Management and outcome of stage 3 neuroblastoma

Survival of Patients With Neuroblastoma After Assignment to Reduced Therapy Because of the 12- to 18-Month Change in Age Cutoff in Children's Oncology Group Risk Stratification

PURPOSE

In 2006, Children's Oncology Group (COG) reclassified subgroups of toddlers diagnosed with neuroblastoma from high-risk to intermediate-risk, when the age cutoff for high-risk assignment was raised from 365 days (12 months) to 547 days (18 months). The primary aim of this retrospective study was to determine if excellent outcome was maintained after assigned reduction of therapy.

PATIENTS AND METHODS

Children <3 years old at diagnosis, enrolled on a COG biology study from 1990 to 2018, were eligible (n = 9,189). Assigned therapy was reduced for two cohorts of interest on the basis of the age cutoff change: 365-546 days old with International Neuroblastoma Staging System (INSS) stage 4, MYCN not amplified (MYCN-NA), favorable International Neuroblastoma Pathology Classification (INPC), hyperdiploid tumors (12-18mo/Stage4/FavBiology), and 365-546 days old with INSS stage 3, MYCN-NA, and unfavorable INPC tumors (12-18mo/Stage3/MYCN-NA/Unfav). Log-rank tests compared event-free survival (EFS) and overall survival (OS) curves.

RESULTS

For 12-18mo/Stage4/FavBiology, 5-year EFS/OS (± SE) before (≤2006; n = 40) versus after (>2006; n = 55) assigned reduction in therapy was similar: 89% ± 5.1%/89% ± 5.1% versus 87% ± 4.6%/94% ± 3.2% (P = .7; P = .4, respectively). For 12-18mo/Stage3/MYCN-NA/Unfav, the 5-year EFS and OS were both 100%, before (n = 6) and after (n = 4) 2006. The 12-18mo/Stage4/FavBiology plus 12-18mo/Stage3/MYCN-NA/Unfav classified as high-risk ≤2006 had an EFS/OS of 91% ± 4.4%/91% ± 4.5% versus 38% ± 1.3%/43% ± 1.3% for all other high-risk patients <3 years old (P < .0001; P < .0001, respectively). The 12-18mo/Stage4/FavBiology plus 12-18mo/Stage3/MYCN-NA/Unfav classified as intermediate-risk >2006 had an EFS/OS of 88% ± 4.3%/95% ± 2.9% versus 88% ± 0.9%/95% ± 0.6% for all other intermediate-risk patients <3 years old (P = .87; P = .85, respectively).

CONCLUSION

Excellent outcome was maintained among subsets of toddlers with neuroblastoma assigned to reduced treatment after reclassification of risk group from high to intermediate on the basis of new age cutoffs. Importantly, as documented in prior trials, intermediate-risk therapy is not associated with the degree of acute toxicity and late effects commonly observed with high-risk regimens.

Impact of Genomic and Clinical Factors on Outcome of Children ≥18 Months of Age with Stage 3 Neuroblastoma with Unfavorable Histology and without MYCN Amplification: A Children's Oncology Group (COG) Report

PURPOSE

Patients ≥18 months of age with International Neuroblastoma Staging System (INSS) stage 3 unfavorable histology (UH), MYCN-nonamplified (MYCN-NA) tumors have favorable survival rates compared with other high-risk neuroblastoma populations. The impact of select clinical and biological factors on overall survival (OS) and event-free survival (EFS) were evaluated.

EXPERIMENTAL DESIGN

Patients enrolled on Children's Oncology Group (COG) A3973 (n = 34), ANBL0532 (n = 27), and/or biology protocol ANBL00B1 (n = 72) were analyzed. Tumors with available DNA (n = 65) and RNA (n = 42) were subjected to whole-exome sequencing (WES) and RNA sequencing. WES analyses and gene expression profiling were evaluated for their impact on survival. Multivariate analyses of EFS/OS using significant factors from univariate analyses were performed.

RESULTS

5-year EFS/OS for patients treated with high-risk therapy on A3973 and ANBL0532 were 73.0% ± 8.1%/87.9% ± 5.9% and 61.4% ± 10.2%/73.0% ± 9.2%, respectively (P = 0.1286 and P = 0.2180). In the A3973/ANBL0532 cohort, patients with less than partial response (PR; n = 5) at end-induction had poor outcomes (5-year EFS/OS: 0%/20.0% ± 17.9%. Univariate analyses of WES data revealed that subjects whose tumors had chromosome 1p or 11q loss/LOH and chromosome 5 or 9 segmental chromosomal aberrations had inferior EFS compared with those with tumors without these aberrations. Multivariate analysis revealed that 11q loss/LOH was an independent predictor of inferior OS [HR, 3.116 (95% confidence interval, 1.034-9.389), P = 0.0435].

CONCLUSIONS

Patients ≥18 months of age at diagnosis who had tumors with UH and MYCN-NA INSS stage 3 neuroblastoma assigned to high-risk therapy had an 81.6% ± 5.3% 5-year OS. Less than PR to induction therapy and chromosome 11q loss/LOH are independent predictors of inferior outcome and identify patients who should be eligible for future high-risk clinical trials.

Segmental chromosomal aberrations as the poor prognostic factor in children over 18 months with stage 3 neuroblastoma without MYCN amplification

Introduction

Patients with stage 3 neuroblastoma (NBL) according to International Neuroblastoma Staging System (INSS) without MYCN amplification represent a heterogenous group with respect to disease presentation and prognosis.

Methods

Retrospective analysis of 40 stage 3 patients with NBL without MYCN amplification was performed. The prognostic value of age at diagnosis (under 18 vs over 18 months), International Neuroblastoma Pathology Classification (INPC) diagnostic category and presence of segmental or numerical chromosomes aberrations were evaluated, as well as biochemical markers. Array comparative genomic hybridization (aCGH) for analyzing copy number variations and Sanger sequencing for ALK point mutations were done.

Results

In 12 patients (two patients under 18 months), segmental chromosomal aberrations (SCA) were found and numerical chromosomal aberrations (NCA) were found in 16 patients (14 patients under 18 months). In children over 18 months SCA were more common (p=0.0001). Unfavorable pathology was significantly correlated with SCA genomic profile (p=0.04) and age over 18 months (p=0.008). No therapy failures occurred in children with NCA profile over or under 18 months or in children under 18 months, irrespective of pathology and CGH results. Three treatment failures occurred in the SCA group, in one patient CGH profile was not available. For the whole group at 3, 5 and 10-year OS and DFS were 0.95 (95% CI 0.81-0.99), 0.91 (95% CI 0.77-0.97) and 0.91 (95% CI 0.77-0.97), and 0.95 (95% CI 0.90-0.99), 0.92 (95% CI 0.85-0.98) and 0.86 (95% CI 0.78-0.97), respectively. DFS was significantly lower in the SCA group than in the NCA group (3-years, 5-years, and 10-years DFS 0.92 (95% CI 0.53-0.95), 0.80 (95% CI 0.40-0.95) and 0.60 (95% CI 0.16-0.87) vs 1.0, 1.0 and 1.0, respectively, p=0.005).

