoring methods in a retrospective study of 58 patients with stage 4 neuroblastoma who were older than 1 year. The study found concordance in prognostic value (of these two methods) at diagnosis and after induction chemotherapy. At diagnosis, a Curie score of 2 or lower and a SIOPEN score of 4 or lower (best cutoff) correlated with significantly better EFS and overall survival (OS) rates, compared with higher scores. After four cycles of induction chemotherapy, patients with a complete response by SIOPEN and Curie scoring had a better outcome than patients with residual uptake in metastases. However, subsequent resolution of MIBG-positive metastases occurring between the fourth and sixth cycles of chemotherapy did not affect prognosis.[32]
The cited clinical trials did not include postinduction-phase assessments of Curie or SIOPEN scores after transplant and immunotherapy. Cutoffs and outcomes associated with those assessments may differ from the preinduction and postinduction scores.
Fluorine F 18-fludeoxyglucose PET scans are used to evaluate extent of disease in patients with tumors that are not MIBG avid.[27]
Bone marrow is assessed by bilateral iliac crest marrow aspirates and trephine (core) bone marrow biopsies to exclude bone marrow involvement. To be considered adequate, core biopsy specimens must contain at least 1 cm of marrow, excluding cartilage. Many COG studies require two core biopsies and two aspirates. Bone marrow sampling may not be necessary for tumors that are otherwise stage 1.[33]
Other tests and procedures used to stage neuroblastoma include the following:
Children with neuroblastoma can be divided into subsets with different predicted risks of relapse based on clinical factors and biological markers at the time of diagnosis.
Biological subtypes of high-risk neuroblastoma can be defined by the mostly nonoverlapping genomic alterations listed below:
The subtypes listed have specific clinical characteristics, as discussed below. Variants in ALK, which occur across the different subtypes of high-risk neuroblastoma, are observed in approximately 15% of cases and are discussed separately.
Key genomic characteristics of high-risk neuroblastoma that are present in most cases of high-risk neuroblastoma are discussed below.
The SCAs frequently observed in neuroblastoma and used when assigning SCA status include losses of or at chromosome arms 1p, 3p, 4p, and 11q and gains of or at chromosome arms 1q, 2p, and 17q.[8] These alterations can be detected by multiple methods, including fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH), and next-generation sequencing (NGS) assays. SCAs are present in most high-risk and/or stage 4 neuroblastoma tumors.[3,4,6,7,9] Among all patients with neuroblastoma, a higher number of chromosome breakpoints (i.e., a higher number of SCAs) correlated with the following:[3-7][Level of evidence C2]
Determining the presence of SCAs is potentially clinically useful. Detecting SCAs can help distinguish patients with clinically favorable presentation who are at higher risk of treatment failure. Examples are provided below.
In an analysis of localized, resectable, non-MYCN amplified neuroblastoma, cases from two consecutive European studies and a North American cohort (including International Neuroblastoma Staging System [INSS] stages 1, 2A, and 2B) were analyzed for selected SCAs (namely loss of 1p, 3p, 4p, and 11q and gain of 1q, 2p, and 17q). The study revealed a different prognostic impact of tumor genomics depending on patient age (<18 months vs. >18 months) and stage (1 vs. 2). Patients were treated with surgery alone regardless of a tumor residuum.[10][Level of evidence C1]
In a study of children older than 12 months who had unresectable primary neuroblastomas without metastases, SCAs were found in most patients. Older children were more likely to have them and to have more SCAs per tumor cell. In children aged 12 to 18 months, the presence of SCAs had a significant effect on EFS but not on OS. However, in children older than 18 months, there was a significant difference in OS between children with SCAs (67%) and children without SCAs (100%), regardless of tumor histology.[7]
SCAs were also found to be predictive of recurrence in infants with localized unresectable or metastatic neuroblastoma without MYCN gene amplification.[1,2] An analysis of 133 patients (aged ≥18 months) with INSS stage 3 tumors without MYCN amplification demonstrated that SCAs were associated with inferior EFS, and chromosome 11q loss was independently associated with worse OS.[11]
Chromosome 11q loss occurs in approximately 30% of high-risk neuroblastoma cases, but it is uncommonly observed in tumors with MYCN amplification.[3] Chromosome 11q loss is frequently observed in high-risk neuroblastoma cases with either TERT rearrangements or with ALT pathway activation.[12,13] Chromosome 11q loss has also been associated with inferior EFS and poor response to induction therapy in patients with high-risk neuroblastoma, as described below:
Distal chromosome 6q losses have also been associated with poor outcome. An international collaboration studied 556 patients with high-risk neuroblastoma. Distal 6q losses were found in 6% of patients and were associated with a 10-year survival rate of only 3.4%.[16] A second study confirmed the very poor prognosis of patients with high-risk neuroblastoma who have distal 6q loss. Pooling across both studies, MYCN amplification occurred in only 20% of cases with distal chromosome 6q loss.[17]
The same study of 556 patients with high-risk neuroblastoma that identified poor prognosis for patients with distal 6q loss also evaluated amplifications of regions not encompassing the MYCN locus. Regions of non-MYCN amplification were detected in 18% of the patients and were associated with a 10-year survival rate of 5.8%.[16]
MYCN amplification is detected in 16% to 25% of neuroblastoma tumors.[18] Among patients with high-risk neuroblastoma, 40% to 50% of cases show MYCN amplification.[19]
In all stages of disease, amplification of the MYCN gene strongly predicts a poorer prognosis, in both time to tumor progression and OS, in almost all multivariate regression analyses of prognostic factors.[1,2] In the ANBL00B1 (NCT00904241) study of 4,832 newly diagnosed patients enrolled between 2007 to 2017, the 5-year EFS and OS rates were 77% and 87%, respectively, for patients whose tumors were MYCN nonamplified (n = 3,647; 81%). In comparison, the 5-year EFS and OS rates were 51% and 57%, respectively, for patients whose tumors were MYCN amplified (n = 827; 19%).[9]
Within the localized-tumor MYCN-amplified cohort, patients with hyperdiploid tumors have better outcomes than patients with diploid tumors.[20] However, patients with hyperdiploid tumors with MYCN amplification or any SCAs do relatively poorly, compared with patients with hyperdiploid tumors without MYCN amplification.[3]
Most unfavorable clinical and pathobiological features are associated, to some degree, with MYCN amplification. In a multivariable logistic regression analysis of 7,102 patients in the International Neuroblastoma Risk Group (INRG) study, pooled SCAs and gains of 17q were poor prognostic features, even when not associated with MYCN amplification. However, another poor prognostic feature, SCAs at 11q, are almost entirely mutually exclusive of MYCN amplification.[21,22]
In a cohort of 6,223 patients from the INRG database with known MYCN status, the OS hazard ratio (HR) associated with MYCN amplification was 6.3 (95% confidence interval [CI], 5.7–7.0; P < .001). The greatest adverse prognostic impact of MYCN amplification for OS was in the youngest patients (aged <18 months: HR, 19.6; aged ≥18 months: HR, 3.0). Patients whose outcome was most impacted by MYCN status were those with otherwise favorable features, including age younger than 18 months, high mitosis-karyorrhexis index, and low ferritin.[23][Level of evidence C1]
Intratumoral heterogeneous MYCN amplification (hetMNA) refers to the coexistence of MYCN-amplified cells (as a cluster or as single scattered cells) and non–MYCN-amplified tumor cells. HetMNA has been reported infrequently. It can occur spatially within the tumor as well as between the tumor and the metastasis at the same time or temporally during the disease course. The International Society of Paediatric Oncology Europe Neuroblastoma (SIOPEN) biology group investigated the prognostic significance of this neuroblastoma subtype. Tumor tissue from 99 patients identified as having hetMNA and diagnosed between 1991 and 2015 was analyzed to elucidate the prognostic significance of MYCN-amplified clones in otherwise non-MYCN–amplified neuroblastomas. Patients younger than 18 months showed a better outcome in all stages compared with older patients. The genomic background correlated significantly with relapse frequency and OS. No relapses occurred in cases of only numerical chromosomal aberrations. This study suggests that hetMNA tumors be evaluated in the context of the genomic tumor background in combination with the clinical pattern, including the patient's age and disease stage. Future studies are needed in patients younger than 18 months who have localized disease with hetMNA.[24]
Lengthening of telomeres, the tips of chromosomes, promotes cell survival. Telomeres otherwise shorten with each cell replication, eventually resulting in the cell’s inability to replicate. Patients whose tumors lack telomere maintenance mechanisms have an excellent prognosis, while patients whose tumors harbored telomere maintenance mechanisms have a substantially worse prognosis.[25] Low-risk neuroblastoma tumors, as defined by clinical/biological features, have little telomere lengthening activity. Aberrant genetic mechanisms for telomere lengthening have been identified in high-risk neuroblastoma tumors.[25-28] Thus far, the following three mechanisms, which appear to be mutually exclusive, have been described:
FOXR2 gene expression is observed in approximately 8% of neuroblastoma cases. FOXR2 gene expression is normally absent postnatally, with the exception of male reproductive tissues.[34] FOXR2 expression is also observed in a subset of central nervous system (CNS) primitive neuroectodermal tumors, termed CNS NB-FOXR2.[35] FOXR2 overexpression was virtually mutually exclusive in neuroblastoma tumors with both elevated MYC and MYCN expression. Although MYCN gene expression was not elevated in neuroblastoma with FOXR2 activation, the gene expression profile for the FOXR2 expressing cases closely resembled that of MYCN-amplified neuroblastoma. FOXR2 binds MYCN and appears to stabilize the MYCN protein, leading to high levels of MYCN protein in neuroblastoma with FOXR2 activation. This finding provides an explanation for the similar gene expression profiles for neuroblastoma with FOXR2 activation and neuroblastoma with MYCN amplification.
