High-risk neuroblastoma treated with tandem autologous peripheral-blood stem cell-supported transplantation: long-term survival update

Natural killer cells in neuroblastoma: immunological insights and therapeutic perspectives

Natural killer (NK) cells have multifaceted roles within the complex tumor milieu. They are pivotal components of innate immunity and shape the dynamic landscape of tumor-immune cell interactions, and thus can be leveraged for use in therapeutic interventions. NK-based immunotherapies have had remarkable success in hematological malignancies, but these therapies are met with many challenges in solid tumors, including neuroblastoma (NB), a childhood tumor arising from the sympathetic nervous system. With a focus on NB, this review outlines the mechanisms employed by NK cells to recognize and eliminate malignant cells, delving into the dynamic relationship between ligand-receptor interactions, cytokines, and other molecules that facilitate the cross talk between NK and NB cells. We discuss the immunomodulatory functions of NK cells and the mechanisms that contribute to loss of this immunosurveillance in NB, with a focus on how this dynamic has been utilized in recent immunotherapy advancements for NB.

Response-adapted consolidation therapy strategy for patients with metastatic high-risk neuroblastoma: Results of the SMC NB-2014 study

BACKGROUND

Tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) and incorporation of 131I-metaiodobenzylguanidine (131I-MIBG) treatment have shown positive outcomes in high-risk neuroblastoma. However, more optimized treatment strategies are still needed.

PROCEDURE

The NB-2014 study was a nonrandomized, prospective trial that examined survival outcomes in metastatic high-risk neuroblastoma patients using response-adapted consolidation therapy. We used post-induction residual 123I-MIBG status at metastatic sites as a treatment response marker. Patients achieving complete resolution of MIBG uptake at metastatic sites underwent a reduced first HDCT/auto-SCT with a 20% dose reduction in HDCT. After the first HDCT/auto-SCT, patients with remaining MIBG uptake received dose-escalated (18 mCi/kg) 131I-MIBG treatment. In contrast, those with complete resolution of MIBG at metastatic sites received a standard dose (12 mCi/kg) of 131I-MIBG. We compared survival and toxicity outcomes with a historical control group from the NB-2009.

RESULTS

Of 65 patients treated, 63% achieved complete resolution of MIBG uptake at metastatic sites following induction chemotherapy, while 29% of patients still had MIBG uptake at metastatic sites after the first HDCT/auto-SCT. The 3-year event-free survival (EFS) and overall survival (OS) rates were 68.2% ± 6.0% and 86.5% ± 4.5%, respectively. Compared to NB-2009, EFS was similar (p = .855); however, NB-2014 had a higher OS (p = .031), a lower cumulative incidence of treatment-related mortality (p = .036), and fewer acute and late toxicities.

CONCLUSIONS

Our results suggest that response-adaptive consolidation therapy based on chemotherapy response at metastatic sites facilitates better treatment tailoring, and appears promising for patients with metastatic high-risk neuroblastoma.

Patterns of recurrence after radiotherapy for high-risk neuroblastoma: Implications for radiation dose and field

BACKGROUND

Prognosis for patients with high-risk neuroblastoma (HR-NBL) is guarded despite aggressive therapy, and few studies have characterized outcomes after radiotherapy in relation to radiation treatment fields.

METHODS

Multi-institutional retrospective cohort of 293 patients with HR-NBL who received autologous stem cell transplant (ASCT) and EBRT between 1997-2021. LRR was defined as recurrence at the primary site or within one nodal echelon beyond disease present at diagnosis. Follow-up was defined from the end of EBRT. Event-free survival (EFS) and OS were analyzed by Kaplan-Meier method. Cumulative incidence of locoregional progression (CILP) was analyzed using competing risks of distant-only relapse and death with Gray's test.

RESULTS

Median follow-up was 7.0 years (range: 0.01-22.4). Five-year CILP, EFS, and OS were 11.9 %, 65.2 %, and 77.5 %, respectively. Of the 31 patients with LRR and imaging review, 15 (48.4 %) had in-field recurrences (>12 Gy), 6 (19.4 %) had marginal failures (≤12 Gy), and 10 (32.3 %) had both in-field and marginal recurrences. No patients receiving total body irradiation (12 Gy) experienced marginal-only failures (p = 0.069). On multivariable analyses, MYCN amplification had higher risk of LRR (HR: 2.42, 95 % CI: 1.06-5.50, p = 0.035) and post-consolidation isotretinoin and anti-GD2 antibody therapy (HR: 0.42, 95 % CI: 0.19-0.94, p = 0.035) had lower risk of LRR.

CONCLUSIONS

Despite EBRT, LRR remains a contributor to treatment failure in HR-NBL with approximately half of LRRs including a component of marginal failure. Future prospective studies are needed to explore whether radiation fields and doses should be defined based on molecular features such as MYCN amplification, and/or response to chemotherapy.

Increased MCL1 dependency leads to new applications of BH3-mimetics in drug-resistant neuroblastoma

BACKGROUND

Neuroblastoma is a paediatric cancer that is characterised by poor prognosis for chemoresistant disease, highlighting the need for better treatment options. Here, we asked whether BH3-mimetics inhibiting BCL2 proteins may eliminate chemoresistant neuroblastoma cells.

METHODS

We utilised cisplatin-adapted neuroblastoma cell lines as well as patient tissues before and after relapse to study alterations of BCL2 proteins upon chemoresistance.

RESULTS

In a direct comparison of cisplatin-resistant cells we identified a prominent loss of sensitivity to BCL2/BCL-XL inhibitors that is associated with an increase in MCL1 dependency and high expression of MCL1 in patient tumour tissues. Screening of FDA-approved anti-cancer drugs in chemoresistant cells identified therapeutics that may be beneficial in combination with the clinically tested BH3-mimetic ABT263, but no synergistic drug interactions with the selective MCL1 inhibitor S63845. Further exploration of potential treatment options for chemoresistant neuroblastoma identified immunotherapy based on NK cells as highly promising, since NK cells are able to efficiently kill both parental and chemoresistant cells.

CONCLUSIONS

These data highlight that the application of BH3-mimetics may differ between first line treatment and relapsed disease. Combination of NK cell-based immunotherapy with BH3-mimetics may further increase killing of chemoresistant neuroblastoma, outlining a new treatment strategy for relapsed neuroblastoma.

To transplant, or not to transplant? That is the question. A patient advocate evaluation of autologous stem cell transplant in neuroblastoma

High-dose chemotherapy with autologous stem cell transplant (ASCT) has been a mainstay of high-risk neuroblastoma treatment for several decades, demonstrating improvements in event-free survival but with risks of serious or even life-threatening acute toxicities, severe long-term adverse health effects for survivors, and ongoing contention regarding overall survival benefit. The merits of ASCT in the modern era of immunotherapy are a source of debate among parents, advocates, and some physicians. Here we examine evidence for and against ASCT, explore parent attitudes and their turmoil over decision-making, and strongly encourage international research consortia to develop a coordinated strategy to accelerate progress toward a future that avoids the routine use of ASCT in high-risk neuroblastoma.

A Metastatic Neuroblastic Tumor in a 28-Month-old Boy: Unusual Spontaneous Regression From Neuroblastoma to Ganglioneuroma?

Neuroblastoma with bone metastasis is well known to have an extremely poor prognosis. We experienced the case of a patient with adrenal ganglioneuroblastoma (GNB) with metastases of subcutaneous nodules, a lymph node, and multiple bones. A pathologic examination of tumors from different sites revealed both GNB and ganglioneuroma. A genetic comparison between these tumors identified the same molecular signatures, suggesting the possibility of spontaneous differentiation in the remaining GNB. The patient has been healthy without aggressive chemotherapy, and the patient's pathologic urinary catecholamines normalized. Even if unusual, we have to recognize probable spontaneous differentiation from neuroblastoma to GNB and then to ganglioneuroma, even in sites of bone metastasis.

Pediatric high risk neuroblastoma with autologous stem cell transplant - 20 years of experience

BACKGROUND AND OBJECTIVE

Neuroblastoma is the most common extracranial solid tumor found in pediatric patients. High-risk neuroblastoma (HR-NBL) can be characterized by metastasis, age, and other tumor characteristics that result in an adverse outlook for this patient cohort. The standard of care includes induction chemotherapy, surgery, followed by stem cell autologous transplant (ASCT), and later, antidisialoganglioside (anti-GD2) antibodies. In this study, we provide the survival and toxicity data of our HR-NBL patients treated with a single ASCT.

