Metastatic sites in stage IV and IVS neuroblastoma correlate with age, tumor biology, and survival

PRMT5 activates AKT via methylation to promote tumor metastasis

Protein arginine methyltransferase 5 (PRMT5) is the primary methyltransferase generating symmetric-dimethyl-arginine marks on histone and non-histone proteins. PRMT5 dysregulation is implicated in multiple oncogenic processes. Here, we report that PRMT5-mediated methylation of protein kinase B (AKT) is required for its subsequent phosphorylation at Thr308 and Ser473. Moreover, pharmacologic or genetic inhibition of PRMT5 abolishes AKT1 arginine 15 methylation, thereby preventing AKT1 translocation to the plasma membrane and subsequent recruitment of its upstream activating kinases PDK1 and mTOR2. We show that PRMT5/AKT signaling controls the expression of the epithelial-mesenchymal-transition transcription factors ZEB1, SNAIL, and TWIST1. PRMT5 inhibition significantly attenuates primary tumor growth and broadly blocks metastasis in multiple organs in xenograft tumor models of high-risk neuroblastoma. Collectively, our results suggest that PRMT5 inhibition augments anti-AKT or other downstream targeted therapeutics in high-risk metastatic cancers.

Isolated central nervous system relapses in patients with high-risk neuroblastoma -clinical presentation and prognosis: experience of the Polish Paediatric Solid Tumours Study Group

Although isolated central nervous system (CNS) relapses are rare, they may become a serious clinical problem in intensively treated patients with high-risk neuroblastoma (NBL). The aim of this study is the presentation and assessment of the incidence and clinical course of isolated CNS relapses. Retrospective analysis involved 848 NBL patients treated from 2001 to 2019 at 8 centres of the Polish Paediatric Solid Tumours Study Group (PPSTSG). Group characteristics at diagnosis, treatment and patterns of relapse were analysed. Observation was completed in December 2020. We analysed 286 high risk patients, including 16 infants. Isolated CNS relapse, defined as the presence of a tumour in brain parenchyma or leptomeningeal involvement, was found in 13 patients (4.5%; 8.4% of all relapses), all of whom were stage 4 at diagnosis. Isolated CNS relapses seem to be more common in young patients with stage 4 MYCN amplified NBL, and in this group they may occur early during first line therapy. The only or the first symptom may be bleeding into the CNS, especially in younger children, even without a clear relapse picture on imaging, or the relapse may be clinically asymptomatic and found during routine screening. Although the incidence of isolated CNS relapses is not statistically significantly higher in patients after immunotherapy, their occurrence should be carefully monitored, especially in intensively treated infants, with potential disruption of the brain-blood barrier.

MIF/CXCR4 signaling axis contributes to survival, invasion, and drug resistance of metastatic neuroblastoma cells in the bone marrow microenvironment

BACKGROUND

The bone marrow (BM) is the most common site of dissemination in patients with aggressive, metastatic neuroblastoma (NB). However, the molecular mechanisms underlying the aggressive behavior of NB cells in the BM niche are still greatly unknown. In the present study, we explored biological mechanisms that play a critical role in NB cell survival and progression in the BM and investigated potential therapeutic targets.

METHODS

Patient-derived bone marrow (BM) primary cultures were generated using fresh BM aspirates obtained from NB patients. NB cell lines were cultured in the presence of BM conditioned media containing cell-secreted factors, and under low oxygen levels (1% O₂) to mimic specific features of the BM microenvironment of high-risk NB patients. The BM niche was explored using cytokine profiling assays, cell migration-invasion and viability assays, flow cytometry and analysis of RNA-sequencing data. Selective pharmacological inhibition of factors identified as potential mediators of NB progression within the BM niche was performed in vitro and in vivo.

RESULTS

We identified macrophage migration inhibitory factor (MIF) as a key inflammatory cytokine involved in BM infiltration. Cytokine profiling and RNA-sequencing data analysis revealed NB cells as the main source of MIF in the BM, suggesting a potential role of MIF in tumor invasion. Exposure of NB cells to BM-conditions increased NB cell-surface expression of the MIF receptor CXCR4, which was associated with increased cell viability, enhanced migration-invasion, and activation of PI3K/AKT and MAPK/ERK signaling pathways. Moreover, subcutaneous co-injection of NB and BM cells enhanced tumor engraftment in mice. MIF inhibition with 4-IPP impaired in vitro NB aggressiveness, and improved drug response while delayed NB growth, improving survival of the NB xenograft model.

CONCLUSIONS

Our findings suggest that BM infiltration by NB cells may be mediated, in part, by MIF-CXCR4 signaling. We demonstrate the antitumor efficacy of MIF targeting in vitro and in vivo that could represent a novel therapeutic target for patients with disseminated high-risk NB.

How we approach the treatment of patients with high-risk neuroblastoma with naxitamab: experience from the Hospital Sant Joan de Déu in Barcelona, Spain

Naxitamab [humanized 3f8 (hu3F8)] is a humanized monoclonal antibody (mAb) targeting the disialoganglioside GD2. It was approved in 2020 by the United States Food and Drug Administration (FDA) in combination with granulocyte–macrophage colony-stimulating factor (GM-CSF) for treatment of pediatric and adult patients with relapsed/refractory high-risk neuroblastoma, limited to the bone or bone marrow (BM). The team at Sant Joan de Déu Children’s Hospital in Barcelona, Spain, have been using naxitamab to treat neuroblastoma under clinical trial protocols [e.g. Trial 201, and hu3F8, irinotecan, temozolomide, and sargramostim (GM-CSF) (HITS) study] and compassionate use since 2017. The team has experience with two primary regimens: naxitamab with GM-CSF only, or naxitamab in combination with irinotecan, temozolomide, and GM-CSF (chemoimmunotherapy). This article aims to provide a practical overview of the team’s experience with naxitamab to date, including preparing the treatment room and selecting the team. Adverse event management, including the use of ketamine to manage pain during anti-GD2 mAb infusions, is also discussed. We hope this will provide practical information for other health care providers considering offering this treatment.

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Immunotherapy with anti-GD2 antibodies has revolutionized the treatment of patients with high-risk neuroblastoma.

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In 2020, FDA approved naxitamab + GM-CSF for treatment of patients with R/R neuroblastoma in the bone and/or BM.

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Outpatient treatment with naxitamab-based immunotherapy may improve health-related quality of life.

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Naxitamab infusions require specific training and teamwork to prevent and efficiently manage most frequent adverse events.