Neuroblastoma with FOXR2 activation is observed at comparable rates in high-risk and non–high-risk cases.[34] Among high-risk cases, outcomes for patients whose tumors showed FOXR2 activation were similar to those for cases with MYCN amplification. In a multivariable analysis, FOXR2 activation was significantly associated with inferior OS, along with INSS stage 4, age 18 months or older, and MYCN amplification.
CDK4 and MDM2 amplification are observed together in 1% to 2% of neuroblastoma cases, and these cases have distinctive biological and clinical features:[36,37]
Compared with adult cancers, pediatric neuroblastoma tumors show a low number of variants per genome that affect protein sequence (10–20 per genome).[39] The most common gene variant is ALK, which is altered in approximately 10% of patients (see below). Other genes with even lower frequencies of variants include ATRX, PTPN11, ARID1A, and ARID1B.[26,27,30,40-43] As shown in Figure 2, most neuroblastoma cases lack variants in genes that are altered in a recurrent manner.
The ALK gene provides instructions for making a cell surface receptor tyrosine kinase, expressed at significant levels only in developing embryonic and neonatal brains. ALK is the exonic variant found most commonly in neuroblastoma. Germline pathogenic variants in ALK have been identified as the major cause of hereditary neuroblastoma. Somatically acquired ALK-activating exonic variants are also found as oncogenic drivers in neuroblastoma.[42]
Two large cohort studies examined the clinical correlates and prognostic significance of ALK alterations. One study from the COG examined ALK status in 1,596 diagnostic neuroblastoma samples across all risk groups.[42] Another study from SIOPEN evaluated 1,092 patients with high-risk neuroblastoma.[44]
In a study that compared the genomic data of primary diagnostic neuroblastomas originating in the adrenal gland (n = 646) with that of neuroblastomas originating in the thoracic sympathetic ganglia (n = 118), 16% of thoracic tumors harbored ALK variants.[45]
Small-molecule ALK kinase inhibitors such as lorlatinib (added to conventional therapy) are being tested in patients with recurrent ALK-altered neuroblastoma (NCT03107988) and in patients with newly diagnosed high-risk neuroblastoma with activated ALK (COG ANBL1531).[42] For more information, see the sections on Treatment of High-Risk Neuroblastoma and Treatment of Recurrent or Refractory Neuroblastoma in Neuroblastoma Treatment.
There are limited data regarding the genomic evolution of exonic variants from diagnosis to relapse for neuroblastoma. Whole-genome sequencing was applied to 23 paired diagnostic and relapsed neuroblastoma tumor samples to define somatic genetic alterations associated with relapse,[46] while a second study evaluated 16 paired diagnostic and relapsed specimens.[47] Both studies identified an increased number of variants in the relapsed samples compared with the samples at diagnosis. This has been confirmed in a study of neuroblastoma tumor samples sent for NGS.[48]
In addition, three relapse samples showed structural alterations involving MAPK pathway genes consistent with pathway activation, so aberrations in this pathway were detected in 18 of 23 (78%) relapse samples. Aberrations were found in ALK (n = 10), NF1 (n = 2), and one each in NRAS, KRAS, HRAS, BRAF, PTPN11, and FGFR1. Even with deep sequencing, 7 of the 18 alterations were not detectable in the primary tumor, highlighting the evolution of variants presumably leading to relapse and the importance of genomic evaluations of tissues obtained at relapse.
Given the widespread metastatic nature of high-risk and relapsed neuroblastoma, use of circulating tumor DNA (ctDNA) technologies may reveal additional genomic alterations not found in conventional tumor biopsies. Moreover, these approaches have demonstrated the ability to detect resistant variants in patients with neuroblastoma who were treated with ALK inhibitors.[50][Level of evidence C1] In one analysis of serial ctDNA samples from patients treated with lorlatinib, ALK VAF tracked with disease burden in most but not all patients.[51] In subsets of patients who progressed while taking lorlatinib, second compound variants in ALK or variants in other genes, including RAS pathway genes and TP53, have been reported.[51,52]
In a deep-sequencing study, 276 neuroblastoma samples (comprised of all stages and from patients of all ages at diagnosis) underwent very deep (33,000X) sequencing of just two amplified ALK variant hot spots, which revealed 4.8% clonal variants and an additional 5% subclonal variants. This finding suggests that subclonal ALK gene variants are common.[53] Thus, deep sequencing can reveal the presence of variants in tiny subsets of neuroblastoma tumor cells that may be able to survive during treatment and grow to constitute a relapse.
Immunostaining for MYC and MYCN proteins on a restricted subset of 357 undifferentiated/poorly differentiated neuroblastoma tumors demonstrated that elevated MYC/MYCN protein expression is prognostically significant.[54] Sixty-eight tumors (19%) highly expressed the MYCN protein, and 81 were MYCN amplified. Thirty-nine tumors (10.9%) expressed MYC highly and were mutually exclusive of high MYCN expression. In the MYC-expressing tumors, MYC or MYCN gene amplification was not seen. SCAs were not examined in this study.[54]
Cancer in children and adolescents is rare, although the overall incidence has slowly increased since 1975.[1] Children and adolescents with cancer should be referred to medical centers that have a multidisciplinary team of cancer specialists with experience treating the cancers that occur during childhood and adolescence. This multidisciplinary team approach incorporates the skills of the following pediatric specialists and others to ensure that children receive treatment, supportive care, and rehabilitation to achieve optimal survival and quality of life:
For specific information about supportive care for children and adolescents with cancer, see the summaries on Supportive and Palliative Care.
The American Academy of Pediatrics has outlined guidelines for pediatric cancer centers and their role in the treatment of children and adolescents with cancer.[2] At these centers, clinical trials are available for most types of cancer that occur in children and adolescents, and the opportunity to participate is offered to most patients and their families. Clinical trials for children and adolescents diagnosed with cancer are generally designed to compare potentially better therapy with current standard therapy. Other types of clinical trials test novel therapies when there is no standard therapy for a cancer diagnosis. Most of the progress in identifying curative therapies for childhood cancers has been achieved through clinical trials. Information about ongoing clinical trials is available from the NCI website.