METHODS

We retrospectively analyzed pediatric HR-NBL patients treated with single ASCT after a carboplatin, etoposide, and melphalan (CEM) regimen in our institution between January 1993 and December 2014.

RESULTS

There were 99 evaluable patients with male predominance. The median age at diagnosis was 3 years. Most of our HR-NBL patients were stage 4 (88%). All patients received ASCT. Peripheral blood was the graft source in 58% of the patients. Time for hematological count recovery with bone marrow as a graft source was prolonged but not statistically significant when compared with PBSCs. Of all the patients, 58% received radiation therapy to residual disease. Overt secondary leukemia was not seen in any of these patients. Three-year overall survival (OS) was 68.5% ± 5.2% and the 3-year event-free survival (EFS) was (48.3% ± 5.2%).

CONCLUSION

Our HR-NBL patients tolerated high-dose chemotherapy well followed by single autologous stem cell transplant. Tandem transplant is a feasible option in our patient cohort. Apart from secondary solid tumors, there were no long-term complications seen.

Myeloablative Carboplatin and Thiotepa With Autologous Stem Cell Rescue for Nonmedulloblastoma High-risk CNS Tumors in Young Children

Malignant central nervous system (CNS) tumors in young children have a poor prognosis and pose a therapeutic challenge. We describe 11 patients with high-risk CNS tumors (6 atypical teratoid/rhabdoid tumor, 4 nonmedulloblastoma CNS embryonal tumors, and 1 glioblastoma multiforme) who received 32 consolidation cycles of myeloablative carboplatin/thiotepa followed by autologous peripheral blood stem cell rescue. All patients underwent successful stem cell harvest without significant complications. Mean time to absolute neutrophil count ≥0.5×103/µL was 10.2±1.3 days and the mean length of hospital stay was 15.7±3.0 days. There were no regimen-related deaths. Five-year event-free survival and overall survival were 45.5±15.0% and 58.4±16.3%, respectively. Tandem carboplatin/thiotepa consolidation with autologous stem cell rescue is well-tolerated in young children with nonmedulloblastoma CNS tumors.

Sarcopenia and preserved bone mineral density in paediatric survivors of high-risk neuroblastoma with growth failure

BACKGROUND

Survival from paediatric high-risk neuroblastoma (HR-NBL) has increased, but cis-retinoic acid (cis-RA), the cornerstone of HR-NBL therapy, can cause osteoporosis and premature physeal closure and is a potential threat to skeletal structure in HR-NBL survivors. Sarcopenia is associated with increased morbidity in survivors of paediatric malignancies. Low muscle mass may be associated with poor prognosis in HR-NBL patients but has not been studied in these survivors. The study objective was to assess bone density, body composition and muscle strength in HR-NBL survivors compared with controls.

METHODS

This prospective cross-sectional study assessed areal bone mineral density (aBMD) of the whole body, lumbar spine, total hip, femoral neck, distal 1/3 and ultradistal radius and body composition (muscle and fat mass) using dual-energy X-ray absorptiometry (DXA) and lower leg muscle strength using a dynamometer. Measures expressed as sex-specific standard deviation scores (Z-scores) included aBMD (adjusted for height Z-score), bone mineral apparent density (BMAD), leg lean mass (adjusted for leg length), whole-body fat mass index (FMI) and ankle dorsiflexion peak torque adjusted for leg length (strength-Z). Muscle-specific force was assessed as strength relative to leg lean mass. Outcomes were compared between HR-NBL survivors and controls using Student's t-test or Mann-Whitney U test. Linear regression models examined correlations between DXA and dynamometer outcomes.

RESULTS

We enrolled 20 survivors of HR-NBL treated with cis-RA [13 male; mean age: 12.4 ± 1.6 years; median (range) age at therapy initiation: 2.6 (0.3-9.1) years] and 20 age-, sex- and race-matched controls. Height-Z was significantly lower in HR-NBL survivors compared with controls (-1.73 ± 1.38 vs. 0.34 ± 1.12, P < 0.001). Areal BMD-Z, BMAD-Z, FMI-Z, visceral adipose tissue and subcutaneous adipose tissue were not significantly different in HR-NBL survivors compared with controls. Compared with controls, HR-NBL survivors had lower leg lean mass-Z (-1.46 ± 1.35 vs. - 0.17 ± 0.84, P < 0.001) and strength-Z (-1.13 ± 0.86 vs. - 0.15 ± 0.71, P < 0.001). Muscle-specific force was lower in HR-NBL survivors compared with controls (P < 0.05).

CONCLUSIONS

Bone mineral density and adiposity are not severely impacted in HR-NBL survivors with growth failure, but significant sarcopenia persists years after treatment. Future studies are needed to determine if sarcopenia improves with muscle-specific interventions in this population of cancer survivors.

Long-Term Outcome and Role of Biology within Risk-Adapted Treatment Strategies: The Austrian Neuroblastoma Trial A-NB94

Simple Summary

Neuroblastoma, the most common extracranial malignancy of childhood, shows a highly variable course of disease ranging from spontaneous regression or maturation into a benign tumor to an aggressive and intractable cancer in up to 60% of patients. To adapt treatment intensity, risk staging at diagnosis is of utmost importance. The A-NB94 trial was the first in Austria to stratify therapy intensity according to tumor staging, patient’s age, and MYCN amplification status, the latter being a biologic marker turning otherwise low-risk tumors into high-risk disease. Recent publications showed a prognostic impact of various genomic features including segmental chromosomal aberrations (SCAs). We retrospectively investigated the relevance of SCAs within this risk-adapted treatment strategy. The A-NB94 approach resulted in an excellent long-term survival for the majority of patients with acceptable long-term morbidity. An age- and stage-dependent frequency of SCAs was confirmed and SCAs should always be considered in future treatment decision making processes.

Abstract

We evaluated long-term outcome and genomic profiles in the Austrian Neuroblastoma Trial A-NB94 which applied a risk-adapted strategy of treatment (RAST) using stage, age and MYCN amplification (MNA) status for stratification. RAST ranged from surgery only to intensity-adjusted chemotherapy, single or multiple courses of high-dose chemotherapy (HDT) followed by autologous stem cell rescue depending on response to induction chemotherapy, and irradiation to the primary tumor site. Segmental chromosomal alterations (SCAs) were investigated retrospectively using multi- and pan-genomic techniques. The A-NB94 trial enrolled 163 patients. Patients with localized disease had an excellent ten-year (10y) event free survival (EFS) and overall survival (OS) of 99 ± 1% and 93 ± 2% whilst it was 80 ± 13% and 90 ± 9% for infants with stage 4S and for infants with stage 4 non-MNA disease both 83 ± 15%. Stage 4 patients either >12 months or ≤12 months but with MNA had a 10y-EFS and OS of 45 ± 8% and 47 ± 8%, respectively. SCAs were present in increasing frequencies according to stage and age: in 29% of localized tumors but in 92% of stage 4 tumors (p < 0.001), and in 39% of patients ≤ 12 months but in 63% of patients > 12 months (p < 0.001). RAST successfully reduced chemotherapy exposure in low- and intermediate-risk patients with excellent long-term results while the outcome of high-risk disease met contemporary trials.

Tandem high-dose chemotherapy with autologous stem cell rescue for stage M high-risk neuroblastoma: Experience using melphalan/etoposide/carboplatin and busulfan/melphalan regimens

The efficacy of tandem HDCT against high-risk neuroblastoma has been reported; however, an optimal regimen remains to be established. In this paper, we report our experience using tandem HDCT comprising the MEC and BuMel regimens in patients with high-risk neuroblastoma. We retrospectively analyzed four patients with stage M high-risk neuroblastoma who received HDCT with MEC followed by BuMel combined with autologous stem cell rescue. Although none of their metastatic lesions had disappeared after induction chemotherapy, three patients showed a CR after tandem HDCT. Gastrointestinal mucosal injuries and renal dysfunction were observed as non-hematologic adverse events of grade 3 or higher. Gastrointestinal mucosal injuries were observed in all four patients following the first HDCT and in one patient following the second HDCT and were treated with parenteral nutrition and analgesics. One patient experienced renal dysfunction during the first HDCT, which was alleviated by sufficient hydration and diuretics and resulted in the reduction of melphalan dosage for the second HDCT. SOS was not observed in any patient. The HDCT regimens examined in this study were observed to be feasible and did not result in any life-threatening adverse events. Our findings indicate that tandem HDCT comprising MEC and BuMel is a potentially effective regimen for patients with high-risk neuroblastoma, including for those who respond poorly to induction chemotherapy, although additional studies in a larger population should be conducted to verify any long-term outcomes and toxicity.

