Use of bevacizumab as a single agent or in adjunct with traditional chemotherapy regimens in children with unresectable or progressive low-grade glioma

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.

Amide proton transfer weighted imaging in pediatric neuro-oncology: initial experience

Amide proton transfer weighted (APTw) imaging enables in vivo assessment of tissue-bound mobile proteins and peptides through the detection of chemical exchange saturation transfer. Promising applications of APTw imaging have been shown in adult brain tumors. As pediatric brain tumors differ from their adult counterparts, we investigate the radiological appearance of pediatric brain tumors on APTw imaging. APTw imaging was conducted at 3 T. APTw maps were calculated using magnetization transfer ratio asymmetry at 3.5 ppm. First, the repeatability of APTw imaging was assessed in a phantom and in five healthy volunteers by calculating the within-subject coefficient of variation (wCV). APTw images of pediatric brain tumor patients were analyzed retrospectively. APTw levels were compared between solid tumor tissue and normal-appearing white matter (NAWM) and between pediatric high-grade glioma (pHGG) and pediatric low-grade glioma (pLGG) using t-tests. APTw maps were repeatable in supratentorial and infratentorial brain regions (wCV ranged from 11% to 39%), except those from the pontine region (wCV between 39% and 50%). APTw images of 23 children with brain tumor were analyzed (mean age 12 years ± 5, 12 male). Significantly higher APTw values are present in tumor compared with NAWM for both pHGG and pLGG (p < 0.05). APTw values were higher in pLGG subtype pilocytic astrocytoma compared with other pLGG subtypes (p < 0.05). Non-invasive characterization of pediatric brain tumor biology with APTw imaging could aid the radiologist in clinical decision-making.

Visual Deficits and Diagnostic and Therapeutic Strategies for Neurofibromatosis Type 1: Bridging Science and Patient-Centered Care

Neurofibromatosis type 1 (NF1) is an inherited autosomal dominant disorder primarily affecting children and adolescents characterized by multisystemic clinical manifestations. Mutations in neurofibromin, the protein encoded by the Nf1 tumor suppressor gene, result in dysregulation of the RAS/MAPK pathway leading to uncontrolled cell growth and migration. Neurofibromin is highly expressed in several cell lineages including melanocytes, glial cells, neurons, and Schwann cells. Individuals with NF1 possess a genetic predisposition to central nervous system neoplasms, particularly gliomas affecting the visual pathway, known as optic pathway gliomas (OPGs). While OPGs are typically asymptomatic and benign, they can induce visual impairment in some patients. This review provides insight into the spectrum and visual outcomes of NF1, current diagnostic techniques and therapeutic interventions, and explores the influence of NF1-OPGS on visual abnormalities. We focus on recent advancements in preclinical animal models to elucidate the underlying mechanisms of NF1 pathology and therapies targeting NF1-OPGs. Overall, our review highlights the involvement of retinal ganglion cell dysfunction and degeneration in NF1 disease, and the need for further research to transform scientific laboratory discoveries to improved patient outcomes.

Visual outcomes after bevacizumab-based therapy for optic pathway glioma

In optic pathway glioma (OPG), bevacizumab-based therapy (BBT) has promising effects on radiographic tumor burden, but the impact on vision is less clear. This single-institution study characterized visual acuity (VA) and visual field (VF) outcomes in 17 pediatric OPG patients treated with BBT. VA was stable or improved in 14 patients. Nine patients had evaluable VF data, six of whom experienced stability or improvement. Among six patients with vision deterioration as a treatment indication, stable or improved was observed for both VA and VF in five patients. In summary, BBT was associated with favorable visual outcomes in this cohort of patients with OPG.

Optic Pathway Gliomas in Pediatric Population-Current Approach in Diagnosis and Management: Literature Review

In this paper, the authors present a clinical picture of the diagnosis and current treatment regimens of optic pathway glioma in the pediatric population, with an emphasis on the role of an ophthalmic diagnosis in the differentiation and monitoring of lesions. Glioma is the most common optic nerve tumor in children.

MATERIAL

Articles in PubMed, Scholar and Website were reviewed, taking into account current standards of management related to sporadic or NF1-related optic glioma, epidemiology, location, course of the disease, clinical manifestations, histological types of the tumor, genetic predisposition, diagnostic ophthalmic tests currently applicable in therapeutic monitoring of the tumor, neurological diagnosis, therapeutic management and prognosis. The importance of current screening recommendations, in line with standards, was emphasized.

RESULTS

Glioma occurs in children most often in the first decade of life. Initially, they may be asymptomatic, and clinically ophthalmic changes are associated with the organ of vision or with systemic changes. Gliomas associated with the NF1 mutation have a better prognosis for sporadic gliomas. Diagnosis includes radiological imaging methods/MRI/ophthalmology/OCT and visual acuity log MAR assessment. The basis of treatment is clinical observation. In the case of disease progression, surgical treatment, chemotherapy and targeted therapy are used.

CONCLUSION

Further research into novel techniques for detecting gliomas would allow for early monitoring of the disease.