Generally, treatment of neuroblastoma is based on whether the tumor is classified as non-high risk (low or intermediate risk) or high risk. Because 5-year survival rates are generally 90% or higher, the goal of treatment for non–high-risk disease is to cure the disease with minimal toxicity. Outcomes for patients with high-risk disease have improved over time with the use of increasingly intensive multimodal therapy, but they remain suboptimal.
Table 6 summarizes the treatment options for patients with low-risk, intermediate-risk, and high-risk disease.
COG Risk-Group Assignment | Treatment Options | |
---|---|---|
COG = Children's Oncology Group; GM-CSF = granulocyte-macrophage colony-stimulating factor; HSCT = hematopoietic stem cell transplant. | ||
Low-Risk Neuroblastoma | Surgery followed by observation. | |
Observation with or without biopsy. | ||
Chemotherapy with or without surgery (for symptomatic disease or unresectable progressive disease after surgery). | ||
Radiation therapy (only for emergency therapy). | ||
Intermediate-Risk Neuroblastoma | Chemotherapy with or without surgery. | |
Surgery and observation (in infants). | ||
Radiation therapy (for progressive disease, if needed). | ||
High-Risk Neuroblastoma | A regimen of chemotherapy, surgery, tandem cycles of myeloablative therapy and HSCT, radiation therapy, and dinutuximab, with GM-CSF and isotretinoin. | |
Stage 4S Neuroblastoma | Observation with supportive care (for asymptomatic patients with favorable tumor biology). | |
Chemotherapy (for symptomatic patients, those with unfavorable tumor biology, and infants aged <3 months). | ||
Surgery (rarely, for patients with hepatomegaly that compromises the kidney or other abdominal organs). | ||
Radiation therapy (rarely, for patients with symptoms related to hepatomegaly from metastatic disease). |
In patients without metastatic disease, the standard of care is to perform an initial surgery. This surgery aims to accomplish the following, based on the disease stage and the risk group:
The COG reported that expectant observation in infants younger than 6 months with small (L1) adrenal masses resulted in an excellent EFS and OS while avoiding surgical intervention in a large majority of patients.[10] According to the surgical guidelines described in the intermediate-risk neuroblastoma clinical trial (ANBL0531 [NCT00499616]), the primary tumor is not routinely resected in patients with 4S neuroblastoma. German studies of selected groups of patients have biopsied tissue and observed infants with both L1 and L2 tumors without MYCN amplification, avoiding additional surgery and chemotherapy in most patients.[11]
Whether there is any advantage to gross-total resection (>90%) of the primary tumor mass after chemotherapy in patients older than 18 months with stage 4 disease remains controversial.[12-17] A meta-analysis of patients with stage 3 versus stage 4 neuroblastoma, at all ages combined, found an advantage for gross-total resection (>90%) over subtotal resection in stage 3 neuroblastoma only.[18] A small study suggested that after neoadjuvant chemotherapy, completeness of resection was affected by the number of IDRFs remaining.[19] When an experienced surgeon performed the procedure, a 90% or greater resection of the primary tumor in stage 4 neuroblastoma resulted in a higher local control rate, but it did not have a statistically significant impact on OS.[20]
For more information about IDRFs, see the International Neuroblastoma Risk Group Staging System (INRGSS) section.
In the current treatment paradigm, radiation therapy for patients with low-risk or intermediate-risk neuroblastoma is reserved for symptomatic life-threatening or organ-threatening tumor bulk that did not respond rapidly enough to chemotherapy. Common situations in which radiation therapy is used in these patients include the following:
Radiation therapy has become part of the standard of care for patients with high-risk disease and is usually delivered after high-dose chemotherapy and stem cell rescue. For more information, see the Treatment of High-Risk Neuroblastoma section.
Limiting the use of radiation therapy in infants with neuroblastoma (who generally have non–high-risk disease) is supported by long-term follow-up data from the Childhood Cancer Survivor Study. This study demonstrated higher rates of second malignant neoplasms and significant chronic health conditions in infants who were treated with radiation therapy.[23][Level of evidence C1]
Spinal cord compression is considered a medical emergency. Patients receive immediate treatment because neurological recovery is more likely when symptoms are present for a relatively short time before diagnosis and treatment. Recovery also depends on the severity of neurological defects (weakness vs. paralysis). Neurological outcome appears to be similar whether cord compression is treated with chemotherapy, radiation therapy, or surgery, although radiation therapy is used less frequently than in the past.
The completed COG neuroblastoma clinical trials recommended immediate chemotherapy for cord compression in low-risk or intermediate-risk patients.[22,24,25] In a single study in this setting looking at the effect of glucocorticoids on neurological outcome, treatment was associated with improved early symptom relief. However, glucocorticoids did not prevent late residual impairment.[25]
Children with severe spinal cord compression that does not promptly improve or those with worsening symptoms may benefit from neurosurgical intervention. Laminectomy may result in later kyphoscoliosis and may not eliminate the need for chemotherapy.[22,24,25] Osteoplastic laminotomy, a procedure that does not remove bone, was thought to lessen spinal deformity. Osteoplastic laminotomy may be associated with a lower incidence of progressive spinal deformity requiring fusion, but there is no evidence that functional neurological deficit is improved with laminoplasty.[26]
The burden of long-term health problems in survivors of neuroblastoma with intraspinal extension is high. In a systematic review of 28 studies of treatment and outcome of patients with intraspinal extension, the severity of the symptoms at diagnosis and the treatment modalities were most associated with the presence of long-term health problems. In particular, the severity of neurological motor deficits was most likely to predict neurological outcome.[27] The severity of motor deficits at diagnosis is associated with spinal deformity and sphincter dysfunction at the end of follow-up, while sphincter dysfunction at diagnosis was correlated with long-term sphincter problems.[28] This supports the initiation of treatment before symptoms have deteriorated to complete loss of neurological function.
In a series of 34 infants with symptomatic epidural spinal cord compression, both surgery and chemotherapy provided unsatisfactory results once paraplegia had been established. The frequency of grade 3 motor deficits and bowel dysfunction increased with a longer symptom duration interval. Most infants with symptomatic epidural spinal cord compression developed sequelae, which were severe in about one-half of patients.[29]
An analysis of patients with intermediate-risk disease treated in the COG ANBL0531 [NCT00499616] study included 92 patients with intraspinal disease.[30] Of these patients, 42 (46%) were symptomatic. Among patients who were symptomatic, motor symptoms and bowel/bladder symptoms resolved completely in 73% and 88% of patients, respectively. Laminectomy or laminoplasty was performed in 22 of 42 symptomatic patients and was not significantly associated with improvements in symptoms.
Although the role of surveillance imaging for detection of neuroblastoma relapse has not been well studied, most patients will undergo regular imaging tests after completing therapy. Many patients who relapse are asymptomatic, and relapse is detected on surveillance evaluations. Factors such as risk stratification, disease sites, biomolecular markers, and cumulative radiation dose may be considered in surveillance after treatment.[31-33]
One series included 154 patients with high-risk neuroblastoma who had a complete or very good partial response and subsequently had relapsed disease. The study found that 113 of the patients (73%) had asymptomatic relapse, while only 41 (27%) presented with symptoms. Metaiodobenzylguanidine (MIBG) scans were the most reliable study to detect asymptomatic relapse.[32]
In another series of 183 patients diagnosed with neuroblastoma, 50 patients experienced recurrence or progression. Relapsed disease was detected in most patients by symptoms/examination, MIBG scan, urinary catecholamines, and/or x-rays or ultrasonography.[33]
Cross-sectional imaging with CT scans is controversial because of the amount of radiation received and the low proportion of relapses detected with this modality.[33]
Evaluation of response is critical for the management of individual patients, but it is also necessary for comparing results of clinical trials. Given the complexities of a disease with propensity for bone and bone marrow metastasis, international consensus criteria have been developed and refined over the last several decades. The current version of these International Neuroblastoma Response Criteria (INRC) is presented below.