High-Risk Neuroblastoma: Poor Outcomes Despite Aggressive Multimodal Therapy

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Neuroblastoma (NBL) is a highly malignant embryonal tumor that originates from the primordial neural crest cells. NBL is the most common tumor in infants and the most common extracranial solid tumor in children. The tumor is more commonly diagnosed in children of 1-4 years of age. NBL is characterized by enigmatic clinical behavior that ranges from spontaneous regression to an aggressive clinical course leading to frequent relapses and death. Based on the likelihood of progression and relapse, the International Neuroblastoma Risk Group classification system categorized NBL into very low risk, low risk, intermediate risk, and high risk (HR) groups. HR NBL is defined based on the patient's age (> 18 months), disease metastasis, tumor histology, and MYCN gene amplification. HR NBL is diagnosed in nearly 40% of patients, mainly those > 18 months of age, and is associated with aggressive clinical behavior. Treatment strategies involve the use of intensive chemotherapy (CTR), surgical resection, high dose CTR with hematopoietic stem cell support, radiotherapy, biotherapy, and immunotherapy with Anti-ganglioside 2 monoclonal antibodies. Although HR NBL is now better characterized and aggressive multimodal therapy is applied, the outcomes of treatment are still poor, with overall survival and event-free survival of approximately 40% and 30% at 3-years, respectively. The short and long-term side effects of therapy are tremendous. HR NBL carries a high mortality rate accounting for nearly 15% of pediatric cancer deaths. However, most mortalities are attributed to the high frequency of disease relapse (50%) and disease reactiveness to therapy (20%). Newer treatment strategies are therefore urgently needed. Recent discoveries in the field of biology and molecular genetics of NBL have led to the identification of several targets that can improve the treatment results. In this review, we discuss the different aspects of the epidemiology, biology, clinical presentations, diagnosis, and treatment of HR NBL, in addition to the recent developments in the management of the disease.

Anatomic patterns of relapse and progression following treatment with 131 I-MIBG in relapsed or refractory neuroblastoma

OBJECTIVES

Patients with metaiodobenzylguanidine (MIBG)-avid relapsed or refractory neuroblastoma after initial therapy may exhibit transient responses to salvage treatment with iodine-131 metaiodobenzylguanidine (¹³¹ I-MIBG). It is unclear whether disease progression following ¹³¹ I-MIBG treatment occurs in previously involved versus new anatomic sites of disease. Understanding this pattern of relapse will inform the use of consolidation therapy following ¹³¹ I-MIBG administration.

METHODS

Patients with relapsed or refractory metastatic MIBG-avid neuroblastoma or ganglioneuroblastoma, who received single-agent ¹³¹ I-MIBG, had stable or responding disease 6-8 weeks following ¹³¹ I-MIBG, but subsequently experienced disease progression were included. MIBG scans were reviewed to establish anatomic and temporal evolution of MIBG-avid disease.

RESULTS

A total of 84 MIBG-avid metastatic sites were identified immediately prior to MIBG therapy in a cohort of 12 patients. At first progression, a total of 101 MIBG-avid sites were identified, of which 69 (68%) overlapped with pre-treatment disease sites, while 32 (32%) represented anatomically new disease areas. Eight of 12 patients had one or more new MIBG-avid sites at first progression. Of the 69 involved sites at progression that overlapped with pre-treatment disease, 11 represented relapsed sites that had cleared following MIBG therapy, two were persistent but increasingly MIBG-avid, and 56 were stably persistent.

CONCLUSIONS

Previously involved anatomic disease sites predominate at disease progression following ¹³¹ I-MIBG treatment. Nevertheless, the majority of patients progressed in at least one new anatomic disease site. This suggests that consolidation focal therapies targeting residual disease sites may be of limited benefit in preventing systemic disease progression following ¹³¹ I-MIBG treatment of relapsed or refractory neuroblastoma.

Factors of Recurrence After Complete Response in Children with Neuroblastoma: A 16-Year Retrospective Study of 179 Cases

Background

It is not clear which known adverse prognostic factors of neuroblastoma are closely associated with tumor recurrence after complete response. We analyzed the factors for post-remission recurrence in children with neuroblastoma through a retrospective study.

Methods

A total of 179 children with neuroblastoma who achieved initial complete response were included in this study. Kaplan–Meier method and multivariate Cox regression model were used to assess the factors that may have impact on tumor recurrence after complete response.

Results

The 5-year overall survival rates of the entire cohort (n = 179), recurrence group (n = 86) and non-recurrence group (n = 93) were 81.9%, 66.2%, and 98.7%, respectively. The 5-year recurrence-free survival (RFS) rates of the entire cohort and the high-risk cohort were 47.3% and 31.2%, respectively. RFSs were significantly reduced in children with age ≥18 months, INSS stage 4, unfavorable histology, bone marrow metastasis, osseous metastasis, serum NSE level ≥100 ng/mL, and serum LDH level ≥1400 U/L (P < 0.05). The independent risk factors for post-remission recurrence in the entire cohort were age ≥18 months, unfavorable histology, and serum LDH level ≥1400 U/L (P < 0.05). In the high-risk cohort, the independent risk factor for recurrence was serum LDH ≥1400 U/L (P < 0.05). Based on a new recurrence risk stratification, the 5-year RFSs of the children were 93.5%, 66.4%, and 22.5% in the low-risk, intermediate-risk, and high-risk groups, respectively. The area under the ROC curve of the new stratification was 0.773 (95% CI: 0.704−0.842).

Conclusion

Age ≥18 months, unfavorable histology, and serum LDH level ≥1400 U/L are independent risk factors for post-remission recurrence in children with neuroblastoma. A newly established recurrence risk stratification has diagnostic advantages in predicting risk of recurrence, which is especially suitable for low- and middle-income countries or regions.

A 16-miRNA Prognostic Model to Predict Overall Survival in Neuroblastoma

Neuroblastoma is the most malignant childhood tumor. The outcome of neuroblastoma is hard to predict due to the limitation of prognostic markers. In our study, we constructed a 16-miRNA prognostic model to predict the overall survival of neuroblastoma patients for early diagnosis. A total of 205 DE miRNAs were screened using RNA sequencing data from GSE121513. Lasso Cox regression analysis generated a 16-miRNA signature consisting of hsa-let-7c, hsa-miR-135a, hsa-miR-137, hsa-miR-146a, hsa-miR-149, hsa-miR-15a, hsa-miR-195, hsa-miR-197, hsa-miR-200c, hsa-miR-204, hsa-miR-302a, hsa-miR-331, hsa-miR-345, hsa-miR-383, hsa-miR-93, and hsa-miR-9star. The concordance index of multivariate Cox regression analysis was 0.9, and the area under the curve (AUC) values of 3-year and 5-year survival were 0.92 and 0.943, respectively. The mechanism was further investigated using the TCGA and GSE90689 datasets. Two miRNA-gene interaction networks were constructed among DEGs from two datasets. Functional analysis revealed that immune-related processes were involved in the initiation and metastasis of neuroblastoma. CIBERSORT and survival analysis suggested that lower CD8 T-cell proportion and higher SPTA1 expressions were related to a better prognosis. Our study demonstrated that the miRNA signature may be useful in prognosis prediction and management improvement.