Neurofibromatosis Type 1-Associated Optic Pathway Gliomas: Current Challenges and Future Prospects

Optic pathway glioma (OPG) occurs in as many as one-fifth of individuals with the neurofibromatosis type 1 (NF1) cancer predisposition syndrome. Generally considered low-grade and slow growing, many children with NF1-OPGs remain asymptomatic. However, due to their location within the optic pathway, ~20-30% of those harboring NF1-OPGs will experience symptoms, including progressive vision loss, proptosis, diplopia, and precocious puberty. While treatment with conventional chemotherapy is largely effective at attenuating tumor growth, it is not clear whether there is much long-term recovery of visual function. Additionally, because these tumors predominantly affect young children, there are unique challenges to NF1-OPG diagnosis, monitoring, and longitudinal management. Over the past two decades, the employment of authenticated genetically engineered Nf1-OPG mouse models have provided key insights into the function of the NF1 protein, neurofibromin, as well as the molecular and cellular pathways that contribute to optic gliomagenesis. Findings from these studies have resulted in the identification of new molecular targets whose inhibition blocks murine Nf1-OPG growth in preclinical studies. Some of these promising compounds have now entered into early clinical trials. Future research focused on defining the determinants that underlie optic glioma initiation, expansion, and tumor-induced optic nerve injury will pave the way to personalized risk assessment strategies, improved tumor monitoring, and optimized treatment plans for children with NF1-OPG.

Visual outcomes and predictors in optic pathway glioma: a single centre study

BACKGROUND/AIMS

Optic pathway gliomas (OPGs) may cause progressive visual loss despite chemotherapy. Newer, less toxic treatments might be given earlier, depending on visual prognosis. We aimed to investigate the prognostic value of visual evoked potentials (VEP) and optical coherence tomography (OCT).

METHODS

A retrospective study of OPG patients (treated 2003-2017) was conducted. Primary outcome was PEDIG category visual acuity in better and worse eyes (good < = 0.2, moderate 0.3-0.6 and poor > = 0.7 logMAR). Binary logistic regression analysis was used to identify predictors of these outcomes.

RESULTS

60 patients (32 Neurofibromatosis type 1 [NF1] and 28 sporadic) had median presentation age 49 months (range 17-183) (NF1) and 27 months (range 4-92) (sporadic). Median follow up was 82 months (range 12-189 months). At follow up 24/32 (75%) of NF1 children and 14/28 (50%) of sporadic children had good better eye visual acuity and 11/32 (34%) of NF1 children and 15/28 (54%) of sporadics had poor worse eye acuity. Mean peripapillary retinal nerve fibre layer (RNFL) thickness predicted good better eye final acuity (OR 0.799, 95%CI 0.646-0.987, p = 0.038). Presenting with visual symptoms (OR 0.22 95% CI 0.001-0.508, p = 0.017) and poorer VEP scores (OR 2.35 95% CI 1.1-5.03, p = 0.027) predicted poor worse eye final acuity. 16 children had homonymous hemianopias at follow up, predicted by poor presenting binocular VEP score (OR 1.449 95%CI 1.052-1.995, p = 0.02).

CONCLUSIONS

We found that both RNFL thickness on OCT and VEP were useful in predicting future visual acuity and vision and potentially in planning treatment. We had a high prevalence of homonymous hemianopia.

Personality Changes and Staring Spells in a 12-Year-Old Child: A Case Report Incorporating ChatGPT, a Natural Language Processing Tool Driven by Artificial Intelligence (AI)

Low grade gliomas (LGGs) are the most common type of brain tumors diagnosed in children. The presentation of intracranial tumors in pediatric patients is varied and diverse. The early identification and treatment of LGGs are important to achieve favorable outcomes. Although personality changes can be a symptom of intracranial tumors, they are rarely the only main presenting feature. In addition to central nervous system (CNS) tumors, personality changes can be associated with psychological and endocrine conditions, contributing to a broad differential diagnosis. Because symptoms such as personality changes have the potential to be missed, communication between family members and clinicians is imperative to identify these symptoms early. We report the case of a 12-year-old child who presented with personality changes as her main symptom and was found to have an intracranial neoplasm. This case report integrates original author writing with output from ChatGPT, a natural language processing tool driven by artificial intelligence (AI). In addition to the case itself, this report will explore the benefits and drawbacks of using natural language AI in this context.

Neurofibromatosis type 1 system-based manifestations and treatments: a review

INTRODUCTION

Neurofibromatosis type 1 (NF1) is a genetic disorder caused by a mutation in the NF1 gene. This disease presents with various system-based manifestations, including cardiac, musculoskeletal, and neuronal issues, which have been well-studied in previous research and have prompted the development of current and emerging treatments. These treatments, mainly medications targeting specific manifestations of NF1, aim to mitigate the negative impacts of the disease on patients' lives. NF1 is associated with an increased risk of malignancy and a significant decrease in life expectancy. In this paper, we review the current and emerging treatments for NF1 in relation to its system-based manifestations.

METHODS

We conducted an extensive literature search using specific keywords through databases such as PubMed, Scopus, and Cochrane. The articles we found were compiled and subjected to strict inclusion and exclusion criteria.