INRC is used to assess response to treatment.[34-36] Overall response in the revised INRC integrates tumor response in three components: primary tumor, soft tissue and bone metastases, and bone marrow. Primary and metastatic soft tissue sites are assessed using Response Evaluation Criteria in Solid Tumors (RECIST) and iodine I 123 (123I) MIBG scans or fluorine F 18-fludeoxyglucose (18F-FDG) positron emission tomography (PET) scans if the tumor is MIBG nonavid. 123I-MIBG scans, or 18F-FDG PET scans for MIBG-nonavid disease, replaced Technetium Tc 99m (99mTc) diphosphonate bone scintigraphy for osteomedullary metastasis assessment. Bone marrow is assessed by histology with or without immunohistochemistry and cytology or immunocytology. Bone marrow with 5% or less tumor involvement is classified as minimal disease. Urinary catecholamine levels are not included in response assessment. Overall response is defined as complete response, partial response, minor response, stable disease, or progressive disease.[36]
The overall INRC response criteria are defined as follows:[34,35]
Care should be taken in interpreting the development of metastatic disease in an infant who was initially considered to have stage 1 or 2 disease. If the pattern of metastases in such a patient is consistent with a 4S pattern of disease (involvement of skin, liver, and/or bone marrow, the latter less than 10% involved), these patients are not classified as having progressive/metastatic disease, which would typically be a criterion for removal from protocol therapy. Instead, these patients are managed as stage 4S patients.
Controversy exists regarding the necessity of measuring the primary tumor response in all three dimensions or whether the single longest dimension, as in RECIST tumor response determination, is equally useful.[37] The latter has been adopted for use in the INRC.
Approximately one-half of all newly diagnosed patients with neuroblastoma have non–high-risk disease (i.e., low and intermediate risk).[1] Since these patients have excellent survival, with 5-year survival rates higher than 95% for patients with low-risk disease and between 90% and 95% for patients with intermediate-risk disease, the goal of therapy for these patients is to cure the disease with minimal toxicity.
The staging system, risk classification system, and response criteria definitions for neuroblastoma have evolved over the past 20 years. As a result, published results from clinical trials for patients with non–high-risk neuroblastoma from the past used different staging systems (International Neuroblastoma Staging System) and response criteria or protocol-specific response criteria, making it difficult to compare trial results.
The success of previous Children's Oncology Group (COG) clinical trials has contributed to the continued reduction in therapy for select patients with neuroblastoma. According to the COG risk categorization, patients with low-risk disease generally have low-stage disease (International Neuroblastoma Risk Group [INRG] stage L1) and the tumors are MYCN-nonamplified, hyperdiploid, and have favorable histology (FH). For more information about the COG risk categories, see Table 3.
For more information about low-stage disease, see the Treatment of INSS Stage 4S and INRG Stage MS Neuroblastoma section.
Surgery, by an experienced surgeon, is the treatment of choice for patients with low-risk, INRG stage L1 tumors. The exception is for patients who are younger than 6 months with isolated adrenal masses with maximum diameter smaller than 3.1 cm if solid, or 5 cm if at least 25% of the mass is cystic. For these patients, observation without biopsy is the recommended approach. If the biology is confirmed to be favorable, residual disease after surgery is not considered a risk factor for relapse and chemotherapy is not indicated. Several studies have shown that patients with favorable biology and residual disease have excellent outcomes, with event-free survival (EFS) rates exceeding 90% and overall survival (OS) rates ranging from 99% to 100%.[2,3]
In patients with INRG stage MS disease who are asymptomatic and have tumors with favorable biology, observation is the preferred approach.
Some patients with presumed neuroblastoma have been observed without biopsy. The COG is studying this strategy further in the ANBL1232 (NCT02176967) trial (closed to accrual).[4,5]
Treatment options for low-risk neuroblastoma include the following:
Treatment for patients categorized as low risk may be surgery alone. For more information, see Table 3.
Evidence (surgery followed by observation):
Observation without biopsy has been used to treat perinatal neuroblastoma with small adrenal tumors.
A COG study determined that selected small INSS stage 1 or stage 2 adrenal masses, presumed to be neuroblastoma, detected in infants younger than 6 months by screening or incidental ultrasonography, may safely be observed without obtaining a definitive histological diagnosis and without surgical intervention. This technique avoids potential complications of surgery in newborn patients.[4] Patients are observed frequently to detect any tumor growth or spread, indicating a need for intervention. Additional studies, including an expansion of criteria allowing observation without surgery, are under way in the COG ANBL1232 (NCT02176967) study (closed to accrual).
Evidence (observation without biopsy):
Controversy exists about the need to attempt resection, at the time of diagnosis or later, in asymptomatic infants aged 12 months or younger with apparent stage 2B and stage 3 MYCN-nonamplified and favorable-biology disease. In a German clinical trial, some of these patients were observed after biopsy or partial resection without chemotherapy or radiation therapy. Many patients did not progress locally and never underwent a first or additional resection.[5] In the COG ANBL1232 (NCT02176967) study (closed to accrual), infants younger than 18 months who have L2 tumors with favorable biology are being observed after tumor biopsy.
Chemotherapy with or without surgery is used to treat the following:
Evidence (for removal of chemotherapy):
Information about National Cancer Institute (NCI)–supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
According to the 2021 COG risk classifier, intermediate risk includes the following for localized, INRG stage L2 tumors (no MYCN amplification):[1]
Stage M (no MYCN amplification):[1]
Stage MS (no MYCN amplification):[1]
For infants with stage MS tumors who are too unstable to undergo biopsy before starting treatment, chemotherapy is initiated, and a biopsy is obtained when safe.
For more information about the COG risk categories, see Table 3.
For more information about stage 4S and MS tumors, see the Treatment of INSS Stage 4S and INRG Stage MS Neuroblastoma section.
Treatment options for intermediate-risk neuroblastoma include the following:
Patients categorized as intermediate risk have been successfully treated with complete surgical resection and two, four, or eight cycles of neoadjuvant chemotherapy. The chemotherapy regimen consists of carboplatin, cyclophosphamide, doxorubicin, and etoposide. The cumulative dose of each agent is kept low to minimize long-term effects from the chemotherapy regimen (ANBL0531 [NCT00499616]). As a rule, patients whose tumors had unfavorable biology received eight cycles of chemotherapy, and patients whose tumors had favorable biology received either two or four cycles of chemotherapy. Favorable biological features include FH, DI higher than 1, and no SCAs.
Tumor response assessment is measured with a single dimension, as per Response Evaluation Criteria in Solid Tumors (RECIST). After the number of assigned cycles of chemotherapy (based on disease stage, age, and biological features), if greater than a partial response has not been obtained, then a multidisciplinary discussion should occur to discuss the role of surgery versus additional chemotherapy. Patients who achieve a partial response or greater will enter surveillance. Surgical resection should be considered if chemotherapy has resulted in less than 50% reduction in tumor size. For patients unable to undergo surgical resection, and additional chemotherapy is given, response should be re-evaluated after every two cycles of therapy. Another biopsy to look for histological differentiation may be necessary to assess a residual mass that did not shrink sufficiently with chemotherapy.[7]
In cases of abdominal neuroblastoma thought to involve a kidney, nephrectomy is not undertaken before a course of chemotherapy has been given.[8] Nephrectomy should be avoided in all cases.
Cyclophosphamide and topotecan were used in the ANBL0531 (NCT00499616) study as additional treatment in patients who had received eight cycles of intermediate-risk chemotherapy and did not achieve the targeted response.[9,10]
Whether initial chemotherapy is indicated for all intermediate-risk infants with localized neuroblastoma requires further study.
Evidence (chemotherapy with or without surgery):
The need for chemotherapy in all asymptomatic infants with stage 3 or stage 4 disease is controversial, as some European studies have shown favorable outcomes with surgery and observation.[13]
Evidence (surgery and observation in infants):
Radiation therapy for children with intermediate-risk disease is reserved for patients with progressive disease during treatment with chemotherapy or progressive unresectable disease after treatment with chemotherapy.
