Pediatric Brain Tumors: Innovative Genomic Information Is Transforming the Diagnostic and Clinical Landscape

Exploring Maintenance Therapy in Pediatric Embryonal Tumor With Multilayered Rosettes

Embryonal tumors with multilayered rosettes (ETMR) represent a distinct entity characterized by aggressive behavior. Historical retrospective analyses have documented dire overall survival rates ranging from 0% to 14% at 1 year. However, a contemporary report by Khan and colleagues shows overall survival rates reaching 29% at 2 years and 27% at 4 years. We present the case of an 18-month-old girl diagnosed with ETMR, confirmed by chromosome 19 microRNA cluster amplification following initial presentation with focal seizures. The patient underwent a combination of surgical interventions, high-dose chemotherapy with stem cell rescue, and proton therapy, achieving a disease-free status after completing standard treatment. Subsequently, a 12-month maintenance regimen comprising intrathecal topotecan, oral sodium valproate, and oral cis-retinoic acid was administered. The maintenance therapy was well tolerated, with manageable adverse effects. The patient remains progression-free for 32 months postmaintenance therapy (50 months from initial presentation). This study explores the feasibility and safety profile of maintenance therapy in ETMR. Future studies may explore this approach to determine its efficacy in children with ETMR.

Allies not enemies-creating a more empathetic and uplifting patient experience through technology and art

OBJECTIVE

To understand whether art and technology (mainly conversational agents) may help oncology patients to experience a more humanized journey.

METHODS

This narrative review encompasses a comprehensive examination of the existing literature in this field by a multicenter, multidisciplinary, and multiprofessional team aiming to analyze the current developments and potential future directions of using art and technology for patient engagement.

RESULTS

We identified three major themes of patient engagement with art and three major themes of patient engagement with technologies. Two real-case scenarios are reported from our experience to practically envision how findings from the literature can be implemented in different contexts.

CONCLUSION

Art therapy and technologies can be ancillary supports for healthcare professionals but are not substitutive of their expertise and responsibilities. Such tools may help to convey a more empathetic and uplifting patient journey if properly integrated within clinical practice, whereby the humanistic touch of medicine remains pivotal.

Systematic Review and Meta-Analysis of Adjuvant Radiation Dose for Pediatric Patients (≤22 years) with Nonmetastatic Intracranial Ependymomas

PURPOSE

Ependymomas are the third most common brain tumors in children. Standard of care is surgery followed by adjuvant radiation therapy. Controversy in the literature still exists over optimal radiation therapy dose. We completed a systematic review and meta-analysis to determine the optimal dose for local control (LC), event-free survival (EFS), and overall survival (OS) in pediatric patients.

METHODS AND MATERIALS

We searched MEDLINE (PubMed), Cochrane Database of Systematic Reviews, and Web of Science through January 2024. We included cohort studies that compared adjuvant radiation therapy of ≤54 Gy with >54 Gy in pediatric patients (≤22 years) with nonmetastatic intracranial ependymomas. We assessed study quality using the Newcastle-Ottawa Quality Assessment Scale of Cohort Studies. We pooled studies using a random effects meta-analysis for hazard ratios (HR), 95% confidence intervals (CI), and assessed statistical heterogeneity via I2. When HRs were unavailable, we transformed risks using established methods. We narratively summarized qualitative outcomes.

RESULTS

Seven studies met our inclusion criteria, covering a combined 1321 patients. Studies included a range of doses from 45 to 66.6 Gy. Compared with >54 Gy, we found no difference in LC for those receiving ≤54 Gy (HR, 0.83; 95% CI, 0.56-1.24; I2, 49.1%), in EFS (HR, 1.02; 95% CI, 0.95-1.09; I2, 0.00%), and OS (HR, 0.99; 95% CI, 0.82-1.20; I2, 37.5%). Two studies reported on subtotal resection by radiation therapy dose, neither study reporting statistical differences in LC, EFS, or OS, although the number of patients was small (n ≤ 30). Five studies reported on late effects, with brainstem radionecrosis, radiation-induced vasculopathy, and secondary tumors being the most frequent. Overall study quality was high, although lower scores were consistently seen in comparability of cohorts. To our knowledge, no studies reported on molecular subgroups.

CONCLUSIONS

We found no difference in LC, EFS, or OS for those treated with ≤54 Gy compared with >54 Gy. There were insufficient data to complete a subgroup meta-analysis on radiation therapy dosing based on extent of resection or molecular subgroups.

Current situation of central nervous system tumour survivors in a spanish hospital

INTRODUCTION

Despite the increasing number of central nervous system (CNS) tumour survivors, long-term (LT) sequelae remain a substantial burden on their health through various life stages. The aim of our study was to evaluate late morbidity, health-related quality of life (HRQoL), self-esteem, functional status, adaptive behaviour, physical activity and social outcomes such as education, employment, relationship status and possession of a driver's license, in addition to the role of LT effects of radiotherapy (RTx) on these outcomes.

METHODS

The study included 111 CNS tumour survivors with a minimum of 10 years of follow-up. The assessment of patients included a comprehensive clinical evaluation and psychological questionnaires: SF-36 for HRQoL and Rosenberg self-esteem scale. Functional status was assessed with the Lansky/Karnosky scales and adaptive behaviour with the Vineland-II scale. Patients also completed one questionnaire that assessed physical activity and another that assessed other social variables.

RESULTS

The mean current age of CNS tumour survivors was 20 years (range, 12-34). The median time since diagnosis was 13 years (range, 10-26). The median age at diagnosis was 6 years (range, 1-18). The most prevalent LT sequelae were neurologic (55%), followed by neuropsychiatric (53.1%) and endocrine (49.5%) sequelae. Survivors treated with RTx (n = 52) had poorer outcomes in terms of adaptive behaviour, educational attainment and relationship status compared to those who did not receive RTx, but we did not find differences in quality of life or self-esteem scores between these groups.

CONCLUSION

We found a high prevalence of long-term sequelae in CNS tumour survivors, especially in those who received RTx. In these patients, LT sequelae have a significant impact on functional status and social outcomes, but not on quality of life or self-esteem.

Radiotherapy dosing in intracranial ependymoma using the national cancer database

PURPOSE

To determine the dose-dependent effect of adjuvant radiotherapy on survival for pediatric intracranial ependymomas and explore patient and disease characteristics that experience survival benefit from higher doses.

METHODS

Data was accessed from the National Cancer Database. Inclusion criteria was comprised of a diagnosis of non-metastatic intracranial ependymoma, World Health Organization (WHO) grade 2 or 3, surgical resection, adjuvant radiotherapy between 4500-6300 cGy, and non-missing survivorship data. Crude and adjusted Cox proportional hazard ratios (HRs) were calculated to estimate the associations of patient, tumor, and treatment characteristics with overall survival (OS). Kaplan-Meier (KM) estimations were used to visualize survival curves for dosing for the general cohort and by subgroups (age, resection extent, and grade).

RESULTS

Of the 1154 patients who met inclusion criteria, 405 received ≤ 5400 cGy and 749 received > 5400 cGy. We found no difference in OS crude (0.95, 95% CI 0.72-1.06) or adjusted (0.88, 95% CI 0.46-1.69) HR for those receiving ≤ 5400 cGy. KM curves showed no difference in OS for dosing for the general cohort based on age, surgical extent, and grade. However, there was better OS in those with WHO grade 2 tumors compared to grade 3 regardless of dose received.

CONCLUSIONS

There was no difference in OS between patients who received ≤ 5400 cGy compared to > 5400 cGy. We found improved OS in those with grade 2 tumors compared to grade 3, however there was no difference in OS based on dose received by tumor grade, age, or resection extent. Limitations in data available prevent exploring other outcomes or toxicity.

