Histopathologic prognostic factors in neuroblastic tumors: definition of subtypes of ganglioneuroblastoma and an age-linked classification of neuroblastomas

Diagnostic Challenges and Updates in Peripheral Neuroblastic Tumors

Peripheral neuroblastic tumors consist of a variety of neoplasms ranging from benign to highly malignant, with significant intertumoral and intratumoral heterogeneity. The current gold standard in classification, the International Neuroblastoma Pathology Committee classification, relies on morphologic features and patient age to assign favorable or unfavorable histology for each patient. The International Neuroblastoma Risk Group uses a subset of this pathologic data, along with patient age and several key molecular features, to assign one of several prognostic categories.

Colchicine Binding Site Tubulin Inhibitors Impair Vincristine-Resistant Neuroblastoma Cell Function

High-risk neuroblastoma remains a clinically challenging pediatric cancer, with an approximate five-year survival rate of ~60%. Frontline therapy for this group of patients includes surgery and intensive chemotherapy that involves combinations of the tubulin inhibitor vincristine with several other chemotherapeutics. Unfortunately, unresponsiveness to therapy and relapse are common, with tumors often displaying resistance to vincristine. Recently, we characterized a novel set of tubulin inhibitors that are distinct from vincristine and bind within the colchicine binding site present on tubulin monomers. Colchicine binding site inhibitors (CBSIs) have gained traction as improved chemotherapeutics due to their potential to overcome tubulin inhibitor-induced resistance. In this study, we investigate the functional impact of CBSI treatment on multiple neuroblastoma cell lines, including those that are vincristine-resistant. We demonstrate that our newly developed compounds are effective at disrupting cell division in non-resistant and resistant cells and have cellular activity against vincristine-resistant cell lines. Interestingly, we find that vincristine-resistant cell lines differ in their ability to undergo apoptotic cell death in response to CBSI treatment. Taken together, these findings provide a solid foundation to further investigate the utility of CBSIs for neuroblastoma treatment, while highlighting the distinct resistance mechanisms that can emerge in these childhood cancers.

Peripheral neuroblastic tumors behaving badly: an update on high-risk morphologic and molecular groupings

Peripheral neuroblastic tumors occur on a histologic spectrum from benign ganglioneuromas to malignant neuroblastomas, but even within the latter category, there is extensive heterogeneity in morphologic appearance and genetic composition. The International Neuroblastoma Pathology Committee classification has traditionally been used to successfully categorize tumors with favorable or unfavorable histology, but morphology must be supplemented with the results of additional testing. While MYCN amplification, diploid DNA content, and 11q loss have long been known to be negative prognostic factors, a new group of molecular biomarkers has emerged that define discrete high-risk categories. These include MYCN/MYC overexpression, dysregulated telomere maintenance mechanisms (both increased expression of telomere reverse transcriptase and alternate lengthening of telomeres), and ALK aberrations. Testing for these biomarkers and an integrated classification scheme may lead to improved risk stratification and selection of emerging targeted therapies.

Ultrasonic-Based Radiomics Signature With Machine Learning for Differentiating Prognostic Subsets of Pediatric Peripheral Neuroblastic Tumors: A Retrospective Study

OBJECTIVE

To construct and select a better model based on ultrasonic-based radiomics features and clinical characteristics for prognostic subsets of pediatric neuroblastic tumors.

METHODS

Data from 73 children with neuroblastic tumors were included and divided into a training group and a validation group. Data 1 contained the subjects' radiomics features and clinical characteristics, while data 2 contained radiomics features. With the help of machine learning, five models were constructed for data 1 and data 2, respectively. The model with the highest accuracy and area under the curve was selected as the combined model and radiomics model for data 1 and data 2, respectively. A superior model was then chosen from the models after further comparison.

RESULTS

The extreme gradient-boosting model for data 1 was chosen as the combined model and the extreme gradient-boosting model for data 2 was chosen as the radiomics model. The area under the curve of the combined and radiomics models in the validation group was 0.941 and 0.918 (p = 0.6906). The balanced accuracy, kappa value and F1 score of the radiomics model (0.9045, 0.8091 and 0.9091, respectively) were higher than those of the combined model (0.8545, 0.7123 and 0.8696, respectively). The top eight features of the radiomics model included five first-order statistical features and three textural features, all of which were high-dimensional features.

CONCLUSION

Our study proved that the radiomics model outperformed the combined model at differentiating prognostic subsets of pediatric neuroblastic tumors. Additionally, we found that high-dimensional ultrasonic-based radiomics features surpassed other features and clinical characteristics.

Expression evaluated by digital image analysis techniques of PRAME more than MCM6 is associated with poor prognosis in neuroblastoma: A pilot study with 84 cases

Neuroblastoma is a common childhood tumor originating from neural crest progenitors with variable clinical behavior. Despite improved overall survival, factors such as stage, histoprognosis, MYCN status, and age still influence outcome. MCM6 regulates DNA replication and contributes to cancer progression. PRAME, first identified in melanoma, also acts on cell replication, epithelial-mesenchymal transition, and cell migration and has been associated with poor outcomes in several cancers, including neuroblastoma, using molecular biology techniques. The study aims to investigate MCM6 and PRAME expression and prognostic roles in neuroblastoma. A retrospective study was conducted, which included data of 84 patients with neuroblastoma diagnosed between 2000 and 2022, sourced from the pediatric tumor registry. Patient's characteristics and prognostic tumor factors were collected. Expression of MCM6 and PRAME proteins was evaluated using digital image analysis techniques. Univariate and multivariate analyses were performed using Cox regression to assess the impact of protein expression on survival and their associations with these prognostic factors. A total of 84 children diagnosed with neuroblastoma were included. MCM6 and PRAME were associated with unfavorable histologies (p = 0.03). PRAME was associated with bone marrow metastases (p < 0.01), high mitotic-karyorrhectic index (p = 0.04), and poor histoprognosis (p < 0.01). PRAME and MCM6 expression was correlated with several neuroblastoma prognostic factors. PRAME was significantly (p = 0.05) associated with poor event-free survival (EFS) and not significantly (p = 0.08) associated with overall survival (OS). Although statistical significance was not reached in multivariate analysis, the trends strongly suggested that the overexpression of MCM6 and PRAME was correlated with decreased survival.

Tumor Microenvironment Modulation by Cancer-Derived Extracellular Vesicles

The tumor microenvironment (TME) plays an important role in the process of tumorigenesis, regulating the growth, metabolism, proliferation, and invasion of cancer cells, as well as contributing to tumor resistance to the conventional chemoradiotherapies. Several types of cells with relatively stable phenotypes have been identified within the TME, including cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), neutrophils, and natural killer (NK) cells, which have been shown to modulate cancer cell proliferation, metastasis, and interaction with the immune system, thus promoting tumor heterogeneity. Growing evidence suggests that tumor-cell-derived extracellular vesicles (EVs), via the transfer of various molecules (e.g., RNA, proteins, peptides, and lipids), play a pivotal role in the transformation of normal cells in the TME into their tumor-associated protumorigenic counterparts. This review article focuses on the functions of EVs in the modulation of the TME with a view to how exosomes contribute to the transformation of normal cells, as well as their importance for cancer diagnosis and therapy.

Revisiting Neuroblastoma: Nrf2, NF-κB and Phox2B as a Promising Network in Neuroblastoma

Neuroblastoma is the most common solid extracranial tumor during childhood; it displays extraordinary heterogeneous clinical courses, from spontaneous regression to poor outcome in high-risk patients due to aggressive growth, metastasizing, and treatment resistance. Therefore, the identification and detailed analysis of promising tumorigenic molecular mechanisms are inevitable. This review highlights the abnormal regulation of NF-κB, Nrf2, and Phox2B as well as their interactions among each other in neuroblastoma. NF-κB and Nrf2 play a key role in antioxidant responses, anti-inflammatory regulation and tumor chemoresistance. Recent studies revealed a regulation of NF-κB by means of the Nrf2/antioxidant response element (ARE) system. On the other hand, Phox2B contributes to the differentiation of immature sympathetic nervous system stem cells: this transcription factor regulates the expression of RET, thereby facilitating cell survival and proliferation. As observed in other tumors, we presume striking interactions between NF-κB, Nrf2, and Phox2B, which might constitute an important crosstalk triangle, whose decompensation may trigger a more aggressive phenotype. Consequently, these transcription factors could be a promising target for novel therapeutic approaches and hence, further investigation on their regulation in neuroblastoma shall be reinforced.