Conclusions

The risk of treatment failure was higher in patients with SCA profile, but only in patients over 18 months. All relapses occurred in children having obtained the complete remission, with no previous radiotherapy. In patients over 18 months, SCA profile should be taken into consideration for therapy stratification as it increases the risk of relapse and this group may require more intensive treatment.

The application and value of radiotherapy at the primary site in patients with high-risk neuroblastoma

OBJECTIVE

To retrospectively analyze radiotherapy (RT) regimens for patients with high-risk neuroblastoma (HRNB) at the primary site after surgery, and to further analyze the characteristics of patients who would benefit more from RT.

METHODS

98 pediatric patients with HRNB were analyzed for local control (LC), RT dose, extent of excision and prognostic factors. Among them, 69 children received RT.

RESULTS

The 3 year LC rates were 96.9 and 62.1% (p < 0.001) in the RT and non-RT groups, respectively. In the non-RT group, LC was better in patients with complete macroscopic resection (CME) than in those with incomplete macroscopic resection (IME) (p = 0.026), while in the RT group, no significant difference in LC was found (p = 0.985). Among patients with IME, the LC was 100% in patients with RT doses >= 36 Gy and 66.7% in patients with doses <36 Gy.

CONCLUSION

RT is valuable, provides patients with excellent LC, and is safe in the short term. RT had a complementary therapeutic effect on incompletely resected tumors, thus bringing their LC to the level of patients with CME. For patients with IME, RT at a dose of not less than 36 Gy may improve LC.

ADVANCES IN KNOWLEDGE

This study analysed the role of radiotherapy in HRNB, investigated the dose of RT depending on the degree of resection, and explored the characteristics of patients who would benefit more from RT.

Unresectable thoracic neuroblastic tumors: Changes in image-defined risk factors after chemotherapy and impact on surgical management

PURPOSE

Neuroblastoma management in children is multimodal and depends on multiple factors, including the possibility of complete surgical resection. Image-defined risk factors (IDRFs) are used to assess the feasibility of primary surgery. We studied the changes in IDRFs after neoadjuvant chemotherapy for thoracic neurogenic tumors.

METHODS

We performed a multicenter review of 27 patients presenting with unresectable thoracic neurogenic tumors. Patients received neoadjuvant chemotherapy, according to their risk group. IDRF at diagnosis and before surgery were retrospectively analyzed by a radiologist and a surgeon, blind to the initial assessment. Surgical and oncologic outcomes were reviewed.

RESULTS

None of the patients presented MYCN amplification, and 78 IDRFs were identified at diagnosis. Vascular IDRFs were the most frequent, with 28 vascular IDRFs detected in 18 patients, 22 of which disappeared after chemotherapy. Reductions of tumor volume were associated with a regression of IDRFs. Patients undergoing minimally invasive surgery had smaller tumor volumes than those undergoing open surgery, and no vascular IDRF. Two patients received two additional courses of chemotherapy to reduce tumor volume sufficiently for surgery. One patient with ganglioneuroblastoma underwent early surgery due to a lack of response to initial chemotherapy.

CONCLUSION

Tumor volume reduction with neoadjuvant chemotherapy eliminates most IDRF in thoracic neurogenic tumors. Vascular IDRF are rapidly resolved at this site, making surgical resection and minimally invasive surgery possible.

Genetic Alterations and Resectability Predict Outcome in Patients with Neuroblastoma Assigned to High-Risk Solely by MYCN Amplification

Simple Summary

Currently, patients with high-risk neuroblastoma are uniformly treated with maximum therapy. This study investigated a high-risk subgroup characterized by the presence of the amplified MYCN oncogene in the tumor regardless of the stage. In contrast to the corresponding high-risk subgroup consisting of patients with metastases and age at diagnosis over 18 months, the investigated subgroup had generally a superior survival chance. However, the detection of mutations of specific genes in the tumor tissue (RAS and p53 pathway including ALK) had a strong, negative impact. These genes should be therefore also investigated in the future. Complete surgical removal of the primary tumor proved to be beneficial for high-risk neuroblastoma patients assigned to the high-risk category solely by MYCN amplification.

Abstract

Background: To identify variables predicting outcome in neuroblastoma patients assigned to the high-risk group solely by the presence of MYCN oncogene amplification (MNA). Methods: Clinical characteristics, genomic information, and outcome of 190 patients solely assigned to high-risk neuroblastoma by MNA were analyzed and compared to 205 patients with stage 4 neuroblastoma aged ≥18 months with MNA (control group). Results: Event-free survival (EFS) and overall survival (OS) at 10 years were 47% (95%-CI 39–54%) and 56% (95%-CI 49–63%), respectively, which was significantly better than EFS and OS of the control group (EFS 25%, 95%-CI 18–31%, p < 0.001; OS 32% 95%-CI 25–39%, p < 0.001). The presence of RAS-/p53-pathway gene alterations was associated with impaired 10-year EFS and OS (19% vs. 55%, and 19% vs. 67%, respectively; both p < 0.001). In time-dependent multivariable analyses, alterations of RAS-/p53-pathway genes and the extent of the best primary tumor resection were the only independent prognostic variables for OS (p < 0.001 and p = 0.011, respectively). Conclusions: Neuroblastoma patients attributed to high risk solely by MYCN amplification have generally a more favorable outcome. Mutations of genes of the RAS and/or p53 pathways and incomplete resection are the main risk factors predicting poor outcome.

Differential Impact of ALK Mutations in Neuroblastoma

PURPOSE

The tyrosine kinase receptor anaplastic lymphoma kinase (ALK) can be abnormally activated in neuroblastoma, and somatic ALK mutations occur in 6%-10% of patients. The differential clinical impact of these mutations has not been clearly elucidated.

METHODS

Data on patients with neuroblastoma harboring ALK mutations were retrospectively analyzed. ALK sequencing was performed by whole-genome sequencing, hybrid-based capture of targeted exomes, or hotspot ALK mutation profiling. The differential impact of ALK mutation site on clinical characteristics, response to treatment, and survival was analyzed. In a subgroup of patients with locoregional neuroblastoma diagnosed after 2014, the impact of all ALK mutations was compared with wild-type ALK.