Current Landscape of NTRK Inhibition for Pediatric CNS Tumors

Over the last decade, as molecular platforms have permitted the characterization of the genomic landscape of pediatric central nervous system (CNS) tumors, pediatric neuro-oncology has dramatically transformed. NTRK fusions are oncogenic driver alterations that have been found in a multitude of tumor types, including pediatric CNS tumors. In recent years, NTRK inhibitors have emerged as a promising class of targeted therapies for pediatric CNS tumors with NTRK gene fusions. The use of larotrectinib and entrectinib in the relapsed setting for pediatric CNS tumors has resulted in rapid and robust responses in an important fraction of patients. These agents are well tolerated, although close to 20% of patients have spontaneous bone fractures. Given the existing data for patients with relapsed disease, clinical trials using NTRK inhibitors in the upfront setting is the next natural progression of efficacy testing and many are currently underway. There are still several challenges that need to be addressed to optimize the use of NTRK inhibitors and identify the patients with NTRK fusion-positive CNS tumors who are most likely to benefit from them. As these agents are more broadly used, resistance will become a more pervasive issue and strategies will need to be determined for this scenario. This article summarizes the current status of NTRK inhibitors for pediatric CNS tumors and discusses the opportunities and challenges of their expanding use in the future.

The safety and efficacy of bevacizumab in treatment of recurrent low-grade glioma: a systematic review and meta-analysis

BACKGROUND

Central nervous system (CNS) tumors are among the most common malignancies in various age ranges. Low-grade glioma (LGG) can account for nearly 30% of pediatric CNS malignancies. Progression or recurrence after the first-line treatments is common among these patients. Therefore, more treatments are required. Bevacizumab as an anti-VEGF antibody has come into the spotlight recently and is especially used in relapse or recurrence settings. This review aims to study the safety and efficacy of bevacizumab for patients with recurrent LGG.

METHODS

This study was conducted according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses. PubMed, Scopus, Web of Science, and Embase were comprehensively searched using the relevant key terms until 24th August 2023 to retrieve the studies that investigated clinical outcomes of bevacizumab in patients with recurrent LGG. All statistical analysis was performed by STATA v.17.

RESULTS

A total of 1306 papers were gathered, out of which 13 were incorporated in the meta-analysis. The pooled incidence rate of treatment according to the RANO scale was 70% (95% CI = 43-98%) for objective response rate, 26% (95% CI = 58-96%) for partial response, 21% (95% CI = 15-28%) for minor response, 14% (95% CI = 3-24%) for complete response, 48% (95% CI = 37-59%) for stable disease, and 8% (95% CI = 4-11%) for progressive disease. Furthermore, according to progressive survival after treatment, it was 4% (95% CI = -1 to 9%) for 6-month PFS, 41% (95% CI = 32-50%) for 2-year PFS, and 29% (95% CI = 22-35%) for 3-year PFS.

CONCLUSION

According to the RANO scale and PFS, clinicians should be aware that Bevacizumab could be a favorable alternative therapy for recurrent LGG. Furthermore, bevacizumab exhibits minimal toxicity and high tolerability in recurrent LGG.

Resources for the practice of pediatric neuro-oncology in Mexico: a cross-sectional evaluation

Background

The evaluation of existing resources and services is key to identify gaps and prioritize interventions to expand care capacity for children with central nervous system (CNS) tumors. We sought to evaluate the resources for pediatric neuro-oncology (PNO) in Mexico.

Methods

A cross-sectional online survey with 35 questions was designed to assess PNO resources and services, covering aspects including number of patients, infrastructure, human resources, and diagnostic and treatment time intervals. The survey was distributed to the members of the Mexican Association of Pediatric Oncology and Hematology (AMOHP) who belong to the nation's many different health systems.

Results

Responses were obtained from 33 institutions, distributed throughout the country and part of the many health systems that exist in Mexico. Twenty-one (64%) institutions had less than 10 new cases of pediatric CNS tumors per year. Although 30 (91%) institutions saw pediatric patients up to the age of 18 years, 2 (6%) had a cutoff of 15 years. Twenty-four (73%) institutions had between 1 and 3 pediatric oncologists providing care for children with CNS tumors. Six (18%) institutions did not have a neurosurgeon, while 19 (57%) institutions had a pediatric neurosurgeon. All centers had a pathology department, but 13 (39%) institutions only had access to basic histopathology. Eleven (33%) institutions reported histopathological diagnoses within one week, but 3 (9%) took more than 4 weeks. Radiotherapy for pediatric CNS tumors was referred to outside centers at 18 (55%) institutions. All centers had access to conventional cytotoxic chemotherapy, but only 6 (18%) had access to targeted therapy. Eighteen (55%) respondents estimated a survival rate of less than 60%. Fifteen (45%) centers attributed the main cause of mortality to non-tumor related factors, including infection and post-surgical complications.

Conclusions

This is the first national assessment of the resources available in Mexico for the treatment of CNS tumors. It shows disparities in resource capacity and a lack of the specific and efficient diagnoses that allow timely initiation of treatment. These data will enable the prioritization of collaborative interventions in the future.

Molecular Pathology of Gliomas

Gliomas are the most common adult and pediatric primary brain tumors. Molecular studies have identified features that can enhance diagnosis and provide biomarkers. IDH1/2 mutation with ATRX and TP53 mutations defines diffuse astrocytomas, whereas IDH1/2 mutations with 1p19q loss defines oligodendroglioma. Focal amplifications of receptor tyrosine kinase genes, TERT promoter mutation, and loss of chromosomes 10 and 13 with trisomy of chromosome 7 are characteristic features of glioblastoma and can be used for diagnosis. BRAF gene fusions and mutations in low-grade gliomas and histone H3 mutations in high-grade gliomas also can be used for diagnostics.

Novel insights on genetics and epigenetics as clinical targets for paediatric astrocytoma

Paediatric and adult astrocytomas are notably different, where clinical treatments used for adults are not as effective on children with the same form of cancer and these treatments lead to adverse long-term health concerns. Integrative omics-based studies have shown the pathology and fundamental molecular characteristics differ significantly and cannot be extrapolated from the more widely studied adult disease. Recent clinical advances in our understanding of paediatric astrocytomas, with the aid of next-generation sequencing and epigenome-wide profiling, have led to the identification of key canonical mutations that vary based on the tumour location and age of onset. These driver mutations, in particular the identification of the recurrent histone H3 mutations in high-grade tumours, have confirmed the important role epigenetic dysregulations play in cancer progression. This review summarises the current updates of the classification, epidemiology, pathogenesis and clinical management of paediatric astrocytoma based on their grades and the ongoing clinical trials. It also provides novel insights on genetic and epigenetic alterations as diagnostic biomarkers, highlighting the potential of targeting these pathways as therapeutics for this devastating childhood cancer.

Challenges and limitations of clinical trials in the adolescent and young adult CNS cancer population: A systematic review

Background

The adolescent and young adult (AYA) cancer population, aged 15-39, carries significant morbidity and mortality. Despite growing recognition of unique challenges with this age group, there has been little documentation of unmet needs in their care, trial participation, and quality of life, particularly in those with primary brain tumors.

Methods

A systematic literature review of 4 databases was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. Studies included editorials, reviews, and practice guidelines on the challenges and limitations faced by the AYA population. Papers had to address CNS tumors.

Results

Sixty-eight studies met the inclusion criteria. The challenges and limitations in clinical trials in the AYA population were synthesized into 11 categories: molecular heterogeneity, tumor biology, diagnostic delay, access to care, physician factors, patient factors, primary brain tumor (PBT) factors, accrual, limited trials, long term follow up, and trial design. The published papers' recommendations were categorized based on the target of the recommendation: providers, coordination of care, organizations, accrual, and trial design. The AYA cancer population was found to suffer from unique challenges and barriers to care and the construction of trials.

Conclusions

The AYA CNS cancer population suffers from unique challenges and barriers to care and construction of trials that make it critical to acknowledge AYAs as a distinct patient population. In addition, AYAs with primary brain tumors are underrecognized and underreported in current literature. More studies in the AYA primary brain tumor patient population are needed to improve their care and participation in trials.

Verschlimmbesserung: Craniospinal Radiotherapy Is Essential in WNT Medulloblastoma Patients

Standard-risk WNT medulloblastoma patients have an excellent prognosis (>90% progression-free survival) using the combination of standard dose craniospinal radiotherapy (CSI) (23.4 Gy) followed by platinum and alkylator based chemotherapy. A recent pilot study that attempted to completely omit radiotherapy was terminated early as all patients (n = 3) relapsed rapidly (on treatment or within 6 months of completing treatment). The study highlights that therapy is the most important prognostic factor, with CSI still required to cure even the most favorable subgroup of medulloblastoma patients. See related article by Cohen et al., p. 5031.