In a prospective randomized COG trial that tested reduced-intensity chemotherapy for patients with intermediate-risk neuroblastoma, only 12 of 479 patients (2.5%) received local radiation therapy (21 Gy). One patient had stage 4S disease, five patients had stage 3 disease, and six patients had stage 4 disease. Radiation therapy was administered for clinical deterioration despite initial therapy (eight patients), residual macroscopic disease and unfavorable biological features (three patients), or relapse after therapy (one patient).[2,11,17]
Information about National Cancer Institute (NCI)–supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
Patients most at risk for disease progression and mortality are older than 18 months, have metastatic disease or localized disease with unfavorable biology such as MYCN amplification, or have unfavorable histology. For more information about the Children's Oncology Group (COG) risk categories, see Table 3.
Approximately 8% to 10% of infants with stage MS disease have MYCN-amplified tumors and are usually treated using high-risk protocols. The 5-year event-free survival (EFS) and overall survival (OS) rates were 60% and 64%, respectively, for the infants with stage MS disease and MYCN amplification (n = 23), among the 5,000 patients enrolled in the COG ANBL00B1 (NCT00904241) trial.[1]
For children with high-risk neuroblastoma who received current treatments, the 5-year OS rate was about 60% for patients diagnosed between 2007 and 2017.[1] Children with aggressively treated, high-risk neuroblastoma may develop late recurrences, some more than 5 years after completion of therapy.[2,3]
A study from the International Neuroblastoma Risk Group (INRG) database found 146 patients with distant metastases limited to lymph nodes, termed stage 4N, who tended to have favorable-biology disease and a good outcome (5-year OS rate, 85%). This finding suggests that for this very rare, special subgroup of high-risk, stage 4 patients, less-intensive therapy might be considered.[4] These more favorable outcomes were confirmed in a single-institution study of 51 patients.[5]
Outcomes for patients with high-risk neuroblastoma remain poor despite recent improvements in survival in randomized trials.
Treatment options for high-risk neuroblastoma typically include the following:
Treatment for patients with high-risk disease is generally divided into the following three phases:
The backbone of the most commonly used induction therapy includes dose-intensive cycles of cisplatin and etoposide alternating with vincristine, cyclophosphamide, and doxorubicin.[6] Topotecan and cyclophosphamide were added to this regimen based on the antineuroblastoma activity seen in patients with relapsed disease.[7] Response to therapy after four cycles of chemotherapy or at the end of induction chemotherapy correlates with EFS at the completion of high-risk therapy.[8-10]
Evidence (induction chemotherapy with or without additional treatments):
After a response to induction chemotherapy, resection of the primary tumor is recommended by most treatment protocols. Whether a gross-total resection is beneficial is controversial.[14]
Evidence (extent of resection of the primary tumor):
The potential benefit of aggressive surgical approaches in high-risk patients with metastatic disease to achieve complete tumor resection, either at the time of diagnosis or after chemotherapy, has not been unequivocally demonstrated. Several studies have reported that complete resection of the primary tumor at diagnosis improved survival. However, the outcome in these patients may be more dependent on the biology of the tumor, which itself may determine resectability, than on the extent of surgical resection.[17-19]
In patients older than 18 months with stage 4 neuroblastoma, controversy exists about whether there is any advantage to gross-total resection of the primary tumor after chemotherapy.[15,18-20] In some studies, patients who underwent incomplete resections fared less well than those who underwent complete resections.[21] These outcomes could have resulted from either the biology of unresectable tumors or reduction of tumor bulk.[22][Level of evidence B1] Complete resection that requires nephrectomy is not recommended because of the nephrotoxic nature of standard chemotherapy and unproven effect of complete resection on outcome.
In most group studies, surgical resection of the primary tumor is performed during the induction phase. However, the JN-H-11 trial evaluated the feasibility of delayed resection after high-dose chemotherapy with stem cell rescue, with the goal of prioritizing systemic therapy.[23] Rates of complete or greater-than-90% resection were similar to those seen in a previous trial, in which surgery was performed during induction. The rate of nephrectomy was nominally lower (5.8% vs. 17%), and the 3-year cumulative incidence of local failure rate was nominally higher (17.3% vs. 11.6%), compared with the rates found in the previous trial.
At the end of induction therapy, patients with high-risk disease typically undergo a full disease evaluation. Management of patients with residual disease at the end of conventional induction therapy is not standardized. A retrospective study analyzed 201 patients with high-risk disease who had a partial response or less at the end of induction therapy. Patients were selected to immediately receive either high-dose chemotherapy (cohort 1), bridging therapy (usually chemoimmunotherapy or iodine I 131-metaiodobenzylguanidine [MIBG]) followed by high-dose chemotherapy (cohort 2), or additional therapy but not high-dose chemotherapy (cohort 3).[24]
These retrospective data suggest a role for bridging therapy in patients with incomplete response to conventional induction therapy.
The consolidation phase of high-risk regimens involves myeloablative chemotherapy and HSCT, which attempts to eradicate minimal residual disease (MRD) using otherwise lethal doses of ablative chemotherapy rescued by autologous stem cells (collected during induction chemotherapy) to repopulate the bone marrow. Several large randomized controlled studies showed improved 3-year EFS rates for treatment with HSCT (31%–47%) versus conventional chemotherapy (22%–31%).[25-27] Previously, total-body irradiation had been used in HSCT conditioning regimens. Most current protocols in North America use tandem cycles of chemotherapy and HSCT with cyclophosphamide/thiotepa and carboplatin/etoposide/melphalan.[28][Level of evidence C1] In Europe, clinical trials have also evaluated busulfan/melphalan and HSCT.
Evidence (myeloablative chemotherapy and stem cell rescue):
In a separate prospective randomized study, there was no advantage to purging harvested autologous stem cells of neuroblastoma cells before transplant.[34]
For more information about transplant, see Pediatric Autologous Hematopoietic Stem Cell Transplant and Pediatric Hematopoietic Stem Cell Transplant and Cellular Therapy for Cancer.
Radiation to the primary tumor site (whether or not a complete excision was obtained) is indicated after myeloablative therapy.[35,36]; [37][Level of evidence C1] Boost radiation therapy for gross-residual disease did not show improved local control when studied prospectively in the ANBL0532 (NCT00567567) trial.[38][Level of evidence C1] The optimal dose of radiation therapy has not been determined.[39]
Evidence (radiation therapy with a boost vs. radiation therapy without a boost for incomplete resection):
Extensive lymph node irradiation, regardless of the extent of surgical resection preceding HSCT, did not benefit patients for local progression or OS.[40][Level of evidence C1]
A detailed retrospective multicenter review of locoregional recurrences demonstrated that 48.4% were in-field recurrences and another 19.4% were marginal recurrences.[41] These findings suggest that additional optimization of radiation therapy approaches are still needed.
Treatment of bony metastatic disease, delivered at the time of primary tumor bed irradiation, is also considered to maximize disease control. Radiation therapy to metastatic disease sites is determined on an individual basis or according to protocol guidelines for patients enrolled in studies. Many children present with widespread bony metastases. Because it is not feasible to irradiate all initial sites, the current practice is to treat the sites that have not responded, as assessed by MIBG before HSCT.[42-44] Metastatic sites identified at diagnosis that did not receive radiation during frontline therapy appeared to have a higher risk of involvement at first relapse relative to previously irradiated metastatic sites.[42] In one single-institution study, 17 of 24 patients with residual MIBG-avid skeletal uptake at the end of front-line therapy without metastatic-site radiation therapy had disease recurrence. Of the 17 patients, 13 (76.5%) had disease recurrence at sites of prior skeletal disease.[45]
In a retrospective series of 159 children with high-risk stage M neuroblastoma, focal irradiation was delivered to all metastatic sites, regardless of response to chemotherapy, unless metastases were too numerous.[46]
These observations support the current paradigm of irradiating metastases that persist by MIBG uptake after induction chemotherapy in high-risk patients. Irradiation of more than 50% of the bone marrow is not advised.[46]
In cases where diffuse bone metastases remain after induction chemotherapy, high-dose chemotherapy is followed by reassessment before deciding on consolidative radiation therapy.