[Surgery for abdominal neuroblastoma in children]

This review is devoted to surgical approach for neurogenic tumors in children. The authors discuss epidemiological data, history of surgical approaches, preoperative imaging and risk factors. A special attention is paid to the influence of surgical interventions for various neuroblastomas on overall and event-free survival in pediatric population, as well as the most common surgical complications and modern approaches to their treatment.

[Peripheral neuroblastic tumors in childhood]

Peripheral neuroblastic tumors represent the fourth-largest group of malignant tumors in childhood. The majority of these tumors are neuroblastomas, which can be classified into undifferentiated, poorly differentiated, and differentiating subtypes. In addition, peripheral neuroblastic tumors include ganglioneuroblastoma, a composite tumor composed of Schwannian cell stroma and neuroblasts as well as benign ganglioneuroma. In this overview, histopathological diagnostic criteria and grading systems, as well as common molecular alterations that are of prognostic and therapeutic significance, are discussed.

Image-defined risk factors in localized thoracic neuroblastoma and ganglioneuroma

BACKGROUND

The pretreatment International Neuroblastoma Risk Group Staging System (INRGSS) discriminates localized tumors L1/L2 depending on the absence/presence of image-defined risk factors (IDRFs) at diagnosis. Referring to this new staging system, we assessed initial imaging of localized thoracic neuroblastoma (NB) and ganglioneuroma (GN) and the extent of initial tumor resection.

METHODS

Patients with localized thoracic NB/GN from the German clinical trials NB97 and NB2004 were included. Imaging at diagnosis and operative reports were reviewed retrospectively. IDRFs were assessed centrally and correlated to International Neuroblastoma Staging System (INSS) stage and extent of tumor resection. Additionally, we analyzed data on surgery-related complications.

RESULTS

Imaging series of 88 patients were available for central review. In 18 children, no IDRF was present, 28 exhibited one IDRF, 42 two or more IDRFs, resulting in 70 patients with L2 disease. The most frequently observed IDRF was encasement of any vessel (n = 38). Initial surgical resection was aimed for in 45 patients (L1: n = 11; L2: n = 34). Complete and gross total resection rates were higher children with L2 NB (n = 8/25 L1, n = 17/25 L2 vs. n = 2/15 L1, n = 13/15 L2, respectively). The proportion of surgical complications was very similar between INRGSS L1 and L2 (n = 4/11 vs. n = 17/34). All complications were manageable, and no surgery-related deaths were observed.

CONCLUSION

In this retrospective cohort, the extent of resection and the rate of surgical complications did not differ substantially between patients classified as L1/L2, indicating that INRGSS L2 does not equate unresectability. It appeared that individual IDRFs differ in value. Larger studies are needed to assess the significance and therapeutic/prognostic impact of such findings.

MYCN amplification, TERT rearrangements and ATRX mutations in neuroblastoma: clinicopathological correlates- an Indian perspective

BACKGROUND

Neuroblastoma (NB) is the most common extracranial solid tumour in childhood with a diverse clinical presentation and course. The early age of onset, high frequency of metastatic disease at diagnosis and tendency for spontaneous regression in infancy sets it apart from other childhood tumors. This heterogeneity is largely attributed to underlying genetic aberrations which are distinct in low-risk and high-risk NB. To this end, we sought to analyse our NB cases for the molecular alterations and find its correlation with clinical behaviour.

METHODS

NB cases (n = 50) diagnosed over last 7 years were retrospectively analysed for MYCN amplification (fluorescent-in-situ hybridization), TERT rearrangements (qRT-PCR), ATRX mutations (immunohistochemistry). These findings were correlated with demographic profiles, histologic features and clinical outcome.

RESULTS

Age ranged from 1 month to 30 years (mean 2.8 years) with male preponderance. Poorly differentiated subtype constituted the majority (64%), followed by differentiating (28%) and undifferentiated subtype (8%) which were equally distributed across all age groups. MYCN amplification, TERT-mRNA upregulation and ATRX mutations was observed in 30%, 42% and 24%, respectively. Cases with TERT-mRNA upregulation were distributed equally across all histological subtypes while those with ATRX mutations and MYCN amplification were frequent in poorly differentiated NB. ATRX mutation was mutually exclusive of TERT-mRNA upregulation and MYCN amplification. Kaplan-Meier analysis revealed significantly shorter overall and progression-free survival for tumors harboring MYCN amplification and TERT-mRNA upregulation, while that for ATRX mutant tumors was not significant.

CONCLUSIONS

Our results provide data indicating poor clinical outcome in NB carrying MYCN amplification and TERT-mRNA upregulation.

WDR5 facilitates recruitment of N-MYC to conserved WDR5 gene targets in neuroblastoma cell lines

Collectively, the MYC family of oncoprotein transcription factors is overexpressed in more than half of all malignancies. The ability of MYC proteins to access chromatin is fundamental to their role in promoting oncogenic gene expression programs in cancer and this function depends on MYC-cofactor interactions. One such cofactor is the chromatin regulator WDR5, which in models of Burkitt lymphoma facilitates recruitment of the c-MYC protein to chromatin at genes associated with protein synthesis, allowing for tumor progression and maintenance. However, beyond Burkitt lymphoma, it is unknown whether these observations extend to other cancers or MYC family members, and whether WDR5 can be deemed as a "universal" MYC recruiter. Here, we focus on N-MYC amplified neuroblastoma to determine the extent of colocalization between N-MYC and WDR5 on chromatin while also demonstrating that like c-MYC, WDR5 can facilitate the recruitment of N-MYC to conserved WDR5-bound genes. We conclude based on this analysis that N-MYC and WDR5 colocalize invariantly across cell lines at predicted sites of facilitated recruitment associated with protein synthesis genes. Surprisingly, we also identify N-MYC-WDR5 cobound genes that are associated with DNA repair and cell cycle processes. Dissection of chromatin binding characteristics for N-MYC and WDR5 at all cobound genes reveals that sites of facilitated recruitment are inherently different than most N-MYC-WDR5 cobound sites. Our data reveals that WDR5 acts as a universal MYC recruiter at a small cohort of previously identified genes and highlights novel biological functions that may be coregulated by N-MYC and WDR5 to sustain the neuroblastoma state.

Suppression of epithelial-mesenchymal transition and SIRT1/AKT signaling pathway in breast cancer by montelukast

BACKGROUND

Breast cancer is usually associated with metastatic features, poor prognosis, and high mortality. The epithelial-mesenchymal transition (EMT) process has been implicated in the initiation and metastasis of breast cancer.

OBJECTIVE

The study aimed to investigate the possible role of montelukast (Mont), the cysteinyl leukotriene receptor (CystLT1R) antagonist, in mitigating EMT in triple-negative breast cancer (TNBC) (in vitro study) and solid Ehrlich carcinoma (SEC) bearing mice (in vivo study) as well as to clarify the underlying molecular mechanisms in the presence and absence of sirtuin-1 inhibitor (sirtinol; Sirt).

METHODS

TNBC MDA-MB-231 cells were treated with either 5 μM Mont or 25 μM Sirt or both for 48 h. Alternatively, SEC cells were inoculated in mice to induce breast cancer. After 12 days, the mice were divided into four groups: Untreated SEC group (vehicle), Sirt group (1 mg/kg), Mont group (10 mg/kg), and cotreatment Sirt/Mont group. The mice groups received the assigned treatment for the consequent 16 days.

RESULTS

Mont and/or Sirt decreased cell proliferation, migration and suppressed EMT in both in vitro and in vivo experiments. All treatments downregulated sirtuin-1 and vimentin expression but upregulated E-cadherin expression. Furthermore, all treatments retarded angiogenesis as evidenced by decreased VEGF expression. These findings were associated with suppressing active protein kinase B (p-AKT).

CONCLUSION

Cotreatment with Sirt and Mont proved more effective anti-tumor activity in TNBC cell line and in SEC bearing mice than either treatment alone, which could be attributed to the inhibition of sirtuin-1 and AKT- activated pathways, with the subsequent inhibition of EMT.

Cervical ganglioneuroma arising from the dorsal root ganglion: illustrative case

BACKGROUND

Ganglioneuroma is a benign and well-differentiated tumor derived from neural crest cells, which occurs infrequently, with most patients being female and adolescents. While predilection sites are the posterior mediastinum and retroperitoneal cavity, ganglioneuroma originating from the dorsal root ganglion is very rare. Here the authors report a case with C2 dorsal root ganglion-derived ganglioneuroma with some literature review.