Prognostic significance of molecular subgroups in survival outcome for children with medulloblastoma in Malaysia

Introduction

Advancements in genomic profiling led to the discovery of four major molecular subgroups in medulloblastoma (MB), which have now been incorporated into the World Health Organization classification of central nervous system tumors. The current study aimed to determine the prognostic significance of the MB molecular subgroups among children in Malaysia.

Methods

We assembled MB samples from children <18 years between January 2003 and June 2017 from four pediatric oncology centers in Malaysia. MB was sub-grouped using 850k DNA methylation testing at German Cancer Research Centre, Heidelberg, Germany.

Results

Fifty samples from patients diagnosed and treated as MB were identified. Two (4%) of the 50 patients' tumor DNA samples were insufficient for analysis. Of the remaining 48 patients, 41 (85%) samples were confirmed as MB, while for 7 (15%) patients, DNA methylation classification results were discrepant with the histopathological diagnosis of MB, with various other diagnoses. Of the 41 MB patients, 15 patients were stratified as standard-risk (SR), 16 patients as high-risk (HR), and ten as infants (age <3 years old). Molecular subgrouping of the whole cohort revealed four (14%) WNT, 11 (27%) SHH, 10 (24%) Group 3, and 16 (39%) Group 4. Treatment abandonment rates for older children and infants were 22.5% and 10%, respectively. After censoring treatment abandonment, for SR patients, the 5-year event-free survival (EFS) and overall survival (OS) were 43.1% ± 14.7% and 46.9 ± 15.6%, respectively, while in HR, 5-year EFS and OS were both 63.6% ± 14.5%. Infants had a 5-year EFS and OS of 55.6% ± 16.6% and 66.7% ± 15.7%, respectively. WNT tumors had the best 5y-OS, followed by Group 3, Group 4, and SHH in children ≥3 years old. In younger children, SHH MB patients showed favorable outcomes.

Conclusion

The study highlights the importance of DNA methylation profiling for diagnostic accuracy. Most infants had SHH MB, and their EFS and OS were comparable to those reported in high-income countries. Due to the relatively small cohort and the high treatment abandonment rate, definite conclusions cannot be made regarding the prognostic significance of molecular subgroups of MB. Implementing this high-technology investigation would assist pathologists in improving the diagnosis and provide molecular subgrouping of MB, permitting subgroup-specific therapies.

Improving quality and quantity of life for childhood cancer survivors globally in the twenty-first century

The contributions of cooperative groups to performing large-cohort clinical trials and long-term survivorship studies have facilitated advances in treatment, supportive care and, ultimately, survival for patients with paediatric cancers. As a result, the number of childhood cancer survivors in the USA alone is expected to reach almost 580,000 by 2040. Despite these substantial improvements, childhood cancer survivors continue to have an elevated burden of chronic disease and an excess risk of early death compared with the general population and therefore constitute a large, medically vulnerable population for which delivery of high-quality, personalized care is much needed. Data from large survivorship cohorts have enabled the identification of compelling associations between paediatric cancers, cancer therapy and long-term health conditions. Effectively translating these findings into clinical care that improves the quality and quantity of life for survivors remains an important focus of ongoing research. Continued development of well-designed clinical studies incorporating dissemination and implementation strategies with input from patient advocates and other key stakeholders is crucial to overcoming these gaps. This Review highlights the global progress made and future efforts that will be needed to further increase the quality and quantity of life-years gained for childhood cancer survivors.

EpiGe: A machine-learning strategy for rapid classification of medulloblastoma using PCR-based methyl-genotyping

Molecular classification of medulloblastoma is critical for the treatment of this brain tumor. Array-based DNA methylation profiling has emerged as a powerful approach for brain tumor classification. However, this technology is currently not widely available. We present a machine-learning decision support system (DSS) that enables the classification of the principal molecular groups-WNT, SHH, and non-WNT/non-SHH-directly from quantitative PCR (qPCR) data. We propose a framework where the developed DSS appears as a user-friendly web-application-EpiGe-App-that enables automated interpretation of qPCR methylation data and subsequent molecular group prediction. The basis of our classification strategy is a previously validated six-cytosine signature with subgroup-specific methylation profiles. This reduced set of markers enabled us to develop a methyl-genotyping assay capable of determining the methylation status of cytosines using qPCR instruments. This study provides a comprehensive approach for rapid classification of clinically relevant medulloblastoma groups, using readily accessible equipment and an easy-to-use web-application.t.

Afatinib in paediatric patients with recurrent/refractory ErbB-dysregulated tumours: Results of a phase I/expansion trial

AIM

This phase I/expansion study assessed the safety, pharmacokinetics and preliminary antitumor activity of afatinib in paediatric patients with cancer.

METHODS

The dose-finding part enroled patients (2-<18 years) with recurrent/refractory tumours. Patients received 18 or 23 mg/m2/d afatinib orally (tablet or solution) in 28-d cycles. In the maximum tolerated dose (MTD) expansion, eligible patients (1-<18 years) had tumours fulfilling ≥2 of the following criteria in the pre-screening: EGFR amplification; HER2 amplification; EGFR membrane staining (H-score>150); HER2 membrane staining (H-score>0). The primary end-points were dose-limiting toxicities (DLTs), afatinib exposure, and objective response.

RESULTS

Of 564 patients pre-screened, 536 patients had biomarker data and 63 (12%) fulfilled ≥2 EGFR/HER2 criteria required for inclusion in the expansion part. A total of 56 patients were treated (17 in the dose-finding and 39 in the expansion part). DLTs were observed in one of six MTD-evaluable patients receiving 18 mg/m²/d and in two of five MTD-evaluable patients receiving 23 mg/m²/d; 18 mg/m²/d was defined as the MTD. There were no new safety signals. Pharmacokinetics confirmed exposure consistent with the approved dose in adults. One partial response (-81% per Response Assessment in Neuro-Oncology) was observed in a patient with a glioneuronal tumour harbouring a CLIP2::EGFR fusion; unconfirmed partial responses were observed in two patients. In total, 25% of patients experienced objective response or stable disease (95% confidence interval: 14-38).

CONCLUSION

Targetable EGFR/HER2 drivers are rare in paediatric cancers. Treatment with afatinib led to a durable response (>3 years) in one patient with a glioneuronal tumour with CLIP2::EGFR fusion.

Giant Supratentorial Brain Tumors in Children: Functional Outcome and Progression-Free Survival Analysis

INTRODUCTION

This study aimed to identify factors affecting progression-free survival (PFS) in pediatric patients with giant supratentorial brain tumors (GSBTs) treated with surgical excision. The secondary aim was to analyze how these same factors affected the functional outcome in the long term.

METHODS

We performed a retrospective, analytical, single-center cohort study. We included all pediatric patients with GSBT between January 2014 and June 2018. Patients were followed for a minimum of 24 months for the PFS and overall survival (OS) analysis. Functional status score (FSS) was used to assess the functional outcome.

RESULTS

We included 27 patients with GSBT, the median age was six (range 2-12), and eleven patients had a grade IV tumor. The 24-month PFS and OS were 51.85% and 74.04%, respectively. A PFS-ending event or treatment failure occurred in 13 patients. We found that patients with postoperative FFS >16 have a worse PFS than patients with a postoperative FSS <15 (HR 4.51; p = 0.03). Patients with more than three surgeries had worse PFS than patients with one or two procedures (HR 11.39; p = 0.004). High-grade tumors were associated with worse PFS than low-grade tumors (HR 1.55; p = 0.04). Finally, patients with CNS infections had worse PFS than patients without that complication (HR 2.70; p = 0.04).

CONCLUSIONS

GSBTs in pediatric patients are complex lesions that require multidisciplinary management. Surgical management and quality of life should be considered when choosing the best treatment. Factors influencing long-term PFS were high-grade histopathology, the need for three or more surgeries, postoperative FSS >16, and CNS infections.