RESULTS

Of 641 patients with neuroblastoma with ALK status analyzed on at least one tumor sample, 103 (16%) had tumors harboring ALK mutations. Mutations existed across all ages (birth to 67.8 years), stages (30% locoregional and 70% metastatic), and risk groups (20%, 11%, and 69% with low-, intermediate-, and high-risk disease, respectively). Mutation sites included F1174 (51%), R1275 (29%), R1245 (10%), and others (10%). Mutation site was not prognostic for progression-free survival or overall survival in the entire cohort, high-risk subgroup, or locoregional subgroup. Locoregional tumors with any ALK mutation were generally invasive: L2 by International Neuroblastoma Research Group staging in 30/31 patients with a 2-year progression-free survival (59%, 95% CI, 37.4 to 80.5) that was inferior to historical controls. This observation was corroborated in the post-2014 subgroup in which gross total resection was less likely for ALK-mutated tumors.

CONCLUSION

Somatic ALK mutations are present across all stages and risk groups of neuroblastoma. No specific mutation carries differential prognostic significance. Locoregional neuroblastoma has an invasive phenotype when harboring somatic ALK mutations in this population.

Association of RASSF1A, DCR2, and CASP8 Methylation with Survival in Neuroblastoma: A Pooled Analysis Using Reconstructed Individual Patient Data

Neuroblastoma (NB) is a heterogeneous tumor affecting children. It shows a wide spectrum of clinical outcomes; therefore, development of risk stratification is critical to provide optimum treatment. Since epigenetic alterations such as DNA methylation have emerged as an important feature of both development and progression in NB, in this study, we aimed to quantify the effect of methylation of three distinct genes (RASSF1A, DCR2, and CASP8) on overall survival in NB patients. We performed a systematic review using PubMed, Embase, and Cochrane libraries. Individual patient data was retrieved from extracted Kaplan–Meier curves. Data from studies was then merged, and analysis was done on the full data set. Seven studies met the inclusion criteria. Methylation of the three genes had worse overall survival than the unmethylated arms. Five-year survival for the methylated arm of RASSF1A, DCR2, and CASP8 was 63.19% (95% CI 56.55-70.60), 57.78% (95% CI 47.63-70.08), and 56.39% (95% CI 49.53-64.19), respectively, while for the unmethylated arm, it was 93.10% (95% CI 87.40–99.1), 84.84% (95% CI 80.04-89.92), and 83.68% (95% CI 80.28-87.22), respectively. In conclusion, our results indicate that in NB patients, RASSF1A, DCR2, and CASP8 methylation is associated with poor prognosis. Large prospective studies will be necessary to confirm definitive correlation between methylation of these genes and survival taking into account all other known risk factors. (PROSPERO registration number CRD42017082264).

The importance of local control management in high-risk neuroblastoma in South Africa

PURPOSE

To investigate the impact of local therapies on high-risk neuroblastoma (HR-NB) outcomes in South Africa.

METHODS

Data from 295 patients with HR-NB from nine pediatric oncology units between 2000 and 2014 were analysed. All patients received chemotherapy. Five-year overall (OS) and event free survival (EFS) were determined for patients who had received local therapy, either surgery or radiotherapy or both.

RESULTS

Surgery was performed in only 35.9% (n = 106/295) patients. Surgical excision was done for 34.8% (n = 85/244) of abdominal primaries, 50.0% (n = 11/22) of thoracic primaries; 22.2% (n = 2/9) neck primaries and 66.7% (n = 8/12) of the paraspinal primaries. Only 15.9% (n = 47/295) of all patients received radiotherapy. Children, who had surgery, had an improved five-year OS of 32.1% versus 5.9% without surgery (p < 0.001). Completely resected disease had a five-year OS of 30.5%, incomplete resections 31.4% versus no surgery 6.0% (p < 0.001). Radiated patients had a five-year OS of 21.3% versus 14.2% without radiotherapy (p < 0.001). Patients who received radiotherapy without surgical interventions, had a marginally better five-year OS of 12.5% as opposed to 5.4% (p < 0.001). Patients who underwent surgery had a longer mean overall survival of 60.9 months, while patients, who were irradiated, had a longer mean overall survival of 7.9 months (p < 0.001). On multivariate analysis, complete metastatic remission (p < 0.001), surgical status (p = 0.027), and radiotherapy status (p = 0.040) were significant predictive factors in abdominal primaries.

CONCLUSION

Surgery and radiotherapy significantly improve outcomes regardless of the primary tumor site, emphasizing the importance of local control in neuroblastoma.

Enhanced metastatic growth after local tumor resection in the presence of synchronous metastasis in a mouse allograft model of neuroblastoma

PURPOSE

We investigated how local tumor resection affects metastatic lesions in neuroblastoma.

METHODS

MYCN Tg tumor-derived cells were injected subcutaneously into 129^+Ter/SvJcl wild-type mice. First, the frequency of metastasis-bearing mice was investigated immunohistochemically (metastatic ratio) at endpoint or post-injection day (PID) 90. Second, the threshold volume of local tumor in mice bearing microscopic lymph node metastasis (mLNM) was investigated at PID 30. Finally, local tumors were resected after exceeding the threshold. Mice were divided into local tumor resection (Resection) and observation (Observation) groups, and the metastatic ratio and volume of LNM were compared between the groups at endpoint or PID 74.

RESULTS

The metastatic ratio without local resection was 88% at PID 78-90. The threshold local tumor volume in the mice with mLNM was 745 mm³ at PID 30, so local tumors were resected after exceeding 700 mm³. The metastatic ratio and LNM volume were significantly greater in the Resection group (n = 16) than in the Observation group (n = 16) (94% vs. 38%, p < 0.001; 2092 ± 2310 vs. 275 ± 218 mm³, p < 0.01; respectively) at PID 50-74.

CONCLUSION

Local tumor resection might augment the growth of synchronous microscopic metastases. Our results provide insights into the appropriate timing of local resection for high-risk neuroblastoma.

Error traps and culture of safety in pediatric surgical oncology

This article reviews technical issues to improve surgical safety and avoid surgical errors in pediatric surgical oncology, particularly in the three most common extracranial solid tumors: neuroblastoma, hepatoblastoma and Wilms tumor. The use of adjuvant chemotherapy - when indicated - the use of tumor specific classifications, adequate surgical planning, that may include the use of 3D printable models, improved surgical instruments and technology, and following surgical guidelines, would result in avoiding error, increased safety, and therefore in improved surgical outcomes.