RESULTS

Pharmacological advances have led to the development of products that hold promise as future treatments for NF1. Given the diverse manifestations that can affect multiple organ systems in patients with NF1, it is important to consider a variety of treatment options to achieve optimal results. However, one of the major challenges in diagnosing and treating NF1 is that patients present asymptomatically, making it necessary to rely on clinical features for diagnosis.

CONCLUSION

In conclusion, NF1 is a complex disease with varying manifestations and a growing field of pharmacologic treatments. The information presented in this article synthesizes current knowledge and available therapies for NF1.

Bevacizumab as Single Agent in Children and Teenagers with Optic Pathway Glioma

This is a retrospective study conducted on patients with OPG, aged less than 19 years, treated with bevacizumab as a single agent, since 2010 at IHOPe (Institute of Pediatric Hematology and Oncology). Efficacy of the treatment was evaluated on the tumor response rate on MRI with a centralized review basing upon RAPNO criteria and with visual assessment basing upon a 0.2 log change in the logMAR scale. Thirty-one patients with OPG have been included. From a radiological point of view, best anytime responses were: 1 major response, 6 partial responses, 7 minor responses and 14 stable diseases; achieving disease control in 28 (96%) out of 29 patients. Ophthalmological response was evaluated in 25 patients and disease control was achieved in 22 (88%) out of 25, with 14 steady states and 8 significant improvements. Among patients treated with chemotherapy after the bevacizumab course, nine relapsed and have been retreated with objective responses. Bevacizumab used as single agent seems effective in children and adolescents with OPG. Our work paves the way for a phase II study in which bevacizumab alone could be used as frontline therapy.

Single-agent Bevacizumab in the Treatment of Symptomatic Newly Diagnosed and Recurrent/Refractory Pediatric Cervicomedullary Brainstem Low-grade Gliomas: A Single Institutional Experience

Bevacizumab-based therapies have been utilized as single or combination therapy of refractory/recurrent pediatric low-grade gliomas. Its efficacy for symptomatic cervicomedullary low-grade gliomas (cmLGGs) in the upfront and the recurrent setting is less known. We report our retrospective single institutional experience from 2015 to 2021 with single-agent bevacizumab for symptomatic cmLGG. Six consecutive patients (4 female, ages 2 to 12 y) with newly diagnosed (n=3) and recurrent/refractory (n=3) symptomatic nondisseminated cmLGG (5/6 biopsy-proven, 2 BRAFV600E, 2 BRAF-KIAA1549) were treated with single-agent bevacizumab. All demonstrated radiographic response most pronounced on post-gadolinium T1-weighted magnetic resonance imaging (2 complete, 4 partial) at a median of 8 weeks (range: 2 to 12 wk). Clinical response was seen in all patients with improvement in cranial nerve abnormalities (3 recurrent/refractory, 1 newly diagnosed), strength (2 recurrent/refractory, 2 newly diagnosed), pain (2 recurrent/refractory), and anorexia (1 newly diagnosed). Four patients (2 recurrent/refractory, 2 newly diagnosed) experienced disease progression on subsequent adjunct therapies, 2 of which (the 2 newly diagnosed patients) are currently being rechallenged. At a mean follow-up of 7 months, all patients are clinically stable without disease progression. Single-agent bevacizumab may be effective in the management of symptomatic newly diagnosed and recurrent/refractory cmLGG and warrants further evaluation in a clinical trial setting.

Optic Pathway Gliomas: The Trends of Basic Research to Reduce the Impact of the Disease on Visual Function

Pediatric optic pathway gliomas (OPG) are low-grade brain tumors characterized by slow progression and invalidating visual loss. Common therapeutic strategies include surgery, radiotherapy, chemotherapy, and combinations of these modalities, but despite the different treatment strategies, no actual treatment exists to prevent or revert visual impairment. Nowadays, several reports of the literature show promising results regarding NGF eye drop instillation and improvement of visual outcome. Such results seem to be related with the NGF-linked prevention in caspase activation, which reduces retinal ganglion cell loss.Reducing retinal ganglion cell loss results clinically in visual field improvement as well as visual electric potential and optical coherence tomography gain. Nonetheless, visual acuity fails to show significant changes.Visual impairment represents nowadays one of the major issues in dealing with OPGs. Secondary to the interesting results offered by NGF eye drop administration, further studies are warranted to better comprehend potential treatment strategies.

Impact of Bevacizumab on Visual Function, Tumor Size, and Toxicity in Pediatric Progressive Optic Pathway Glioma: A Retrospective Nationwide Multicentre Study

BACKGROUNDS

Bevacizumab (BVZ) is used as a subsequent line of treatment for pediatric optic pathway glioma (OPG) in the case of progression. Data on the treatment effect concerning tumor progression and visual function are scarce and nationwide studies are lacking.

METHODS

We performed a retrospective, nationwide, multicentre cohort study including all pediatric patients with OPG treated with BVZ in the Netherlands (2009-2021). Progression-free survival, change in visual acuity and visual field, MRI-based radiologic response, and toxicity were evaluated.