OBSERVATIONS

A 45-year-old male patient complained of persistent right-side throbbing occipital headache for more than a year. Magnetic resonance imaging (MRI) of the cervical spine revealed a dumbbell-shaped intradural extramedullary tumor from the C2 posterior surface of the odontoid to right C1-2 intervertebral foramen with high T2- and low T1-weighted signal intensities. The tumor displayed homogeneous contrast enhancement by MRI. The authors suspected schwannoma and performed a tumorectomy for both diagnosis and treatment purposes. Intraoperative findings showed that the tumor originated from the dorsal root ganglion, and pathological examination revealed ganglioneuroma. Immediately after the tumorectomy, the throbbing occipital headache disappeared and the patient was discharged from the hospital without major complications.

LESSONS

Although ganglioneuroma derived from the dorsal root ganglion is very rare, a differential diagnosis of the ganglioneuroma should be made, when schwannoma is suspected.

More Abundant Superoxide Dismutase2 Protein Levels in Blood May Act as a Prognostic Marker for High-Risk Neuroblastoma Patients

Purpose: Determination of proteomic differences plays an important role in biomarker investigations. Due to its heterogenic molecular background, identification of certain biomarkers is still a demand both for diagnosis and for prognosis of neuroblastoma. In this study, it is aimed to identify some marker proteins/mechanisms that may play role in neuroblastoma prognosis. Methods: A proteomic approach was performed for different risk groups of the disease by using matrix-assisted laser desorption ionization–time of flight (MALDI-TOF/TOF) approach. Mononuclear cell pools from blood samples of patients for risk groups were constructed and protein expression changes for different groups were identified. Real-time PCR analysis were performed for N-MYC, 11q, 1p and 17q status of these patients and risk groups were determined from tumor samples. Results: Manganese-superoxide dismutase (SOD2) protein was significantly increased in high-risk group of neuroblastoma patients. Conclusion: SOD2 may play an important role in neuroblastoma progression and be a candidate prognostic peripheral blood marker for neuroblastoma patients.

Automated Tumor Count for Mitosis-Karyorrhexis Index Determination in Neuroblastoma Using Whole Slide Image and Qupath, an Image Analytic Software

INTRODUCTION

Mitosis-karyorrhexis index (MKI) is important for risk stratification workup of neuroblastic tumors. MKI is calculated by estimating the denominator (5000 tumor cells). We hypothesized that whole slide image (WSI) with appropriate digital image analytical software could provide an objective aid to pathologist's MKI workup.

MATERIALS & METHODS

With IRB approval, sixteen cases of neuroblastic tumors as convenient cases were used. H&E slides were scanned at 40X using an Aperio Scanscope AT2 scanner and stored in SVS format. Digital photos were also taken and stored in TIFF format. Qupath, an open source image analytical software, was used to annotate, define region of interest (ROI) and automatically count the cells within ROI.

RESULTS

With selected parameters, Qupath was able to provide cell count using both WSI (.svs) and digital images (.TIFF). Comparison of automated count and eyeball manual count generated precision above .96, recall above .96, F1 scores above .98, with false positive rate ranging from .6 to 3.7%, and false negative rate from .6 to 3.8%. Compared to original pathological report, automated tumor cell count led to lower MKI in 3 of 16 cases (18.8%) and change of "unfavorable histology" to "favorable" in one case (1/16, 6.3%).

CONCLUSION

Combination of WSI (or digital images) with Qupath is able to provide an automated, objective and consistent way for cell count to facilitate pathologist's MKI determination in neuroblastic tumors' workup and research.

Retroperitoneal ganglioneuroblastoma with postoperative stress ulcer perforation in an adolescent: A case report and review of the literature

Ganglioneuroblastoma (GNB) is a condition belonging to the neuroblastoma family. It is a transitional tumor consisting of a mixture of mature ganglioneuromas and malignant neuroblastomas. Its biological behavior is intermediate between benign and malignant, with a risk of recurrence and metastasis. It usually occurs in pediatric patients aged <10 years, particularly between the ages of 1 and 2 years, but may also occur in adolescents or adults. The present study reported on the clinical management of a case of postoperative stress ulcer with perforation in a 17-year-old female patient with retroperitoneal GNB and provided a review of the literature on retroperitoneal GNB in adolescents and adults.

Risk Factors Associated with Metastatic Site Failure in Patients with High-Risk Neuroblastoma

•

We observed an increased hazard for failure at metastatic sites which remain persistently avid on MIBG following systemic therapy.

•

-Limited response to induction therapy described by Curie and SIOPEN score selects patients at greater risk for poly-metastatic site failure.

•

-The low proportion of metastatic sites treated with radiotherapy precluded definitive testing of its impact on the hazard for metastatic site failure.

•

-Patients who are unable to undergo transplant, and/or have extensive disease at diagnosis (lung metastases) may be poor candidates for consolidative metastatic site directed radiotherapy given the high competing risk of failure at a new metastatic site.

Purpose

This retrospective study sought to identify predictors of metastatic site failure (MSF) at new and/or original (present at diagnosis) sites in high-risk neuroblastoma patients.

Methods and materials

Seventy-six high-risk neuroblastoma patients treated on four institutional prospective trials from 1997 to 2014 with induction chemotherapy, surgery, myeloablative chemotherapy, stem-cell rescue, and were eligible for consolidative primary and metastatic site (MS) radiotherapy were eligible for study inclusion. Computed-tomography and I­123 MIBG scans were used to assess disease response and Curie scores at diagnosis, post-induction, post-transplant, and treatment failure. Outcomes were described using the Kaplan–Meier estimator. Cox proportional hazards frailty (cphfR) and CPH regression (CPHr) were used to identify covariates predictive of MSF at a site identified either at diagnosis or later.

Results

MSF occurred in 42 patients (55%). Consolidative MS RT was applied to 30 MSs in 10 patients. Original-MSF occurred in 146 of 383 (38%) non­irradiated and 18 of 30 (60%) irradiated MSs (p = 0.018). Original- MSF occurred in post­induction MIBG-avid MSs in 68 of 81 (84%) non­irradiated and 12 of 14 (85%) radiated MSs (p = 0.867). The median overall and progression-free survival rates were 61 months (95% CI 42.6­Not Reached) and 24.1 months (95% CI 16.5­38.7), respectively. Multivariate CPHr identified inability to undergo transplant (HR 32.4 95%CI 9.3­96.8, p < 0.001) and/or maintenance chemotherapy (HR 5.2, 95%CI 1.7­16.2, p = 0.005), and the presence of lung metastases at diagnosis (HR 4.4 95%CI 1.7­11.1, p = 0.002) as predictors of new MSF. The new MSF-free survival rate at 3 years was 25% and 87% in patients with and without high-risk factors.

Conclusions

Incremental improvements in systemic therapy influence the patterns and type of metastatic site failure in neuroblastoma. Persistence of MIBG-avidity following induction chemotherapy and transplant at MSs increased the hazard for MSF.

High-Risk Neuroblastoma: Poor Outcomes Despite Aggressive Multimodal Therapy

:

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.

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.

Genetic and Histopathological Heterogeneity of Neuroblastoma and Precision Therapeutic Approaches for Extremely Unfavorable Histology Subgroups

Peripheral neuroblastic tumors (neuroblastoma, ganglioneuroblastoma and ganglioneuroma) are heterogeneous and their diverse and wide range of clinical behaviors (spontaneous regression, tumor maturation and aggressive progression) are closely associated with genetic/molecular properties of the individual tumors. The International Neuroblastoma Pathology Classification, a biologically relevant and prognostically significant morphology classification distinguishing the favorable histology (FH) and unfavorable histology (UH) groups in this disease, predicts survival probabilities of the patients with the highest hazard ratio. The recent advance of neuroblastoma research with precision medicine approaches demonstrates that tumors in the UH group are also heterogeneous and four distinct subgroups—MYC, TERT, ALT and null—are identified. Among them, the first three subgroups are collectively named extremely unfavorable histology (EUH) tumors because of their highly aggressive clinical behavior. As indicated by their names, these EUH tumors are individually defined by their potential targets detected molecularly and immunohistochemically, such as MYC-family protein overexpression, TERT overexpression and ATRX (or DAXX) loss. In the latter half on this paper, the current status of therapeutic targeting of these EUH tumors is discussed for the future development of effective treatments of the patients.