Preliminary outcomes of proton radiation therapy to treat patients with high-risk neuroblastoma primary tumors have been published, demonstrating acceptable efficacy and toxicity.[47]
Postconsolidation therapy is designed to treat potential MRD after HSCT.[31] For high-risk patients in remission after HSCT, dinutuximab combined with GM-CSF given together with isotretinoin demonstrated improved EFS.[48,49]
Evidence (all treatments):
Based on the SIOPEN data, the COG removed IL-2 from standard postconsolidation immunotherapy.
Radioactive MIBG therapy has been used to treat recurrent neuroblastoma with some success. This therapy has been shown to be safe and feasible to incorporate into the treatment regimen for children with newly diagnosed high-risk neuroblastoma.[58] A randomized trial (ANBL1531 [NCT03126916]) incorporating radioactive MIBG therapy into the complex therapy for newly diagnosed high-risk neuroblastoma has completed accrual.
A multi-institution, phase II clinical trial of children with high-risk neuroblastoma evaluated 2 years of continuation therapy using eflornithine (previously known as difluoromethylornithine [DFMO]), an oral ornithine decarboxylase inhibitor.[59] Although the study concluded that survival was improved compared with a subset of patients who were previously treated in the ANBL0032 (NCT00026312) trial, the historical comparison and potential patient selection bias limit the validity of this finding. An updated report describes the results of a propensity matching analysis that compared patients who were treated with eflornithine with patients in the ANBL0032 trial who were not treated with eflornithine.[60] Propensity matching generally balanced differences in available patient characteristics. In the matched analysis, patients in the eflornithine cohort had statistically significantly higher EFS and OS, compared with patients in the non-eflornithine cohort (4-year EFS rates, 84% vs. 73% and 4-year OS rates, 96% vs. 84%). The authors noted that uncontrolled confounders may exist in this nonrandomized comparison. Based on these results, the FDA approved the use of eflornithine as continuation therapy in December 2023.
A GD2/GD3 ganglioside vaccine has been studied for patients in first remission after completion of standard therapy. In a randomized trial that mainly included patients in first remission, early introduction of beta-glucan along with a GD2/GD3 vaccine increased GD2/GD3 antibody titers without increasing toxicity. Progression-free survival (PFS) rates were similar for patients in both randomized treatment arms. However, patients with higher titers had more favorable PFS rates, regardless of the treatment arm.[61][Level of evidence B1]
Information about National Cancer Institute (NCI)–supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following is an example of a national and/or institutional clinical trial that is currently being conducted:
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
International Neuroblastoma Staging System (INSS) stage 4S patients are younger than 12 months and have an INSS stage 1 or stage 2 primary tumor. International Neuroblastoma Risk Group (INRG) stage MS patients are younger than 18 months with any stage of primary tumor. Both staging systems have the same definition of limited pattern of metastases.
The decision by the INRG Task Force to replace the category of 4S disease with that of the new MS definition was based on reports in which small numbers of infants with L2 primary tumors and 4S metastatic patterns, including patients aged 12 to 18 months, had favorable outcomes.[1,2] A subsequent study of the actual INRG data found that a number of biological characteristics predicted poor outcome of patients aged 12 to 18 months with stage MS disease, and that only those infants with favorable biology had long-term outcomes similar to those with the traditional 4S diagnosis.[2]
Infants with INRG stage MS disease have more favorable biology and superior outcomes despite receiving less aggressive therapy. The 5-year event-free survival (EFS) rate was 86%, and the overall survival (OS) rate was 95%. For patients with MYCN-amplified tumors, the 5-year EFS rate was 60%, and the OS rate was 65%.[3]
Many patients with stage 4S/MS neuroblastoma do not require therapy. However, tumors with unfavorable biology or patients who are symptomatic because of evolving hepatomegaly and organ compromise are at increased risk of death and are treated with low-dose to moderate-dose chemotherapy. Eight percent to 10% of these patients will have MYCN amplification and are treated with high-risk treatment regimens.[4]
For more information about the Children's Oncology Group (COG) classification schema for stage 4S/MS neuroblastoma, see Table 3.
There is no standard approach for the treatment of stage 4S/MS neuroblastoma.
Treatment options for stage 4S/MS neuroblastoma include the following:
Resection of the primary tumor is not associated with improved outcome.[5-7] Rarely, infants with massive hepatic 4S/MS neuroblastoma develop cirrhosis from the chemotherapy and/or radiation therapy that is used to control the disease and may benefit from orthotopic liver transplant.[8]
Observation with supportive care is used to treat asymptomatic patients with favorable tumor biology.
The treatment of children with stage 4S/MS disease depends on clinical presentation.[5,6] Most patients do not require therapy unless bulky disease causes organ compromise and risk of death.
Chemotherapy is used to treat symptomatic patients or patients with unfavorable tumor biology. Patients with evidence of rapid tumor growth in the first several weeks of life require immediate intervention with chemotherapy to avoid potentially irreversible abdominal compartment syndrome and hepatic and/or renal failure.[9]
Infants diagnosed with INSS stage 4S/MS neuroblastoma, particularly those with hepatomegaly or those younger than 2 months with high-risk features or hepatomegaly, have the potential for rapid clinical deterioration and may benefit from early initiation of therapy.[9] It has been difficult to identify infants with stage 4S disease who will benefit from chemotherapy.
A scoring system to measure signs and symptoms of deterioration or compromise was developed to better assess this group of stage 4S patients.[10] This scoring system has been evaluated retrospectively, was predictive of the clinical course, and has been applied prospectively to guide the management of patients with INSS stage 4S disease.[10,11] The scoring system has been modified based on the ANBL0531 (NCT00499616) study results in the youngest infants discussed above to guide chemotherapeutic intervention for 4S/MS in infants.[9]
Various chemotherapy regimens (cyclophosphamide alone, carboplatin/etoposide, cyclophosphamide/doxorubicin/vincristine) have been used to treat symptomatic patients. The approach is to administer the chemotherapy only as long as symptoms persist to avoid toxicity, which contributes to poorer survival. Additionally, lower doses of chemotherapy are often recommended for very young or low-weight infants, along with granulocyte colony-stimulating factors after each cycle of chemotherapy.
Evidence (chemotherapy for 4S/MS disease):
Previously, chemotherapy toxicity was thought to be responsible for the poorer survival of patients with stage 4S disease. However, the use of chemotherapy on the COG-P9641 trial was restricted to specific clinical situations with a recommended number of cycles.
The chemotherapy for patients with high symptom scores included two to four 3-day courses of carboplatin and etoposide. If symptoms persisted or progressive disease developed, up to four 5-day courses of cyclophosphamide, doxorubicin, and vincristine were administered. One-half of the patients underwent complete or partial resection of the primary tumor.
Occasionally, if the liver becomes too large and is compromising the kidney and other abdominal organs, a decompressive laparotomy may be necessary,[13,14] although this would typically be an indication for chemotherapy as well. Likewise, emergent surgical abdominal decompression can be used to avoid respiratory deterioration and improve ventilation.[13,14]
In rare cases of marked hepatomegaly in symptomatic MS (4S) infants with neuroblastoma who were unresponsive to chemotherapy, very low-dose radiation therapy has been used. In a series of 41 symptomatic infants with MS disease, radiation therapy was administered to five infants, three of whom died.[9]
Information about National Cancer Institute (NCI)–supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
Tumor growth resulting from maturation should be differentiated from tumor progression by performing a biopsy and reviewing histology. Patients may have persistent maturing disease with metaiodobenzylguanidine (MIBG) uptake that does not affect outcome, particularly patients with low-risk and intermediate-risk disease.[1] An analysis of 23 paired MIBG and positron emission tomography (PET) scans in 14 patients with refractory or recurrent high-risk neuroblastoma treated with iodine I 131-MIBG (131I-MIBG) found that the MIBG scan was more sensitive than fluorine F 18-fludeoxyglucose (18F-FDG) PET for detecting metastatic bone lesions, although there was a trend for 18F-FDG PET to be more sensitive for soft tissue lesions.[2]
Subclonal ALK variants or other MAPK pathway lesions may be present at diagnosis, with subsequent clonal expansion at relapse. Consequently, serial sampling of progressive tumors may lead to the identification of potentially actionable variants.[3,4] Modern comprehensive molecular analysis comparing primary and relapsed neuroblastoma from the same patients revealed extensive clonal enrichment and several newly discovered variants, with many tumors showing new or clonal-enriched variants in the RAS-MAPK pathway. This was true for patients with both high-risk and low-risk tumors at diagnosis.[5,6] For more information, see the Genomic and Biological Features of Neuroblastoma section.