Refractory Stage M Ganglioneuroblastoma With Bone Metastases and a Favorable, Chronic Course of Disease: Description of a Patient Cohort

Refractory stage M neuroblastoma (NB) is associated with a poor prognosis and a progressive course of disease. Here, we describe a unique group of patients with a discrepant clinical course. Seven histologically confirmed ganglioneuroblastoma (GNB) (n=6) and differentiating NB (n=1) patients were identified who were diagnosed with stage M disease based on iodine-123-metaiodobenzylguanidine avid bone metastases. Six patients started on high-risk treatment, without tumor response (stable disease). Treatment was discontinued before the start of consolidation treatment because of refractory response in all patients. Unexpectedly, after cessation of treatment no progression of disease occurred. In 2 patients, the primary tumors expanded (>25%) very slowly during 1.5 and 3 years, and remained stable thereafter. Metabolically, a slow decrease of urinary homovanillic acid and vanillylmandelic acid levels and iodine-123-metaiodobenzylguanidine avidity was observed. All patients are alive with presence of metastatic disease after a median follow-up of 17 years (range: 6.7 to 27 y). Interestingly, at diagnosis, 6 patients were asymptomatic, 6 patients had GNB morphology, and 5 patients had meningeal metastases. These are all features seen in only a small minority of stage M patients. This GNB entity illustrates the clinical heterogeneity of neuroblastic tumors and can be used to further study the developmental origin of different NB subtypes.

Is IV contrast necessary for MRI follow-up in children with abdominal neuroblastoma?

PURPOSE

The safety of multiple doses of gadolinium-based MRI IV contrast has recently been called in to question. While the long-term safety is being investigated, here, we seek to determine if there is added value to the use of IV contrast for improving detection of tumoral recurrences in children with a history of abdominal neuroblastoma.

METHODS

This is a retrospective review of children who underwent abdominal MRI with gadolinium contrast. One radiologist reviewer determined presence or absence of tumor, both before and after administration of IV contrast material and documented level of confidence when a finding was encountered. Change in reader confidence after the use of contrast was measured and fraction of missed lesions on pre-contrast was calculated. Liver and spleen lesions were documented separately.

RESULTS

453 MRI scans in 110 unique patients were reviewed. 65 patients were documented to have a total of 125 lesions, excluding liver, spleen and bones. There were 23 instances of contrast altering the radiologist's confidence and one lesion was missed without the use of contrast. Among liver and spleen, several hepatic lesions were seen only after contrast, but all were benign lesions.

CONCLUSION

In selected patients who are undergoing MRI for neuroblastoma, it may be reasonable to forgo the use of IV contrast.

Unusual Case of Neuroblastoma with Only Growth Plate Metastasis in Bilateral Lower Limbs on Metaiodobenzylguanidine Scintigraphy

Neuroblastoma is the most common extracranial solid tumor in childhood developing from primitive neural crest cells. I-131-metaiodobenzylguanidine (MIBG) a norepinephrine analog is highly sensitive and specific to identify primary and distant metastatic sites. We report the case of a 2-year-old female child with progressively increasing abdominal distention. Computed tomography (CT) revealed a large mass lesion involving the right suprarenal region with no hepatic or lymph node metastasis. No obvious skeletal abnormality was detected on the whole-body skeletal survey and Tc-99 m-methylene diphosphonate bone scan to suggest metastasis. I-131-MIBG scintigraphy with single-photon emission computerized tomography-CT showed MIBG-avid primary tumor in a suprarenal location with bilateral lower limbs growth plate as the only site of metastasis.

Biomarkers in Neuroblastoma: An Insight into Their Potential Diagnostic and Prognostic Utilities

OPINION STATEMENT

Neuroblastoma (NB) is a heterogeneous solid tumor of the pediatric population that originates from neural crest cells and affects the developing sympathetic nervous system. It is the most common neuroblastic tumor accounting for approximately 10% of all childhood cancers and 10-15% of pediatric tumor mortalities. The outcomes range from spontaneous tumor regression in low-risk groups to metastasis and death even after multimodal therapy in high-risk groups. Hence, the detection of NB at an early stage improves outcomes and provides a better prognosis for patients. Early detection and prognosis of NB depend on specific molecules termed biomarkers which can be tissue-specific or circulating. Certain biomarkers are employed in the classification of NB into different groups to improve the treatment and prognosis, and others can be used as therapeutic targets. Therefore, novel biomarker discovery is essential for the early detection of NB, predicting the course of the disease, and developing new targeted treatment strategies. In this review, we aim to summarize the literature pertinent to some important biomarkers of NB and discuss the prognostic role of these biomarkers as well as their potential role in targeted therapy.

Neuroblastoma Soft Tissue Metastasis in a 10-Month-Old Infant with a Right Thigh Mass

Background

Neuroblastoma is a solid tumor that occurs more frequently in pediatric populations. It may originate from any part of the sympathetic nervous system, but it most commonly arises from the paraspinal sympathetic ganglia in the abdomen or mediastinum. Local lymphadenopathy and distant metastasis to the central nervous system, orbit, and liver might be detected; however, it rarely includes soft tissue or musculoskeletal involvement. Case Report. Here, we report a 10-month-old infant presented with a right thigh mass with an otherwise benign physical exam and medical history. MRI of the lower extremities suggested tumoral infiltration in the soft tissue of both thighs, predominantly on the right side. Surgical pathology of the lesion confirmed neuroblastoma. A large subhepatic mass and paraaortic lymphadenopathy in the abdominal CT scan and metaiodobenzylguanidine scan findings favored primary abdominal neuroblastoma that had spread to lower extremities. The patient has been in remission since the completion of chemotherapy.

Conclusion

Neuroblastoma should be considered in infants with an abnormal mass in extremities. Due to its aggressive nature, most patients struggle with distant and local tumor spread at diagnosis. Therefore, any abnormal signs and symptoms, especially in younger pediatrics, warrant immediate evaluation to avoid tumor expansion.

Does the Incremental Value of 123I-Metaiodobenzylguanidine SPECT/CT over Planar Imaging Justify the Increase in Radiation Exposure?

Purpose

Planar scintigraphy with ¹²³I-radiolabeled metaiodobenzylguanidine (¹²³I-mIBG) is an important imaging modality to evaluate neuroblastoma. In recent years, Single Photon Emission Computed Tomography combined with Computed Tomography (SPECT/CT) has revolutionized nuclear medicine. Nevertheless, the addition of the CT has increased the patients' irradiation. We aimed to evaluate the incremental benefits of ¹²³I-mIBG SPECT/CT over conventional planar imaging and to estimate the relative increase of radiation dose.

Methods

We retrospectively evaluated the added value of 56 SPECT/CT performed in 40 children in terms of better characterization of the lesion and its locoregional extension, better lymph node staging, detection of new lesions, and elimination of false positives by a paired comparison between the planar images and the SPECT/CT ones. Then, we calculated the percentage contribution of the additional radiation of the CT in this hybrid imagery.

Results

In 88% (49 out of 56) of the examinations, SPECT/CT provided additional information, which was crucial in 20% of the cases. It allowed a better characterization of the lesion and its locoregional extension in 44 cases, a better lymph node staging in 28 cases, the detection of 33 new lesions, and the elimination of 9 false positives. The CT effective dose was significantly lower than the SPECT one. The average additional radiation exposure due to CT was 12% (4-23%).

Conclusion

¹²³I-mIBG SPECT/CT has an undeniable added value that improves planar imaging interpretation and impacts patient management. These potential benefits would justify the low additional radiation induced by the CT.

Subcutaneous swellings as the initial presentation of malignancy in an infant: Highlighting the cytological mimics at the metastatic site

Cytodiagnosis of metastatic neuroblastoma presenting as subcutaneous swellings.