Adrenocortical Tumors and Pheochromocytoma/Paraganglioma Initially Mistaken as Neuroblastoma-Experiences From the GPOH-MET Registry

In children and adolescents, neuroblastoma (NBL), pheochromocytoma (PCC), and adrenocortical tumors (ACT) can arise from the adrenal gland. It may be difficult to distinguish between these three entities including associated extra-adrenal tumors (paraganglioma, PGL). Precise discrimination, however, is of crucial importance for management. Biopsy in ACT or PCC is potentially harmful and should be avoided whenever possible. We herein report data on 10 children and adolescents with ACT and five with PCC/PGL, previously mistaken as NBL. Two patients with adrenocortical carcinoma died due to disease progression. Two (2/9, missing data in one patient) patients with a final diagnosis of ACT clearly presented with obvious clinical signs and symptoms of steroid hormone excess, while seven patients did not. Blood analyses indicated increased levels of steroid hormones in one additional patient; however, urinary steroid metabolome analysis was not performed in any patient. Two (2/10) patients underwent tumor biopsy, and in two others tumor rupture occurred intraoperatively. In 6/10 patients, ACT diagnosis was only established by a reference pediatric pathology laboratory. Four (4/5) patients with a final diagnosis of PCC/PGL presented with clinical signs and symptoms of catecholamine excess. Urine tests indicated possible catecholamine excess in two patients, while no testing was carried out in three patients. Measurements of plasma metanephrines were not performed in any patient. None of the five patients with PCC/PGL received adrenergic blockers before surgery. In four patients, PCC/PGL diagnosis was established by a local pathologist, and in one patient diagnosis was revised to PGL by a pediatric reference pathologist. Genetic testing, performed in three out of five patients with PCC/PGL, indicated pathogenic variants of PCC/PGL susceptibility genes. The differential diagnosis of adrenal neoplasias and associated extra-adrenal tumors in children and adolescents may be challenging, necessitating interdisciplinary and multidisciplinary efforts. In ambiguous and/or hormonally inactive cases through comprehensive biochemical testing, microscopical complete tumor resection by an experienced surgeon is vital to preventing poor outcome in children and adolescents with ACT and/or PCC/PGL. Finally, specimens need to be assessed by an experienced pediatric pathologist to establish diagnosis.

Overexpression of INSM1, NOTCH1, NEUROD1, and YAP1 genes is associated with adverse clinical outcome in pediatric neuroblastoma

Pediatric neuroblastoma is responsible for approximately 8-10% of pediatric tumors, and it is one of the leading causes of tumor-related deaths in children. Although significant progress has been made in the characterization of neuroblastoma in recent years, the mechanisms influencing the prognosis of neuroblastoma patients remain largely unknown. Our aim was to investigate if the major neuroendocrine-associated transcriptional drivers, including ASCL1, NEUROD1, DLL3, NOTCH1, INSM1, MYCL1, POU2F3 and YAP1 are correlated with specific clinical and pathological characteristics. We selected a retrospective series of 46 primary pediatric neuroblastoma, composed of 30 treatment-naïve and 16 post-chemotherapy cases. Gene expression levels were explored by means of quantitative real-time PCR. An increased expression of NOTCH1 (p = 0.005), NEUROD1 (p = 0.0059), and YAP1 (p = 0.0008) was found in stage IV tumors, while the highest levels of MYCL1 and ASCL1 were seen in stages IVS and III, respectively (p = 0.0182 and p = 0.0134). A higher level of NOTCH1 (p = 0.0079) and YAP1 (p = 0.0026) was found in cases with differentiating morphology, while high mitosis-karyorrhexis index cases demonstrated significantly lower levels of POU2F3 (p = 0.0277). High expression of NOTCH1 (p = 0.008), NEUROD1 (p = 0.026), INSM1 (p = 0.010), and YAP1 (p = 0.005) together with stage IV (p = 0.043) was associated with shorter disease-free survival. In summary, our data indicate that the assessment of gene expression levels of neuroendocrine-lineage transcription factors might help to identify neuroblastoma patients with the risk of relapse.

Upfront Treatment of Pediatric High-Risk Neuroblastoma With Chemotherapy, Surgery, and Radiotherapy Combination: The CCCG-NB-2014 Protocol

Purpose

The Chinese Children’s Cancer Group developed the CCCG-NB-2014 study to formulate optimal treatment strategies for high-risk (HR) neuroblastoma (NB). The safety and efficacy of this protocol were evaluated.

Method

Patients with newly diagnosed neuroblastoma and defined as HR according to the Children’s Oncology Group study were included. They were treated with a combination of chemotherapy, surgery, and radiotherapy. The treatment-related toxicities, response rate, 3-year progression-free survival (PFS), and overall survival (OS) were analyzed.

Results

Of 159 patients enrolled between 2014 and 2018, 80 were eligible, including 19 girls and 61 boys, with a median age of 3.9 years (range 0.9–11). After a median follow-up of 24 months (range 3–40), the median OS was 31.8 months, and 3-year OS was 83.8%. In multivariate analyses, the OS was affected by N-MYC amplification (hazard ratio 0.212, 95% confidence interval (CI) 0.049–0.910; p = 0.037) and giant tumor mass (hazard ratio 0.197, 95% CI 0.071–0.552; p = 0.002). The median 3-year PFS was 25.8 months, and 3-year PFS was 57.5%. The univariate analysis showed that only the giant tumor mass was associated with the outcome. Of the 13 deaths, 11 died from the rapid progression of the disease and two from treatment-related toxicities. The most common adverse reaction was chemotherapy-induced hematological toxicity.

Conclusion

The PFS and OS reported in our study were similar to Western countries. The CCCG-NB-2014 protocol proved to be an efficient regimen with tolerable side-effect for the treatment of pediatric HR-NB.

CHAF1A Blocks Neuronal Differentiation and Promotes Neuroblastoma Oncogenesis via Metabolic Reprogramming

Neuroblastoma (NB) arises from oncogenic disruption of neural crest (NC) differentiation. Treatment with retinoic acid (RA) to induce differentiation has improved survival in some NB patients, but not all patients respond, and most NBs eventually develop resistance to RA. Loss of the chromatin modifier chromatin assembly factor 1 subunit p150 (CHAF1A) promotes NB cell differentiation; however, the mechanism by which CHAF1A drives NB oncogenesis has remained unexplored. This study shows that CHAF1A gain-of-function supports cell malignancy, blocks neuronal differentiation in three models (zebrafish NC, human NC, and human NB), and promotes NB oncogenesis. Mechanistically, CHAF1A upregulates polyamine metabolism, which blocks neuronal differentiation and promotes cell cycle progression. Targeting polyamine synthesis promotes NB differentiation and enhances the anti-tumor activity of RA. The authors' results provide insight into the mechanisms that drive NB oncogenesis and suggest a rapidly translatable therapeutic approach (DFMO plus RA) to enhance the clinical efficacy of differentiation therapy in NB patients.

Extracellular domain shedding of the ALK receptor mediates neuroblastoma cell migration

Although activating mutations of the anaplastic lymphoma kinase (ALK) membrane receptor occur in ~10% of neuroblastoma (NB) tumors, the role of the wild-type (WT) receptor, which is aberrantly expressed in most non-mutated cases, is unclear. Both WT and mutant proteins undergo extracellular domain (ECD) cleavage. Here, we map the cleavage site to Asn654-Leu655 and demonstrate that cleavage inhibition of WT ALK significantly impedes NB cell migration with subsequent prolongation of survival in mouse models. Cleavage inhibition results in the downregulation of an epithelial-to-mesenchymal transition (EMT) gene signature, with decreased nuclear localization and occupancy of β-catenin at EMT gene promoters. We further show that cleavage is mediated by matrix metalloproteinase 9, whose genetic and pharmacologic inactivation inhibits cleavage and decreases NB cell migration. Together, our results indicate a pivotal role for WT ALK ECD cleavage in NB pathogenesis, which may be harnessed for therapeutic benefit.

Huang et al. show that extracellular domain (ECD) cleavage of the ALK cell surface tyrosine kinase receptor mediates neuroblastoma cell migration through induction of an EMT phenotype. ECD cleavage is caused by MMP-9 whose inhibition leads to decreased cell migration.