Factors Impacting Time to Engraftment in Patients With High-risk Neuroblastoma Following Autologous Stem Cell Transplant

BACKGROUND

Despite advances in supportive measures, myeloablative chemotherapy with stem cell rescue remains limited by toxicity and treatment-related mortality. The purpose of this study was to identify factors influencing the rate of hematopoietic recovery following autologous stem cell transplant in high-risk neuroblastoma.

PROCEDURE

We retrospectively studied 54 patients with high-risk neuroblastoma who received a single autologous stem cell transplant between 2006 and 2016. Race, sex, conditioning regimen, chemotherapy delays and bone marrow involvement were analyzed using Kaplan-Meier Log-Rank test while the amount of cells infused, age, and length of hospital stay were analyzed using univariate Cox Proportional Hazards Regression.

RESULTS

The conditioning regimen administered was significant (P=0.016) for time to engraftment of neutrophils, with busulfan/melphalan (Bu/Mel) at 16.6 days, and carboplatin/etoposide/melphalan at 12.1 days. A delay of chemotherapy during induction (n=24) was significant (P<0.001) for time to platelet engraftment of >75,000/µL. Female patients had a longer time to engraftment (P=0.029).

CONCLUSION

Patients receiving Bu/Mel as a conditioning regimen, patients who had a delay in induction chemotherapy and patients of female sex were found to be significant for delayed engraftment of neutrophils, platelets, and hemoglobin, respectively, in patients with high-risk neuroblastoma undergoing autologous stem cell transplant. Knowing these factors may lead to new expectations and possible interventions to decrease the morbidity and mortality of treatment and recovery.

Significance of hematopoietic surface antigen CD34 in neuroblastoma prognosis and the genetic landscape of CD34-expressing neuroblastoma CSCs

High-risk neuroblastoma (HR-NB) is branded with hematogenous metastasis, relapses, and dismal long-term survival. Intensification of consolidation therapy with tandem/triple autologous stem cell (SC) rescue (with bone marrow [BM]/peripheral blood [PB] CD34⁺ selection) after myeloablative chemotherapy has improved long-term survival. However, the benefit is limited by the indication of NB cells in CD34⁺ PBSCs, CD34 expression in NB cells, and the risk of reinfusing NB cancer stem cells (NB CSCs) that could lead to post-transplant relapse. We investigated the association of CD34 surface expression (92 patients) with NB evolution/clinical outcomes. CD34 gene-level status in NB was assessed through RNA-Seq data mining (18 cohorts, n, 3324). Genetic landscape of CD34-expressing NB CSCs (CD133⁺CD34⁺) was compared with CD34^- CSCs (CD133⁺CD34^-). RNA-seq data revealed equivocal association patterns of CD34 expression with patient survival. Our immunohistochemistry data revealed definite, but rare (mean, 0.73%; range 0.00-7.87%; median, 0.20%) CD34 positivity in NB. CD34⁺ significantly associated with MYCN amplification (p, 0.003), advanced disease stage (p, 0.016), and progressive disease (PD, p < 0.0009) after clinical therapy. A general high-is-worse tendency was observed in patients with relapsed disease. High CD34⁺ correlated with poor survival in patients with N-MYC-amplified HR-NB. Gene expression analysis of CD34⁺-NB CSCs identified significant up (4631) and downmodulation (4678) of genes compared with NB CSCs that lack CD34. IPA recognized the modulation of crucial signaling elements (EMT, stemness maintenance, differentiation, inflammation, clonal expansion, drug resistance, metastasis) that orchestrate NB disease evolution in CD34⁺ CSCs compared with CD34^- CSCs. While the function of CD34 in NB evolution requires further in-depth investigation, careful consideration should be exercised for autologous stem cell rescue with CD34⁺ selection in NB patients. Graphical abstract.

Role and toxicity of radiation therapy in neuroblastoma patients: A literature review

Neuroblastoma is the most common extracranial solid tumor, arising from primitive sympathetic ganglion cells, in pediatric patients. The unique features of neuroblastoma include variable clinical behaviors, such as rapid progression to death and maturation to benign ganglioneuroma, followed by regression. Radiation therapy (RT) is usually administered to both the primary tumor bed and persistent metastatic sites after induction chemotherapy for high-risk neuroblastoma. RT to the tumor bed after surgical resection contributes significantly to local disease control and prevention of local relapse, confirming the role of RT. Palliative radiotherapy for metastatic neuroblastoma is also effective and safe and mainly provides symptomatic relief. The late side effects of RT in neuroblastoma patients include growth and developmental failure, hypothyroidism, gastrointestinal dysfunction, neurocognitive defects, pulmonary and cardiac abnormalities, infertility, and secondary cancers. In this article, we reviewed the role and toxicity of RT in neuroblastoma patients.

Safety and immune cell kinetics after donor natural killer cell infusion following haploidentical stem cell transplantation in children with recurrent neuroblastoma

INTRODUCTION

Under the hypothesis that early natural killer cell infusion (NKI) following haploidentical stem cell transplantation (haplo-SCT) will reduce relapse in the early post-transplant period, we conducted a pilot study to evaluate the safety and feasibility of NKI following haplo-SCT in children with recurrent neuroblastoma who failed previous tandem high-dose chemotherapy and autologous SCT.

METHODS

We used the high-dose 131I-metaiodobenzylguanidine and cyclophosphamide/fludarabine/anti-thymocyte globulin regimen for conditioning and infused 3 × 107/kg of ex-vivo expanded NK cells derived from a haploidentical parent donor on days 2, 9, and 16 post-transplant. Interleukin-2 was administered (1 × 106 IU/m2/day) subcutaneously to activate infused donor NK cells on days 2, 4, 6, 9, 11, 13, 16, 18, and 20 post-transplant.

RESULTS

Seven children received a total of 19 NKIs, and NKI-related acute toxicities were fever (n = 4) followed by chills (n = 3) and hypertension (n = 3); all toxicities were tolerable. Grade ≥II acute GVHD and chronic GVHD developed in two and five patients, respectively. Higher amount of NK cell population was detected in peripheral blood until 60 days post-transplant than that in the reference cohort. Cytomegalovirus and BK virus reactivation occurred in all patients and Epstein-Barr virus in six patients. Six patients died of relapse/progression (n = 5) or treatment-related mortality (n = 1), and one patient remained alive.

CONCLUSION

NKI following haplo-SCT was relatively safe and feasible in patients with recurrent neuroblastoma. Further studies to enhance the graft-versus-tumor effect without increasing GVHD are needed.

Cancer stem cells in neuroblastoma therapy resistance

Neuroblastoma (NB) is the most common cancer of infancy and accounts for nearly one tenth of pediatric cancer deaths. This mortality rate has been attributed to the > 50% frequency of relapse despite intensive, multimodal clinical therapy in patients with progressive NB. Given the disease’s heterogeneity and developed resistance, attaining a cure after relapse of progressive NB is highly challenging. A rapid decrease in the timeline between successive recurrences is likely due to the ongoing acquisition of genetic rearrangements in undifferentiated NB-cancer stem cells (CSCs). In this review, we present the current understanding of NB-CSCs, their intrinsic role in tumorigenesis, their function in disease progression, and their influence on acquired therapy resistance and tumor evolution. In particular, this review focus on the intrinsic involvement of stem cells and signaling in the genesis of NB, the function of pre-existing CSCs in NB progression and therapy response, the formation and influence of induced CSCs (iCSCs) in drug resistance and tumor evolution, and the development of a CSC-targeted therapeutic approach.

Patterns of recurrence after radiation therapy for high-risk neuroblastoma

Purpose

To investigate the patterns of recurrence in patients with neuroblastoma treated with radiation therapy to the primary tumor site.

Materials and Methods

We retrospectively analyzed patients with high-risk neuroblastoma managed with definitive treatment with radiation therapy to the primary tumor site between January 2003 and June 2017. These patients underwent three-dimensional conformal radiation therapy or intensity-modulated radiation therapy. A total of 14–36 Gy was delivered to the planning target volume, which included the primary tumor bed and the selected metastatic site. The disease stage was determined according to the International Neuroblastoma Staging System (INSS). We evaluated the recurrence pattern (i.e., local or systemic), progression-free survival, and overall survival.