RESULTS

In total, 33 pediatric patients with OPG were treated with BVZ (median 12 months). Visual acuity improved in 20.5%, remained stable in 74.4%, and decreased in 5.1% of 39 of all analysed eyes. The monocular visual field improved in 73.1%, remained stable in 15.4%, and decreased in 7.7% of 25 analysed eyes. Radiologic response at the end of therapy showed a partial response in 7 patients (21.9%), minor response in 7 (21.9%), stable disease in 15 (46.9%), and progressive disease in 3 (9.3%). Progression-free survival at 18 and 36 months after the start of BVZ reduced from 70.9% to 38.0%. Toxicity (≥grade 3 CTCAE) during treatment was observed in five patients (15.2%).

CONCLUSION

Treatment of BVZ in pediatric patients with OPG revealed stabilisation in the majority of patients, but was followed by progression at a later time point in more than 60% of patients. This profile seems relatively acceptable given the benefits of visual field improvement in more than 70% of analysed eyes and visual acuity improvement in more than 20% of eyes at the cessation of BVZ.

Treatment of NF1-associated Optic Pathway/Hypothalamic Gliomas in Patients With Diencephalic Syndrome

Diencephalic syndrome is usually associated with tumors in the hypothalamic region, rarely occurring in patients with neurofibromatosis type 1 (NF1)-associated gliomas. We describe the clinical presentation and response to treatment in 3 patients with NF1 presenting with diencephalic syndrome as first symptom of optic pathway/hypothalamic glioma (OPHG). Because of the rarity of this constellation, knowledge about the clinical course and best treatment options for patients with NF1-associated OPHG and diencephalic syndrome is still limited. All 3 patients showed good response to treatment with normalization of body mass index and decrease in tumor volume within 6 months.

Novel treatments in optic pathway gliomas

Optic pathway gliomas (OPG) are primary tumors of the optic nerve, chiasm, and/or tract that can be associated with neurofibromatosis type 1 (NF1). OPG generally have a benign histopathology, but a variable clinical course. Observation is generally recommended at initial diagnosis if vision is stable or normal for age, however, treatment may include chemotherapy, radiotherapy, or surgery in select cases. This manuscript reviews the literature on OPG with an emphasis on recent developments in treatment.

Recent Update in Pharmacological Agents for Optic Pathway Glioma

Optic pathway gliomas (OPGs) are insidious, debilitating low-grade tumors. They can affect the optic nerve, optic chiasm, and optic tracts and can be sporadic or associated with neurofibromatosis type 1 (NF1). The location of OPGs within the optic pathway typically precludes complete resection or optimal radiation dose. Treatment is unnecessary for sporadic and NF1-related OPGs that do not cause visual impairments. Chemotherapy is the mainstay of treatment for patients with progressive disease. However, outcomes following standard treatments have been mixed, and standardized outcome measurements are lacking. In recent years, newer molecularly targeted therapies such as anti-vascular endothelial growth factor (VEGF) monoclonal antibody, mitogen-activated protein kinase (MAPK) inhibitor, and mammalian target of rapamycin (mTOR) inhibitor, represent a promising treatment modality.

Optic Pathway Glioma in Children with Neurofibromatosis Type 1: A Multidisciplinary Entity, Posing Dilemmas in Diagnosis and Management Multidisciplinary Management of Optic Pathway Glioma in Children with Neurofibromatosis Type 1

Introduction

Neurofibromatosis type 1 (NF1) has an incidence of 1 in 2,000 to 3,000 individuals and in 15% is associated with optic pathway glioma (OPG). Given the variability in clinical presentation and related morbidity, a multidisciplinary approach for diagnosis and management of children with NF1 and OPG is required, but often lacks coordination and regular information exchange. Herein we summarize our experience and describe the care pathways/network provided by a multidisciplinary team. The role of the distinct team members is elucidated as well as the care amendments made over time.

Methods

We performed a retrospective single-center observational study, including children treated at our institution between 1990 and 2021. Inclusion criteria were clinical diagnosis of NF1, radiographic and/or histopathological diagnosis of OPG and age below 18 years. Patients being treated elsewhere were excluded from the study. Data was abstracted from each child’s health record using a standardized data collection form. Characteristics of children with NF1 and OPG were described using means (SD) and percentages. Outcomes were determined using Kaplan-Meier estimates.

Results

From 1990 to 2021, 1,337 children were followed in our institution. Of those, 195 were diagnosed with OPG (14.6%), including 94 (48.21%) females and 101 (51.79%) males. Comprehensive data were available in 150 patients. The mean (SD) age at diagnosis was 5.31(4.08) years (range: 0.8–17.04 years). Sixty-two (41.3%) patients remained stable and did not undergo treatment, whereas 88 (58.7%) patients required at least one treatment. The mean (SD) duration of follow up was 8.14 (5.46) years (range: 0.1–25.9 years; median 6.8 years). Overall survival was of 23.6 years (±1.08), comprising 5 deaths. A dedicated NF clinic, including pediatricians and a nurse, provides regular follow up and plays a central role in the management of children with NF1, identifying those at risk of OPG, coordinating referrals to Neuroradiology and other specialists as indicated. All children are assessed annually by Ophthalmology. Comprehensive care was provided by a multidisciplinary team consisting of Dermatology, Genetics, Neuro-oncology, Neuroradiology, Neurosurgery, Ophthalmology and Pediatrics.

Conclusions

The care of children with NF1 and OPG is optimized with a multidisciplinary team approach, coordinated by a central specialty clinic.