Caval replacement strategy in pediatric retroperitoneal tumors encasing the vena cava: a single-center experience and review of literature

BACKGROUND

Complete encasement of the inferior vena cava by retroperitoneal tumors is rare. Although replacement of the vena cava has been considered for various conditions in adults, it is rarely used in children except for challenging resections and as a last chance approach - often aiming more at debulking than cure.

MATERIALS AND METHODS

From January 2009 to February 2017, 4 patients (2 adrenal neuroblastomas, 1 renal cell carcinoma, 1 infantile fibrosarcoma) underwent elective en-bloc resection of tumor and of the infrahepatic portion of the inferior vena cava (IVC), with planned IVC prosthetic replacement. In three cases a portion of the left renal vein had to be resected as well, with the vein reanastomosed onto the prosthesis, and a concomitant auto-transplantation of the right kidney was associated in one neuroblastoma patient.

RESULTS

All patients had an uncomplicated postoperative course. In one patient, the prosthetic conduit is patent at long-term (43 months), while the middle portion of the prosthesis did eventually thrombose at mid-term after surgery in the three others - with no related symptoms. Interestingly, all renal venous reconstructions remain patent. Three patients (2 neuroblastomas and 1 infantile fibrosarcoma) are alive and disease-free at 43, 74 and 108 months after surgery, respectively. One patient with renal cell carcinoma died of recurrence of the disease 21 months after surgery.

CONCLUSION

Resection and reconstruction of the vena cava, including the renal vein portion, can be considered and planned electively in case of tumoral encasement. This strategy is associated with good tolerance of the operation, low morbidity and satisfactory long-term function, even in cases with progressive and/or secondary partial thrombosis.

LEVEL OF EVIDENCE

IV.

The Evidence for External Beam Radiotherapy in High-Risk Neuroblastoma of Childhood: A Systematic Review

AIMS

External beam radiotherapy is widely used in various ways in the management of neuroblastoma. Despite extensive clinical experience, the precise role of radiotherapy in neuroblastoma remains unclear. The purpose of this systematic review was to survey the published literature to identify, without bias, the evidence for the clinical effectiveness of external beam radiotherapy as part of the initial multimodality treatment of high-risk neuroblastoma. We considered four areas: treatment of the tumour bed and residual primary tumour, identification of any dose-response relationship, treatment of metastatic sites, identification of any technical advances that may be beneficial. We also aimed to define uncertainties, which may be clarified in future clinical trials.

MATERIALS AND METHODS

Bibliographic databases were searched for neuroblastoma and radiotherapy. Reviewers assessed 1283 papers for inclusion by title and abstract, with consensus achieved through discussion. Data extraction on 57 included papers was carried out by one reviewer and checked by another. Studies were assessed for their level of evidence and risk of bias, and a descriptive analysis of data was carried out.

RESULTS

Fifteen papers provided some evidence that radiotherapy to the tumour bed and residual tumour may possibly be of value. However, there is a significant risk of bias and no evidence that all subgroups will benefit. There is some suggestion from six papers that dose may be important, but no hard evidence. It remains unclear whether irradiation of metastatic sites is helpful. Technical advances may be of value in radiotherapy of high-risk neuroblastoma.

CONCLUSIONS

There are data that show that radiotherapy is of some efficacy in the management of high-risk neuroblastoma, but there is no level one evidence that shows that it is being used in the best possible way. Prospective randomised trials are necessary to provide more evidence to guide development of optimal radiotherapy treatment schedules.

Role of surgery in localized initially unresectable neuroblastoma

PURPOSE

Evaluating the role of surgery and the extent of tumor resection on the outcome of patients with localized initially unresectable neuroblastoma (NB).

PATIENTS AND METHODS

This was a retrospective case review study including patients with localized initially unresectable NB. The primary tumor was considered unresectable according to imaging defined risk factors (IDRFs). Surgical resection was attempted after four to six courses of chemotherapy. The extent of resection was classified as follows: ≥90% resection, incomplete resection (50-90%) and cases with <50% resection or just a biopsy. Survival analysis was performed using an intention-to-treat approach.

RESULTS

A total of 202 patients with NB were included. Surgical resection was done in 106 patients. It was ≥90% in 89 patients (83.9%). Surgical resection was not performed in 96 patients (47.5%). Fifty-five (57.2%) were in good response after primary chemotherapy and 41 patients (42.7%) had persisting IDRFs, nine of them had biopsy only, and a follow-up strategy was considered in the other 32 patients. The overall 5-year event-free survival (EFS) and overall survival (OS) were 89.1 ± 2.4% and 94.9 ± 1.7%, respectively, with significantly better OS and EFS for patients who had resection versus no resection (p = 0.003 and 0.04, respectively). There was no impact of extent of resection on EFS and OS in the whole group (p = 0.91, p = 0.9) and in subgroup analysis stratified by site, histology, and age of the patients.

CONCLUSION

In children with localized initially unresectable NB, surgical resection was the only significant risk factor associated with better survival. The extent of tumor resection had no impact on EFS and OS. The concept of accepting incomplete resection to avoid serious complications was successful.

Outcomes and complications of surgery in patients with intermediate-risk neuroblastoma: experience from an Indian tertiary Cancer Centre

PURPOSE

The treatment of intermediate risk (IR) neuroblastoma has evolved with the focus now on reducing the drugs, dosage, and duration of chemotherapy. The aim of this study is to present the outcomes of treatment and the complications of surgery in patients with IR neuroblastoma treated at a tertiary cancer center in India.

METHODS

All eligible patients with IR neuroblastoma treated between April 2005 and August 2016 were identified. The presence and number of image-defined risk factors (IDRF) before and after neoadjuvant chemotherapy were retrospectively analyzed as were the extent of surgery, complications, and outcomes.

RESULTS

Of 282 neuroblastoma patients treated during the study period, 54 had IR neuroblastoma. Complete excision was achieved in 25 patients. There were 26 surgical complications in 22 patients with a similar incidence in patients with complete (n = 13) or incomplete (n = 13) resection (p = 0.78). After a median follow-up of 47 months, the 4-year overall and event-free survival was 91.5% and 75%, respectively. There was no difference in survival between patients who underwent complete resection versus those with incomplete resection (p = 0.9).

CONCLUSION

Outcomes of IR neuroblastoma are favorable. The extent of resection does not affect the survival and complications can occur even when the resection is incomplete.

Prognostic impact of postoperative 123I-metaiodobenzylguanidine scintigraphy: added value of SPECT/CT and semiquantification of the uptake at the surgical site

BACKGROUND

The aim of this study was to assess the prognostic value of postoperative 123I-MIBG scintigraphy, including systematic SPECT/CT and semiquantification of the uptake at the surgical site, in a prospective series of NB patients.