Treatment of Pediatric Low-Grade Gliomas

PURPOSE OF REVIEW

Pediatric low-grade gliomas and glioneuronal tumors (pLGG) account for approximately 30% of pediatric CNS neoplasms, encompassing a heterogeneous group of tumors of primarily glial or mixed neuronal-glial histology. This article reviews the treatment of pLGG with emphasis on an individualized approach incorporating multidisciplinary input from surgery, radiation oncology, neuroradiology, neuropathology, and pediatric oncology to carefully weigh the risks and benefits of specific interventions against tumor-related morbidity. Complete surgical resection can be curative for cerebellar and hemispheric lesions, while use of radiotherapy is restricted to older patients or those refractory to medical therapy. Chemotherapy remains the preferred first-line therapy for adjuvant treatment of the majority of recurrent or progressive pLGG.

RECENT FINDINGS

Technologic advances offer the potential to limit volume of normal brain exposed to low doses of radiation when treating pLGG with either conformal photon or proton RT. Recent neurosurgical techniques such as laser interstitial thermal therapy offer a "dual" diagnostic and therapeutic treatment modality for pLGG in specific surgically inaccessible anatomical locations. The emergence of novel molecular diagnostic tools has enabled scientific discoveries elucidating driver alterations in mitogen-activated protein kinase (MAPK) pathway components and enhanced our understanding of the natural history (oncogenic senescence). Molecular characterization strongly supplements the clinical risk stratification (age, extent of resection, histological grade) to improve diagnostic precision and accuracy, prognostication, and can lead to the identification of patients who stand to benefit from precision medicine treatment approaches. The success of molecular targeted therapy (BRAF inhibitors and/or MEK inhibitors) in the recurrent setting has led to a gradual and yet significant paradigm shift in the treatment of pLGG. Ongoing randomized trials comparing targeted therapy to standard of care chemotherapy are anticipated to further inform the approach to upfront management of pLGG patients.

Progress in precision therapy in pediatric oncology

PURPOSE OF REVIEW

The fields of precision medicine and cancer genomics in pediatric oncology are rapidly evolving. Novel diagnostic tools are critical in refining cancer diagnoses, stratifying patient risk, and informing treatment decisions. This review is timely and relevant as it discusses advantages and drawbacks of common molecular profiling techniques and highlights novel platforms, which may address select limitations. We discuss recent publications demonstrating utility of large-scale molecular profiling and feasibility and logistics of matching targeted therapies to patients.

RECENT FINDINGS

We describe the increased accessibility of next-generation sequencing, complementary profiling methods, and strategies to guide treatment decisions. We describe curation and sharing of large genomic datasets and novel mechanisms to obtain matched targeted therapies. Importantly, we discuss relevant publications in distinct disease domains that support indications for evidence-based precision therapy. Lastly, we introduce the incremental analyses that can be obtained via whole-genome and transcriptome sequencing.

SUMMARY

Here we highlight high-yield clinical scenarios of precision medicine approaches and identify the ongoing challenges including universally defining clinical actionability, optimizing trial design to account for molecular heterogeneity while acknowledging limitations in patient accrual, expanding access to molecularly targeted therapies, and validating new tools and technology to aid in precision medicine therapeutic approaches.

Childhood cancer survival and avoided deaths in Australia, 1983-2016

BACKGROUND

Large improvements in childhood cancer survival have been reported over recent decades. Data from cancer registries have the advantage of providing a 'whole of population' approach to gauge the success of cancer control efforts.

OBJECTIVES

The aim of this study was to investigate recent survival estimates for children diagnosed with cancer Australia and to examine the extent of changes in survival over the last 35 years. For the first time, we also estimated the number of deaths among Australian children that were potentially avoided due to improvements in survival.

METHODS

A retrospective, population-based cohort study design was used. Case information was extracted from the Australian Childhood Cancer Registry for 1983-2016, with follow-up to 31 December 2017. Eligible children were aged 0-14 with a basis of diagnosis other than autopsy or death certificate only. Five-year relative survival was calculated using the semi-complete cohort method for three diagnosis periods (1983-1994, 1995-2006 and 2007-2016), and changes in survival over time were assessed via flexible parametric models. Avoided deaths within 5 years for those diagnosed between 1995 and 2016 were estimated under the assumption that survival rates remained the same as for 1983-1994.

RESULTS

Overall 5-year survival within the study cohort (n = 20,871) increased from 72.8% between 1983 and1994 to 86.1% between 2007 and 2016, equating to an adjusted excess mortality hazard ratio of 1.82 (95% confidence interval 1.67, 1.97). Most cancers showed improvements in survival; other gliomas, hepatoblastoma and osteosarcoma were exceptions. Among children diagnosed between 1995 and 2016, 38.7% of expected deaths within 5 years of diagnosis (n = 1537 of 3970) were avoided due to temporal improvements in survival.

CONCLUSIONS

Survival for childhood cancer has continued to improve over recent years, thanks mainly to ongoing progress in treatment development combined with improved supportive care. Providing innovative measures of survival, such as avoided deaths, may assist with understanding outcome data produced by cancer registries.

Targeting of the ELR+CXCL/CXCR1/2 Pathway Is a Relevant Strategy for the Treatment of Paediatric Medulloblastomas

Medulloblastoma (MB) is the most common and aggressive paediatric brain tumour. Although the cure rate can be as high as 70%, current treatments (surgery, radio- and chemotherapy) excessively affect the patients' quality of life. Relapses cannot be controlled by conventional or targeted treatments and are usually fatal. The strong heterogeneity of the disease (four subgroups and several subtypes) is related to innate or acquired resistance to reference treatments. Therefore, more efficient and less-toxic therapies are needed. Here, we demonstrated the efficacy of a novel inhibitor (C29) of CXCR1/2 receptors for ELR+CXCL cytokines for the treatment of childhood MB. The correlation between ELR+CXCL/CXCR1/2 expression and patient survival was determined using the R2: Genomics Analysis and Visualization platform. In vitro efficacy of C29 was evaluated by its ability to inhibit proliferation, migration, invasion, and pseudo-vessel formation of MB cell lines sensitive or resistant to radiotherapy. The growth of experimental MB obtained by MB spheroids on organotypic mouse cerebellar slices was also assayed. ELR+CXCL/CXCR1/2 levels correlated with shorter survival. C29 inhibited proliferation, clone formation, CXCL8/CXCR1/2-dependent migration, invasion, and pseudo-vessel formation by sensitive and radioresistant MB cells. C29 reduced experimental growth of MB in the ex vivo organotypic mouse model and crossed the blood-brain barrier. Targeting CXCR1/2 represents a promising therapeutic strategy for the treatment of paediatric MB in first-line treatment or after relapse following conventional therapy.

The Diagnostic Efficiency of Quantitative Diffusion Weighted Imaging in Differentiating Medulloblastoma from Posterior Fossa Tumors: A Systematic Review and Meta-Analysis

Medulloblastoma (MB) is considered the most common and highly malignant posterior fossa tumor (PFT) in children. The accurate preoperative diagnosis of MB is beneficial in choosing the appropriate surgical methods and treatment strategies. Diffusion-weighted imaging (DWI) has improved the accuracy of differential diagnosis of posterior fossa tumors. Nonetheless, further studies are needed to confirm its value for clinical application. This study aimed to evaluate the performance of DWI in differentiating MB from other PFT. A literature search was conducted using databases PubMed, Embase, and Web of Science for studies reporting the diagnostic performance of DWI for PFT from January 2000 to January 2022. A bivariate random-effects model was employed to evaluate the pooled sensitivities and specificities. A univariable meta-regression analysis was used to assess relevant factors for heterogeneity, and subgroup analyses were performed. A total of 15 studies with 823 patients were eligible for data extraction. Overall pooled sensitivity and specificity of DWI were 0.94 (95% confident interval [CI]: 0.89-0.97) and 0.94 (95% CI: 0.90-0.96) respectively. The area under the curve (AUC) of DWI was 0.98 (95% CI: 0.96-0.99). Heterogeneity was found in the sensitivity (I² = 62.59%) and the specificity (I² = 35.94%). Magnetic field intensity, region of interest definition and DWI diagnostic parameters are the factors that affect the diagnostic performance of DWI. DWI has excellent diagnostic accuracy for differentiating MB from other PFT. Hence, it is necessary to set DWI as a routine examination sequence for posterior fossa tumors.