Current State of Pediatric Cardio-Oncology: A Review

The landscape of pediatric oncology has dramatically changed over the course of the past several decades with five-year survival rates surpassing 80%. Anthracycline therapy has been the cornerstone of many chemotherapy regimens for pediatric patients since its introduction in the 1960s, and recent improved survival has been in large part due to advancements in chemotherapy, refinement of supportive care treatments, and development of novel therapeutics such as small molecule inhibitors, chimeric antigen receptor T-cell therapy, and immune checkpoint inhibitors. Unfortunately, many cancer-targeted therapies can lead to acute and chronic cardiovascular pathologies. The range of cardiotoxicity can vary but includes symptomatic or asymptotic heart failure, arrhythmias, coronary artery disease, valvar disease, pericardial disease, hypertension, and peripheral vascular disease. There is lack of data guiding primary prevention and treatment strategies in the pediatric population, which leads to substantial practice variability. Several important future research directions have been identified, including as they relate to cardiac disease, prevention strategies, management of cardiovascular risk factors, risk prediction, early detection, and the role of genetic susceptibility in development of cardiotoxicity. Continued collaborative research will be key in advancing the field. The ideal model for pediatric cardio-oncology is a proactive partnership between pediatric cardiologists and oncologists in order to better understand, treat, and ideally prevent cardiac disease in pediatric oncology patients.

Impact of systemic anticancer therapy in pediatric optic pathway glioma on visual function: A systematic review

Pediatric optic pathway glioma (OPG) can seriously decrease visual function in the case of progression. Systemic anticancer therapy (SAT) is considered the treatment of first choice for unresectable OPG. New SAT modalities for the treatment of progressive OPG have been introduced in the last decade, including VEGF and MAPK pathway inhibition. This systematic review evaluated the effect of SAT on change in visual acuity and visual field in OPG. A systematic review was performed on SAT for OPG (January 1990 to August 2020). MEDLINE and EMBASE (Ovid) were searched for studies reporting on change in visual acuity and visual field after treatment with SAT for OPG. Overall, 11 series, including 358 patients, fulfilled the eligibility criteria. After follow-up of median 3.7 years (range: cessation of SAT- 8.2 years), improvement in binocular VA was found in 0-45% of studies, stability in 18-77% and a decrease in 0-82%. Two studies reported on change in visual field (improvement in 19% and 71% of patients), although either the change was not defined or the testing strategy was lacking. Considerable heterogeneity was present among the included studies, such as variety in the combinations of SAT administered, status of neurofibromatosis type 1, definition regarding change in visual acuity, 1- or 2-eye analysis, diversity in anatomic location, and extent of follow-up, all of which made meta-analysis inappropriate. This systematic review suggests that the impact of SAT in OPG on visual function is still unclear. The wide ranges reported on the efficacy of SAT and the observed heterogeneity highlight the need for prospective studies with uniform definitions of outcome parameters.

Multiple Intraspinal Gangliogliomas in a Child With Neurofibromatosis Type 1: Case Report and Literature Review

Neurofibromatosis type 1 (NF1)-associated primary intramedullary spinal cord ganglioglioma has only rarely been reported. Because of frequent nonresectability, they pose significant management challenges despite clinical indolence. This report describes a 4-year-old girl with NF1 who was found to have multiple discrete, infiltrative intramedullary cord masses, and biopsy demonstrated World Health Organization grade I ganglioglioma. Panel-based next-generation sequencing showed her previously identified germline NF1 mutation and a second somatic NF1 mutation. This represents the first report of multiple primary intramedullary gangliogliomas in a child with NF1 and demonstrates how biopsy with panel-based next-generation sequencing provides potential targets for MAPK/MEK/BRAF pathway inhibitor therapy.

Pharmacological Approaches in Neurofibromatosis Type 1-Associated Nervous System Tumors

Simple Summary

Neurofibromatosis type 1 (NF1) is a common cancer predisposition genetic disease that is associated with significant morbidity and mortality. In this literature review, we discuss the major pathways in the nervous system that are affected by NF1, tumors that are associated with NF1, drugs that target these pathways, and genetic models of NF1. We also summarize the latest updates from clinical trials that are evaluating pharmacological agents to treat these tumors and discuss the efforts that are being made to cure the disease in the future

Abstract

Neurofibromatosis type 1 is an autosomal dominant genetic disease and a common tumor predisposition syndrome that affects 1 in 3000 to 4000 patients in the USA. Although studies have been conducted to better understand and manage this disease, the underlying pathogenesis of neurofibromatosis type 1 has not been completely elucidated, and this disease is still associated with significant morbidity and mortality. Treatment options are limited to surgery with chemotherapy for tumors in cases of malignant transformation. In this review, we summarize the advances in the development of targeted pharmacological interventions for neurofibromatosis type 1 and related conditions.

Metronomic Maintenance With Weekly Vinblastine After Induction With Bevacizumab-Irinotecan in Children With Low-grade Glioma Prevents Early Relapse

BACKGROUND

Pediatric low-grade glioma (pLGG) represents the most common brain tumor in childhood. Previous studies have reported that a therapeutic strategy on the basis of the association of bevacizumab alone (B) or in combination with irinotecan (BI) could produce rapid tumor response and clinical improvement in children with pLGG. Nevertheless, a majority of patients relapses shortly (median, 5 mo) after stopping B or BI treatment. We proposed metronomic maintenance with weekly vinblastine added after a 6 months induction of B/BI to prevent early relapse.