METHODS

Patients operated for neuroblastoma and who had benefited from postoperative 123I-MIBG scintigraphy were prospectively and consecutively included. Completeness of surgery was assessed on operative report. One month postoperative 123I-MIBG scintigraphy included planar acquisition and SPECT/CT. Semi-quantification of the 123I-MIBG SPECT/CT uptake at the surgical site was performed and ratios to reference (liver and mediastinum) areas were calculated.

RESULTS

Thirty patients were included between August 2012 and July 2015. Median follow-up was 36 months (range 10-98). Surgery was considered as complete in 23 patients and incomplete in 7 patients. Eight patients (26.7%) presented progressive disease (1 progression and 7 recurrences). Seven patients died (23.3%), all from NB. Six (20%) patients had positive 123I-MIBG scintigraphy (3 on planar acquisitions and 6 on SPECT/CT) and 24 patients had negative 123I-MIBG scintigraphy. Five of the 6 patients (83%) with positive 123I-MIBG scintigraphy presented progressive disease. Ratio of the uptake at the surgical site to mediastinum was strongly and independently correlated with disease-free interval and overall survival (P=0.02 and 0.01 respectively). The amplified MYCN status was also confirmed as correlated with poorer outcomes.

CONCLUSIONS

Postoperative 123I-MIBG scintigraphy including SPECT/CT and semiquantification of the uptake at the surgical site appeared to be a valuable prognostic tool in neuroblastoma.

MYCN-amplified stage 2/3 neuroblastoma: excellent survival in the era of anti-GD2 immunotherapy

High-risk neuroblastoma (HR-NB) includes MYCN-amplified stage 2/3, but reports covering anti-G_D2 immunotherapy, which recently became standard for HR-NB, do not provide details on this subset. We now report on all 20 MYCN-amplified stage 2/3 patients who received induction chemotherapy at our center during the era of consolidation with anti-G_D2 antibody 3F8/ granulocyte-macrophage colony-stimulating factor (GM-CSF) (2000-2015). Early in this period, consolidation included autologous stem-cell transplantation (ASCT). Event-free survival (EFS) and overall survival (OS) were estimated using Kaplan-Meier analyses. With induction, 19/20 (95%) patients achieved complete/very good partial remission (CR/VGPR) but one had progressive disease with early death. One responder did not receive consolidation and died of relapse. Five-year post-diagnosis EFS/OS rates for all 20 patients were 72%/84%. The 18 CR/VGPR patients who received consolidation had EFS/OS 81%/94% at five years from starting 3F8/GM-CSF: 4/4 ASCT patients remained relapse-free, while 11/14 non-ASCT patients remained relapse-free and two of the three relapsed patients achieved 2^nd CR (consolidated by retreatment with 3F8/GM-CSF) and remained in 2^nd CR at 36+ and 95+ months post-relapse. The 14 non-ASCT patients had EFS/OS 73.5%/93% at five years from starting 3F8/GM-CSF. This subset appears to have a good prognosis with contemporary multi-modality therapy, possibly even without ASCT.

Incidence, Survival, and Treatment of Localized and Metastatic Neuroblastoma in Germany 1979-2015

BACKGROUND

A comprehensive clinical long-term survey over the complete spectrum of neuroblatoma disease is lacking in the literature.

OBJECTIVE

Our objective was to describe the incidence, risk profiles, therapies, and outcomes for the total cohort of German patients with neuroblastoma including all clinical stages and risk groups.

METHODS

Epidemiological, clinical, and outcome data of neuroblastoma patients who participated in one of the six consecutive national trials between 1979 and 2015 were analyzed retrospectively.

RESULTS

Of all German neuroblastoma patients known to the national childhood cancer registry, ninety seven percent enrolled in one of the trials. The absolute neuroblastoma rate has increased slightly, whereas the median age at diagnosis has decreased. Except for the screening period (1995-2000), the risk factors lactate dehydrogenase (LDH), ferritin, chromosome 1p, and the MYCN oncogene have remained largely constant, with the exception of an increase in MYCN amplification at stage 4 for those aged ≥18 months between trials NB97 (27%) and NB2004 (35%). The 10-year overall survival increased in patients with stage 1-3 neuroblastoma from 83 to 91%, for stage 4S from 80 to 85%, and for stage 4 aged ≥18 months from 2 to 38%. The fraction of patients in stages 1-3 who never received chemotherapy (neither for frontline nor at recurrence) increased from 35 to 60%. The proportion of macroscopically complete surgical resections of the primary tumor decreased for the total population as well as for patients with stage 4 aged ≥18 months. The impact of chemotherapy response on the outcome was trial dependent. The overall proportion of toxic death during the time of the protocol therapy was 6% for stage 4 patients aged ≥18 months and 2% for low-/intermediate-risk patients. The most frequently reported late sequelae in stage 4 patients aged ≥18 months were renal dysfunctions, hypothyroidism, major hearing impairment, and second malignancies.

CONCLUSION

The body of data for incidences, risk profiles, and survival rates from this survey of more than 37 years provides a useful perspective for future studies on neuroblastoma sub-cohorts.

Neuroblastoma (Peripheral neuroblastic tumours)

Peripheral neuroblastic tumours (PNTs), a family of tumours arising in the embryonal remnants of the sympathetic nervous system, account for 7-10% of all tumours in children. In two-thirds of cases, PNTs originate in the adrenal glands or the retroperitoneal ganglia. At least one third present metastases at onset, with bone and bone marrow being the most frequent metastatic sites. Disease extension, MYCN oncogene status and age are the most relevant prognostic factors, and their influence on outcome have been considered in the design of the recent treatment protocols. Consequently, the probability of cure has increased significantly in the last two decades. In children with localised operable disease, surgical resection alone is usually a sufficient treatment, with 3-year event-free survival (EFS) being greater than 85%. For locally advanced disease, primary chemotherapy followed by surgery and/or radiotherapy yields an EFS of around 75%. The greatest problem is posed by children with metastatic disease or amplified MYCN gene, who continue to do badly despite intensive treatments. Ongoing trials are exploring the efficacy of new drugs and novel immunological approaches in order to save a greater number of these patients.

Is complete resection of high-risk stage IV neuroblastoma associated with better survival?

BACKGROUND

The role of surgery in the management of stage IV neuroblastoma is controversial. In this study, we attempted to study if complete tumor resection had any impact on event-free survival (EFS) and overall survival (OS).

METHODS

A retrospective analysis of patients with stage IV neuroblastoma between November 2000 and July 2014 in a tertiary referral center was performed. Demographics data, extent of surgical resection, and outcomes were analyzed.