Medulloblastoma in the Modern Era: Review of Contemporary Trials, Molecular Advances, and Updates in Management

Critical discoveries over the past two decades have transformed our understanding of medulloblastoma from a single entity into a clinically and biologically heterogeneous disease composed of at least four molecularly distinct subgroups with prognostically and therapeutically relevant genomic signatures. Contemporary clinical trials also have provided valuable insight guiding appropriate treatment strategies. Despite therapeutic and biological advances, medulloblastoma patients across the age spectrum experience tumor- and treatment-related morbidity and mortality. Using an updated risk stratification approach integrating both clinical and molecular features, ongoing research seeks to (1) cautiously reduce therapy and mitigate toxicity in low-average risk patients, and (2) thoughtfully intensify treatment with incorporation of novel, biologically guided agents for patients with high-risk disease. Herein, we review important historical and contemporary studies, discuss management updates, and summarize current knowledge of the biological landscape across unique pediatric, infant, young adult, and relapsed medulloblastoma populations.

Joint EANM/SIOPE/RAPNO practice guidelines/SNMMI procedure standards for imaging of paediatric gliomas using PET with radiolabelled amino acids and [18F]FDG: version 1.0

Positron emission tomography (PET) has been widely used in paediatric oncology. 2-Deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) is the most commonly used radiopharmaceutical for PET imaging. For oncological brain imaging, different amino acid PET radiopharmaceuticals have been introduced in the last years. The purpose of this document is to provide imaging specialists and clinicians guidelines for indication, acquisition, and interpretation of [18F]FDG and radiolabelled amino acid PET in paediatric patients affected by brain gliomas. There is no high level of evidence for all recommendations suggested in this paper. These recommendations represent instead the consensus opinion of experienced leaders in the field. Further studies are needed to reach evidence-based recommendations for the applications of [18F]FDG and radiolabelled amino acid PET in paediatric neuro-oncology. These recommendations are not intended to be a substitute for national and international legal or regulatory provisions and should be considered in the context of good practice in nuclear medicine. The present guidelines/standards were developed collaboratively by the EANM and SNMMI with the European Society for Paediatric Oncology (SIOPE) Brain Tumour Group and the Response Assessment in Paediatric Neuro-Oncology (RAPNO) working group. They summarize also the views of the Neuroimaging and Oncology and Theranostics Committees of the EANM and reflect recommendations for which the EANM and other societies cannot be held responsible.

MiR-1248: a new prognostic biomarker able to identify supratentorial hemispheric pediatric low-grade gliomas patients associated with progression

Background

Pediatric low-grade gliomas (pLGGs), particularly incompletely resected supratentorial tumours, can undergo progression after surgery. However to date, there are no predictive biomarkers for progression. Here, we aimed to identify pLGG-specific microRNA signatures and evaluate their value as a prognostic tool.

Methods

We identified and validated supratentorial incompletey resected pLGG-specific microRNAs in independent cohorts from four European Pediatric Neuro-Oncology Centres.

Results

These microRNAs demonstrated high accuracy in differentiating patients with or without progression. Specifically, incompletely resected supratentorial pLGGs with disease progression showed significantly higher miR-1248 combined with lower miR-376a-3p and miR-888-5p levels than tumours without progression. A significant (p < 0.001) prognostic performance for miR-1248 was reported with an area under the curve (AUC) of 1.00. We also highlighted a critical oncogenic role for miR-1248 in gliomas tumours. Indeed, high miR-1248 levels maintain low its validated target genes (CDKN1A (p21)/FRK/SPOP/VHL/MTAP) and consequently sustain the activation of oncogenic pathways.

Conclusions

Altogether, we provide a novel molecular biomarker able to successfully identify pLGG patients associated with disease progression that could support the clinicians in the decision-making strategy, advancing personalized medicine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40364-022-00389-x.

NTRK2 gene fusions are uncommon in pilocytic astrocytoma

BACKGROUND

Pilocytic astrocytoma is the most frequent pediatric glioma. Despite its overall good prognosis, complete surgical resection is sometimes unfeasible, especially for patients with deep-seated tumors. For these patients, the identification of targetable genetic alterations such as NTRK fusions, raised as a new hope for therapy. The presence of gene fusions involving NTRK2 has been rarely reported in pilocytic astrocytoma. The aim of the present study was to investigate the frequency of NTRK2 alterations in a series of Brazilian pilocytic astrocytomas.

METHODS

Sixty-nine pilocytic astrocytomas, previously characterized for BRAF and FGFR1 alterations were evaluated. The analysis of NTRK2 alterations was performed using a dual color break apart fluorescence in situ hybridization (FISH) assay.

RESULTS

NTRK2 fusions were successfully evaluated by FISH in 62 of the 69 cases. Neither evidence of NTRK2 gene rearrangements nor NTRK2 copy number alterations were found.

CONCLUSIONS

NTRK2 alterations are uncommon genetic events in pilocytic astrocytomas, regardless of patients' clinicopathological and molecular features.

Multi-institutional study of the frequency, genomic landscape, and outcome of IDH-mutant glioma in pediatrics

BACKGROUND

The incidence and biology of IDH1/2 mutations in pediatric gliomas are unclear. Notably, current treatment approaches by pediatric and adult providers vary significantly. We describe the frequency and clinical outcomes of IDH1/2-mutant gliomas in pediatrics.

METHODS

We performed a multi-institutional analysis of the frequency of pediatric IDH1/2-mutant gliomas, identified by next-generation sequencing (NGS). In parallel, we retrospectively reviewed pediatric IDH1/2-mutant gliomas, analyzing clinico-genomic features, treatment approaches, and outcomes.

RESULTS

Incidence: Among 851 patients with pediatric glioma who underwent NGS, we identified 78 with IDH1/2 mutations. Among patients 0-9 and 10-21 years old, 2/378 (0.5%) and 76/473 (16.1%) had IDH1/2-mutant tumors, respectively. Frequency of IDH mutations was similar between low-grade glioma (52/570, 9.1%) and high-grade glioma (25/277, 9.0%). Four tumors were graded as intermediate histologically, with one IDH1 mutation. Outcome: Seventy-six patients with IDH1/2-mutant glioma had outcome data available. Eighty-four percent of patients with low-grade glioma (LGG) were managed observantly without additional therapy. For low-grade astrocytoma, 5-year progression-free survival (PFS) was 42.9% (95%CI:20.3-63.8) and, despite excellent short-term overall survival (OS), numerous disease-related deaths after year 10 were reported. Patients with high-grade astrocytoma had a 5-year PFS/OS of 36.8% (95%CI:8.8-66.4) and 84% (95%CI:50.1-95.6), respectively. Patients with oligodendroglioma had excellent OS.

CONCLUSIONS

A subset of pediatric gliomas is driven by IDH1/2 mutations, with a higher rate among adolescents. The majority of patients underwent upfront observant management without adjuvant therapy. Findings suggest that the natural history of pediatric IDH1/2-mutant glioma may be similar to that of adults, though additional studies are needed.

Characteristics of children ≤36 months of age with DIPG: A report from the international DIPG registry

BACKGROUND

Children ≤36 months with diffuse intrinsic pontine glioma (DIPG) have increased long-term survival (LTS, overall survival (OS) ≥24 months). Understanding distinguishing characteristics in this population is critical to improving outcomes.

METHODS

Patients ≤36 months at diagnosis enrolled on the International DIPG Registry (IDIPGR) with central imaging confirmation were included. Presentation, clinical course, imaging, pathology and molecular findings were analyzed.

RESULTS

Among 1183 patients in IDIPGR, 40 were eligible (median age: 29 months). Median OS was 15 months. Twelve patients (30%) were LTS, 3 (7.5%) very long-term survivors ≥5 years. Among 8 untreated patients, median OS was 2 months. Patients enrolled in the registry but excluded from our study by central radiology review or tissue diagnosis had median OS of 7 months. All but 1 LTS received radiation. Among 32 treated patients, 1-, 2-, 3-, and 5-year OS rates were 68.8%, 31.2%, 15.6% and 12.5%, respectively. LTS had longer duration of presenting symptoms (P = .018). No imaging features were predictive of outcome. Tissue and genomic data were available in 18 (45%) and 10 patients, respectively. Among 9 with known H3K27M status, 6 had a mutation.

CONCLUSIONS

Children ≤36 months demonstrated significantly more LTS, with an improved median OS of 15 months; 92% of LTS received radiation. Median OS in untreated children was 2 months, compared to 17 months for treated children. LTS had longer duration of symptoms. Excluded patients demonstrated a lower OS, contradicting the hypothesis that children ≤36 months with DIPG show improved outcomes due to misdiagnosis.