Management of Neuroblastoma in Pediatric Patients

Surgeons caring for patients with neuroblastoma must be familiar with recent developments in assessing risk. In particular, the Children's Oncology Group, along with major international groups, uses the International Neuroblastoma Risk Group Staging System as a risk assessment tool. Accurate risk determination is essential for optimal surgical therapy. Some tumors like neonatal adrenal neuroblastomas and those in the metastatic category can be observed. Very-low-risk and low-risk neuroblastomas can be treated with surgery alone. Intermediate-risk tumors also often require systemic chemotherapy.

Differentiating Neuroblastoma: A Systematic Review of the Retinoic Acid, Its Derivatives, and Synergistic Interactions

A neuroblastoma (NB) is a solid paediatric tumour arising from undifferentiated neuronal cells. Despite the recent advances in disease management and treatment, it remains one of the leading causes of childhood cancer deaths, thereby necessitating the development of new therapeutic agents and regimens. Retinoic acid (RA), a vitamin A derivative, is a promising agent that can induce differentiation in NB cells. Its isoform, 13-cis RA or isotretinoin, is used in NB therapy; however, its effectiveness is limited to treating a minimal residual disease as maintenance therapy. As such, research focuses on RA derivatives that might increase the anti-NB action or explores the potential synergy between RA and other classes of drugs, such as cellular processes mediators, epigenetic modifiers, and immune modulators. This review summarises the in vitro, in vivo, and clinical data of RA, its derivatives, and synergising compounds, thereby establishing the most promising RA derivatives and combinations of RA for further investigation.

Schwann cell plasticity regulates neuroblastic tumor cell differentiation via epidermal growth factor-like protein 8

Adult Schwann cells (SCs) possess an inherent plastic potential. This plasticity allows SCs to acquire repair-specific functions essential for peripheral nerve regeneration. Here, we investigate whether stromal SCs in benign-behaving peripheral neuroblastic tumors adopt a similar cellular state. We profile ganglioneuromas and neuroblastomas, rich and poor in SC stroma, respectively, and peripheral nerves after injury, rich in repair SCs. Indeed, stromal SCs in ganglioneuromas and repair SCs share the expression of nerve repair-associated genes. Neuroblastoma cells, derived from aggressive tumors, respond to primary repair-related SCs and their secretome with increased neuronal differentiation and reduced proliferation. Within the pool of secreted stromal and repair SC factors, we identify EGFL8, a matricellular protein with so far undescribed function, to act as neuritogen and to rewire cellular signaling by activating kinases involved in neurogenesis. In summary, we report that human SCs undergo a similar adaptive response in two patho-physiologically distinct situations, peripheral nerve injury and tumor development.

Biological categories of neuroblastoma based on the international neuroblastoma pathology classification for treatment stratification

The International Neuroblastoma Pathology Classification (INPC), which distinguishes a favorable histology (FH) and an unfavorable histology (UH), is one of the most powerful prognostic factors in patients with neuroblastoma. FH that shows spontaneous regression or age-appropriate tumor differentiation/maturation, is common in infants and has mutual interaction with Schwann cells via the NGF/NTRK1 pathway and gain of whole chromosome 17. In contrast, UH is prevalent in older children and is molecularly heterogeneous. MYCN amplification is the most frequent genomic abnormality in tumors with UH. MYCN-amplified tumors demonstrate characteristic histology, the same as MYC-positive neuroblastoma. Chromosome 1pLOH is often associated with MYCN amplification, but on the other hand, chromosome 11qLOH rarely occurs in combination with MYCN amplification. 11qLOH has an inferior prognostic impact in UH without MYCN amplification. The high expression of ALK protein is a negative prognostic factor in both ALK mutated or amplified tumors and FH, but not in UH. Abnormal maintenance/elongation of telomeres; overexpression of telomerase reverse transcriptase (TERT) and the alternative lengthening of telomeres (ALT) phenotype due to ATRX mutation, are another molecular event in UH. The INPC, incorporating immunohistochemistry for MYCN, MYC, ALK, TERT and ATRX, represents a practical and implementable approach to create the biological category for the future management of patients with this unique disease.

Questioning How to Define the "Ultra-High-Risk" Subgroup of Neuroblastoma Patients

Neuroblastic tumours exhibit heterogeneity, which results in different therapeutic outcomes. Neuroblastoma is categorized into three major risk groups (low, intermediate, high risk). Recent identification of new genes raised the possibility of new biomarkers to identify sub-risk groups. In this retrospective cross-sectional study, we aimed to assess new biomarkers defining the ultra-high-risk subgroup within the high-risk group that differ in clinical situation with very bad prognosis. Twenty-five low- and 29 high-risk groups of patients were analysed for their expression of ALK, ATRX, HIF1a, HIF2a (EPAS), H2AFX, and ETV5 genes at the RNA level. Immunohistochemistry was performed to confirm the protein expression level of ALK. The risk group of patients was determined according to the International Neuroblastoma Risk Group Stratification System. Spearman correlation analysis and Mann-Whitney-U nonparametric test were used to assess the importance of expression levels among the groups. P < 0.05 was considered as significant. Sensitivity of the results was checked by ROC curve analysis. All analysed genes were found to be highly expressed in the high-risk group compared to the low-risk group, except for ETV5. When the ultra-high-risk and highrisk groups were compared, ALK was found to be highly expressed in the ultra-high-risk group. Our results show that ALK may be a candidate gene whose mRNA expression levels can distinguish the ultrahigh- risk subgroup of patients in the high-risk group of patients with non-familial neuroblastoma.

Super enhancers define regulatory subtypes and cell identity in neuroblastoma

Half of the children diagnosed with neuroblastoma (NB) have high-risk disease, disproportionately contributing to overall childhood cancer-related deaths. In addition to recurrent gene mutations, there is increasing evidence supporting the role of epigenetic deregulation in disease pathogenesis. Yet, comprehensive cis-regulatory network descriptions from NB are lacking. Here, using genome-wide H3K27ac profiles across 60 NBs, covering the different clinical and molecular subtypes, we identified four major super-enhancer-driven epigenetic subtypes and their underlying master regulatory networks. Three of these subtypes recapitulated known clinical groups; namely, MYCN-amplified, MYCN non-amplified high-risk and MYCN non-amplified low-risk NBs. The fourth subtype, exhibiting mesenchymal characteristics, shared cellular identity with multipotent Schwann cell precursors, was induced by RAS activation and was enriched in relapsed disease. Notably, CCND1, an essential gene in NB, was regulated by both mesenchymal and adrenergic regulatory networks converging on distinct super-enhancer modules. Overall, this study reveals subtype-specific super-enhancer regulation in NBs.

Emerging Neuroblastoma 3D In Vitro Models for Pre-Clinical Assessments

The potential of tumor three-dimensional (3D) in vitro models for the validation of existing or novel anti-cancer therapies has been largely recognized. During the last decade, diverse in vitro 3D cell systems have been proposed as a bridging link between two-dimensional (2D) cell cultures and in vivo animal models, both considered gold standards in pre-clinical settings. The latest awareness about the power of tailored therapies and cell-based therapies in eradicating tumor cells raises the need for versatile 3D cell culture systems through which we might rapidly understand the specificity of promising anti-cancer approaches. Yet, a faithful reproduction of the complex tumor microenvironment is demanding as it implies a suitable organization of several cell types and extracellular matrix components. The proposed 3D tumor models discussed here are expected to offer the required structural complexity while also assuring cost-effectiveness during pre-selection of the most promising therapies. As neuroblastoma is an extremely heterogenous extracranial solid tumor, translation from 2D cultures into innovative 3D in vitro systems is particularly challenging. In recent years, the number of 3D in vitro models mimicking native neuroblastoma tumors has been rapidly increasing. However, in vitro platforms that efficiently sustain patient-derived tumor cell growth, thus allowing comprehensive drug discovery studies on tailored therapies, are still lacking. In this review, the latest neuroblastoma 3D in vitro models are presented and their applicability for a more accurate prediction of therapy outcomes is discussed.