RESULTS

A total of 34 patients with stage IV neuroblastoma according to International Neuroblastoma Staging System (INSS) were identified. The median age at diagnosis and operation was 3.5 (±1.9) years and 3.8 (±2.0) years, respectively. Complete gross tumor resection (CTR) was achieved in twenty-four patients (70.1%), in which one of the patients had nephrectomy and another had distal pancreatectomy. Gross total resection (GTR) with removal of >95% of tumor was performed in six patients (17.6%) and subtotal tumor resection (STR) with removal of >50%, but <95% of tumor was performed in four patients (11.8%). There was no statistical significance in terms of 5-year EFS and OS among the 3 groups. There was no surgery-related mortality or morbidity.

CONCLUSIONS

From our center's experience, as there was no substantial survival benefit in stage IV neuroblastoma patients undergoing complete tumor resection, organ preservation and minimalization of morbidity should also be taken into consideration.

Image-defined risk factor assessment of neurogenic tumors after neoadjuvant chemotherapy is useful for predicting intra-operative risk factors and the completeness of resection

BACKGROUND

Patients with neuroblastoma are now stratified at diagnosis according to the presence and number of image-defined risk factors (IDRFs). We examined the added value of IDRF assessment after neoadjuvant chemotherapy for predicting surgical resection.

MATERIAL AND METHODS

From 2009-2012, 39 out of 91 patients operated on in our institution for neuroblastic tumors received neoadjuvant chemotherapy based on ongoing SIOPEN protocols or treatment guidelines. IDRFs were assessed both at diagnosis and preoperatively on CT and/or MRI.

RESULTS

Median age at diagnosis was 30 months [range 2-191]. The tumor locations were adrenal (n = 20), paravertebral (n = 13) and perivascular (n = 6). INRGSS stages were L2 (n = 13), M (n = 25) and Ms (n = 1). Eleven tumors (28%) were MYCN-amplified. Chemotherapy reduced the number of IDRFs in 54% of patients overall (21/39): 61.5% (16/26) of M and Ms patients, and 38.5% (5/13) of non metastatic patients (P < 0.001). The number of IDRFs lost after chemotherapy was proportional to the degree of tumor shrinkage (P = 0.002), independent of the primary tumor location (P = 0.73), although the number was higher in patients with left versus right adrenal locations (P = 0.004). Patients with neuroblastoma on post-surgical histology lost more IDRFs (median: 1[0-9]) than patients with ganglioneuroblastoma (median: 0[0-4]) (P < 0.001). The completeness of resection was related only to the number of preoperative IDRFs (P = 0.028).

CONCLUSION

IDRF assessment after neoadjuvant chemotherapy is useful for predicting completeness of resection of neurogenic tumors. A larger international study is needed to confirm these results and to explore a possible correlation between preoperative IDRF status and survival.

Multidisciplinary management of cervical neuroblastoma in infants

OBJECTIVES

Neuroblastoma is the most common malignancy in infancy, it is a histologically and genetically heterogeneous tumor, the therapy and outcome of which is influenced by age, histological variant and genetic background as well.

METHODS

We present two consecutive infant patients with neuroblastoma of the neck discussing the etiology, the diagnosis and the surgical and oncological treatment of the tumor, which was observed in a relatively rare manifestation in the head-neck region.

RESULTS

Our first patient (age: 5.5 months) was MYCN (v-myc myelocytomatosis viral related oncogene, neuroblastoma derived) negative, INSS (International Neuroblastoma Staging System) Stage 3 and INRGSS (International Neuroblastoma Risk Group Staging System) Stage 3 because of the contralateral lymph node involvement while the complete gross resection of the primary tumor mass was feasible. The patient is tumor free after three years of follow-up. Our second patient (age: 5 months) was MYCN negative, INSS Stage 2 and INRGSS Stage 1, as both the primary tumor and the ipsilateral lymph nodes were totally removed via a modified radical neck dissection. The patient is tumor free after three years of follow-up.

CONCLUSION

For MYCN negative patients, especially in early age, the prognosis of neuroblastoma is good, surgical resection and chemotherapy together is an adequate treatment protocol (as in our two patients). While MYCN-amplified patients require a combined and aggressive treatment with surgery, chemotherapy, radiotherapy, and immunotherapy to be able to obtain a favorable survival rate according to the literature.

Significance of clinical and biologic features in Stage 3 neuroblastoma: a report from the International Neuroblastoma Risk Group project

BACKGROUND

International Neuroblastoma Staging System (INSS) Stage 3 neuroblastoma is a heterogeneous disease. Data from the International Neuroblastoma Risk Group (INRG) database were analyzed to define patient and tumor characteristics predictive of outcome.

PROCEDURE

Of 8,800 patients in the INRG database, 1,483 with INSS Stage 3 neuroblastoma and complete follow-up data were analyzed. Secondary analysis was performed in 1,013 patients (68%) with MYCN-non-amplified (NA) tumors. Significant prognostic factors were identified via log-rank test comparisons of survival curves. Multivariable Cox proportional hazards regression model was used to identify factors independently predictive of event-free survival (EFS).

RESULTS

Age at diagnosis (P < 0.0001), tumor MYCN status (P < 0.0001), and poorly differentiating/undifferentiated histology (P = 0.03) were independent predictors of EFS. Compared to other Stage 3 subgroups, outcome was inferior for patients ≥ 547 days with MYCN-NA neuroblastoma (P < 0.0001), and within this cohort, serum ferritin ≥ 96 ng/ml was associated with inferior EFS (P = 0.02). For patients <547 days of age with MYCN-NA tumors, serum ferritin levels were prognostic of overall survival (OS) (P = 0.04) and chromosome 11q aberration was prognostic of EFS (P = 0.03).

CONCLUSIONS

Among patients with INSS Stage 3 neuroblastoma patients, age at diagnosis, MYCN status and histology predict outcome. Patients <547 days of age with MYCN-NA tumors that lack chromosome 11q aberrations or those with serum ferritin <96 ng/ml have excellent prognosis and should be considered for therapy reduction. Prospective clinical trials are needed to identify optimal therapy for those patients ≥ 547 days of age with undifferentiated histology or elevated serum ferritin.