Immunovirotherapy for Pediatric Solid Tumors: A Promising Treatment That is Becoming a Reality

Immunotherapy has seen tremendous strides in the last decade, acquiring a prominent position at the forefront of cancer treatment since it has been proven to be efficacious for a wide variety of tumors. Nevertheless, while immunotherapy has changed the paradigm of adult tumor treatment, this progress has not yet been translated to the pediatric solid tumor population. For this reason, alternative curative therapies are urgently needed for the most aggressive pediatric tumors. In recent years, oncolytic virotherapy has consolidated as a feasible strategy for cancer treatment, not only for its tumor-specific effects and safety profile but also for its capacity to trigger an antitumor immune response. This review will summarize the current status of immunovirotherapy to treat cancer, focusing on pediatric solid malignancies. We will revisit previous basic, translational, and clinical research and discuss advances in overcoming the existing barriers and limitations to translate this promising therapeutic as an every-day cancer treatment for the pediatric and young adult populations.

Transitional Care in Pediatric Brain Tumor Patients: A Systematic Literature Review

BACKGROUND

Due to advances in the treatment of pediatric brain tumors (PBT), an increasing number of patients are experiencing the transition from the pediatric to the adult health care system. This requires efficient transitional models.

METHODS

We systematically reviewed the literature regarding PBT concerning different transitional models and aspects of the transitional period. For this purpose, PubMed, Medline, and Embase databases were searched systematically through January 2022.

RESULTS

We reviewed a total of 304 studies, of which 15 were ultimately included. We identified five transition models described within the literature, while the most frequently mentioned ones were the "adult caregiver model" (45.5%), "joint caregiver model" (45.5%), "continued caregiver model" (27.3%), and the "specialized clinic model" (27.3%). During the transition, the most frequent challenges mentioned by the patients were the lack of knowledge about the disease by the adult health care professionals (62.5%) and the difficulty of establishing a new relationship with the new physician, environment, or hospital (37.5%).

CONCLUSIONS

An efficient transitional model is mandatory for patients with PBT. Continuity in the treatment and care of the patient and their family is essential. For this purpose, in patients with PBT, the "continued caregiver model", and for NF1 and TSC patients, the "specialized clinic model" seems optimal to offer continuity of care. If such models are unavailable, efficient communication with patients, families, and specialists in a multidisciplinary network is even more critical.

Circulating tumor DNA profiling for childhood brain tumors: Technical challenges and evidence for utility

Cell-free DNA (cfDNA) profiling as liquid biopsy has proven value in adult-onset malignancies, serving as a patient-specific surrogate for residual disease and providing a non-invasive tool for serial interrogation of tumor genomics. However, its application in neoplasms of the central nervous system (CNS) has not been as extensively studied. Unique considerations and methodological challenges exist, which need to be addressed before cfDNA studies can be incorporated as a clinical assay for primary CNS diseases. Here, we review the current status of applying cfDNA analysis in patients with CNS tumors, with special attention to diagnosis in pediatric patients. Technical concerns, evidence for utility, and potential developments are discussed.

Comprehensive analysis of the ErbB receptor family in pediatric nervous system tumors and rhabdomyosarcoma

BACKGROUND

There is a paucity of knowledge regarding pediatric biomarkers, including the relevance of ErbB pathway aberrations in pediatric tumors. We investigated the occurrence of ErbB receptor aberrations across different pediatric malignancies, to identify patterns of ErbB dysregulation and define biomarkers suitable for patient enrichment in clinical studies.

PROCEDURE

Tissue samples from 297 patients with nervous system tumors and rhabdomyosarcoma were analyzed for immunohistochemical expression or gene amplification of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). Exploratory analyses of HER3/HER4 expression, and mRNA expression of ErbB receptors/ligands (NanoString) were performed. Assay validation followed general procedures, with additional validation to address Clinical Laboratory Improvement Amendments (CLIA) requirements.

RESULTS

In most tumor types, samples with high ErbB receptor expression were found with heterogeneous distribution. We considered increased/aberrant ErbB pathway activation when greater than or equal to two EGFR/HER2 markers were simultaneously upregulated. ErbB pathway dysregulation was identified in ∼20%-30% of samples for most tumor types (medulloblastoma/primitive neuroectodermal tumors 31.1%, high-grade glioma 27.1%, neuroblastoma 22.7%, rhabdomyosarcoma 23.1%, ependymoma 18.8%), 4.2% of diffuse intrinsic pontine gliomas, and no recurrent or refractory low-grade astrocytomas. In medulloblastoma/primitive neuroectodermal tumors and neuroblastoma, this was attributed mainly to high EGFR polysomy/HER2 amplification, whereas EGFR gene amplification was observed in some high-grade glioma samples. EGFR/HER2 overexpression was most prevalent in ependymoma.

CONCLUSIONS

Overexpression and/or amplification of EGFR/HER2 were identified as potential enrichment biomarkers for clinical trials of ErbB-targeted drugs.

Role of Precision Medicine in Pediatric Oncology

Childhood cancer is the leading cause of nonaccidental death in children and adolescents. Over the past 50 years, development of novel therapies and improvements in supportive care have led to improvements in long-term survival rates. However, there remains great morbidity associated with cancer treatment among childhood cancer survivors, and the outcomes for patients who relapse remain poor. The introduction of precision medicine, an approach that uses the understanding of genetic and biochemical profiles of a disease (as enabled by next-generation sequencing) to tailor treatment to a patient, has quickly started to change the diagnostic and therapeutic landscape of pediatric oncology. With its use, a better understanding of tumor biology, improved classification systems for various cancers, and genetically and molecularly targeted therapeutic strategies have been developed. We review the implementation of precision medicine in pediatric oncology and its effect on diagnosis, management, and treatment of pediatric cancers. [Pediatr Ann. 2022;51(1):e8-e14.].

Magnetic Resonance Imaging in the Contemporary Management of Medulloblastoma: Current and Emerging Applications

Medulloblastoma, the most common malignant primary brain tumor in children, is now considered to comprise of four distinct molecular subgroups-wingless (WNT), sonic hedgehog (SHH), Group 3, and Group 4 medulloblastoma, each associated with distinct developmental origins, unique transcriptional profiles, diverse phenotypes, and variable clinical behavior. Due to its exquisite anatomic resolution, multiparametric nature, and ability to image the entire craniospinal axis, magnetic resonance imaging (MRI) is the preferred and recommended first-line imaging modality for suspected brain tumors including medulloblastoma. Preoperative MRI can reliably differentiate medulloblastoma from other common childhood posterior fossa masses such as ependymoma, pilocytic astrocytoma, and brainstem glioma. On T1-weighted images, medulloblastoma is generally iso- to hypointense, while on T2-weighted images, the densely packed cellular component of the tumor is significantly hypointense and displays restricted diffusion on diffusion-weighted imaging. Following intravenous gadolinium, medulloblastoma shows significant but variable and heterogeneous contrast enhancement. Given the propensity of neuraxial spread in medulloblastoma, sagittal fat-suppressed T1-postcontrast spinal MRI is recommended to rule out leptomeningeal metastases for accurate staging. Following neurosurgical excision, postoperative MRI done within 24-48 h confirms the extent of resection, accurately quantifying residual tumor burden imperative for risk assignment. Post-treatment MRI is needed to assess response and effectiveness of adjuvant radiotherapy and systemic chemotherapy. After completion of planned therapy, surveillance MRI is recommended periodically on follow-up for early detection of recurrence for timely institution of salvage therapy, as well as for monitoring treatment-related late complications. Recent studies suggest that preoperative MRI can reliably identify SHH and Group 4 medulloblastoma but has suboptimal predictive accuracy for WNT and Group 3 tumors. In this review, we focus on the role of MRI in the diagnosis, staging, and quantifying residual disease; post-treatment response assessment; and periodic surveillance, and provide a brief summary on radiogenomics in the contemporary management of medulloblastoma.