Molecular targeting therapies for neuroblastoma: Progress and challenges

There is an urgent need to identify novel therapies for childhood cancers. Neuroblastoma is the most common pediatric solid tumor, and accounts for ~15% of childhood cancer‐related mortality. Neuroblastomas exhibit genetic, morphological and clinical heterogeneity, which limits the efficacy of existing treatment modalities. Gaining detailed knowledge of the molecular signatures and genetic variations involved in the pathogenesis of neuroblastoma is necessary to develop safer and more effective treatments for this devastating disease. Recent studies with advanced high‐throughput “omics” techniques have revealed numerous genetic/genomic alterations and dysfunctional pathways that drive the onset, growth, progression, and resistance of neuroblastoma to therapy. A variety of molecular signatures are being evaluated to better understand the disease, with many of them being used as targets to develop new treatments for neuroblastoma patients. In this review, we have summarized the contemporary understanding of the molecular pathways and genetic aberrations, such as those in MYCN, BIRC5, PHOX2B, and LIN28B, involved in the pathogenesis of neuroblastoma, and provide a comprehensive overview of the molecular targeted therapies under preclinical and clinical investigations, particularly those targeting ALK signaling, MDM2, PI3K/Akt/mTOR and RAS‐MAPK pathways, as well as epigenetic regulators. We also give insights on the use of combination therapies involving novel agents that target various pathways. Further, we discuss the future directions that would help identify novel targets and therapeutics and improve the currently available therapies, enhancing the treatment outcomes and survival of patients with neuroblastoma.

Primary orbital ganglioneuroblastoma in a child: A case report

RATIONALE

Ganglioneuroblastoma (GNB) is a transitional tumor of sympathetic origin that has never been described as primarily involving the orbit. Herein we report an extremely rare case of GNB with primary orbital involvement and its treatment strategies.

PATIENT CONCERNS

A 9-year-old girl presented with progressive and recurring right orbital mass for 2 years.

DIAGNOSIS

Computed tomography (CT) showed a well-defined, well-circumscribed, and homogeneous extraconal soft tissue mass occupying most of the right superior orbital area. Magnetic resonance imaging (MRI) revealed that there was a neoplasm of the right superior orbit molding around the globe with long T1 and T2 signals, and contrast-enhanced MR image showed a heterogeneous enhancement of the mass. Histopathologic examinations were performed after surgery and the characteristics were consistent with a diagnosis of GNB.

INTERVENTIONS

Surgery was performed and the mass was completely resected.

OUTCOMES

Postoperatively, the patient was on a regular follow-up for 19 months and so far, has had no orbital mass recurrence.

LESSONS

Herein we present a rare case of GNB primarily involving the orbit, and the findings showed that GNB could originate from the orbit. The patient underwent surgical tumor resection. The histopathological and immunohistochemical features were consistent with the diagnosis of GNB. For this case, there was no recurrence for 19 months after complete surgical excision of the tumor; however, a regular long-term follow-up is required.

Age Dependency of the Prognostic Impact of Tumor Genomics in Localized Resectable MYCN-Nonamplified Neuroblastomas. Report From the SIOPEN Biology Group on the LNESG Trials and a COG Validation Group

PURPOSE

For localized, resectable neuroblastoma without MYCN amplification, surgery only is recommended even if incomplete. However, it is not known whether the genomic background of these tumors may influence outcome.

PATIENTS AND METHODS

Diagnostic samples were obtained from 317 tumors, International Neuroblastoma Staging System stages 1/2A/2B, from 3 cohorts: Localized Neuroblastoma European Study Group I/II and Children's Oncology Group. Genomic data were analyzed using multi- and pangenomic techniques and fluorescence in-situ hybridization in 2 age groups (cutoff age, 18 months) and were quality controlled by the International Society of Pediatric Oncology European Neuroblastoma (SIOPEN) Biology Group.

RESULTS

Patients with stage 1 tumors had an excellent outcome (5-year event-free survival [EFS] ± standard deviation [SD], 95% ± 2%; 5-year overall survival [OS], 99% ± 1%). In contrast, patients with stage 2 tumors had a reduced EFS in both age groups (5-year EFS ± SD, 84% ± 3% in patients < 18 months of age and 75% ± 7% in patients ≥ 18 months of age). However, OS was significantly decreased only in the latter group (5-year OS ± SD in < 18months and ≥ 18months, 96% ± 2% and 81% ± 7%, respectively; P = .001). In < 18months, relapses occurred independent of segmental chromosome aberrations (SCAs); only 1p loss decreased EFS (5-year EFS ± SD in patients 1p loss and no 1p loss, 62% ± 13% and 87% ± 3%, respectively; P = .019) but not OS (5-year OS ± SD, 92% ± 8% and 97% ± 2%, respectively). In patients ≥ 18 months, only SCAs led to relapse and death, with 11q loss as the strongest marker (11q loss and no 11q loss: 5-year EFS ± SD, 48% ± 16% and 85% ± 7%, P = .033; 5-year OS ± SD, 46% ± 22% and 92% ± 6%, P = .038).

CONCLUSION

Genomic aberrations of resectable non-MYCN-amplified stage 2 neuroblastomas have a distinct age-dependent prognostic impact. Chromosome 1p loss is a risk factor for relapse but not for diminished OS in patients < 18 months, SCAs (especially 11q loss) are risk factors for reduced EFS and OS in those > 18months. In older patients with SCA, a randomized trial of postoperative chemotherapy compared with observation alone may be indicated.

Tailoring Therapy for Children With Neuroblastoma on the Basis of Risk Group Classification: Past, Present, and Future

For children with neuroblastoma, the likelihood of cure varies widely according to age at diagnosis, disease stage, and tumor biology. Treatments are tailored for children with this clinically heterogeneous malignancy on the basis of a combination of markers that are predictive of risk of relapse and death. Sequential risk-based, cooperative-group clinical trials conducted during the past 4 decades have led to improved outcome for children with neuroblastoma. Increasingly accurate risk classification and refinements in treatment stratification strategies have been achieved with the more recent discovery of robust genomic and molecular biomarkers. In this review, we discuss the history of neuroblastoma risk classification in North America and Europe and highlight efforts by the International Neuroblastoma Risk Group (INRG) Task Force to develop a consensus approach for pretreatment stratification using seven risk criteria including an image-based staging system-the INRG Staging System. We also update readers on the current Children's Oncology Group risk classifier and outline plans for the development of a revised 2021 Children's Oncology Group classifier that will incorporate INRG Staging System criteria to facilitate harmonization of risk-based frontline treatment strategies conducted around the globe. In addition, we discuss new approaches to establish increasingly robust, future risk classification algorithms that will further refine treatment stratification using machine learning tools and expanded data from electronic health records and the INRG Data Commons.

Distribution of segmental chromosomal alterations in neuroblastoma

BACKGROUND

Neuroblastoma (NB) is a heterogeneous tumor with extremely diverse prognosis according to clinical and genetic factors such as specific combinations of chromosomal imbalances.

METHODS

Molecular karyotyping data from a national neuroblastic tumor database of 155 NB samples were analyzed and related to clinical data.

RESULTS

Segmental chromosomal alterations (SCA) were detected in 102 NB, whereas 45 only displayed numerical alterations. Incidence of SCA was higher in stage M (92%) and MYCN amplified (MNA) NB (96%). Presence of SCA was associated with older age, especially 1q gain and 3p deletion. 96% of the deaths were observed in the SCA group and 85% of the relapsed NB contained SCA. The alteration most commonly associated with a higher number of other segmental rearrangements was 11q deletion, followed by 4p deletion. Whole-chromosome 19 gain was associated with lower stages, absence of SCA and better outcome.

CONCLUSIONS

SCA are not randomly distributed and are concentrated on recurrent chromosomes. The most frequently affected chromosomes identify prognostic factors in specific risk groups. SCA are associated with older age and MNA. We have identified a small subset of patients with better outcome that share whole-chromosome 19 numeric gain, suggesting its use as a prognostic biomarker in NB.

Neuroblastoma patient-derived cultures are enriched for a mesenchymal gene signature and reflect individual drug response

Ex vivo evaluation of personalized models can facilitate individualized treatment selection for patients, and advance the discovery of novel therapeutic options. However, for embryonal malignancies, representative primary cultures have been difficult to establish. We developed patient‐derived cell cultures (PDCs) from chemo‐naïve and post–treatment neuroblastoma tumors in a consistent and efficient manner, and characterized their in vitro growth dynamics, histomorphology, gene expression, and functional chemo‐response. From 34 neuroblastoma tumors, 22 engrafted in vitro to generate 31 individual PDC lines, with higher engraftment seen with metastatic tumors. PDCs displayed characteristic immunohistochemical staining patterns of PHOX2B, TH, and GD2 synthase. Concordance of MYCN amplification, 1p and 11q deletion between PDCs and patient tumors was 83.3%, 72.7%, and 80.0% respectively. PDCs displayed a predominantly mesenchymal‐type gene expression signature and showed upregulation of pro‐angiogenic factors that were similarly enriched in culture medium and paired patient serum samples. When tested with standard‐of‐care cytotoxics at human C_max‐equivalent concentrations, MYCN‐amplified and non‐MYCN‐amplified PDCs showed a differential response to cyclophosphamide and topotecan, which mirrored the corresponding patients’ responses, and correlated with gene signatures of chemosensitivity. In this translational proof‐of‐concept study, early‐phase neuroblastoma PDCs enriched for the mesenchymal cell subpopulation recapitulated the individual molecular and phenotypic profile of patient tumors, and highlighted their potential as a platform for individualized ex vivo drug‐response testing.