Does aggressive surgical resection improve survival in advanced stage 3 and 4 neuroblastoma? A systematic review and meta-analysis

The role of surgery in the management of advanced staged neuroblastoma (NBL) is controversial. A systematic review and meta-analysis is reported to address robust evidence for curative "gross total tumor resection" (GTR) in Stage 3 and Stage 4 neuroblastoma. Studies were identified using Medline, Embase, and Cochrane databases using pre-specified search terms. Primary outcomes were 5-year overall (OS) and disease-free survival (DFS) after GTR and subtotal resection (STR) in Stage 3 or 4 NBL. Data were analyzed using Review Manager. The Mantel-Haenszel method and a random effects model was utilized to calculate odds ratios (95% CI). Fifteen studies (five Stage 3 and 13 Stage 4) met full inclusion criteria. The pooled odds ratio for 5 year OS in Stage 3 following GTR compared to STR was 2.4 (95% CI 1.19-4.85). In Stage 4 disease, the pooled odds ratio for 5 year overall survival (OS) following GTR compared to STR was 1.65 (95% CI 0.96-1.91); a pooled odds ratio for 5 year DFS following GTR compared to STR was 1.55 (95% CI 1.12-2.14). A clear survival benefit is shown for GTR over STR in Stage 3 NBL only. Though some advantage can be demonstrated for GTR as defined by DFS in Stage 4 NBL GTR did not significantly improve OS in Stage 4 disease.

Role of surgery in the treatment of patients with high-risk neuroblastoma who have a poor response to induction chemotherapy

BACKGROUND

In instances of high-risk neuroblastoma that do not show a clinical response to induction therapy, whether it is worth performing surgical resection or not and whether gross total resection (GTR) is more important than subtotal resection (STR) remain controversial.

METHODS

We retrospectively analyzed the data of patients with stage 4 neuroblastoma aged 18 months or older at diagnosis. Primary tumor volumes were measured both at diagnosis and at the first tumor response evaluation (after 6 cycles of induction chemotherapy). If the tumor volume at the first response evaluation was > 50% of the initial tumor volume, the patient was categorized as a poor responder. Otherwise, the patient was categorized as a good responder. Only poor responders were included. Patients were evaluated for event-free survival (EFS), overall survival (OS), and complications of surgery based on extent of surgical intervention.

RESULTS

Sixty-five patients were included in this study. The 41 patients who underwent surgical intervention had a higher 3-year OS than the 24 patients who had a biopsy only (55.4% ± 8.1% vs. 31.3% ± 10.2%, P=0.02). However, there was limited improvement in 3-year EFS following surgical intervention. Three-year EFS rates of BX group (biopsy only) and OP group (surgical resection) were 24.2% ± 9.3% and 37.7% ± 7.9%, respectively (P=0.063). The extent of resection had no impact on 3-year OS (P=0.631) and 3-year EFS (P=0.796). Patients in the GTR group trended to have more severe surgical complications than patients in the STR group (P=0.105).

CONCLUSIONS

For high-risk neuroblastomas that do not show a clinical response to induction therapy, surgical resection is important in predicting outcome, but the extent of resection is not.

Striking dichotomy in outcome of MYCN-amplified neuroblastoma in the contemporary era

BACKGROUND

The authors exploited a large database to investigate the outcomes of patients with high-risk neuroblastoma in the contemporary era.

METHODS

All patients with high-risk neuroblastoma aged <12 years who were treated during induction at the authors' institution from 2000 through 2011 were studied, including 118 patients with MYCN-amplified [MYCN(+)] disease and 127 patients aged >18 months with MYCN-nonamplified [MYCN(-)] stage 4 disease.

RESULTS

A complete response/very good partial response (CR/VGPR) to induction was correlated with significantly superior event-free survival (EFS) (P < .001) and overall survival (OS) (P < .001) compared with a partial response or less. Patients with MYCN(+) and MYCN(-) disease had similar rates of CR/VGPR to induction (P = .366), and those with MYCN(+) and MYCN(-) disease who attained a CR/VGPR had similar EFS (P = .346) and OS (P = .542). In contrast, only MYCN(+) patients had progressive disease as a response to induction (P < .001), and early death from progressive disease (<366 days after diagnosis) was significantly more common (P < .001) among those with MYCN(+) disease. Overall, among patients who had a partial response or less, MYCN(+) patients had significantly inferior EFS (P < .001) and OS (P < .001) compared with MYCN(-) patients, which accounted for the significantly worse EFS (P = .008) and OS (P = .002) for the entire MYCN(+) cohort versus the MYCN(-) cohort.

CONCLUSIONS

Patients with MYCN(-), high-risk neuroblastoma display a broad, continuous spectrum with regard to response and outcome, whereas MYCN(+) patients either have an excellent response to induction associated with good long-term outcome or develop early progressive disease with a poor outcome. This extreme dichotomy in the clinical course of MYCN(+) patients points to underlying biologic differences with MYCN(+) neuroblastoma, the elucidation of which may have far-reaching implications, including improved risk classification at diagnosis and the identification of targets for treatment.

Long-term follow-up of children with high-risk neuroblastoma: the ENSG5 trial experience

BACKGROUND

Therapy for high-risk neuroblastoma is intensive and multimodal, and significant long-term adverse effects have been described. The aim of this study was to identify the nature and severity of late complications of metastatic neuroblastoma survivors included in the ENSG5 clinical trial.

PROCEDURE

The trial protocol included induction chemotherapy (randomized "Standard" OPEC/OJEC vs. "Rapid" COJEC), surgery of primary tumor and high-dose melphalan with stem cell rescue. Two hundred and sixty-two children were randomized, 69 survived >5 years, and 57 were analyzed. Data were obtained from the ENSG5 trial database and verified with questionnaires sent to participating centers.

RESULTS

Median follow-up was 12.9 (6.9-16.5) years. No differences were found in late toxicities between treatment arms. Twenty-eight children (49.1%) developed hearing loss. Nine patients (15.8%) developed glomerular filtration rate <80 ml/min/1.73 m(2), but no cases of chronic renal failure were documented. Endocrine complications (28.1% of children) included mainly hypogonadism and delayed growth. Four children developed second malignancies, three of them 5 years after diagnosis: one osteosarcoma, one carcinoma of the parotid gland and one ependymoma. There were no hematological malignancies or deaths in remission.

CONCLUSIONS

This study analyzed a wide cohort of high-risk neuroblastoma survivors from a multi-institutional randomized trial and established the profile of long-term toxicity within the setting of an international clinical trial.

Basic principles of paediatric radiotherapy

This article gives an introduction to the fundamentals of paediatric radiotherapy, describing the historical development of the speciality and its organisation in the UK, the clinical pathway (including issues around immobilisation) and an overview of indications for radiotherapy in the paediatric population. Late effects of radiotherapy, their mitigation and the role of the late effects clinic are summarised.

Is complete surgical resection of stage 4 neuroblastoma a prerequisite for optimal survival or may >95 % tumour resection suffice?