PATIENTS AND METHODS

Monocentric retrospective analysis of a patient with pLGG treated with B or BI for 6 months followed by a 12-month maintenance with weekly vinblastine (6 mg/m²) from October 2012 to September 2019 in a single institution.

RESULTS

In total, 18 patients (7 males and 11 females) were identified. Because of progression during the B or BI induction 2/18 children were excluded. In total, 16 patients were analyzed with a median age of 10 years (range, 4 to 16 y). A total of 13 patients received BI and 3 patients received B alone. The mean duration of induction was 6.2 months (range, 2 to 12 mo). After induction 5/16 patients had a partial radiologic response, 11/16 patients had stable disease. All patients started maintenance (median duration, 12 mo; range, 3 to 12 mo). With a median follow-up of 3.9 years after the end of B or BI (range, 11 mo to 7.2 y), 15/16 patients were alive and 9/16 patients were progression-free. Seven of 16 children progressed with a median time to progression of 23 months (ranges, 5 to 39 mo). Three of 16 (18%) children progressed during vinblastine maintenance and 4/16 (25%) patients after the end of maintenance. After the total duration of treatment, clinical improvement was noted in 4 patients, 9 patients had stable symptoms, and only 3 patients progressed. One and 2-year event-free survival were, respectively, 81.2% and 56.2%. Two-year overall survival was 93.7%.

CONCLUSIONS

We report here, the potential benefit and the improvement of progression-free survival by adding metronomic maintenance with weekly vinblastine after initial induction with B or BI in children with low-grade glioma.

Pediatric low-grade gliomas: molecular characterization of patient-derived cellular models

PURPOSE

Pediatric low-grade gliomas (pLGGs), the most frequent pediatric brain tumors, include different entities harboring distinct histological and molecular features. A major limitation in the development of treatments for these tumors is the absence of reliable in vitro models that would allow a better understanding of the molecular mechanisms that support their growth. Surgical excision is the primary treatment method and the extent of resection represents one of the strongest prognostic factors. pLGGs that cannot be completely resected are prone to recur and associated with relapses and extensive morbidities, thus remaining a major clinical challenge.

METHODS

We established a protocol to successfully derive primary patient-derived pLGG cells and to fully characterize them from a molecular point of view.

RESULTS

Primary patients-derived pLGG cells were extensively analyzed in order to confirm their reliability as cellular models. Specifically, we evaluated the growth rate, senescence, and molecular features, such as BRAF mutational status, methylation, and protein expression profile.

CONCLUSION

This study extensively describes pLGG primary cellular models in terms of isolation, culture method, and molecular characterization that can be used to investigate pLGG biology.

Use of Antiangiogenic Therapies in Pediatric Solid Tumors

Cancer is an important cause of death in childhood. In recent years, scientists have made an important effort to achieve greater precision and more personalized treatments against cancer. But since only a few pediatric patients have identifiable therapeutic targets, other ways to stop the neoplastic cell proliferation and dissemination are needed. Therefore, the inhibition of general processes involved in the growth and behavior of tumors can be a relevant strategy for the development of new cancer therapies. In the case of solid tumors, one of these processes is angiogenesis, essential for tumor growth and generation of metastases. This review summarizes the results obtained with the use of antiangiogenic drugs in the main pediatric malignant solid tumors and also an overview of clinical trials currently underway. It should be noted that due to the rarity and heterogeneity of the different types of pediatric cancer, most studies on antiangiogenic drugs include only a small number of patients or isolated clinical cases, so they are not conclusive and further studies are needed.

Proteogenomics for pediatric brain cancer

Pediatric central nervous system tumors are the most common tumors in children, it constitute 15%-20% of all malignancies in children and are the leading cause of cancer related deaths in children. Proteogenomics is an emerging field of biological research that utilizes a combination of proteomics, genomics, and transcriptomics to aid in the discovery and identification of biomarkers for diagnosis and therapeutic purposes. Integrative proteogenomics analysis of pediatric tumors identified underlying biological processes and potential treatments as well as the functional effects of somatic mutations and copy number variation driving tumorigenesis.

A systematic review of ongoing clinical trials in optic pathway gliomas

INTRODUCTION

Optic pathway gliomas (OPGs), also known as Visual Pathway Gliomas, are insidious, debilitating tumours. They are most commonly WHO grade 1 pilocytic astrocytomas and frequently occur in patients with neurofibromatosis type 1. The location of OPGs within the optic pathway typically precludes complete resection or optimal radiation dosing, hence outcomes remain poor compared to many other low-grade gliomas. The aim of this systematic review was to formulate a comprehensive list of all current ongoing clinical trials that are specifically looking at clinical care of OPGs in order to identify trends in current research and provide an overview to guide future research efforts.

METHODS

This systematic review was conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The Cochrane Controlled Register of Trials (CENTRAL) and ClinicalTrials.gov were searched. Inclusion and exclusion criteria were applied and final results were reviewed.