Mediastinal neuroblastoma, ganglioneuroblastoma, and ganglioneuroma: Pathology review and diagnostic approach

Neuroblastic tumors are a group of tumors of the sympathetic ganglia and adrenal medulla that derive from primordial neural crest cells. These tumors include neuroblastoma, intermixed ganglioneuroblastoma, nodular ganglioneuroblastoma, and ganglioneuroma. Neuroblastomas are the most common extracranial solid tumor arising in childhood and may occur in different anatomic sites. Neuroblastic tumors are common mesenchymal tumors of the mediastinum. Herein, we describe advances in our understanding of neuroblastic tumor biology. Pathologists should be aware of diagnostic challenges associated with these tumors to ensure correct histologic diagnosis and appropriate clinical management. We describe updated mediastinal neuroblastic tumor pathology, focusing on morphological, immunohistochemical, and molecular features and differential diagnoses.

Clinical Characteristics and Survival Outcomes in Neuroblastoma With Bone Metastasis Based on SEER Database Analysis

Purpose

Clinical features and survival analysis of neuroblastoma (NB) are well explored. However, clinical research of NB patients with bone metastasis is rarely reported. Thus, the current study was performed to analyze the clinical features, survival outcome, and risk factors in those patients.

Materials and Methods

We reviewed the Surveillance, Epidemiology, and End Results (SEER) database to select cases diagnosed with NB with bone metastasis from 2010 to 2016. Overall survival (OS) and cancer-specific survival (CSS) were analyzed through univariate Cox regression analysis. Subsequently, we performed multivariate analysis to determine independent predictors of survival. The Kaplan–Meier method was applied to intuitively show differences in prognostic value between independent risk factors.

Results

We finally identified 393 NB patients with bone metastasis who were selected for survival analysis. Nearly half of the patients (47.3%) were aged >3 years. The adrenal gland was the primary tumor site, accounting for approximately two thirds of cases (66.2%). The 5-year OS and CSS rates of all patients were 62.1% and 64.1%, respectively. The univariate analysis indicated that age, lung metastasis, and tumor size were significantly associated with OS and CSS. Based on the multivariable analysis, age at 2 and 3 years, lung metastasis, and tumor size >10 cm remained significant negative predictors of OS and CSS.

Conclusion

For NB patients with bone metastasis, three independent prognostic risk factors (age, lung metastasis, and tumor size) are helpful to clinicians for predicting prognosis and guiding treatment. Reasonable treatment modalities for these patients should be further investigated to prolong survival.

Molecular Genetics in Neuroblastoma Prognosis

In recent years, much research has been carried out to identify the biological and genetic characteristics of the neuroblastoma (NB) tumor in order to precisely define the prognostic subgroups for improving treatment stratification. This review will describe the major genetic features and the recent scientific advances, focusing on their impact on diagnosis, prognosis, and therapeutic solutions in NB clinical management.

Development of Fe3O4 core–TiO2 shell nanocomposites and nanoconjugates as a foundation for neuroblastoma radiosensitization

Background

Neuroblastoma is the most common extracranial solid malignancy in childhood which, despite the current progress in radiotherapy and chemotherapy protocols, still has a high mortality rate in high risk tumors. Nanomedicine offers exciting and unexploited opportunities to overcome the shortcomings of conventional medicine. The photocatalytic properties of Fe3O4 core-TiO2 shell nanocomposites and their potential for cell specific targeting suggest that nanoconstructs produced using Fe3O4 core-TiO2 shell nanocomposites could be used to enhance radiation effects in neuroblastoma. In this study, we evaluated bare, metaiodobenzylguanidine (MIBG) and 3,4-Dihydroxyphenylacetic acid (DOPAC) coated Fe3O4@TiO2 as potential radiosensitizers for neuroblastoma in vitro.

Results

The uptake of bare and MIBG coated nanocomposites modestly sensitized neuroblastoma cells to ionizing radiation. Conversely, cells exposed to DOPAC coated nanocomposites exhibited a five-fold enhanced sensitivity to radiation, increased numbers of radiation induced DNA double-strand breaks, and apoptotic cell death. The addition of a peptide mimic of the epidermal growth factor (EGF) to nanoconjugates coated with MIBG altered their intracellular distribution. Cryo X-ray fluorescence microscopy tomography of frozen hydrated cells treated with these nanoconjugates revealed cytoplasmic as well as nuclear distribution of the nanoconstructs.

Conclusions

The intracellular distribution pattern of different nanoconjugates used in this study was different for different nanoconjugate surface molecules. Cells exposed to DOPAC covered nanoconjugates showed the smallest nanoconjugate uptake, with the most prominent pattern of large intracellular aggregates. Interestingly, cells treated with this nanoconjugate also showed the most pronounced radiosensitization effect in combination with the external beam x-ray irradiation. Further studies are necessary to evaluate mechanistic basis for this increased radiosensitization effect. Preliminary studies with the nanoparticles carrying an EGF mimicking peptide showed that this approach to targeting could perhaps be combined with a different approach to radiosensitization – use of nanoconjugates in combination with the radioactive iodine. Much additional work will be necessary in order to evaluate possible benefits of targeted nanoconjugates carrying radionuclides.

Graphic abstract

Metastatic Neuroblastoma Presenting as a Submandibular Mass with Mandibular Bone Involvement in a Three-Year-Old Child

Although neuroblastoma is one of the most common extra-cranial tumors in the pediatric population, it is rarely seen as a metastasis to the mandibular bone. The following is a case report of a 3-year-old male who initially presented with a submandibular mass that was proven to be a poorly differentiated metastatic neuroblastoma through excisional biopsy. This report is one of the few case reports that demonstrates metastatic submandibular neuroblastoma with mandibular bone involvement in the pediatric population.

Mandibular metastases in neuroblastoma: Outcomes and dental sequelae

BACKGROUND

Although metastatic involvement of bony sites including cranial bones is common in neuroblastoma (NB), mandibular metastases (MM) are uncommon, and specific outcomes have not been reported upon in the modern therapeutic era.

METHODS

In this retrospective study, medical records on patients with MM from NB were reviewed. Statistical analysis was performed using the Kaplan-Meier method.

RESULTS

Of 29 patients, nine (31%) had MM at diagnosis, whereas in 20 (69%) MM were first detected at NB relapse at a median time of 26 (6-89) months from diagnosis. Median maximal diameter of lesions was 3 (range 0.8-4.9) cm. MM were unilateral in 83% of patients, with ascending ramus (55%) and mandibular body (38%) being the two most common sites. All patients received systemic chemotherapy, and 26 (93%) patients received radiotherapy to MM. At a median follow-up of 37.3 (24.2-219.5) months, eight of nine patients with MM at diagnosis did not experience mandibular progressive disease. Eighteen of 20 patients with MM at relapse received therapeutic radiotherapy; objective responses were noted in 78%. Seventy-two percent (5/18) had not experienced relapse within the radiation field at a median of 12 (2-276) months postradiotherapy. Dental findings at follow-up after completion of NB therapy included hypodontia, hypocalcification of enamel, and trismus. Median 3-year overall survival in patients with relapsed MM was 51 ± 12% months from relapse.