Numerous studies have shown that for optimal survival in localized International Neuroblastoma Staging System stage 1-3 neuroblastoma, complete tumour resection (CR, macroscopic total tumour removal) is usually mandatory. In contrast, it is conceivable that in stage 4 disseminated disease, less extensive surgery [gross total resection (GTR), >95 % tumour removal] may suffice. This review shows substantial survival benefit in studies reporting on stage 4 patients undergoing CR, but also in studies reporting on patients undergoing GTR. Comparison between these studies is severely hampered by treatment heterogeneity. We found only four studies that explicitly compared survival between patients undergoing either CR or GTR. Two of these studies showed favourable results for patients treated with CR, while the other two did not show differences in survival.

Neuroblastoma: the impact of biology and cooperation leading to personalized treatments

Neuroblastoma is the most common extra-cranial solid tumor in children. It is a heterogeneous disease, consisting of neural crest-derived tumors with remarkably different clinical behaviors. It can present in a wide variety of ways, including lesions which have the potential to spontaneously regress, or as an extremely aggressive form of metastatic cancer which is resistant to all forms of modern therapy. They can arise anywhere along the sympathetic nervous system. The median age of presentation is approximately 18 months of age. Urinary catecholamines (HVA and VMA) are extremely sensitive and specific tumor markers and are used in diagnosis, treatment response assessment and post-treatment surveillance. The largest national treatment groups from North America, Europe and Japan have formed the International Neuroblastoma Risk Group Task Force (INRG) to identify prognostic factors, to understand the mechanisms of tumorigenesis in this rare disease and to develop multi-modality therapies to improve outcomes and decrease treatment-related toxicities. This international cooperation has resulted in a significant leap in our understanding of the molecular pathogenesis of neuroblastoma. Lower staged disease can be cured if the lesion is resectable. Treatment of unresectable disease (loco-regional and metastatic) is stratified depending on clinical features (age at presentation, staging investigations) and specific tumor biological markers that include histopathological analyses, chromosomal abnormalities and the quantification of expression of an oncogene (MYCN). Modern treatment of high-risk neuroblastoma is the paradigm for the evolution of therapy in pediatric oncology. Outcomes have improved substantially with multi-modality therapy, including chemotherapy, surgery, radiation therapy, myeloablative therapy with stem cell transplant, immunotherapy and differentiation therapy; these comprise the standard of care worldwide. In addition, newer targeted therapies are being tested in phase I/II trials. If successful these agents will be incorporated into mainstream treatment programs.

Progress in treatment and risk stratification of neuroblastoma: impact on future clinical and basic research

Close international collaboration between pediatric oncologists has led to marked improvements in the cure of patients, seen as a long-term overall survival rate of about 80%. Despite this progress, neuroblastoma remains a challenging disease for both clinicians and researchers. Major clinical problems include lack of acceptable cure rates in high-risk neuroblastoma and potential overtreatment of subsets of patients at low and intermediate risk of the disease. Many years of intensive international cooperation have recently led to a promising joint effort to further improve risk classification for treatment stratification, the new International Neuroblastoma Risk Group Classification System. This approach will facilitate comparison of the results of clinical trials performed by different international collaborative groups. This, in turn, should accelerate refinement of risk stratification and thereby aid selection of appropriate therapies for individual patients. To be able to identify new therapeutic modalities, it will be necessary to elucidate the pathogenesis of the different subtypes of neuroblastoma. Basic and translational research have provided new tools for molecular characterization of blood and tumor samples including high-throughput technologies for analysis of DNA, mRNAs, microRNAs and other non-coding RNAs, as well as proteins and epigenetic markers. Most of these studies are array-based in design. In neuroblastoma research they aim to refine risk group stratification through incorporation of molecular tumor fingerprints and also to enable personalized treatment modalities by describing the underlying pathogenesis and aberrant signaling pathways in individual tumors. To make optimal use of these new technologies for the benefit of the patient, it is crucial to have a systematic and detailed documentation of both clinical and molecular data from diagnosis through treatment to follow-up. Close collaboration between clinicians and basic scientists will provide access to combined clinical and molecular data sets and will create more efficient steps in response to the remaining treatment challenges. This review describes the current efforts and trends in neuroblastoma research from a clinical perspective in order to highlight the urgent clinical problems we must address together with basic researchers.

The role of surgery in the treatment of neuroblastoma

The role of surgery varies greatly according to the clinical condition of the patients with neuroblastoma. A surgical resection is the mainstay of treatment for a localized tumor. However, in the era of intense chemotherapy associated with hematopoietic stem cell plant rescue, surgical resections are recommended without sacrificing the kidney or major vessels. Tumor biology further defines the necessity of supportive chemotherapy or radiation after surgical resection. The presence of diverse terminology concerning the range of resection may impose some confusion in the understanding of the previous papers. Therefore, the definition of a surgical resection was initially stated. In high-risk patients, the advantages of surgery for a patient's survival seem to be limited. This article reviews the efficacy of surgical resections in different clinical situations for a better understanding of the meaning of surgery in the treatment of neuroblastoma. The results of surgical resections are summarized according to the International Neuroblastoma Staging System. Finally, the long-term results regarding the strategy-related survival of the patients in the Niigata tumor board are briefly introduced.

Neuroblastoma: Therapeutic strategies for a clinical enigma

Neuroblastoma, the most common extracranial pediatric solid tumor remains a clinical enigma with outcomes ranging from cure in >90% of patients with locoregional tumors with little to no cytotoxic therapy, to <30% for those >18months of age at diagnosis with metastatic disease despite aggressive multimodality therapy. Age, stage and amplification of the MYCN oncogene are the most validated prognostic markers. Recent research has shed light on the biology of neuroblastoma allowing more accurate stratification of patients which has permitted reducing or withholding cytotoxic therapy without affecting outcome for low-risk patients. However, for children with high-risk disease, the development of newer therapeutic strategies is necessary. Current surgery and radiotherapy techniques in conjunction with induction chemotherapy have greatly reduced the risk of local relapse. However, refractory or recurrent osteomedullary disease occurs in most patients with high-risk neuroblastoma. Toxicity limits for high-dose chemotherapy appear to have been reached without further clinical benefit. Neuroblastoma is the first pediatric cancer for which monoclonal-antibody-based immunotherapy has been shown to be effective, particularly for metastatic osteomedullary disease. Radioimmunotherapy appears to be a critical component of a recent, successful regimen for treating patients who relapse in the central nervous system, a possible sanctuary site. Efforts are under way to refine and enhance antibody-based immunotherapy and to determine its optimal use. The identification of newer tumor targets and the harnessing of cell-mediated immunotherapy may generate novel therapeutic approaches. It is likely that a combination of therapeutic modalities will be required to improve survival and cure rates.