RESULTS

501 clinical trials were identified with the search strategy. All were screened and eligible studies extracted and reviewed. This yielded 36 ongoing clinical trials, 27 of which were pharmacological agents in phase I-III. The remaining trials were a mixture of biological agents, radiation optimisation, diagnostic imaging, surgical intervention, and a social function analysis.

CONCLUSION

OPG is a complex multifaceted disease, and advances in care require ongoing research efforts across a spectrum of different research fields. This review provides an update on the current state of research in OPG and summarises ongoing trials.

Cardiovascular Toxicities in Pediatric Cancer Survivors

Advances in cancer therapies have significantly improved patient outcomes. However, with improvements in survival, the toxicities associated with cancer therapy have become of paramount importance and oncologists are faced with the challenge of establishing therapeutic efficacy while minimizing toxicity. Cardiovascular disease represents a significant risk to survivors of childhood cancer and is a major cause of morbidity and mortality. This article outlines the current state of knowledge regarding cardiotoxicity in children undergoing cancer therapies, including the impact of specific oncologic therapies, recommendations for cardiovascular screening, the management of established cardiac disease, and the evolving field of pediatric cardio-oncology.

Efficacy and safety of bevacizumab in progressive pediatric low-grade glioma: a systematic review and meta-analysis of outcome rates

Background

Successful management of pediatric low-grade glioma (pLGG) can be complicated by eloquent anatomical location, as well as specific pathologic and molecular features. Some authors have proposed using the VEGF inhibitor bevacizumab to improve disease control, but its safety and efficacy are poorly defined. Correspondingly, our aim was to pool systematically identified clinical data in the literature to assess the clinical utility of bevacizumab for pLGG at progression.

Methods

A systematic search of 7 electronic databases from inception to June 2019 was conducted following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Articles were screened against prespecified criteria. Outcomes were then pooled by random-effects meta-analyses of proportions.

Results

Seven pertinent studies described the outcomes of 110 progressive pLGG patients managed with bevacizumab in largely multiagent regimens. While on treatment, the rate of clinical response was 58% (95% CI, 43%-72%), and the rate of response on imaging was 80% (95% CI, 58%-96%). The rate of grade 3 or higher toxicity was 8% (95% CI, 2%-17%), with proteinuria the most commonly described. In the off-treatment period up to median 1 year, the rate of progression was estimated to be 51% (95% CI, 28%-74%).

Conclusions

Bevacizumab has the potential to control clinical and radiographic disease with relatively low grade 3 or higher toxicity risk in progressive pLGG patients. However, the long-term off-treatment benefits of this therapy are not yet well defined. Heterogeneity in the literature precludes any formal recommendations regarding its use until larger, more standardized investigations can be performed.

A Tumor-in-Host DEB-Based Approach for Modeling Cachexia and Bevacizumab Resistance

Adequate energy intake and homeostasis are fundamental for the appropriate growth and maintenance of an organism; the presence of a tumor can break this equilibrium. Tumor energy requests can lead to extreme weight loss in animals and cachexia in cancer patients. Angiogenesis inhibitors, acting on tumor vascularization, counteract this tumor-host energy imbalance, with significant results in preclinical models and more limited results in the clinic. Current pharmacokinetic-pharmacodynamic models mainly focus on the antiangiogenic effects on tumor growth but do not provide information about host conditions. A model that can predict energetic conditions that provide significant tumor growth inhibition with acceptable host body weight reduction is therefore needed. We developed a new tumor-in-host dynamic energy budget (DEB)-based model to account for the cytostatic activity of antiangiogenic treatments. Drug effect was implemented as an inhibition of the energy fraction subtracted from the host by the tumor. The model was tested on seven xenograft experiments involving bevacizumab and three different tumor cell lines. The model successfully predicted tumor and host body growth data, providing a quantitative measurement of drug potency and tumor-related cachexia. The inclusion of a hypoxia-triggered resistance mechanism enabled investigation of the decreased efficacy frequently observed with prolonged bevacizumab treatments. In conclusion, the tumor-in-host DEB-based approach has been extended to account for the effect of bevacizumab. The resistance model predicts the response to different administration protocols and, for the first time, the impact of tumor-related cachexia in different cell lines. Finally, the physiologic base of the model strongly suggests its use in translational human research. SIGNIFICANCE: A mathematical model describes tumor growth in animal models, taking into consideration the energy balance involving both the growth of tumor and the physiologic functions of the host.

Bevacizumab in treating the cystic components of pediatric low-grade gliomas: A report of four patients

Low-grade gliomas (LGG) are among the most common types of brain tumors in children and young adults. These tumors often consist of solid and cystic components. Bevacizumab is a documented treatment for progressive LGG, yet the impact of therapy on the cystic component of these tumors is unknown. We present four patients with prominently cystic LGG treated with bevacizumab at the time of progression. In each case, the cystic component responded to treatment. This is the first known study to investigate bevacizumab's impact on the cystic component of low-grade gliomas.