Results

A total of 40 patients with high-risk neuroblastoma were included in this study. The median patient age was 4 years (range, 1 to 11 years). Thirty patients (75%) had INSS stage 4 neuroblastoma. At the median follow-up of 58 months, there were 6 cases of local recurrence and 10 cases of systemic recurrence. Among the 6 local failure cases, 4 relapsed adjacent to the radiation field. The other 2 relapsed in the radiation field (i.e., para-aortic and retroperitoneal areas). The main sites of distant metastasis were the bone, lymph nodes, and bone marrow. The 5-year progression-free survival was 70.9% and the 5-year overall survival was 74.3%.

Conclusion

Radiation therapy directed at the primary tumor site provides good local control. It seems to be adequate for disease control in patients with high-risk neuroblastoma after chemotherapy and surgical resection.

Effect of Tandem Autologous Stem Cell Transplant vs Single Transplant on Event-Free Survival in Patients With High-Risk Neuroblastoma: A Randomized Clinical Trial

IMPORTANCE

Induction chemotherapy followed by high-dose therapy with autologous stem cell transplant and subsequent antidisialoganglioside antibody immunotherapy is standard of care for patients with high-risk neuroblastoma, but survival rate among these patients remains low.

OBJECTIVE

To determine if tandem autologous transplant improves event-free survival (EFS) compared with single transplant.

DESIGN, SETTING, AND PARTICIPANTS

Patients were enrolled in this randomized clinical trial from November 2007 to February 2012 at 142 Children's Oncology Group centers in the United States, Canada, Switzerland, Australia, and New Zealand. A total of 652 eligible patients aged 30 years or younger with protocol-defined high-risk neuroblastoma were enrolled and 355 were randomized. The final date of follow-up was June 29, 2017, and the data analyses cut-off date was June 30, 2017.

INTERVENTIONS

Patients were randomized to receive tandem transplant with thiotepa/cyclophosphamide followed by dose-reduced carboplatin/etoposide/melphalan (n = 176) or single transplant with carboplatin/etoposide/melphalan (n = 179).

MAIN OUTCOMES AND MEASURES

The primary outcome was EFS from randomization to the occurrence of the first event (relapse, progression, secondary malignancy, or death from any cause). The study was designed to test the 1-sided hypothesis of superiority of tandem transplant compared with single transplant.

RESULTS

Among the 652 eligible patients enrolled, 297 did not undergo randomization because they were nonrandomly assigned (n = 27), ineligible for randomization (n = 62), had no therapy (n = 1), or because of physician/parent preference (n = 207). Among 355 patients randomized (median diagnosis age, 36.1 months; 152 [42.8%] female), 297 patients (83.7%) completed the study and 21 (5.9%) were lost to follow-up after completing protocol therapy. Three-year EFS from the time of randomization was 61.6% (95% CI, 54.3%-68.9%) in the tandem transplant group and 48.4% (95% CI, 41.0%-55.7%) in the single transplant group (1-sided log-rank P=.006). The median (range) duration of follow-up after randomization for 181 patients without an event was 5.6 (0.6-8.9) years. The most common significant toxicities following tandem vs single transplant were mucosal (11.7% vs 15.4%) and infectious (17.9% vs 18.3%).

CONCLUSIONS AND RELEVANCE

Among patients aged 30 years or younger with high-risk neuroblastoma, tandem transplant resulted in a significantly better EFS than single transplant. However, because of the low randomization rate, the findings may not be representative of all patients with high-risk neuroblastoma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00567567.

Evaluating growth failure with diffusion tensor imaging in pediatric survivors of high-risk neuroblastoma treated with high-dose cis-retinoic acid

BACKGROUND

The survival of patients with high-risk neuroblastoma has increased with multimodal therapy, but most survivors demonstrate growth failure.

OBJECTIVE

To assess physeal abnormalities in children with high-risk neuroblastoma in comparison to normal controls by using diffusion tensor imaging (DTI) of the distal femoral physis and adjacent metaphysis.

MATERIALS AND METHODS

We prospectively obtained physeal DTI at 3.0 T in 20 subjects (mean age: 12.4 years, 7 females) with high-risk neuroblastoma treated with high-dose cis-retinoic acid, and 20 age- and gender-matched controls. We compared fractional anisotropy (FA), normalized tract volume (cm³/cm²) and tract concentration (tracts/cm²) between the groups, in relation to height Z-score and response to growth hormone therapy. Tractography images were evaluated qualitatively.

RESULTS

DTI parameters were significantly lower in high-risk neuroblastoma survivors compared to controls (P<0.01), particularly if the patients were exposed to both cis-retinoic acid and total body irradiation (P<0.05). For survivors and controls, DTI values were respectively [mean ± standard deviation]: tract concentration (tracts/cm²), 23.2±14.7 and 36.7±10.5; normalized tract volume (cm³/cm²), 0.44±0.27 and 0.70±0.21, and FA, 0.22±0.05 and 0.26±0.02. High-risk neuroblastoma survivors responding to growth hormone compared to non-responders had higher FA (0.25±0.04 and 0.18±0.03, respectively, P=0.02), and tract concentration (tracts/cm²) (31.4±13.7 and 14.8±7.9, respectively, P<0.05). FA, normalized tract volume and tract concentration were linearly related to height Z-score (R²>0.31; P<0.001). Qualitatively, tracts were nearly absent in all non-responders to growth hormone and abundant in all responders (P=0.02).

CONCLUSION

DTI shows physeal abnormalities that correlate with short stature in high-risk neuroblastoma survivors and demonstrates response to growth hormone treatment.

Feasibility and Safety of Treosulfan, Melphalan, and Thiotepa-Based Megachemotherapy with Autologous or Allogeneic Stem Cell Transplantation in Heavily Pretreated Children with Relapsed or Refractory Neuroblastoma

The prognosis of resistant or relapsing children with neuroblastoma remains very poor, and the search for new therapies is ongoing. In this analysis, we assessed the toxicity of a treosulfan, melphalan, and thiotepa (TMT) regimen in 17 children with recurrent or refractory neuroblastoma who underwent stem cell transplantation (SCT). For allogeneic SCT, fludarabine and antithymocyte globulin were added. The stem cell source was autologous in 8 patients, haploidentical in 8 patients, and a matched unrelated donor in 1 patient. The reported nonhematologic toxicities included grade 3 mucositis, grade 1 to 3 hypertransaminasemia, and in 3 patients, veno-occlusive disease. No neurologic, cardiac, or dermatologic toxicities were observed. The probability of overall survival (OS) in patients with primary resistance was superior to that in patients with relapsed disease (100% versus 22.6%; P = .046). Post-transplantation dinutuximab beta immunotherapy was associated with superior 5-year OS (66.7% versus 11.4%; P = .0007). The use of an allogeneic donor, previous autologous SCT with busulfan and melphalan, and pretreatment with high-dose metaiodobenzylguanidine therapy demonstrated no effect on outcomes. In 4 patients, TMT megatherapy alone was enough to achieve complete remission. The TMT conditioning regimen was well tolerated in heavily pretreated patients with neuroblastoma. The manageable toxicity and addition of new anticancer drugs with optional post-SCT immunotherapy or chemotherapy support further trials with the TMT regimen in patients with neuroblastoma.

Gonadal Failure Is Common in Long-Term Survivors of Childhood High-Risk Neuroblastoma Treated With High-Dose Chemotherapy and Autologous Stem Cell Rescue

Background: Neuroblastoma is the most common extra-cranial solid tumor in children. Intensive therapy including autologous stem-cell transplantation (HSCT) has improved the poor prognosis of high-risk neuroblastoma (HR-NBL) but may impair gonadal function. Objectives: To investigate the gonadal function and fertility in long-term survivors of childhood HR-NBL. Design: A cohort including all Finnish (n = 20; 11 females) long-term (>10 years) survivors of HR-NBL and an age- and sex-matched control group (n = 20) was examined at a median age of 22 (16-30) years. Oncologic treatments, pubertal timing, hormonal therapies and the number of off-spring were recorded, and pituitary and gonadal hormones were measured. Results: Altogether 16/20 of the long-term survivors of HR-NBL entered puberty spontaneously; puberty was hormonally induced in four survivors (three females). Among the 8/11 female survivors with spontaneous puberty, seven had spontaneous menarche, but 5/8 developed ovarian failure soon after puberty. Nine females currently needed estrogen substitution. AMH, a marker of ovarian reserve, was lower in the female survivors than controls (median 0.02 vs. 1.7 μg/l, p < 0.001). As a group, male survivors had smaller testicular size (8.5 vs. 39 ml, p < 0.001) and lower inhibin B (<10 vs. 170 ng/l, p < 0.001) compared with control males, with altogether 6/9 survivor males fulfilling the criteria of gonadal failure (absent puberty, small testicle size or increased FSH with need of testosterone substitution). Gonadal failure was more common in female and male survivors treated with total-body irradiation. Three survivors (one male) had offspring, all treated without total-body irradiation and moderate dose of alkylating chemotherapy. Growth velocity was compromised in all survivors after HR-NBL diagnosis, with absent pubertal growth spurt in 7/17 survivors with complete growth data. Conclusion: Gonadal failure is common in long-term survivors of HR-NBL treated with HSCT. Fertility may be preserved in some survivors treated without total-body irradiation.