CONCLUSION

MM when detected at diagnosis is associated with a prognosis similar to that for other skeletal metastases of NB. Radiotherapy is effective for control of MM detected both at diagnosis and relapse. Significant dental abnormalities posttherapy warrant regular dental evaluations and appropriate intervention.

FABP4 deactivates NF-κB-IL1α pathway by ubiquitinating ATPB in tumor-associated macrophages and promotes neuroblastoma progression

Neuroblastoma (NB) is the most common and deadliest pediatric solid tumor. Targeting and reactivating tumor-associated macrophages (TAMs) is necessary for reversing immune suppressive state and stimulating immune defense to exert tumoricidal function. However, studies on the function and regulation of TAMs in NB progression are still limited. Fatty acid binding protein 4 (FABP4) in TAMs was correlated with advanced clinical stages and unfavorable histology of NB. FABP4-mediated macrophages increased migration, invasion, and tumor growth of NB cells. Mechanically, FABP4 could directly bind to ATPB to accelerate ATPB ubiquitination in macrophages. The consequently decreased ATP levels could deactivate NF-κB/RelA-IL1α pathway, which subsequently results in macrophages reprogrammed to an anti-inflammatory phenotype. We also demonstrated that FABP4-enhanced migration and invasion were significantly suppressed by IL1α blocking antibody. Furthermore, circulating FABP4 was also associated with the clinical stages of NB. Our findings suggest that FABP4-mediated macrophages may promote proliferation and migration phenotypes in NB cells through deactivating NF-κB-IL1α pathway by ubiquitinating ATPB. This study reveals the pathologic and biologic role of FABP4-mediated macrophages in NB development and exhibits a novel application of targeting FABP4 in macrophages for NB treatment.

Zebrafish Model of Neuroblastoma Metastasis

Zebrafish has emerged as an important animal model to study human diseases, especially cancer. Along with the robust transgenic and genome editing technologies applied in zebrafish modeling, the ease of maintenance, high-yield productivity, and powerful live imaging altogether make the zebrafish a valuable model system to study metastasis and cellular and molecular bases underlying this process in vivo. The first zebrafish neuroblastoma (NB) model of metastasis was developed by overexpressing two oncogenes, MYCN and LMO1, under control of the dopamine-beta-hydroxylase (dβh) promoter. Co-overexpressed MYCN and LMO1 led to the reduced latency and increased penetrance of neuroblastomagenesis, as well as accelerated distant metastasis of tumor cells. This new model reliably reiterates many key features of human metastatic NB, including involvement of clinically relevant and metastasis-associated genetic alterations; natural and spontaneous development of metastasis in vivo; and conserved sites of metastases. Therefore, the zebrafish model possesses unique advantages to dissect the complex process of tumor metastasis in vivo.

Zebrafish as a Neuroblastoma Model: Progress Made, Promise for the Future

For nearly a decade, researchers in the field of pediatric oncology have been using zebrafish as a model for understanding the contributions of genetic alternations to the pathogenesis of neuroblastoma (NB), and exploring the molecular and cellular mechanisms that underlie neuroblastoma initiation and metastasis. In this review, we will enumerate and illustrate the key advantages of using the zebrafish model in NB research, which allows researchers to: monitor tumor development in real-time; robustly manipulate gene expression (either transiently or stably); rapidly evaluate the cooperative interactions of multiple genetic alterations to disease pathogenesis; and provide a highly efficient and low-cost methodology to screen for effective pharmaceutical interventions (both alone and in combination with one another). This review will then list some of the common challenges of using the zebrafish model and provide strategies for overcoming these difficulties. We have also included visual diagram and figures to illustrate the workflow of cancer model development in zebrafish and provide a summary comparison of commonly used animal models in cancer research, as well as key findings of cooperative contributions between MYCN and diverse singling pathways in NB pathogenesis.

GAS7 Deficiency Promotes Metastasis in MYCN-Driven Neuroblastoma

One of the greatest barriers to curative treatment of neuroblastoma is its frequent metastatic outgrowth prior to diagnosis, especially in cases driven by amplification of the MYCN oncogene. However, only a limited number of regulatory proteins that contribute to this complex MYCN-mediated process have been elucidated. Here we show that the growth arrest-specific 7 (GAS7) gene, located at chromosome band 17p13.1, is preferentially deleted in high-risk MYCN-driven neuroblastoma. GAS7 expression was also suppressed in MYCN-amplified neuroblastoma lacking 17p deletion. GAS7 deficiency led to accelerated metastasis in both zebrafish and mammalian models of neuroblastoma with overexpression or amplification of MYCN. Analysis of expression profiles and the ultrastructure of zebrafish neuroblastoma tumors with MYCN overexpression identified that GAS7 deficiency led to (i) downregulation of genes involved in cell-cell interaction, (ii) loss of contact among tumor cells as critical determinants of accelerated metastasis, and (iii) increased levels of MYCN protein. These results provide the first genetic evidence that GAS7 depletion is a critical early step in the cascade of events culminating in neuroblastoma metastasis in the context of MYCN overexpression. SIGNIFICANCE: Heterozygous deletion or MYCN-mediated repression of GAS7 in neuroblastoma releases an important brake on tumor cell dispersion and migration to distant sites, providing a novel mechanism underlying tumor metastasis in MYCN-driven neuroblastoma.See related commentary by Menard, p. 2815.

Immunotherapy approaches targeting neuroblastoma

PURPOSE OF REVIEW

In the era of immune-oncology, a breakthrough in the field of pediatric solid tumor research has been the demonstration that immunotherapy for patients with high-risk neuroblastoma improves the event-free and overall survival. Immunotherapeutic approaches including a monoclonal antibody targeting the cell surface glycosphingolipid disialoganglioside and cytokines successfully eliminate minimal residual disease.

RECENT FINDINGS

Since this seminal discovery, clinical trials evaluating immunotherapy in combination with chemotherapy and cellular therapies have begun to demonstrate effectiveness in treatment of bulky disease. Broader knowledge has also been gained regarding immunotherapy-limiting side-effects. Furthermore, biologic studies in actively treated patients have contributed to our growing understanding of the underlying immunologic processes and mechanisms of tumor response and immune evasion.

SUMMARY

The example of neuroblastoma is beginning to demonstrate that various immunotherapies combined with more conventional anticancer treatments can be synergistic. These advancements pose new challenges to both clinical researchers and medical provider and herald a new era in pediatric cancer therapy.

Metastatic Spread of Neuroblastoma to the Left Atrium Mimicking Atrial Myxoma: A Rare Occurrence in an Adolescent

Neuroblastoma is the most common childhood malignancy arising from the sympathetic neuroblast cells. The most common sites of origin are the adrenal glands and paravertebral regions. However, the involvement of the heart is a rare occurrence in adolescents. Here, we report a case of a 12-year-old male child who was misdiagnosed as a case of cardiac myxoma on initial presentation. Following surgical resection and histological examination, neuroblastoma was revealed. This case report highlights the differential diagnosis for the cardiac mass in an adolescent with an unknown primary origin and also the importance of tissue histopathology for the diagnosis and management of neuroblastoma.