Sequencing of recurrent and refractory neuroblastoma tumors from pediatric (n = 59) and young adult patients (n = 1) enrolled in the NCI-COG Pediatric MATCH trial revealed genomic alterations that were considered actionable for treatment in MATCH study arms in 27 of 60 tumors (45%).[7] Hotspot variants in ALK were most frequent, reported in 19 of 60 tumors (31.7%). MAPK pathway variants (NF1, NRAS) were detected in 4 of 60 tumors (6.7%), and FGFR1 variants were detected in 3 of 60 tumors (5%).
If neuroblastoma recurs in a child originally diagnosed with high-risk disease, the prognosis is usually poor despite additional intensive therapy.[8-11] However, it is often possible to gain many additional months of life for these patients with alternative chemotherapy regimens.[12,13] Clinical trials are appropriate for these patients and may be offered. Information about ongoing clinical trials is available from the NCI website.
A comprehensive analysis of the patterns of relapse was conducted using the International Neuroblastoma Risk Group (INRG) database on patients diagnosed/enrolled between 1989 and 2017.[14][Level of evidence C1]
The INRG database was used to examine clinical and biological features that are prognostic of survival after relapse or progression of INRG Staging System (INRGSS) stage MS pattern neuroblastoma. Of the 1,511 patients diagnosed between 1984 and 2021 who met the eligibility criteria, 209 patients were identified as having an event. Eligibility criteria included patients younger than 365 days at initial diagnosis with INRGSS stage MS disease or with International Neuroblastoma Staging System (INSS) stage 4S, or patients aged 365 to 546 days with INSS stage 4 disease and metastasis limited to the liver, skin, and/or bone marrow.[15][Level of evidence C1]
The International Neuroblastoma Risk Group Project performed a survival-tree analysis of clinical and biological characteristics (defined at diagnosis) associated with survival after relapse in 2,266 patients with neuroblastoma entered in large clinical trials in well-established clinical trials groups around the world.[8] The survival-tree analysis revealed the following:
Significant prognostic factors determined at diagnosis for postrelapse survival include the following:[8]
The Children’s Oncology Group (COG) experience with recurrence in patients with low-risk and intermediate-risk neuroblastoma showed that most patients can be salvaged. The COG reported a 3-year event free survival (EFS) rate of 88% and an OS rate of 96% in intermediate-risk patients and a 5-year EFS rate of 89% and OS rate of 97% in low-risk patients.[16,17] Moreover, in most patients originally diagnosed with low-risk or intermediate-risk disease, local recurrence or recurrence in the 4S pattern may be treated successfully with observation alone, surgery alone, or with moderate-dose chemotherapy, without myeloablative therapy and stem cell transplant.
The OS after recurrence in children presenting with high-risk neuroblastoma is generally extremely poor. However, such patients at first relapse after complete remission or minimal residual disease (MRD) in whom relapse was a single site of soft tissue mass (a few children also had bone marrow or bone disease at relapse) had a 5-year OS rate of 35% in one single-institution study. All patients underwent surgical resection of the soft tissue disease. MYCN amplification and multifocal soft tissue disease were associated with a worse postprogression survival.[18] Older children with local recurrence, with either unfavorable International Neuroblastoma Pathology Classification at diagnosis or MYCN gene amplification, have a poor prognosis and may be treated with surgery or aggressive combination chemotherapy, or they may be offered entry into a clinical trial.
Table 7 summarizes the treatment options for recurrent neuroblastoma by INSS-based risk group.
COG Risk-Group Assignment | Treatment Options |
---|---|
COG = Children's Oncology Group; 131I-MIBG = iodine I 131-metaiodobenzylguanidine. | |
Locoregional recurrence in patients initially classified as low risk | Surgery followed by observation or chemotherapy. |
Chemotherapy that may be followed by surgery. | |
Metastatic recurrence in patients initially classified as low risk | Observation (if metastatic disease is in a 4S pattern in an infant). |
Chemotherapy. | |
Surgery followed by chemotherapy. | |
Locoregional recurrence in patients initially classified as intermediate risk | Surgery (complete resection). |
Surgery (incomplete resection) followed by chemotherapy. | |
Radiation therapy (only for patients with disease progression after chemotherapy and second-look surgery). | |
Metastatic recurrence in patients initially classified as intermediate risk | High-risk therapy. |
Recurrence in patients initially classified as high risk | Chemotherapy combined with immunotherapy. |
131I-MIBG alone, in combination with other therapy, followed by stem cell rescue. | |
Novel therapies, including ALK inhibitors for those patients with ALK variants. | |
Chemotherapy. | |
Immunotherapy. | |
Recurrence in the central nervous system | Surgery and radiation therapy. |
Chemotherapy in combination with surgery and radiation therapy. | |
Novel therapeutic approaches. |
Treatment options for locoregional recurrent neuroblastoma initially classified as low risk include the following:
Local or regional recurrent cancer is resected if possible.
Patients with favorable biology and regional recurrence more than 3 months after completion of planned treatment are observed if resection of the recurrence is total or near total (≥90% resection). Those with favorable biology and a less-than-near-total resection are treated with chemotherapy.[16,17,19]
Infants younger than 1 year at the time of locoregional recurrence whose tumors have any unfavorable biological properties are observed if resection is total or near total. If the resection is less than near total, these infants are treated with chemotherapy. Chemotherapy may consist of moderate doses of carboplatin, cyclophosphamide, doxorubicin, and etoposide, or cyclophosphamide and topotecan. The cumulative dose of each agent is kept low to minimize long-term effects, as used in previous COG trials (COG-P9641 and COG-A3961).[16,17,19]
Evidence (surgery followed by observation or chemotherapy):
Treatment options for metastatic recurrent neuroblastoma initially classified as low risk include the following:
Metastatic recurrent or progressive neuroblastoma in an infant initially categorized as low risk and younger than 1 year at recurrence may be treated according to tumor biology, as defined in the previous COG trials (COG-P9641 and COG-A3961):
Chemotherapy may consist of moderate doses of carboplatin, cyclophosphamide, doxorubicin, and etoposide. The cumulative dose of each agent is kept low to minimize long-term effects, as used in previous COG trials (COG-P9641 and COG-A3961).
Any child initially categorized as low risk who is older than 18 months at the time of metastatic recurrent or progressive disease and whose recurrence is not in the stage 4S pattern usually has a poor prognosis and is treated as follows:
Patients with metastatic recurrent neuroblastoma are treated like patients with newly diagnosed high-risk neuroblastoma. For more information, see the Treatment Options for High-Risk Neuroblastoma section.