Managing local-regional failure in children with high-risk neuroblastoma: A single institution experience

BACKGROUND

Intensification of systemic therapy for high-risk neuroblastoma (HRNB) has resulted in improved local control and overall survival (OS) leaving potential for de-escalation of primary site radiotherapy. The utility of primary site de-escalation should be evaluated in the context of potential for successful local-regional salvage. We evaluated salvage strategies and outcomes in patients with HRNB with local-regional recurrence as a component of first failure.

METHODS

Twenty of 89 patients with HRNB experienced local-regional recurrence as a component of first relapse after chemotherapy, radiotherapy, surgery, and stem cell transplant from 1997 to 2013. We reviewed salvage therapy strategies and disease control, and report on the impact of local therapy as salvage for local-regional relapse.

RESULTS

Six of 20 patients with local-regional failure (LRF) were alive after a median follow-up of 13 years (range, 0.9-25.2 years). Median OS was 4.6 years (95% CI, 0.6 to not reached) versus 0.6 years (95% CI, 0.05-2.6) after LRF with and without distant failure, respectively (P = 0.03). OS in patients receiving salvage radiotherapy was comparable to those receiving initial adjuvant but no salvage radiotherapy. Time to first failure and death was significantly impacted by the intensity of frontline systemic therapy (P = 0.03). Salvage radiotherapy reduced the hazard for subsequent LRF (hazard ratio 0.3, 95% CI 0.1-0.9, P = 0.04) but not OS (P = 0.07).

CONCLUSIONS

Our study highlights the potential of local control strategies at first failure in patients with LRF when primary site radiotherapy was initially omitted, and delineates potential selection factors which may further improve the therapeutic ratio.

Late Effects and Survivorship Issues in Patients with Neuroblastoma

Over the past two decades, marked progress has been made in understanding the biology of neuroblastoma; this has led to refined risk stratification and treatment modifications with resultant increasing 5-year survival rates for children with neuroblastoma. Survivors, however, remain at risk for a wide variety of potential treatment-related complications, or "late effects", which may lead to excess morbidity and premature mortality in this cohort. This review summarizes the existing survivorship literature on long-term health outcomes for survivors of neuroblastoma, focusing specifically on potential injury to the endocrine, sensory, cardiovascular, pulmonary, and renal systems, as well as survivors' treatment-related risk for subsequent neoplasms and impaired quality of life. Additional work is needed to assess the potential late effects of newer multimodality therapies with the aim of optimizing long-term medical and psychosocial outcomes for all survivors of neuroblastoma.

Long-term outcomes of the GPOH NB97 trial for children with high-risk neuroblastoma comparing high-dose chemotherapy with autologous stem cell transplantation and oral chemotherapy as consolidation

Background

This study was done to investigate the long-term event free and overall survival of high-dose chemotherapy followed by autologous stem cell transplantation (ASCT), compared to maintenance chemotherapy (MT). Patterns of recurrences and late sequelae of both arms were analysed.

Methods

A randomised open label trial was conducted nationwide during 1997–2004 in Germany and Switzerland. 295 patients with high-risk neuroblastoma were randomly assigned to high-dose chemotherapy with autologous stem cell transplantation (ASCT) or maintenance chemotherapy (MT) for consolidation. Analyses were done by intention-to-treat (ITT: ASCT/MT N = 149/146), as treated (AT: N = 110/102), and treated as randomised (TAR: N = 75/70).

Results

The event free survival was superior for the patients receiving ASCT compared to patients treated with MT in all three cohorts (hazard ratio [HR] for ITT 1.39, 95% confidence interval (CI) 1.05-1.85, P = 0.022, HR for AT 1.75, CI 1.24-2.47, P = 0.001; HR for TAR 2.07, CI 1.36-3.16, P = 0.001). Overall survival was also in favour of the ASCT groups (ITT: P = 0.075; AT: P = 0.017; TAR: P = 0.005). The frequencies of late sequelae were not different except for focal nodular hyperplasia of the liver observed more frequently in the ASCT arm.

Conclusions

High-dose chemotherapy with autologous stem cell transplantation had a better long-term outcome compared to maintenance chemotherapy.

Tandem High-dose Chemotherapy and Autologous Stem Cell Transplantation in Children with Brain Tumors : Review of Single Center Experience

The prognosis of brain tumors in children has improved for last a few decades. However, the prognosis remains dismal in patients with recurrent brain tumors. The outcome for infants and young children in whom the use of radiotherapy (RT) is very limited because of unacceptable long-term adverse effect of RT remains poor. The prognosis is also not satisfactory when a large residual tumor remains after surgery or when leptomeningeal seeding is present at diagnosis. In this context, a strategy using high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) has been explored to improve the prognosis of recurrent or high-risk brain tumors. This strategy is based on the hypothesis that chemotherapy dose escalation might result in improvement in survival rates. Recently, the efficacy of tandem HDCT/auto-SCT has been evaluated in further improving the outcome. This strategy is based on the hypothesis that further dose escalation might result in further improvement in survival rates. At present, the number of studies employing tandem HDCT/auto-SCT for brain tumors is limited. However, results of these pilot studies suggest that tandem HDCT/auto-SCT may further improve the outcome. In this review, we will summarize our single center experience with tandem HDCT/auto-SCT for recurrent or high-risk brain tumors.

Neuroblastoma

Neuroblastoma is one of the most common solid tumors in children and has a diverse clinical behavior that largely depends on the tumor biology. Neuroblastoma exhibits unique features, such as early age of onset, high frequency of metastatic disease at diagnosis in patients over 1 year of age and the tendency for spontaneous regression of tumors in infants. The high-risk tumors frequently have amplification of the MYCN oncogene as well as segmental chromosome alterations with poor survival. Recent advanced genomic sequencing technology has revealed that mutation of ALK, which is present in ~10% of primary tumors, often causes familial neuroblastoma with germline mutation. However, the frequency of gene mutations is relatively small and other aberrations, such as epigenetic abnormalities, have also been proposed. The risk-stratified therapy was introduced by the Japan Neuroblastoma Study Group (JNBSG), which is now moving to the Neuroblastoma Committee of Japan Children's Cancer Group (JCCG). Several clinical studies have facilitated the reduction of therapy for children with low-risk neuroblastoma disease and the significant improvement of cure rates for patients with intermediate-risk as well as high-risk disease. Therapy for patients with high-risk disease includes intensive induction chemotherapy and myeloablative chemotherapy, followed by the treatment of minimal residual disease using differentiation therapy and immunotherapy. The JCCG aims for better cures and long-term quality of life for children with cancer by facilitating new approaches targeting novel driver proteins, genetic pathways and the tumor microenvironment.

Spontaneous regression of neuroblastoma

Neuroblastomas are characterized by heterogeneous clinical behavior, from spontaneous regression or differentiation into a benign ganglioneuroma, to relentless progression despite aggressive, multimodality therapy. Indeed, neuroblastoma is unique among human cancers in terms of its propensity to undergo spontaneous regression. The strongest evidence for this comes from the mass screening studies conducted in Japan, North America and Europe and it is most evident in infants with stage 4S disease. This propensity is associated with a pattern of genomic change characterized by whole chromosome gains rather than segmental chromosome changes but the mechanism(s) underlying spontaneous regression are currently a matter of speculation. There is evidence to support several possible mechanisms of spontaneous regression in neuroblastomas: (1) neurotrophin deprivation, (2) loss of telomerase activity, (3) humoral or cellular immunity and (4) alterations in epigenetic regulation and possibly other mechanisms. It is likely that a better understanding of the mechanisms of spontaneous regression will help to identify targeted therapeutic approaches for these tumors. The most easily targeted mechanism is the delayed activation of developmentally programmed cell death regulated by the tropomyosin receptor kinase A (TrkA) pathway. Pan-Trk inhibitors are currently in clinical trials and so Trk inhibition might be used as the first line of therapy in infants with biologically favorable tumors that require treatment. Alternative approaches consist of breaking immune tolerance to tumor antigens but approaches to telomere shortening or epigenetic regulation are not easily druggable. The different mechanisms of spontaneous neuroblastoma regression are reviewed here, along with possible therapeutic approaches.