[Research on Analysis of Final Diagnosis and Prognostic Factors, and Development of New Therapeutic Drugs for Malignant Tumors (Especially Malignant Pediatric Tumors)]

Outcomes of treatment for malignant pediatric tumors including leukemia are improving by conventional multimodal treatment with strong chemotherapy, surgical resection, radiotherapy, and bone marrow transplantation. However, patients with advanced neuroblastoma, metastatic Ewing's sarcoma family of tumor (ESFT), and metastatic osteosarcoma continue to have an extremely poor prognosis. Therefore novel therapeutic strategies are urgently needed to improve their survival. Apoptotic cell death is a key mechanism for normal cellular homeostasis. Intact apoptotic mechanisms are pivotal for embryonic development, tissue remodeling, immune regulation, and tumor regression. Genetic aberrations disrupting programmed cell death often underpin tumorigenesis and drug resistance. Moreover, it has been suggested that apoptosis or cell differentiation proceeds to spontaneous regression in early stage neuroblastoma. Therefore apoptosis or cell differentiation is a critical event in this cancer. We extracted many compounds from natural plants (Angelica keiskei, Alpinia officiarum, Lycaria puchury-major, Brassica rapa) or synthesized cyclophane pyridine, indirubin derivatives, vitamin K3 derivatives, burchellin derivatives, and GANT61, and examined their effects on apoptosis, cell differentiation, and cell cycle in neuroblastoma and ESFT cell lines compared with normal cells. Some compounds were very effective against these tumor cells. These results suggest that they may be applicable as an efficacious and safe drug for the treatment of malignant pediatric tumors.

A three-dimensional bioprinted model to evaluate the effect of stiffness on neuroblastoma cell cluster dynamics and behavior

Three-dimensional (3D) bioprinted culture systems allow to accurately control microenvironment components and analyze their effects at cellular and tissue levels. The main objective of this study was to identify, quantify and localize the effects of physical-chemical communication signals between tumor cells and the surrounding biomaterial stiffness over time, defining how aggressiveness increases in SK-N-BE(2) neuroblastoma (NB) cell line. Biomimetic hydrogels with SK-N-BE(2) cells, methacrylated gelatin and increasing concentrations of methacrylated alginate (AlgMA 0%, 1% and 2%) were used. Young's modulus was used to define the stiffness of bioprinted hydrogels and NB tumors. Stained sections of paraffin-embedded hydrogels were digitally quantified. Human NB and 1% AlgMA hydrogels presented similar Young´s modulus mean, and orthotopic NB mice tumors were equally similar to 0% and 1% AlgMA hydrogels. Porosity increased over time; cell cluster density decreased over time and with stiffness, and cell cluster occupancy generally increased with time and decreased with stiffness. In addition, cell proliferation, mRNA metabolism and antiapoptotic activity advanced over time and with stiffness. Together, this rheological, optical and digital data show the potential of the 3D in vitro cell model described herein to infer how intercellular space stiffness patterns drive the clinical behavior associated with NB patients.

Runt-related transcription factor 1 promotes apoptosis and inhibits neuroblastoma progression in vitro and in vivo

Background

Runt-related transcription factor 1 (RUNX1) is a heterodimeric transcription factor that binds to the core element of many enhancers and promoters and can accelerate apoptosis in various tumors. However, the regulatory mechanisms underlying RUNX1 expression in neuroblastoma (NB), a highly malignant tumor in childhood, remain largely unclear. In this study, we aimed to assess the role of RUNX1 in NB and to reveal the underlying mechanisms that may contribute to finding a potential therapeutics strategy against NB.

Methods

Growth, invasion, metastasis and angiogenesis were assessed using Cell Counting Kit-8 (CCK-8) immunocytochemistry, and studies involving soft agar, cell invasion, tube formation and whole animals. The levels of expression were measured using real-time quantitative PCR for RNA, Western blot and immunostaining analyses for proteins. Luciferase reporter and chromatin immunoprecipitation assays indicated that RUNX1 directly binds within the BIRC5, CSF2RB and NFKBIA promoter regions to facilitate transcription. The level of apoptosis was assessed by determining mitochondrial membrane potential and flow cytometry.

Results

RUNX1 was highly expressed in ganglioneuroma (GN) and well-differentiated (WD) tissues relative to the poorly differentiated (PD) and undifferentiated (UD) ones. Moreover, RUNX1 effectively reduced cell viability, invasion, metastasis, angiogenesis, and promoted apoptosis in vitro and in vivo. RUNX1 reduced BIRC5 transcription and increased CSF2RB and NFKBIA transcription by directly binding BIRC5, CSF2RB and NFKBIA promoters. In addition, cytotoxic drugs, especially cisplatin, significantly increased RUNX1 expression in NB cells and promoted apoptosis.

Conclusions

These data show that RUNX1 is an independent surrogate marker for the progression of NB and it can be used for monitoring NB prognosis during therapy.

Targeting MDR-1 gene expression, BAX/BCL2, caspase-3, and Ki-67 by nanoencapsulated imatinib and hesperidin to enhance anticancer activity and ameliorate cardiotoxicity

There is a great demand to introduce new approaches into cancer treatment field due to incidence of increased breast cancer all over the world. The current study was designed to evaluate the role of imatinib mesylate (IM) and/or hesperidin (HES) nanoparticles alone or in combination in enhancing the anticancer activity and to investigate the ability of nanoencapsulation to reduce cardiotoxicity of IM in solid Ehrlich carcinoma (SEC)-bearing mice. IM and HES were loaded into PLGA (poly(lactic-co-glycolic acid) polymer. SEC was induced in female albino mice as a model for experimentally induced breast cancer. Mice were randomly divided into eight groups (n = 10). On day 28 from tumor inoculation, mice were sacrificed and blood samples were collected in heparinized tubes for hematological studies, biochemical determination of lactate dehydrogenase (LDH), and glutamic oxaloacetic transaminase (SGOT) levels. In addition, tumor and cardiac tissues were utilized for histopathological examination as well as determination of MDR-1 gene expression. Immunohistochemical staining of BAX and BCL-2 was done. Nano IM- and/or Nano HES-treated groups showed a significant reduction in tumor volume, weight, hematological, cardiac markers, and tumor MDR-1 gene downregulation compared to free conventional treated groups. In conclusion, the use of HES as an adjuvant therapy with IM could improve its cytotoxic effects and limit its cardiac toxicity. Furthermore, nanoencapsulation of IM and/or HES with PLGA polymer showed a remarkable anticancer activity.

Enhanced anticancer activity of combined treatment of imatinib and dipyridamole in solid Ehrlich carcinoma-bearing mice

The current study was designed to evaluate potential enhancement of the anticancer activity of imatinib mesylate (IM) with dipyridamole (DIP) and to investigate the underlying mechanisms of the combined therapy (IM/DIP) to reduce hepatotoxicity of IM in solid Ehrlich carcinoma (SEC)-bearing mice. SEC was induced in female albino mice as a model for experimentally induced breast cancer. Mice were randomly divided into seven groups (n = 10): SEC vehicle, IM₅₀ (50 mg/kg), IM₁₀₀ (100 mg/kg), DIP (35 mg/kg), a combination of IM₅₀/DIP and IM₁₀₀/DIP. On day 28th, mice were sacrificed and blood samples were collected for hematological studies. Biochemical determination of liver markers was evaluated. Glutamic oxaloacetic transaminase (SGOT), glutamic pyruvic transaminase (SGPT) and alkaline phosphatase (ALP) levels were assessed. In addition, MDR-1 gene expression and immunohistochemical staining of BAX and BCL-2 was done. Also, in vitro experiment for determination of IC50 of different treatments and combination index (CI) were assessed in both MCF-7 and HCT-116 cell lines. IM- and/or DIP-treated groups showed a significant reduction in tumor volume, weight, and serum levels of SGOT, SGPT, and AIP compared to vehicle group. In addition, reduction of VEGF, Ki67, and adenosine contents was also reported by treated groups. Also, IM/DIP combination showed lower IC50 than monotherapy. Combination index is less than 1 for IM/DIP combination in both cell lines. DIP as an adjuvant therapy potentiated the cytotoxic effect of IM, ameliorated its hepatic toxicity, and showed synergistic effect with IM in vitro cell lines. Furthermore, the resistance against IM therapy may be overcome by the use of DIP independent on mdr-1 gene expression.