Immunotherapeutic Strategies for Neuroblastoma: Present, Past and Future

Neuroblastoma is the most common extracranial pediatric solid tumor with a heterogeneous clinical course, ranging from spontaneous regression to metastatic disease and death, irrespective of intensive chemotherapeutic regimen. On the basis of several parameters, children affected by neuroblastoma are stratified into low, intermediate and high risk. At present, more than 50% of high-risk patients with metastatic spread display an overall poor long-term outcome also complicated by devastating long-term morbidities. Thus, novel and more effective therapies are desperately needed to improve lifespan of high-risk patients. In this regard, adoptive cell therapy holds great promise and several clinical trials are ongoing, demonstrating safety and tolerability, with no toxicities. Starting from the immunological and clinical features of neuroblastoma, we here discuss the immunotherapeutic approaches currently adopted for high-risk patients and different innovative therapeutic strategies currently under investigation. The latter are based on the infusion of natural killer (NK) cells, as support of consolidation therapy in addition to standard treatments, or chimeric antigen receptor (CAR) T cells directed against neuroblastoma associated antigens (e.g., disialoganglioside GD2). Finally, future perspectives of adoptive cell therapies represented by γδ T lymphocyes and CAR NK cells are envisaged.

Iodine-131 metaiodobenzylguanidine (131I-mIBG) treatment in relapsed/refractory neuroblastoma

BACKGROUND

I-meta-iodo-benzylguanidine (I-mIBG) therapy has been used in treatment of for advanced neuroblastoma for many years with promising results. There are several studies regarding predictors and outcomes of I-mIBG therapies in relapsed/refractory neuroblastoma patients.

OBJECTIVE

To identify the predictors and outcomes of I-mIBG treatment in relapsed/refractory neuroblastoma.

METHODS

This study was a retrospective review of 22 patients with high risk stage IV relapsed/refractory neuroblastoma who received at least one cycle of I-mIBG therapy. Patient' characteristics, hematologic toxicity, scintigraphic semi-quantitative scoring, and overall survival were recorded. Factors predicting survival were analyzed.

RESULTS

Twenty-two patients (50% male) with mean age of 3.7 years (4.8 months to 8.3 years) received I-mIBG therapies at an average of 3.8 and mean dose of 136 mCi (5032 MBq) per treatment. Most common acute hematologic toxicity was thrombocytopenia. Overall 5-year survival rate was 37% (95% confidence interval: 16.3-58.0) and median survival time was 2.8 year (95% confidence interval: 1.38-6.34). Patients with rising Curie score of ≥25% upon the second therapy were major determinants of overall survival with poorer response to treatment. At least three treatments of I-mIBG were needed to identify some degrees of survival prolongation (crude hazard ratio: P-value = 0.003). Age, sex, metastatic status, and baseline Curie scoring system were good predictors associated with survival. Seven patients (32%) demonstrated objective responses.

CONCLUSION

Despite multimodality therapy, high risk neuroblastoma had a propensity of treatment failure in terms of relapsed or refractory, with some objective responses after I-mIBG treatments. The declined or non-rising Curie score upon second post-treatment total body scan was an important predictor of survival and aided a decision whether or not to proceed with bone marrow transplantation.

Intracranial Metastases Tend to Be Overt and Predict Poor Prognosis in Children With Neuroblastoma

Background: Neuroblastoma (NB) is the most common pediatric extracranial solid neoplasm after leukemia. Intracranial metastases (IM) rarely occur in patients with NB. The present study aimed to review the clinical characteristics of NB patients from a single center presenting with IM. Methods: Two hundred children (aged 3-91 months) with NB admitted to the Fourth Affiliated Hospital of China Medical University between January 2009 and December 2015 were enrolled, and their clinical characteristics were recorded. The patients were divided into two groups based on the presence of IM. Their clinical characteristics, including demographics, clinical features, and laboratory and imaging studies, were retrospectively analyzed. Results: IM occurred in 22 of 200 (11%) neuroblastoma patients, with a median age of 42.5 months (range, 3-91 months), with a male-to-female ratio of 1.4:1. Seven patients had IM at the initial diagnosis. Among the 15 children who did not have IM at initial presentation, the median interval from presentation to the diagnosis of IM was 17.3 months (range, 1-55 months). Compared with the control group, NB patients with IM tended to be asymptomatic at the time of NB diagnosis, which was made incidentally during routine physical examination (5 of 22, 22.7%, p < 0.05). In addition, this group had more primary intra-abdominal sites (18 of 22, 81.8%, p < 0.001) and worse prognosis (5 of 22, 22.7%, p < 0.05). Conclusions: NB patients with IM have insidious onset in the early stage and a lower survival rate, especially patients with primary intra-abdominal lesions. Regular neurological monitoring could improve the rate of early diagnosis and prognosis of NB children with IM. Familiarity with the characteristic findings of NB with IM is necessary to avoid misdiagnosis and initiate necessary interventions.

Central nervous system relapse in high-risk stage 4 neuroblastoma: The HR-NBL1/SIOPEN trial experience

BACKGROUND

There is rising concern on the impact of new strategies, such as high-dose chemotherapy (HDC) and immunotherapy, on the pattern of relapse in high-risk neuroblastoma (HR-NBL). Our aim is to evaluate the incidence and identify risk factors for first recurrence in the central nervous system (CNS) in HR-NBL.

PATIENTS AND METHODS

Data from patients with stage 4V HR-NBL included from February 2002 to June 2015 in the prospective HR-NBL trial of the European International Society of Pediatric Oncology Neuroblastoma Group were analysed. Characteristics at diagnosis, treatment and the pattern of first relapse were studied. CNS imaging at relapse was centrally reviewed.

RESULTS

The 1977 included patients had a median age of 3 years (1 day-20 years); 1163 were boys. Among the 1161 first relapses, 53 were in the CNS, with an overall incidence of 2.7%, representing 6.2% of all metastatic relapses. One- and three-year post-relapse overall survival was 25 ± 6% and 8 ± 4%, respectively. Higher risk of CNS recurrence was associated with female sex (hazard ratio [HR] = 2.0 [95% confidence interval {CI}: 1.1-3.5]; P = 0.016), MYCN-amplification (HR = 2.4 [95% CI: 1.2-4.4]; P = 0.008), liver (HR = 2.5 [95% CI: 1.2-5.1]; P = 0.01) or >1 metastatic compartment involvement (HR = 7.1 [95% CI: 1.0-48.4]; P = 0.047) at diagnosis. Neither HDC nor immunotherapy was associated with higher risk of CNS recurrence. Stable incidence of CNS relapse was reported over time.

CONCLUSIONS

The risk of CNS recurrence is linked to both patient and disease characteristics, with neither impact of HDC nor immunotherapy. These findings support the current treatment strategy and do not justify a CNS prophylactic treatment.

Long-term follow-up of children with neuroblastoma receiving radiotherapy to metastatic lesions within the German Neuroblastoma Trials NB97 and NB 2004

PURPOSE

Neuroblastoma (NB) is the most common extracranial solid malignancy during childhood. Despite a multimodal treatment approach, the prognosis of patients with metastatic NB is not satisfactory. Although radiotherapy (RT) has become an integral part of treatment of the primary tumor, the role of RT in osteomedullary lesions is not well defined. A retrospective analysis was conducted to evaluate the impact of RT for metastatic sites in children with high-risk NB.