Neuroblastoma: clinical and biological approach to risk stratification and treatment

Neuroblastoma is the most common extra-cranial solid tumor of childhood and the most common in the first year of life. It is a unique malignancy in that infants often present with either localized or metastatic disease that can spontaneously regress without intervention while older children can succumb to the disease after months to years of arduous therapy. Given this wide range of outcomes, the International Neuroblastoma Risk Group was created to stratify patients based on presenting characteristics and tumor biology in order to guide intensity of treatment strategies. The goal has been to decrease therapy for low-risk patients to avoid long-term complications while augmenting and targeting therapies for high-risk patients to improve overall survival. The international risk stratification depends on age, stage, histology, MYCN gene amplification status, tumor cell ploidy and segmental chromosomal abnormalities. Treatment for asymptomatic low-risk patients with an estimated survival of > 98% is often observation or surgical resection alone, whereas intermediate-risk patients with an estimated survival of > 90% require moderate doses of response-adjusted chemotherapy along with resection. High-risk patients undergo multiple cycles of combination chemotherapy before surgery, followed by consolidation with myeloablative autologous hematopoietic stem cell transplantation and local radiation and finally immunotherapy with differentiation therapy as maintenance phase. With this approach, outcome for patients with neuroblastoma has improved, as the field continues to expand efforts in more targeted therapies for high-risk patients.

Bioinformatics analysis of the CDK2 functions in neuroblastoma

The present study aimed to elucidate the potential mechanism of cyclin-dependent kinase 2 (CDK2) in neuroblastoma progression and to identify the candidate genes associated with neuroblastoma with CDK2 silencing. The microarray data of GSE16480 were obtained from the gene expression omnibus database. This dataset contained 15 samples: Neuroblastoma cell line IMR32 transfected with CDK2 shRNA at 0, 8, 24, 48 and 72 h (n=3 per group; total=15). Significant clusters associated with differentially expressed genes (DEGs) were identified using fuzzy C‑Means algorithm in the Mfuzz package. Gene ontology and pathway enrichment analysis of DEGs in each cluster were performed, and a protein‑protein interaction (PPI) network was constructed. Additionally, functional annotation of DEGs in clusters was performed for the detection of transcription factors and tumor‑associated genes. A total of 4 clusters with significant change tendency and 1,683 DEGs were identified. The hub nodes of the PPI network constructed by DEGs in Cluster 1, Cluster 2, Cluster 3 and Cluster 4 were MDM2 oncogene, E3 ubiquitin protein ligase (MDM2), cyclin‑dependent kinase 1 (CDK1), proteasome (prosome, macropain) 26S subunit, non‑ATPase, 14 (PSMD14) and translocator protein (18 kDa) (TSPO) respectively. These genes were significantly enriched in the p53 signaling pathway, cell cycle, proteasome and systemic lupus erythematosus pathways. MDM2, CDK1, PSMD14 and TSPO may be key target genes of CDK2. CDK2 may have key functions in neuroblastoma progression by regulating the expression of these genes.

Late Effects in Pediatric High-risk Neuroblastoma Survivors After Intensive Induction Chemotherapy Followed by Myeloablative Consolidation Chemotherapy and Triple Autologous Stem Cell Transplants

Multimodal treatment in high-risk neuroblastoma has modestly improved survival; limited data exist on the late effects from these regimens. We report the sequelae of treatment incorporating 3 consecutive cycles of high-dose therapy and autologous stem cell transplants (ASCTs) without the use of total body irradiation (TBI). We reviewed the medical records of 61 patients treated on or following the Chicago Pilot 2 protocol between 1991 and 2008. Of the 25 patients who are alive (41%), 19 had near complete data to report. Specific treatment modalities and therapy-related side effects were collected. Fourteen of these 19 patients (74%) received 3 cycles of high-dose therapy with ASCT; follow-up occurred over a median of 13.9 years (range, 5.8 to 18.8 y). The majority of late effects were endocrine-related, including growth failure, hypothyroidism, and hypogonadism. Patients also developed secondary neoplasms and skeletal deformities. The most frequent sequela was hearing loss, seen in 17/19 patients. We found a high prevalence of various late effects in survivors of high-risk neuroblastoma using a non-TBI-based regimen including 3 cycles of high-dose therapy with ASCTs. As current treatment regimens recommend tandem ASCT without TBI, it is imperative that we understand and monitor for the sequelae from these modalities.

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.

Incorporation of high-dose 131 I-metaiodobenzylguanidine treatment into killer immunoglobulin-like receptor/HLA-ligand mismatched haploidentical stem cell transplantation for children with neuroblastoma who failed tandem autologous stem cell transplantation

BACKGROUND

We performed a pilot study (NCT 00793351) to evaluate the effectiveness and feasibility of a strategy incorporating high-dose ¹³¹ I-metaiodobenzylguanidine (HD-MIBG) treatment into killer immunoglobulin-like receptor (KIR)/HLA-ligand mismatched haploidentical stem cell transplantation (haplo-SCT) in improving the survival of children with neuroblastoma who failed previous tandem autologous SCT.

PROCEDURE

If the patient remained progression free with salvage treatment, HD-MIBG treatment (18 mCi/kg) was given prior to reduced-intensity conditioning (cyclophosphamide + fludarabine + antithymocyte globulin). Grafts from KIR/HLA-ligand mismatched, preferably BX haplotype, haploidentical donors were transplanted to enhance the graft-versus-tumor (GVT) effect.

RESULTS

A total of seven patients were enrolled and three donors had a BX haplotype. Toxicities during HD-MIBG treatment and reduced-intensity conditioning were mild. Neutrophil recovery and complete or near complete donor chimerism were rapidly achieved. Six patients experienced acute graft-versus-host disease (GVHD; grade I in five and grade III in one), and four of six evaluable patients experienced chronic GVHD (two mild and two severe). Four patients died from tumor progression, one died from sepsis without progression, and the other two remained alive in complete response during 34 and 48 months posttransplant. All three patients remained progression free after BX haplotype SCT, whereas the other four experienced progression after AA haplotype SCT.

CONCLUSIONS

Our results suggest that the incorporation of HD-MIBG treatment in haplo-SCT and the use of BX haplotype donors might improve outcome, but this approach is currently limited by unacceptable GVHD. Further work focused on enhancement of GVT effects in relapsed neuroblastoma should be coupled with efforts to reduce GVHD.

Incorporation of high-dose 131I-metaiodobenzylguanidine treatment into tandem high-dose chemotherapy and autologous stem cell transplantation for high-risk neuroblastoma: results of the SMC NB-2009 study

Background

In our previous SMC NB-2004 study of patients with high-risk neuroblastomas, which incorporated total-body irradiation (TBI) with second high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT), the survival rate was encouraging; however, short- and long-term toxicities were significant. In the present SMC NB-2009 study, only TBI was replaced with ¹³¹I-meta-iodobenzylguanidine (MIBG) treatment in order to reduce toxicities.

Methods

From January 2009 to December 2013, 54 consecutive patients were assigned to receive tandem HDCT/auto-SCT after nine cycles of induction chemotherapy. The CEC (carboplatin + etoposide + cyclophosphamide) regimen and the TM (thiotepa + melphalan) regimen with (for metastatic MIBG avid tumors) or without (for localized or MIBG non-avid tumors) ¹³¹I-MIBG treatment (18 or 12 mCi/kg) were used for tandem HDCT/auto-SCT. Local radiotherapy, differentiation therapy with 13-cis-retinoic acid, and immunotherapy with interleukin-2 were administered after tandem HDCT/auto-SCT.

Results

Fifty-two patients underwent the first HDCT/auto-SCT and 47 patients completed tandem HDCT/auto-SCT. There was no significant immediate toxicity during the ¹³¹I-MIBG infusion. Acute toxicities during the tandem HDCT/auto-SCT were less severe in the NB-2009 study than in the NB-2004 study. Late effects such as growth hormone deficiency, cataracts, and glomerulopathy evaluated at 3 years after the second HDCT/auto-SCT were also less significant in the NB-2009 study than in NB-2004 study. There was no difference in the 5-year event-free survival (EFS) between the two studies (67.5 ± 6.7% versus 58.3 ± 6.9%, P = 0.340).