The COG ANBL0531 (NCT00499616) study treated patients with newly diagnosed intermediate-risk neuroblastoma with chemotherapy consisting of carboplatin, etoposide, cyclophosphamide, and doxorubicin. Retrieval therapy was included in the protocol for patients who developed progressive nonmetastatic disease within 3 years of study enrollment. Up to six cycles of cyclophosphamide and topotecan could be given to patients. Of 29 patients who received cyclophosphamide and topotecan, 18 remained event free, 9 experienced relapse, and 2 died. Twenty patients who experienced an inadequate initial response to eight cycles of chemotherapy were treated with cyclophosphamide and topotecan. Of those 20 patients, 9 patients achieved a very good partial response or better; however, 6 patients developed progressive disease or experienced relapse, and 1 patient died. This suggests that more aggressive therapy is needed for patients who do not achieve the defined treatment end point after eight cycles of chemotherapy.[19]
A COG study for intermediate-risk neuroblastoma (COG-A3961) enrolled 479 patients, 42 of whom developed disease progression. The recurrence rate was 10% for those with favorable biology and 17% for those with unfavorable biology. Thirty patients had locoregional recurrences, 11 had metastatic recurrences, and 1 had both types of recurrent disease. Six of the 42 patients died of disease, while 36 patients responded to therapy. Thus, most patients with intermediate-risk neuroblastoma and disease progression may be salvaged.[16] It is not feasible to compare these results with the results of the other COG intermediate-risk study (ANBL0531) because of differences between the classification of patients for eligibility in the two studies.[19]
Treatment options for locoregional recurrent neuroblastoma initially classified as intermediate risk include the following:
Locoregional recurrence of neuroblastoma with favorable biology that occurs more than 3 months after completion of chemotherapy may be treated surgically. If resection is less than near total, then additional chemotherapy may be given. Chemotherapy should be selected based on the previous chemotherapy received.[16]
Treatment options for metastatic recurrent neuroblastoma initially classified as intermediate risk include the following:
Patients with metastatic recurrent neuroblastoma are treated like patients with newly diagnosed high-risk neuroblastoma. For more information, see the Treatment Options for High-Risk Neuroblastoma section.
Any recurrence in patients initially classified as high risk signifies a very poor prognosis.[8] Clinical trials may be considered. Palliative care should also be considered as part of the patient's treatment plan.
An analysis of several trials included 383 patients with neuroblastoma whose tumor recurred or progressed in COG modern-era, early-phase trials. The 1-year progression-free survival (PFS) rate was 21%, and the 4-year PFS rate was 6%. The OS rates were 57% at 1 year and 20% at 4 years. Less than 10% of patients experienced no subsequent recurrence or progression. MYCN amplification predicted worse PFS and OS rates.[20] Although the OS after recurrence in children presenting with high-risk neuroblastoma is generally extremely poor, patients with high-risk neuroblastoma at first relapse after complete remission or MRD in whom relapse was a single site of soft tissue mass (a few children also had bone marrow or bone disease at relapse) had a 5-year OS rate of 35% in one single-institution study.[18]
Treatment options for recurrent or refractory neuroblastoma in patients initially classified as high risk include the following:
Chemotherapy combined with immunotherapy produces the best response rate and response duration of treatments for high-risk patients with disease progression.
Evidence (chemotherapy combined with immunotherapy):
Evidence (131I-MIBG alone or in combination with other therapies):
Evidence (chemotherapy):
A range of other immunotherapy approaches have been used in patients with relapsed neuroblastoma. Single-agent anti-GD2 monoclonal antibody therapy has shown activity in this setting. For example, a phase II trial evaluated a 10-day, long-term infusion of dinutuximab in 40 children with relapsed or refractory high-risk neuroblastoma. The study reported an objective response rate of 26%. This approach was tolerable, with no grade 4 or grade 5 events.[49]
Allogeneic transplant has a historically low success rate in recurrent or progressive neuroblastoma. In a retrospective registry study, allogeneic HSCT after a previous autologous HSCT appeared to offer no benefit. Disease recurrence remains the most common cause of treatment failure.[50] A similar conclusion was reached in a multicenter phase II trial of reduced-intensity conditioning allogeneic HSCT in 51 patients, 44 of whom had relapsed or refractory high-risk neuroblastoma. The 5-year disease-free survival (DFS) rate was 11.8%.[51]
The use of GD2-directed therapy after haploidentical transplant may be a more promising strategy. In one trial of 68 patients with relapsed neuroblastoma, the use of dinutuximab and subcutaneous interleukin-2 after haploidentical transplant was feasible, with a low rate of graft-versus-host disease. The 5-year EFS rate was 43%. Superior outcomes were obtained for patients who had complete or partial responses at the start of dinutuximab therapy. Among patients with disease after transplant, the complete response rate to anti-GD2 immunotherapy was 35%.[52]
Clinical trials of vaccines designed to induce host antiganglioside antibodies that can replicate the antineoplastic activities of intravenously administered monoclonal antibodies are ongoing. Patients also receive a beta-glucan treatment, which has a broad range of immunostimulatory effects and synergizes with anti-GD2/GD3 monoclonal antibodies. In a phase I study of 15 children with high-risk neuroblastoma, the therapy was tolerated without any dose-limiting toxicity.[53] Long-term PFS has been reported in patients who achieve a second or later complete or very good partial remission followed by consolidation with anti-GD2 immunotherapy and isotretinoin with or without maintenance therapy. This includes patients who had previously received anti-GD2 immunotherapy and isotretinoin.[54]
In a phase I/II trial, the use of autologous chimeric antigen receptor (CAR)–expressing T cells directed against GD2 was feasible and safe in treating children with relapsed or refractory, high-risk neuroblastoma. This treatment resulted in a response rate of 63%.[55] These findings contrast with earlier reports that showed only modest activity of other GD2-directed CAR T-cell approaches in this same population.
Central nervous system (CNS) involvement, although rare at initial presentation, may occur in 3% to 10% of patients with recurrent neuroblastoma. CNS relapses represented 6% of all metastatic relapses in a series of 1,161 first relapses in 1,977 patients with stage 4 disease treated in a trial of patients with high-risk neuroblastoma.[56] Because up-front treatment for newly diagnosed patients does not adequately treat the CNS, the CNS has emerged as a sanctuary site leading to relapse.[56-58]
Significant risk factors for CNS relapse identified in the International Society of Paediatric Oncology Europe Neuroblastoma (SIOPEN) trial were patient and disease features at diagnosis. These features included female sex (HR, 2.0; P = .016), MYCN amplification (HR, 2.4; P = .0008), hepatic disease (HR, 2.5; P = .01), or more than one metastatic system/compartment involvement (HR, 7.1; P = .047). Neither high-dose chemotherapy nor immunotherapy was associated with higher risk of recurrence. Investigators noted stable incidence of CNS relapse reported over time.[56]
CNS relapses are almost always fatal, with a median time to death of 6 months. The 1-year and 3-year postrelapse OS rates were 25% and 7%, respectively, in the SIOPEN trial.[56] Patients with isolated CNS relapses may be able to achieve long-term survival.[56]
Treatment options for recurrent neuroblastoma in the CNS include the following:
Current treatment approaches generally include eradicating bulky and microscopic residual disease in the CNS and minimal residual systemic disease that may herald further relapses. Neurosurgical interventions serve to decrease edema, control hemorrhage, and remove bulky tumor before starting therapy.
A single institution had some success while testing intraventricular compartmental radioimmunotherapy using intrathecal radioiodinated anti-B7H3 monoclonal antibodies, combined with 18 Gy or 21 Gy of craniospinal irradiation with boosts to gross CNS disease, in patients with recurrent metastatic CNS neuroblastoma.[13] The posttreatment 5-year CNS DFS rate was about 69%, and the 5-year OS rate was about 45%.[59][Level of evidence C2]
For patients who experience prolonged survival after an initial CNS relapse, some may develop a second relapse after cranial spinal irradiation (CSI). Published data for patients who experience a second CNS relapse are limited. A second CNS relapse indicates a poor prognosis.[57]
In a single-institution study that included 128 patients treated with CSI for first CNS relapse, 40 developed a second CNS relapse at a median of 6.3 months from the initial CSI treatment. Patient outcomes after second CNS relapse are poor, although treatment with radiation therapy at the time of second CNS relapse may be associated with longer OS.[60][Level of evidence C1]
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This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the treatment of neuroblastoma. It is intended as a resource to inform and assist clinicians in the care of their patients. It does not provide formal guidelines or recommendations for making health care decisions.
This summary is reviewed regularly and updated as necessary by the PDQ Pediatric Treatment Editorial Board, which is editorially independent of the National Cancer Institute (NCI). The summary reflects an independent review of the literature and does not represent a policy statement of NCI or the National Institutes of Health (NIH).
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PDQ® Pediatric Treatment Editorial Board. PDQ Neuroblastoma Treatment. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/types/neuroblastoma/hp/neuroblastoma-treatment-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389190]
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