METHODS

All patients with stage 4 NB from the prospective, multicenter NB trials NB97 and NB2004 who received RT to metastatic sites during frontline treatment were included in this retrospective analysis.

RESULTS

A total of 18 children were irradiated with a median dose of 36 Gray (Gy; range 20-45 Gy) to one or more (range 1-3) osteomedullary metastases with or without concomitant RT to the primary tumor site. The median follow-up time was 149 months (range 55-220) in survivors. At 5 years, local relapse-free survival (LRFS) at irradiated metastatic sites and metastases-free survival (MFS) at distant, non-irradiated site rates were 51.4 and 39.9%, respectively. The estimated overall survival (OS) rate at 5 years was 49.4%. No high-grade acute or late toxicity and no secondary malignancy was reported.

CONCLUSION

RT to metastases is feasible for patients with stage 4 NB. However, an impact of RT to residual metastatic sites on outcome was not found. Studies with larger cohorts or prospective trials would be desirable in order to elucidate the role of RT for metastases.

Mouse models of high-risk neuroblastoma

Informative and realistic mouse models of high-risk neuroblastoma are central to understanding mechanisms of tumour initiation, progression, and metastasis. They also play vital roles in validating tumour drivers and drug targets, as platforms for assessment of new therapies and in the generation of drug sensitivity data that can inform treatment decisions for individual patients. This review will describe genetically engineered mouse models of specific subsets of high-risk neuroblastoma, the development of patient-derived xenograft models that more broadly represent the diversity and heterogeneity of the disease, and models of primary and metastatic disease. We discuss the research applications, advantages, and limitations of each model type, the importance of model repositories and data standards for supporting reproducible, high-quality research, and potential future directions for neuroblastoma mouse models.

Bone and bone marrow involvement in neuroblastoma: A case report

RATIONALE

Neuroblastoma (NB) can occur in any part of the sympathetic nervous system, and it is highly heterogeneous. Tumors that only involve bone marrow and bone lesions without solid masses have rarely been reported.

PATIENT CONCERNS

A 2-year-old girl child presented with recurrent fever, accompanied by pain in both lower limbs for more than 1 month.

DIAGNOSE

Bone marrow examination revealed NB cell invasion. Femoral and multiple vertebral lesions were observed by MRI, while head MRI, chest CT, abdominal CT, and pelvic CT showed no solid mass.

INTERVENTIONS

The child received the standard therapy for high-risk NB.

OUTCOMES

She was sensitive to the initial chemotherapy protocol. Two years later, a bone marrow examination confirmed NB recurrence.

LESSONS

The prognosis of this special type of NB was not improved mainly based on common chemotherapy and local radiotherapy, and new treatment strategies should be explored.

LIN28B regulates transcription and potentiates MYCN-induced neuroblastoma through binding to ZNF143 at target gene promotors

LIN28B is well known as a RNA-binding protein and a suppressor of microRNA biogenesis by selectively blocking the processing of let-7 precursors. However, little is known about let-7–independent roles of LIN28B. Here, we show that LIN28B is recruited to active promoters by binding to the zinc-finger transcription factor ZNF143. LIN28B acts as a cofactor to upregulate expression of a subset of downstream target genes that are essential for neuroblastoma cell survival and migration. Our paper reveals an unexpected role of LIN28B in transcriptional regulation that is independent of let-7 during neuroblastoma pathogenesis.

LIN28B is highly expressed in neuroblastoma and promotes tumorigenesis, at least, in part, through inhibition of let-7 microRNA biogenesis. Here, we report that overexpression of either wild-type (WT) LIN28B or a LIN28B mutant that is unable to inhibit let-7 processing increases the penetrance of MYCN-induced neuroblastoma, potentiates the invasion and migration of transformed sympathetic neuroblasts, and drives distant metastases in vivo. Genome-wide chromatin immunoprecipitation coupled with massively parallel DNA sequencing (ChIP-seq) and coimmunoprecipitation experiments show that LIN28B binds active gene promoters in neuroblastoma cells through protein–protein interaction with the sequence-specific zinc-finger transcription factor ZNF143 and activates the expression of downstream targets, including transcription factors forming the adrenergic core regulatory circuitry that controls the malignant cell state in neuroblastoma as well as GSK3B and L1CAM that are involved in neuronal cell adhesion and migration. These findings reveal an unexpected let-7–independent function of LIN28B in transcriptional regulation during neuroblastoma pathogenesis.

Activation of cell migration via morphological changes in focal adhesions depends on shear stress in MYCN-amplified neuroblastoma cells

Neuroblastoma is the most common solid tumour of childhood, and it metastasizes to distant organs. However, the mechanism of metastasis, which generally depends on the cell motility of the neuroblastoma, remains unclear. In many solid tumours, it has been reported that shear stress promotes metastasis. Here, we investigated the relationship between shear stress and cell motility in the MYCN-amplified human neuroblastoma cell line IMR32, using a microfluidic device. We confirmed that most of the cells migrated downstream, and cell motility increased dramatically when the cells were exposed to a shear stress of 0.4 Pa, equivalent to that expected in vivo. We observed that the morphological features of focal adhesion were changed under a shear stress of 0.4 Pa. We also investigated the relationship between malignancy and the motility of IMR32 cells under shear stress. Decreasing the expression of MYCN in IMR32 cells via siRNA transfection inhibited cell motility by a shear stress of 0.4 Pa. These results suggest that MYCN-amplified neuroblastoma cells under high shear stress migrate to distant organs due to high cell motility, allowing cell migration to lymphatic vessels and venules.

Venous Tumor Thrombosis and Pulmonary Metastases in a Case of Adrenal Neuroblastoma—Occurrence of Two Rare Manifestations in a Single Patient: Case Report and Review of Literature

Unlike other pediatric extra cranial solid neoplasms, neuroblastomas have very low incidence of pulmonary metastases. Neuroblastomas also tend to encase rather than infiltrate the major vessels with very low incidence of tumor thrombus. Even in cases with inferior vena cava tumor thrombosis, pulmonary metastases are a rare occurrence. These patients usually show widespread disseminated disease at presentation. We present a rare case of adrenal neuroblastoma with tumor thrombus and bilateral pulmonary metastases at presentation. This presentation can be confused with adrenocortical carcinoma and differentiating between the two is essential for further management.

Incidence and Prognostic Role of the Ocular Manifestations of Neuroblastoma in Children

PURPOSE

To describe the ocular manifestations of neuroblastoma in a large cohort of children.

DESIGN

Retrospective cohort study.

METHODS

The medical records of patients diagnosed with neuroblastoma between 1989 and 2017 at a tertiary care pediatric hospital were analyzed. The main outcome measurements were the incidence and prognostic role of ocular findings.