Conclusions

Incorporation of high-dose ¹³¹I-MIBG treatment into tandem HDCT/auto-SCT could reduce short- and long-term toxicities associated with TBI, without jeopardizing the survival rate.

Trial registration

ClinicalTrials.gov NCT03061656

Neuroblastoma

Neuroblastoma is the most common extracranial solid tumour occurring in childhood and has a diverse clinical presentation and course depending on the tumour biology. Unique features of these neuroendocrine tumours are the early age of onset, the high frequency of metastatic disease at diagnosis and the tendency for spontaneous regression of tumours in infancy. The most malignant tumours have amplification of the MYCN oncogene (encoding a transcription factor), which is usually associated with poor survival, even in localized disease. Although transgenic mouse models have shown that MYCN overexpression can be a tumour-initiating factor, many other cooperating genes and tumour suppressor genes are still under investigation and might also have a role in tumour development. Segmental chromosome alterations are frequent in neuroblastoma and are associated with worse outcome. The rare familial neuroblastomas are usually associated with germline mutations in ALK, which is mutated in 10-15% of primary tumours, and provides a potential therapeutic target. Risk-stratified therapy has facilitated the reduction of therapy for children with low-risk and intermediate-risk disease. Advances in therapy for patients with high-risk disease include intensive induction chemotherapy and myeloablative chemotherapy, followed by the treatment of minimal residual disease using differentiation therapy and immunotherapy; these have improved 5-year overall survival to 50%. Currently, new approaches targeting the noradrenaline transporter, genetic pathways and the tumour microenvironment hold promise for further improvements in survival and long-term quality of life.

Lack of survival advantage with autologous stem-cell transplantation in high-risk neuroblastoma consolidated by anti-GD2 immunotherapy and isotretinoin

Since 2003, high-risk neuroblastoma (HR-NB) patients at our center received anti-G_D2 antibody 3F8/GM-CSF + isotretinoin – but not myeloablative therapy with autologous stem-cell transplantation (ASCT). Post-ASCT patients referred from elsewhere also received 3F8/GM-CSF + isotretinoin. We therefore accrued a study population of two groups treated during the same period and whose consolidative therapy, aside from ASCT, was identical. We analyzed patients enrolled in 1st complete/very good partial remission (CR/VGPR). Their event-free survival (EFS) and overall survival (OS) were calculated from study entry. Large study size allowed robust statistical analyses of key prognosticators including MYCN amplification, minimal residual disease (MRD), FCGR2A polymorphisms, and killer immunoglobulin-like receptor genotypes of natural killer cells. The 170 study patients included 60 enrolled following ASCT and 110 following conventional chemotherapy. The two cohorts had similar clinical and biological features. Five-year rates for ASCT and non-ASCT patients were, respectively: EFS 65% vs. 51% (p = .128), and OS 76% vs. 75% (p = .975). In multivariate analysis, ASCT was not prognostic and only MRD-negativity after two cycles of 3F8/GM-CSF correlated with significantly improved EFS and OS. Although a trend towards better EFS is seen with ASCT, OS is near identical. Cure rates may be similar, as close surveillance detects localized relapse and effective salvage treatments are applied. ASCT may not be needed to improve outcome when anti-G_D2 immunotherapy is used for consolidation after dose-intensive conventional chemotherapy.

Local Control With 21-Gy Radiation Therapy for High-Risk Neuroblastoma

PURPOSE

To evaluate local control after 21-Gy radiation therapy (RT) to the primary site in patients with high-risk neuroblastoma.

METHODS AND MATERIALS

After receiving dose-intensive chemotherapy and gross total resection (GTR), 246 patients (aged 1.2-17.9 years, median 4.0 years) with high-risk neuroblastoma underwent RT to the primary site at Memorial Sloan Kettering from 2000 to 2014. Radiation therapy consisted of 21 Gy in twice-daily fractions of 1.5 Gy each. Local failure (LF) was correlated with biologic prognostic factors and clinical findings at the time of diagnosis and start of RT.

RESULTS

Median follow-up of surviving patients was 6.4 years. Cumulative incidence of LF was 7.1% at 2 years after RT and 9.8% at 5 years after RT. The isolated LF rate was 3.0%. Eighty-six percent of all local failures were within the RT field. Local control was worse in patients who required more than 1 surgical resection to achieve GTR (22.4% vs 8.3%, P=.01). There was also a trend toward inferior local control with MYCN-amplified tumors or serum lactate dehydrogenase ≥1500 U/L (P=.09 and P=.06, respectively).

CONCLUSION

After intensive chemotherapy and maximal surgical debulking, hyperfractionated RT with 21 Gy in high-risk neuroblastoma results in excellent local control. Given the young patient age, concern for late effects, and local control >90%, dose reduction may be appropriate for patients without MYCN amplification who achieve GTR.

Survival of high-risk pediatric neuroblastoma patients in a developing country

Little information is available about survival of high-risk pediatric neuroblastoma patients in developing countries. We aimed to assess survival among high-risk pediatric neuroblastoma patients in La Plata, Argentina. Individuals eligible for our cohort were aged <20 yr when diagnosed with high-risk neuroblastoma and received cancer-directed therapy including stem cell transplantation at Hospital de Niños Sor Maria Ludovica between February 1999 and February 2015. We estimated overall survival probabilities using an extended Kaplan-Meier approach. Our study population comprised 39 high-risk neuroblastoma patients, of whom 39% were aged >4 yr at diagnosis, 54% were male, and 62% had adrenal neuroblastoma. We observed 18 deaths, and the median survival time of our study population was 1.7 yr. The five-yr overall survival probability was 24% (95% CL: 10%, 41%). In contrast, five-yr survival of high-risk neuroblastoma patients ranges between 23% and 76% in developed countries. Survival among high-risk neuroblastoma patients is generally poor regardless of geographic location, but our results illustrate dramatically worse survival for patients in a developing country. We speculate that the observed survival differences could be attenuated or eliminated with improvements in treatment and supportive care, but addressing these issues will require creative solutions because of resource limitations.

High-Dose Chemotherapy and Autologous Stem Cell Transplantation in Children with High-Risk or Recurrent Bone and Soft Tissue Sarcomas

Despite increasing evidence that high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) might improve the survival of patients with high-risk or recurrent solid tumors, therapy effectiveness for bone and soft tissue sarcoma treatment remains unclear. This study retrospectively investigated the feasibility and effectiveness of HDCT/auto-SCT for high-risk or recurrent bone and soft tissue sarcoma. A total of 28 patients (18 high-risk and 10 recurrent) underwent single or tandem HDCT/auto-SCT between October 2004 and September 2014. During follow-up of a median 15.3 months, 18 patients exhibited disease progression and 2 died of treatment-related toxicities (1 veno-occlusive disease and 1 sepsis). Overall, 8 patients remained alive and progression-free. The 3-year overall survival (OS) and event-free survival (EFS) rates for all 28 patients were 28.7% and 26.3%, respectively. In the subgroup analysis, OS and EFS rates were higher in patients with complete or partial remission prior to HDCT/auto-SCT than in those with worse responses (OS, 39.1% vs. 0.0%, P = 0.002; EFS, 36.8% vs. 0.0%, P < 0.001). Therefore, careful selection of patients who can benefit from HDCT/auto-SCT and maximal effort to reduce tumor burden prior to treatment will be important to achieve favorable outcomes in patients with high-risk or recurrent bone and soft tissue sarcomas.

Orbital Metastasis Is Associated With Decreased Survival in Stage M Neuroblastoma

BACKGROUND

Approximately 30% of patients with metastatic (stage M) neuroblastoma present with periorbital ecchymosis from orbital osseous disease. Though locoregional disease is staged by imaging, the prognostic significance of metastatic site in stage M disease is unknown. We hypothesize that, compared to nonorbital metastasis, orbital metastasis is associated with decreased survival in patients with stage M neuroblastoma, and that periorbital ecchymosis reflects location and extent of orbital disease.

PROCEDURE

Medical records and imaging from 222 patients with stage M neuroblastoma seen at St. Jude Children's Research Hospital between January 1995 and May 2009 were reviewed. Thirty-seven patients were <18 months of age at diagnosis and 185 were ≥18 months of age. Overall survival (OS) and 5-year survival (5YS) were compared for patients with and without orbital, calvarial and nonorbital osseous metastasis, and with and without periorbital ecchymosis (log-rank test). Associations of periorbital ecchymosis with orbital metastasis location/extent were explored (Fisher's exact test, t-test).