Opposing Roles of Vascular Endothelial Growth Factor C in Metastatic Dissemination and Resistance to Radio/Chemotherapy: Discussion of Mechanisms and Therapeutic Strategies

Many cancers can be cured by combining surgery with healthy margins, radiation therapy and chemotherapies. However, when the pathology becomes metastatic, cancers can be incurable. The best situation involves "chronicization" of the pathology even for several years. However, most of the time, patients die within a few months. To disseminate throughout the body, cancer cells must enter the vascular network and seed in another organ. However, during the initiation of cancer processes, the tumor is avascular. Later, the production of angiogenic factors causes tumor neovascularization and subsequent growth and spread, and the presence of blood and/or lymphatic vessels is associated with high grade tumors. Moreover, during tumor development, cancer cells enter lymphatic vessels and disseminate via the lymphatic network. Hence, blood and lymphatic vessels are considered as main routes of metastatic dissemination and cancer aggressiveness. Therefore, anti-angiogenic drugs entered in the therapeutic arsenal from 2004. Despite undeniable effects however, they are far from curative and only prolong survival by a few months.Recently, the concepts of angio/lymphangiogenesis were revisited by analyzing the role of blood and lymphatic vessels at the initiation steps of tumor development. During this period, cancer cells enter lymphatic vessels and activate immune cells within lymph nodes to initiate an antitumor immune response. Moreover, the presence of blood vessels at the proximity of the initial nodule allows immune cells to reach the tumor and eliminate cancer cells. Therefore, blood and lymphatic networks have a beneficial role during a defined time window. Considering only their detrimental effects is a concern. Hence, administration of anti-angio/lymphangiogenic therapies should be revisited to avoid the destruction of networks involved in antitumor immune response. This review mainly focuses on one of the main drivers of lymphangiogenesis, the VEGFC and its beneficial and pejorative roles according to the grade of aggressive tumors.

Relapsed Medulloblastoma in Pre-Irradiated Patients: Current Practice for Diagnostics and Treatment

Relapsed medulloblastoma (rMB) accounts for a considerable, and disproportionate amount of childhood cancer deaths. Recent advances have gone someway to characterising disease biology at relapse including second malignancies that often cannot be distinguished from relapse on imaging alone. Furthermore, there are now multiple international early-phase trials exploring drug-target matches across a range of high-risk/relapsed paediatric tumours. Despite these advances, treatment at relapse in pre-irradiated patients is typically non-curative and focuses on providing life-prolonging and symptom-modifying care that is tailored to the needs and wishes of the individual and their family. Here, we describe the current understanding of prognostic factors at disease relapse such as principal molecular group, adverse molecular biology, and timing of relapse. We provide an overview of the clinical diagnostic process including signs and symptoms, staging investigations, and molecular pathology, followed by a summary of treatment modalities and considerations. Finally, we summarise future directions to progress understanding of treatment resistance and the biological mechanisms underpinning early therapy-refractory and relapsed disease. These initiatives include development of comprehensive and collaborative molecular profiling approaches at relapse, liquid biopsies such as cerebrospinal fluid (CSF) as a biomarker of minimal residual disease (MRD), modelling strategies, and the use of primary tumour material for real-time drug screening approaches.

Vorinostat and isotretinoin with chemotherapy in young children with embryonal brain tumors: A report from the Pediatric Brain Tumor Consortium (PBTC-026)

BACKGROUND

Embryonal tumors of the CNS are the most common malignant tumors occurring in the first years of life. This study evaluated the feasibility and safety of incorporating novel non-cytotoxic therapy with vorinostat and isotretinoin to an intensive cytotoxic chemotherapy backbone.

METHODS

PBTC-026 was a prospective multi-institutional clinical trial for children <48 months of age with newly diagnosed embryonal tumors of the CNS. Treatment included three 21-day cycles of induction therapy with vorinostat and isotretinoin, cisplatin, vincristine, cyclophosphamide, and etoposide; three 28-day cycles of consolidation therapy with carboplatin and thiotepa followed by stem cell rescue; and twelve 28-day cycles of maintenance therapy with vorinostat and isotretinoin. Patients with M0 medulloblastoma (MB) received focal radiation following consolidation therapy. Molecular classification was by DNA methylation array.

RESULTS

Thirty-one patients with median age of 26 months (range 6-46) received treatment on study; 19 (61%) were male. Diagnosis was MB in 20 and supratentorial CNS embryonal tumor in 11. 24/31 patients completed induction therapy within a pre-specified feasibility window of 98 days. Five-year progression-free survival (PFS) and overall survival (OS) for all 31 patients were 55 ± 15 and 61 ± 13, respectively. Five-year PFS was 42 ± 13 for group 3 MB (n = 12); 80 ± 25 for SHH MB (n = 5); 33 ± 19 for embryonal tumor with multilayered rosettes (ETMR, n = 6).

CONCLUSION

It was safe and feasible to incorporate vorinostat and isotretinoin into an intensive chemotherapy regimen. Further study to define efficacy in this high-risk group of patients is warranted.

Noncoding RNAs in pediatric brain tumors: Molecular functions and pathological implications

Brain tumors are common solid pediatric malignancies and the main reason for cancer-related death in the pediatric setting. Recently, evidence has revealed that noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), play a critical role in brain tumor development and progression. Therefore, in this review article, we describe the functions and molecular mechanisms of ncRNAs in multiple types of cancer, including medulloblastoma, pilocytic astrocytoma, ependymoma, atypical teratoid/rhabdoid tumor, glioblastoma, diffuse intrinsic pontine glioma, and craniopharyngioma. We also mention the limitations of using ncRNAs as therapeutic targets because of the nonspecificity of ncRNA targets and the delivery methods of ncRNAs. Due to the critical role of ncRNAs in brain oncogenesis, targeting aberrantly expressed ncRNAs might be an effective strategy to improve the outcomes of pediatric patients with brain tumors.

Pediatric Myxopapillary Ependymomas: A Clinicopathologic Evaluation

Myxopapillary ependymomas (MPEs) have an indolent clinical course, corresponding to World Health Organization Grade I. A total of 13 pediatric MPEs have been reported in the literature with "anaplastic features," including elevated proliferative activity (≥5 mitoses/10 high-power fields), necrosis, and microvascular proliferation. No consensus exists regarding the prognostic significance of such features. A retrospective clinicopathologic review of pediatric MPEs diagnosed between 1996 and 2018 at Mayo Clinic was performed. Totally, 8 pediatric MPEs (6 male; age: 7.52 to 16.88 y) were identified. Totally, 3 had disseminated disease at presentation. All patients underwent surgical resection (7 gross total; 1 subtotal). Totally, 5 cases harbored ≥5 mitoses/10 high-power fields (range: 5 to 9), 3 of which showed necrosis (2 with disseminated disease). Postsurgery, 2 patients received radiation; one with disseminated disease and another with increased mitotic activity/necrosis; neither has recurred (follow-up: 1.18 and 3.19 y). In all, 2 patients with disseminated disease, elevated mitotic activity, and necrosis had new metastatic disease/progression of nonresected metastatic foci (2.6 and 26.8 mo), received radiation therapy, and remain progression free (3.01 and 9.34 y). All patients are alive (median follow-up 1.31 y, range: 0.66 to 11.75). Among pediatric MPEs, the concurrent presence of elevated mitotic activity and necrosis may be associated with an aggressive clinical course, warranting closer surveillance and consideration of adjuvant therapies.

Incidence and survival for childhood central nervous system tumours in Australia, 1983-2016

PURPOSE

To investigate incidence and survival of childhood tumours of the central nervous system (CNS) by histological subtype, tumour behaviour and tumour grade.

METHODS

National, population-based data on all children under 15 years old diagnosed with a CNS tumour between 1983 and 2016 were sourced from the Australian Childhood Cancer Registry. Incidence rate trends were calculated using Joinpoint regression. Relative survival was calculated using the cohort method, with changes in survival over time by cancer type and tumour grade assessed by multivariable flexible parametric survival modelling.

RESULTS

The study cohort included 4914 patients, with astrocytoma (n = 2181, 44%) and embryonal tumours (n = 931, 19%) the most common diagnostic subgroups. Almost half (n = 2181, 44%) of all tumours were classified as high grade (III or IV). Incidence rates increased by 29% between 1983 and 2016, with high grade tumours rising by an annual average of + 1.1% (95% CI =  + 0.7%, + 1.5%, p < 0.001). 5-year survival for all patients combined was 72% (95% CI = 71-74%), ranging from 50% (46-54%) for those with other gliomas to 81% (79-83%) for astrocytoma (p < 0.001). Survival improved over time for grade II and III ependymomas but not for patients with astrocytoma irrespective of grade.