RESULTS

There were 523 patients with neuroblastoma in the study cohort. Median age at diagnosis was 1.9 years, median follow-up was 4.0 years, and 57.2% were male. At last follow-up, 55.3% were in disease remission, 5.0% had stable disease, 28.1% were deceased, and 11.7% were on active or palliative treatment. A total of 86 patients (16.4%) had ocular manifestations of neuroblastoma, 58 at presentation and 29 during the disease course. The most common findings were orbital involvement in 37 (43.0%), opsoclonus in 20 (23.3%), and Horner syndrome in 24 (27.9%). In 16 patients (3.1%), there were only ocular findings at presentation, including 8 (1.5%) with orbital involvement, 7 (1.3%) with Horner syndrome, and 1 (0.2%) with orbital involvement and a cranial nerve palsy. On survival analysis, a favorable prognosis was associated with opsoclonus, female sex, and diagnosis before 12 months of age, whereas a worse prognosis was associated with orbital involvement.

CONCLUSIONS

In this cohort, approximately 1 in 6 patients with neuroblastoma had ocular manifestations, but only 3% presented with only ocular findings. Orbital involvement was common and associated with a poor prognosis, whereas opsoclonus, female sex, and younger age at diagnosis were associated with a favorable prognosis.

Synthesis, Characterization and Biological Evaluation of Novel Dihydropyranoindoles Improving the Anticancer Effects of HDAC Inhibitors

The dihydropyranoindole scaffold was identified as a promising target for improving the anti-cancer activity of HDAC inhibitors from the preliminary screening of a library of compounds. A suitable methodology has been developed for the preparation of novel dihydropyranoindoles via the Hemetsberger indole synthesis using azido-phenylacrylates, derived from the reaction of corresponding alkynyl-benzaldehydes with methyl azidoacetate, followed by thermal cyclization in high boiling solvents. Anti-cancer activity of all the newly synthesized compounds was evaluated against the SH-SY5Y and Kelly neuroblastoma cells as well as the MDA-MB-231 and MCF-7 breast adenocarcinoma cell lines. Biological studies showed that the tetracyclic systems had significant cytotoxic activity at higher concentration against the neuroblastoma cancer cells. More importantly, these systems, at the lower concentration, considerably enhanced the SAHA toxicity. In addition to that, the toxicity of designated systems on the healthy human cells was found to be significantly less than the cancer cells.

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.

Occurrence of Albifimbria verrucaria in the Blood of a Female Child With Neuroblastoma

We report for the first time the occurrence of a filamentous fungus, Albifimbria verrucaria, in the blood of a pediatric neuroblastoma patient. The Albifimbria genus comprises common soil-inhabiting and saprophytic fungi and has been isolated as a plant pathogen in Northern and Southern Italy. As a human pathogen, A. verrucaria has been implicated in keratitis and can produce trichothecene toxins, which are weakly cytotoxic for mammalian cell lines. A. verrucaria was isolated from blood during the follow-up of a previous coagulase-negative Staphylococcus catheter-related infection. Lung nodules, compatible with fungal infection, had been observed on a CT scan 6 months earlier; they still persist. Possible routes of transmission were considered to be airborne, catheter related, or transfusion dependent, as the patient had undergone platelet and red blood cell transfusions during rescue chemotherapy. No filamentous fungi were isolated from sputum or CVCs. In conclusion, we describe an unprecedented fungemia caused by A. verrucaria and show how an unexpected pathogen may be acquired from the environment by patients at high risk due to immunosuppression. The route of transmission remains unknown.

Preclinical models for neuroblastoma: Advances and challenges

Neuroblastoma is a paediatric cancer of the sympathetic nervous system and the most common solid tumour of infancy, contributing to 15% of paediatric oncology deaths. Current therapies are not effective in the long-term treatment of almost 80% of patients with this clinically aggressive disease. The primary challenge in the identification and validation of new agents for paediatric drug development is the accurate representation of tumour biology and diversity. In addition to this limitation, the low incidence of neuroblastoma makes the recruitment of eligible patients for early phase clinical trials highly challenging and highlights the need for robust preclinical testing to ensure that the best treatments are selected. The research field requires new preclinical models, technologies, and concepts to tackle these problems. Tissue engineering offers attractive tools to assist in the development of three-dimensional (3D) cell models using various biomaterials and manufacturing approaches that recreate the geometry, mechanics, heterogeneity, metabolic gradients, and cell communication of the native tumour microenvironment. In this review, we discuss current experimental models and assess their abilities to reflect the structural organisation and physiological conditions of the human body, in addition to current and new techniques to recapitulate the tumour niche using tissue-engineered platforms. Finally, we will discuss the possible use of novel 3D in vitro culture systems to address open questions in neuroblastoma biology.

Neuroblastoma with intracerebral metastases and the need for neurosurgery: a single-center experience

OBJECTIVE

Intracerebral metastases in neuroblastoma patients are rare, and information about the indication for and the outcome of neurosurgical procedures in this setting is scarce in the literature. The authors' aim in the present study was to report a single-center experience with the neurosurgical treatment of intracerebral metastases in neuroblastoma.

METHODS

This study is a retrospective single-center analysis of all neurosurgical strategies used in the treatment of intracerebral metastases in neuroblastoma patients.

RESULTS

Between 2009 and 2017, 237 pediatric patients (94 girls, 143 boys) with a mean age of 39 months at diagnosis were treated for neuroblastoma. Five (2.1%) of the 237 patients had a neurosurgical procedure for intracerebral metastases. The metastases occurred a mean of 46 months after initial diagnosis. All of these patients had neuroblastoma stage 4. Indications for surgery were recurrent metastases after initial successful oncological treatment or progression of the metastasis under oncological treatment as well as deterioration of neurological function. Intraoperatively, the tumor usually had a distinguishable dissection plane but was infiltrative to adjacent nerves in some spots. Mean overall survival after the neurosurgical procedure was 22 months. Furthermore, in another 3 patients, a neurosurgical procedure was done for an intracranial but extracerebral metastasis.

CONCLUSIONS

Neurosurgical procedures for intracerebral metastases in neuroblastoma patients are rare and were performed in 2.1% of patients in the present study. Intracerebral metastases occurred during disease progression, and the prognosis after surgery was very limited. The main indications for surgery were rapid neurological deterioration or recurrence of the metastasis after initial successful oncological treatment. Intraoperatively, the metastases usually had a distinguishable dissection plane from the normal brain tissue.

The Role of Surgery in High-risk Neuroblastoma

Although intensive multimodal treatment has improved outcomes for patients with high-risk neuroblastoma, the specific role of primary tumor resection remains controversial. Many studies have been designed to determine whether the extent of surgical resection impacts survival; however, these reports have demonstrated conflicting results. There is also ongoing debate regarding the timing of primary tumor resection, with subtle differences in the approach between the large pediatric oncology cooperative consortia. Most of the published literature to date has been approached from a surgical viewpoint. Although most evidence supports surgery as part of the local control approach for high-risk neuroblastoma, recommendations for timing and extent of surgical resection are not consistent. This review summarizes our current understanding from the perspectives of both the pediatric oncologist and pediatric surgeons and discusses how the objectives of neuroblastoma primary surgical resection are different from that of other malignancies. Furthermore, this commentary will address how retrospective surgical outcome data may be interpreted in the setting of modern era high-risk neuroblastoma treatment.