RESULTS

In patients ≥18 months of age, only orbital metastasis was associated with decreased 5YS (P = 0.0323) and OS (P = 0.0288). In patients <18 months of age, neither orbital, calvarial, or nonorbital bone metastasis was associated with OS or 5YS. Periorbital ecchymosis was associated with higher number of involved orbital bones (P = 0.0135), but not location or survival.

CONCLUSIONS

In patients ≥ 18 months of age with stage M neuroblastoma, orbital metastatic disease is associated with decreased 5YS and OS. In future clinical trials, orbital disease may be useful as an imaging-based risk factor for substratification of stage M neuroblastoma.

Advances in Risk Classification and Treatment Strategies for Neuroblastoma

Risk-based treatment approaches for neuroblastoma have been ongoing for decades. However, the criteria used to define risk in various institutional and cooperative groups were disparate, limiting the ability to compare clinical trial results. To mitigate this problem and enhance collaborative research, homogenous pretreatment patient cohorts have been defined by the International Neuroblastoma Risk Group classification system. During the past 30 years, increasingly intensive, multimodality approaches have been developed to treat patients who are classified as high risk, whereas patients with low- or intermediate-risk neuroblastoma have received reduced therapy. This treatment approach has resulted in improved outcome, although survival for high-risk patients remains poor, emphasizing the need for more effective treatments. Increased knowledge regarding the biology and genetic basis of neuroblastoma has led to the discovery of druggable targets and promising, new therapeutic approaches. Collaborative efforts of institutions and international cooperative groups have led to advances in our understanding of neuroblastoma biology, refinements in risk classification, and stratified treatment strategies, resulting in improved outcome. International collaboration will be even more critical when evaluating therapies designed to treat small cohorts of patients with rare actionable mutations.

Acquired genetic alterations in tumor cells dictate the development of high-risk neuroblastoma and clinical outcomes

Background

Determining the driving factors and molecular flow-through that define the switch from favorable to aggressive high-risk disease is critical to the betterment of neuroblastoma cure.

Methods

In this study, we examined the cytogenetic and tumorigenic physiognomies of distinct population of metastatic site- derived aggressive cells (MSDACs) from high-risk tumors, and showed the influence of acquired genetic rearrangements on poor patient outcomes.

Results

Karyotyping in SH-SY5Y and MSDACs revealed trisomy of 1q, with additional non-random chromosomal rearrangements on 1q32, 8p23, 9q34, 15q24, 22q13 (additions), and 7q32 (deletion). Array CGH analysis of individual clones of MSDACs revealed genetic alterations in chromosomes 1, 7, 8, and 22, corresponding to a gain in the copy numbers of LOC100288142, CD1C, CFHR3, FOXP2, MDFIC, RALYL, CSMD3, SAMD12-AS1, and MAL2, and a loss in ADAM5, LOC400927, APOBEC3B, RPL3, MGAT3, SLC25A17, EP300, L3MBTL2, SERHL, POLDIP3, A4GALT, and TTLL1. QPCR analysis and immunoblotting showed a definite association between DNA-copy number changes and matching transcriptional/translational expression in clones of MSDACs. Further, MSDACs exert a stem-like phenotype. Under serum-free conditions, MSDACs demonstrated profound tumorosphere formation ex vivo. Moreover, MSDACs exhibited high tumorigenic capacity in vivo and prompted aggressive metastatic disease. Tissue microarray analysis coupled with automated IHC revealed significant association of RALYL to the tumor grade in a cohort of 25 neuroblastoma patients. Clinical outcome association analysis showed a strong correlation between the expression of CFHR3, CSMD3, MDFIC, FOXP2, RALYL, POLDIP3, SLC25A17, SERHL, MGAT3, TTLL1, or LOC400927 and overall and relapse-free survival in patients with neuroblastoma.

Conclusion

Together, these data highlight the ongoing acquired genetic rearrangements in undifferentiated tumor-forming neural crest cells, and suggest that these alterations could switch favorable neuroblastoma to high-risk aggressive disease, promoting poor clinical outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1463-y) contains supplementary material, which is available to authorized users.

The role of chest computed tomography (CT) as a surveillance tool in children with high-risk neuroblastoma

BACKGROUND

Standardization of imaging obtained in children with neuroblastoma is not well established. This study examines chest CT in pediatric patients with high-risk neuroblastoma.

PROCEDURE

Medical records and imaging from 88 patients with high-risk neuroblastoma, diagnosed at St. Jude Children's Research Hospital between January, 2002 and December, 2009, were reviewed. Surveillance imaging was conducted through 2013. Ten patients with thoracic disease at diagnosis were excluded. Event free survival (EFS) and overall survival (OS) were estimated. Size specific dose estimates for CT scans of the chest, abdomen, and pelvis were used to estimate absolute organ doses to 23 organs. Organ dosimetry was used to calculate cohort effective dose.

RESULTS

The 5 year OS and EFS were 51.9% ± 6.5% and 42.6% ± 6.5%, respectively. Forty-six (58.9%) patients progressed/recurred and 41 (52.6%) died of disease. Eleven patients (14%) developed thoracic disease progression/recurrence identified by chest CT (1 paraspinal mass, 1 pulmonary nodules, and 9 nodal). MIBG (metaiodobenzylguanidine) scans identified thoracic disease in six patients. Five of the 11 had normal chest MIBG scans; three were symptomatic and two were asymptomatic with normal chest MIBG scans but avid bone disease. The estimated radiation dose savings from surveillance without CT chest imaging was 42%, 34% when accounting for modern CT acquisition (2011-2013).

CONCLUSIONS

Neuroblastoma progression/recurrence in the chest is rare and often presents with symptoms or is identified using standard non-CT imaging modalities. For patients with non-thoracic high-risk neuroblastoma at diagnosis, omission of surveillance chest CT imaging can save 35-42% of the radiation burden without compromising disease detection.

Prolonged progression-free survival after consolidating second or later remissions of neuroblastoma with Anti-GD2 immunotherapy and isotretinoin: a prospective Phase II study

Relapse of high-risk neuroblastoma (HR-NB) is deemed invariably fatal yet increasing numbers of HR-NB patients achieve a second complete/very good partial remission (CR/VGPR), hence the urgency to find a successful consolidative therapy. Identifying efficacy in patients without assessable disease, however, is problematic. We report the first study providing outcome data for this group of patients with poor prognosis. To prevent another relapse, HR-NB patients in second or later CR/VGPR received the anti-G_D2 murine antibody 3F8 plus granulocyte-macrophage colony-stimulating factor plus isotretinoin in a Phase II trial. Upon meeting the target aim for progression-free survival (PFS) in the initial cohort of 33 patients, the trial was amended to allow patients who developed human anti-mouse antibody (HAMA) to receive rituximab to ablate HAMA with or without low-dose maintenance chemotherapy until immunotherapy could resume. For the total of 101 study patients, 5-year PFS and overall survival (OS) rates were 33% ± 5% and 48% ± 5%, respectively. Among the 33 long-term progression-free survivors, 19 had MYCN amplification, 19 had previously received anti-G_D2 immunotherapy plus isotretinoin (as first-line therapy), and 15 never received maintenance chemotherapy. In a multivariate analysis of prognostic factors, only absence of minimal residual disease in bone marrow after 2 cycles of immunotherapy and before initiation of isotretinoin or anti-HAMA therapy was significantly favorable for both PFS and OS. Therefore, long-term PFS is possible for HR-NB patients who achieve at least a second CR/VGPR and receive consolidation that includes anti-G_D2 immunotherapy plus isotretinoin, even if the patients received these biological treatments before relapse. Results from this prospective study will aid in the development of future Phase II studies for this growing ultra high-risk patient population.

Neuroblastoma: paradigm for precision medicine

Neuroblastoma (NB) is the third most common pediatric cancer. Although NB accounts for 7% of pediatric malignancies, it is responsible for more than 10% of childhood cancer-related mortality. Prognosis and treatment are determined by clinical and biological risk factors. Estimated 5-year survival rates for patients with non-high-risk and high-risk NB are more than 90% and less than 50%, respectively. Recent clinical trials have continued to reduce therapy for patients with non-high-risk NB, including the most favorable subsets who are often followed with observation approaches. In contrast, high-risk patients are treated aggressively with chemotherapy, radiation, surgery, and myeloablative and immunotherapies.