CONCLUSION

Improvements in diagnostic technology leading to more precise tumour classification are likely to explain some of the differences in incidence rate trends by histological type and grade. While improvements in survival over time were noted for some tumours, outcomes remained poor among patients with high-grade astrocytoma.

Toward a transitional care from childhood and adolescence to adulthood in surgical neurooncology? A lesson from the Necker-Enfants Malades and the Sainte-Anne Hospitals collaboration

OBJECTIVE

Transitional care in surgical neurooncology is poorly studied. However, this period is pivotal, since it allows the patient to be empowered in his or her disease management. Here, the authors describe the experience of the Necker-Enfants Malades and the Sainte-Anne Hospital collaboration.

METHODS

The mixed transitional consultations started in September 2019 in a dedicated space for transitional care, named the "La Suite" department, located in the Necker-Enfants Malades Hospital, Paris, France. The authors organized planned consultations to schedule the clinical and radiological follow-up in the adult neurosurgical department but also emergency consultations to manage tumor recurrence in young adult patients. Transitional care was performed jointly by pediatric and adult neurosurgeons who have developed clinical and research skills in the field of surgical neurooncology. Neuropathological analysis was performed by a neuropathologist who is specialized in pediatric and adult neurooncology.

RESULTS

Fourteen patients benefited from a mixed transitional consultation. All of them accepted to start their management in an adult neurosurgical environment. Eleven patients (78.6%) for whom the disease was controlled benefited from a planned consultation. Three patients (21.4%) required rapid neurosurgical management for a tumor recurrence (n = 2) or for a new primary CNS tumor (n = 1) and benefited from an emergency consultation.

CONCLUSIONS

For adult patients harboring a brain tumor during childhood or adolescence, the authors suggest that neurosurgeons specialized in adult surgical neurooncology with a full knowledge in pediatric neurooncology will combine the required skills to optimize care management for these patients within a dedicated multidisciplinary organization framework.

Malignant brain tumor in an infant showing histopathological features of yolk sac tumor but genetic and epigenetic features of AT/RT

SMARCA4 pathogenic variants are rarely detected in pediatric brain tumors other than atypical teratoid rhabdoid tumors (AT/RTs) without INI1 deficiency or in some cases of medulloblastoma. Here, we report an atypical intracranial immature teratoma that recurred as a yolk sac tumor with metastatic spinal and lung lesions. Sequencing of the tumor revealed two SMARCA4 variants, including a splice-site variant and a non-synonymous variant of uncertain significance. Additionally, the methylation signature of the tumor was close to that of AT/RTs. Our case might be a yet-unrecognized subtype of pediatric tumors in which inactivation of SMARCA4 contributes to the pathogenesis.

Temozolomide with irinotecan versus temozolomide, irinotecan plus bevacizumab for recurrent medulloblastoma of childhood: Report of a COG randomized Phase II screening trial

BACKGROUND

Approximately 30% of children with medulloblastoma (MB) experience recurrence, which is usually incurable. This study compared the overall survival (OS) of patients receiving temozolomide (TMZ) and irinotecan with that of patients receiving TMZ, irinotecan, and bevacizumab for recurrent MB/central nervous system (CNS) primitive neuroectodermal tumor (PNET).

METHODS

Patients with relapsed/refractory MB or CNS PNET were randomly assigned to receive TMZ (150 mg/m² /day PO on days 1-5) and irinotecan (50 mg/m² /day IV on days 1-5) with or without bevacizumab (10 mg/kg IV on days 1 and 15).

RESULTS

One hundred five patients were eligible and treated on study. Median OS was 13 months in the standard arm and 19 months with the addition of bevacizumab; median event-free survival (EFS) was 6 months in the standard arm and 9 months with the addition of bevacizumab. The hazard ratio for death from the stratified relative-risk regression model is 0.63. Overall, 23 patients completed 12 courses of planned protocol therapy, 23% (12/52) in the experimental arm with bevacizumab versus 21% (11/53) in the standard arm. Toxicity profiles were comparable in both treatment arms. The estimate of the incidence of feasibility events associated with the bevacizumab arm is three of 52 (5.8%) (95% CI 1.2-16%). Events included myelosuppression, electrolyte abnormalities, diarrhea, and elevated transaminases. One intracranial hemorrhage event was observed in each arm.

CONCLUSION

The addition of bevacizumab to TMZ/irinotecan significantly reduced the risk of death in children with recurrent MB. The combination was relatively well tolerated in this heavily pretreated cohort. The three-drug regimen demonstrated a sufficient risk reduction to warrant further investigation.

Molecular Pathology of Gliomas

Gliomas are the most common adult and pediatric primary brain tumors. Molecular studies have identified features that can enhance diagnosis and provide biomarkers. IDH1/2 mutation with ATRX and TP53 mutations defines diffuse astrocytomas, whereas IDH1/2 mutations with 1p19q loss defines oligodendroglioma. Focal amplifications of receptor tyrosine kinase genes, TERT promoter mutation, and loss of chromosomes 10 and 13 with trisomy of chromosome 7 are characteristic features of glioblastoma and can be used for diagnosis. BRAF gene fusions and mutations in low-grade gliomas and histone H3 mutations in high-grade gliomas also can be used for diagnostics.

Recent progress in the treatment of cancer in children

Although significant improvements have been made in the outcomes of children with cancer, the pace of improvement has slowed in recent years as the limits of therapy intensification may have been reached for many pediatric cancers. Furthermore, with increasing numbers of pediatric cancer survivors, the long-term side effects of treatment have become increasingly apparent. Therefore, attention has shifted to the use of molecularly targeted agents and immunotherapies to improve the outcomes of children who are not cured by traditional cytotoxic chemotherapies and to decrease exposure to cytotoxic chemotherapy and reduce late effects. This review describes the recent progress in the treatment of children with cancer, focusing in particular on diseases in which targeted and immunotherapeutic agents have made an impact.

Pediatric Neuro-Oncology

Central nervous system (CNS) tumors are the most common solid tumor in pediatrics and represent the largest cause of childhood cancer-related mortality. With advances in molecular characterization of tumors, considerable developments have occurred impacting diagnosis and management, and refined prognostication. Advances in management have led to better survival, but mortality remains high and significant morbidity persists. Novel therapeutic approaches targeting the biology of these tumors are being investigated to improve overall survival and decrease treatment-related morbidity. Further molecular understanding of pediatric CNS tumors will lead to continued refinement of tumor classification, management, and prognostication.

Prognostic implications of immune-related eight-gene signature in pediatric brain tumors

Genomic studies have provided insights into molecular subgroups and oncogenic drivers of pediatric brain tumors (PBT) that may lead to novel therapeutic strategies. Participants of the cohort Pediatric Brain Tumor Atlas: CBTTC (CBTTC cohort), were randomly divided into training and validation cohorts. In the training cohort, Kaplan-Meier analysis and univariate Cox regression model were applied to preliminary screening of prognostic genes. The LASSO Cox regression model was implemented to build a multi-gene signature, which was then validated in the validation and CBTTC cohorts through Kaplan-Meier, Cox, and receiver operating characteristic curve (ROC) analyses. Also, gene set enrichment analysis (GSEA) and immune infiltrating analyses were conducted to understand function annotation and the role of the signature in the tumor microenvironment. An eight-gene signature was built, which was examined by Kaplan-Meier analysis, revealing that a significant overall survival difference was seen, either in the training or validation cohorts. The eight-gene signature was further proven to be independent of other clinic-pathologic parameters via the Cox regression analyses. Moreover, ROC analysis demonstrated that this signature owned a better predictive power of PBT prognosis. Furthermore, GSEA and immune infiltrating analyses showed that the signature had close interactions with immune-related pathways and was closely related to CD8 T cells and monocytes in the tumor environment. Identifying the eight-gene signature (CBX7, JADE2, IGF2BP3, OR2W6P, PRAME, TICRR, KIF4A, and PIMREG) could accurately identify patients' prognosis and the signature had close interactions with the immunodominant tumor environment, which may provide insight into personalized prognosis prediction and new therapies for PBT patients.