Current treatment of optic nerve gliomas

PURPOSE OF REVIEW

Optic pathway gliomas are low-grade neoplasms that affect the precortical visual pathway of children and adolescents. They can affect the optic nerve, optic chiasm, optic tracts and radiations and can either be sporadic or associated with neurofibromatosis type one. Gliomas isolated to the optic nerve (ONG) represent a subgroup of optic pathway gliomas, and their treatment remains controversial. New developments in ONG treatment have emerged in recent years, and it is necessary for clinicians to have a current understanding of available therapies.

RECENT FINDINGS

The current review of the literature covers the background of and recent developments in ONG treatment, with a focus on standard chemotherapy, new molecularly targeted therapies, radiation therapy and surgical resection and debulking.

SUMMARY

Although standard chemotherapy remains the mainstay of ONG treatment, newer molecularly targeted therapies such as mitogen-activated protein kinase kinase inhibitors and bevacizumab represent a promising new treatment modality, and clinical studies are ongoing.

Targeting IL-6 Is a Potential Treatment for Primary Cystic Craniopharyngioma

Adamantinomatous craniopharyngioma (ACP) makes up between 6 and 8% of pediatric brain tumors and is the most common pediatric tumor arising in the sellar/suprasellar region of the brain. The 10-year survival for patients diagnosed with craniopharyngioma ranges between 64 and 92%, but complicating factors such as location, common cyst formation, and potential hypothalamic infiltration cause significant morbidity in this population. There are a number of therapeutic options for children with ACP, including surgery, radiation, and cyst directed therapies such as interferon and bleomycin. Research has raised concerns regarding the efficacy and side effects associated with these conventional therapies, as well as with the difficulty in treating recurrent cystic ACP. Evidence from our group and others has shown that the cystic and solid tumor components of craniopharyngioma have high levels of IL-6R and IL-6, providing a potential target for therapy. Tocilizumab, a humanized monoclonal antibody, acts against soluble and membrane bound IL-6R, and has been widely utilized in pediatric patients. Two patients with recurrent cystic ACP were offered systemically administered tocilizumab or a combination of tocilizumab and bevacizumab on a compassionate use basis. Both patients' tumors had a significant response, with decreased cyst burden, supporting the assertion that tocilizumab with or without bevacizumab may be an option for patients suffering from cystic ACP.

Pediatric Cardio-Oncology: Development of Cancer Treatment-Related Cardiotoxicity and the Therapeutic Approach to Affected Patients

OPINION STATEMENT

The past 5 decades have seen significant improvements in outcomes for pediatric patients with cancer. Unfortunately, children and adolescents who have been treated for cancer are five to six times more likely to develop cardiovascular disease as a result of their therapies. Cardiovascular disease may manifest in a plethora of ways, from asymptomatic ventricular dysfunction to end-stage heart failure, hypertension, arrhythmia, valvular disease, early coronary artery disease, or peripheral vascular disease. A number of treatment modalities are implicated in pediatric and adult populations, including anthracyclines, radiation therapy, alkylating agents, targeted cancer therapies (small molecules and antibody therapies), antimetabolites, antimicrotubule agents, immunotherapy, interleukins, and chimeric antigen receptor T cells. For some therapies, such as anthracyclines, the mechanism of injury is elucidated, but for many others it is not. While a few protective strategies exist, in many cases, observation and close monitoring is the only defense against developing end-stage cardiovascular disease. Because of the variety of potential outcomes after cancer therapy, a one-size-fits-all approach is not appropriate. Rather, a good working relationship between oncology and cardiology to assess the risks and benefits of various therapies and planning for appropriate surveillance is the best model. When disease is identified, any of a number of therapies may be appropriate; however, in the pediatric and adolescent population supportive data are limited.

Use of bevacizumab as a single agent or in adjunct with traditional chemotherapy regimens in children with unresectable or progressive low-grade glioma

In pediatric low‐grade gliomas not amenable to complete resection, various chemotherapy regimens are the mainstream of treatment. An excellent overall survival of these patients makes justification of the intensification of chemotherapy difficult and calls for the development of new strategies. Bevacizumab, a humanized monoclonal antibody directed against Vascular endothelial growth factor (VEGF), has been successfully used in combination with irinotecan in a number of adult and pediatric studies and reports. Fifteen patients at median age of 7 years old (range 3 months to 15 years) were treated with bevacizumab in combination with conventional low‐toxicity chemotherapy. The majority had chiasmatic/hypothalamic and midline tumors, seven had confirmed BRAF pathway alterations including neurofibromatosis type 1 (2). Fourteen patients had more than one progression and three had radiotherapy. No deaths were documented, PFS at 11 and 15 months was 71.5% ± 13.9% and 44.7% ± 17.6% respectively. At the end of follow‐up 40% of patients has radiologically stable disease, three patients progressed shortly after completion of bevacizumab and two showed mixed response with progression of cystic component. Rapid visual improvement was seen in 6/8 patients, resolution of endocrine symptoms in 2/4 and motor function improvement in 4/6. No relation between histology or BRAF status and treatment response was observed. Treatment‐limiting toxicities included grade 4 proteinuria (2) and hypertension (2) managed with cessation (1) and pausing of therapy plus antihypertensives (1). In conclusion, bevacizumab is well tolerated and appears most effective for rapid tumor control to preserve vision and improve morbidity.