Tumor edge-to-core transition promotes malignancy in primary-to-recurrent glioblastoma progression in a PLAGL1/CD109-mediated mechanism

BACKGROUND

Glioblastoma remains highly lethal due to its inevitable recurrence. Most of this recurrence is found locally, indicating that postsurgical tumor-initiating cells (TICs) accumulate at the tumor edge. These edge-TICs then generate local recurrence harboring new core lesions. Here, we investigated the clinical significance of the edge-to-core (E-to-C) signature generating glioblastoma recurrence and sought to identify its central mediators.

METHODS

First, we examined the association of E-to-C-related expression changes to patient outcome in matched primary and recurrent samples (n = 37). Specifically, we tested whether the combined decrease of the edge-TIC marker PROM1 (CD133) with the increase of the core-TIC marker CD109, representing E-to-C transition during the primary-to-recurrence progression, indicates poorer patient outcome. We then investigated the specific molecular mediators that trigger tumor recurrence driven by the E-to-C progression. Subsequently, the functional and translational significance of the identified molecule was validated with our patient-derived edge-TIC models in vitro and in vivo.

RESULTS

Patients exhibiting the CD133low/CD109high signature upon recurrence representing E-to-C transition displayed a strong association with poorer progression-free survival and overall survival among all tested patients. Differential gene expression identified that PLAGL1 was tightly correlated with the core TIC marker CD109 and was linked to shorter patient survival. Experimentally, forced PLAGL1 overexpression enhanced, while its knockdown reduced, glioblastoma edge-derived tumor growth in vivo and subsequent mouse survival, suggesting its essential role in the E-to-C-mediated glioblastoma progression.

CONCLUSIONS

E-to-C axis represents an ongoing lethal process in primary glioblastoma contributing to its recurrence, partly in a PLAGL1/CD109-mediated mechanism.

Neuroblastoma in Adolescents and Children Older than 10 Years: Unusual Clinicopathologic and Biologic Features

Neuroblastoma (NB) in children older than 10 years is rare. We reviewed our archives for patients with NB aged 10 to 18 years and summarized their clinicopathologic/genetic records. Of 96 patients, 4 patients were identified in this age group. Four tumors were abdominal; 1 patient had 2 tumors at diagnosis, one of which was presacral. Tumor sizes ranged from 3 to 20 cm. All tumors were high risk at clinical stages 3 and 4, with metastasis to bone marrow and other areas. Four tumors were poorly differentiated with unfavorable histology and one patient with bilateral adrenal disease had an intermixed ganglioneuroblastoma on one side. Another tumor exhibited pheochromocytoma-like morphology. MYCN amplification was present in bone marrow metastasis in one case. Complex chromosomal gains and 19p deletions were common. Exome sequencing revealed ALK variants in 2 cases and previously unreported MAGI2, RUNX1, and MLL mutations. All patients received standard chemotherapy and 2 patients received ALK-targeted trial therapy. Three patients died of disease, ranging 18 to 23 months after diagnosis. One patient has active disease and is receiving trial therapy. In conclusion, NB in children older than 10 years may exhibit unusual clinicopathologic and genetic features with large tumors, bilateral adrenal disease, rare morphologic features, complex DNA microarray findings and novel mutations. Patients often have grim prognoses despite genomic profiling-guided targeted therapy.

Link between spermine oxidase and apoptosis antagonizing transcription factor: A new pathway in neuroblastoma

Neuroblastoma (NB) is a heterogeneous extra‑cranial childhood type of cancer, responsible for approximately 15% of all paediatric cancer‑related deaths. Although several critical genetic aberrations have been related to NB, only a few established molecular markers have been associated with prognosis [V‑myc avian myelocytomatosis viral oncogene (MYCN) locus amplification, deletions of part of chromosome 1p, 11q23 and gain of 17q]. Regrettably, direct evidence of NB‑related tumour suppressors or oncogenes has not been currently identified at these chromosomal regions. MYCN locus amplification is present in approximately 20‑30% of cases and is associated with a poor clinical outcome, representing the most important genetic prognostic marker. The functional guidelines for the prognosis of NB identify high‑risk patients (<40% survival probabilities), but fail to identify patients at low and intermediate stages of the disease, which remains an issue to be resolved in NB. It has been shown that in NB cell lines and in a total‑spermine oxidase (SMOX) transgenic mouse model, SMOX overexpression induces cellular stress via reactive oxygen species (ROS) imbalance. In this study, we demonstrated that the high expression level of the cytoprotective gene, apoptosis-antagonizing transcription factor (AATF), was driven by SMOX gene overexpression in both NB cells and Total‑SMOX mice. The anti‑apoptotic effect of AATF was supported by analysing the inhibition of the expression of the pro‑apoptotic genes, BAX, BAK and PUMA, which were decreased, in both the in vitro and in vivo SMOX overexpressing model systems investigated. On the whole, this study supports the hypothesis that the SMOX gene can be considered as a novel anti‑apoptotic marker in NB.

Statistical Framework in Support of a Revised Children's Oncology Group Neuroblastoma Risk Classification System

PURPOSE

The International Neuroblastoma Risk Group (INRG) Staging System (INRGSS) was developed through international consensus to provide a presurgical staging system that uses clinical and imaging data at diagnosis. A revised Children's Oncology Group (COG) neuroblastoma (NB) risk classification system is needed to incorporate the INRGSS and within the context of modern therapy. Herein, we provide statistical support for the clinical validity of a revised COG risk classification system.

PATIENTS AND METHODS

Nine factors were tested for potential statistical and clinical significance in 4,569 patients diagnosed with NB who were enrolled in the COG biology/banking study ANBL00B1 (2006-2016). Recursive partitioning was performed to create a survival-tree regression (STR) analysis of event-free survival (EFS), generating a split by selecting the strongest prognostic factor among those that were statistically significant. The least absolute shrinkage and selection operator (LASSO) was applied to obtain the most parsimonious model for EFS. COG patients were risk classified using STR, LASSO, and per the 2009 INRG classification (generated using an STR analysis of INRG data). Results were descriptively compared among the three classification approaches.

RESULTS

The 3-year EFS and overall survival (± SE) were 72.9% ± 0.9% and 84.5% ± 0.7%, respectively (N = 4,569). In each approach, the most statistically and clinically significant factors were diagnostic category (eg, NB, ganglioneuroblastoma), INRGSS, MYCN status, International Neuroblastoma Pathology Classification, ploidy, and 1p/11q status. The results of the STR analysis were more concordant with those of the INRG classification system than with LASSO, although both methods showed moderate agreement with the INRG system.

CONCLUSION

These analyses provide a framework to develop a new COG risk classification incorporating the INRGSS. There is statistical evidence to support the clinical validity of each of the three classifications: STR, LASSO, and INRG.

Clinical Features of Neuroblastoma With 11q Deletion: An Increase in Relapse Probabilities In Localized And 4S Stages

Neuroblastoma (NB) is a heterogeneous tumor with an extremely diverse prognosis according to clinical and genetic factors, such as the presence of an 11q deletion (11q-del). A multicentric study using data from a national neuroblastic tumor database was conducted. This study compared the most important features of NB patients: presence of 11q-del, presence of MYCN amplification (MNA) and remaining cases. A total of 357 patients were followed throughout an 8-year period. 11q-del was found in sixty cases (17%). 11q-del tumors were diagnosed at an older age (median 3.29 years). Overall survival (OS) was lower in 11q-del patients (60% at 5 years), compared to all other cases (76% at 5 years) p = 0.014. Event free survival (EFS) was 35% after 5 years, which is a low number when compared with the remaining cases: 75% after 5 years (p < 0.001). Localized tumors with 11q-del have a higher risk of relapse (HR = 3.312) such as 4 s 11q-del patients (HR 7.581). 11q-del in NB is a dismal prognostic factor. Its presence predicts a bad outcome and increases relapse probability, specially in localized stages and 4 s stages. The presence of 11q aberration should be taken into consideration when stratifying neuroblastoma risk groups.