Comprehensive analysis of MYB/MYBL1-altered pediatric-type diffuse low-grade glioma

BACKGROUND

Pediatric-type diffuse low-grade gliomas (pLGG) harboring recurrent genetic alterations involving MYB or MYBL1 are closely related tumors. Detailed treatment and outcome data of large cohorts are still limited. This study aimed to comprehensively evaluate pLGG with these alterations to define optimal therapeutic strategies.

METHODS

We retrospectively reviewed details of pLGG with MYB or MYBL1 alterations from patients treated or referred for pathologic review at St. Jude Children's Research Hospital. Tumor specimens were centrally reviewed, and clinical data were collated.

RESULTS

Thirty-three patients (18 male; median age, 5 y) were identified. Two tumors had MYBL1 alterations; 31 had MYB alterations, MYB::QKI fusion being the most common (n=10, 30%). Most tumors were in the cerebral hemispheres (n=22, 67%). Two patients (6%) had metastasis at diagnosis. The median follow-up was 6.1 years. The 5-year event-free survival (EFS) rate was 81.3±8.3%; the 5-year overall survival (OS) rate was 96.4±4.1%. Patients receiving a near-total or gross-total resection had a 5-year EFS of 100%; those receiving a biopsy or subtotal resection had a 5-year EFS rate of 56.6±15.2% (p<0.01). No difference in EFS was observed based on location, histology, or molecular alterations. However, the tumors that progressed or metastasized may have distinct methylation profiles with evidence of activation of the MAPK and PI3K/AKT/mTOR pathways.

CONCLUSIONS

pLGG with MYB/MYBL1 alterations have good outcomes. Our findings suggest that surgical resectability is a crucial determinant of EFS. Further characterization is required to identify optimal treatment strategies for progressive tumors.

Trends in pediatric CNS tumors in Armenia: a multicenter retrospective study

PURPOSE

Central nervous system (CNS) tumors are the most common solid malignancies in children worldwide, including in Armenia. The current study aims to analyze epidemiological data, treatment, and outcomes of children and young adults (≤25 years) with CNS tumors in Armenia during the last 26 years.

METHODS

We collected data from pediatric and young adult patients treated in selected sites in Armenia from 1st January 1995 to 31st December 2020. Incidence by sex, age at diagnosis, time from first complaints to diagnosis, histopathology results, treatment strategies, complications, and overall survival (OS) rates were calculated.

RESULTS

The multicenter data analysis revealed 149 patients with diagnosed primary CNS tumors over 26 years. Among them, 84 (56.4%) were male. The median age at diagnosis was 7 years (range, 3 months to 25 years), and the median time from the first complaints to diagnosis was 2 months (range, 1 week to 70 months). Medulloblastomas and other embryonal tumors (47), low-grade gliomas (32), and high-grade gliomas (22) were the most commonly diagnosed malignancies. Ependymomas, craniopharyngiomas, germ cell tumors, and other malignancies were observed in 22 patients. For 26 patients, no histopathological or radiological diagnosis was available. Follow-up information was available for 98 (65.8%) patients. The 5-year OS rate for the whole study group was 67.7%.

CONCLUSION

Consistent with international data, embryonal tumors, and gliomas were the most commonly diagnosed CNS malignancies in Armenia. Multimodal treatment was often not available in Armenia during the study period, especially for early cases.

Smoking-Related Disease Impact in the Eastern Mediterranean Region: A Comprehensive Assessment Using Global Burden of Disease Data

BACKGROUND

Smoking remains a significant risk factor for numerous health issues, including lung cancer, chronic obstructive pulmonary disease, ischemic heart disease, stroke, and respiratory infections. This study investigates the burden of tobacco-related diseases in the Middle East and North Africa (MENA) region.

METHODS

Utilizing the GBD data, we examined the risk of smoking and second-hand smoke exposure and their related causes of death and disability in the 22 MENA countries. Smoking prevalence and disease burden data were analyzed with estimates reported as age-standardized rates.

RESULTS

Tobacco abuse accounted for 14.5% of all deaths and 23.2% of deaths tied to known risk factors, with an age-standardized death rate of 110.8 per 100,000. Cardiovascular diseases were the primary cause of smoking-related deaths and DALYs, representing 53.4% of all deaths and 50.3% of all DALYs. This was followed by neoplasms (24.6% of all deaths and 20.3% of all DALYs), chronic respiratory diseases(12.4% of all deaths and 11.9% of all DALYs), and respiratory infections and tuberculosis(4% of all deaths and 3.4% of all DALYs). Second-hand smoking caused 20.5% of tobacco-related deaths and 21.5% of tobacco-related DALYs, disproportionately affecting younger individuals. An increasing disease burden was observed in Lebanon, Turkey, Syria, Tunisia, UAE, and Libya, and declining rates were most evident in Oman and Qatar.

CONCLUSION

Our study emphasizes the impact of smoking on cardiovascular disease, the primary cause of smoking-related mortality and morbidity in the MENA region. Our findings highlight the urgent need for effective tobacco control policies and interventions.

High-grade glioma in infants and young children is histologically, molecularly, and clinically diverse: Results from the SJYC07 trial and institutional experience

BACKGROUND

High-grade gliomas (HGG) in young children pose a challenge due to favorable but unpredictable outcomes. While retrospective studies broadened our understanding of tumor biology, prospective data is lacking.

METHODS

A cohort of children with histologically diagnosed HGG from the SJYC07 trial was augmented with nonprotocol patients with HGG treated at St. Jude Children's Research Hospital from November 2007 to December 2020. DNA methylome profiling and whole genome, whole exome, and RNA sequencing were performed. These data were integrated with histopathology to yield an integrated diagnosis. Clinical characteristics and preoperative imaging were analyzed.

RESULTS

Fifty-six children (0.0-4.4 years) were identified. Integrated analysis split the cohort into four categories: infant-type hemispheric glioma (IHG), HGG, low-grade glioma (LGG), and other-central nervous system (CNS) tumors. IHG was the most prevalent (n = 22), occurred in the youngest patients (median age = 0.4 years), and commonly harbored receptor tyrosine kinase gene fusions (7 ALK, 2 ROS1, 3 NTRK1/2/3, 4 MET). The 5-year event-free (EFS) and overall survival (OS) for IHG was 53.13% (95%CI: 35.52-79.47) and 90.91% (95%CI: 79.66-100.00) vs. 0.0% and 16.67% (95%CI: 2.78-99.74%) for HGG (p = 0.0043, p = 0.00013). EFS and OS were not different between IHG and LGG (p = 0.95, p = 0.43). Imaging review showed IHGs are associated with circumscribed margins (p = 0.0047), hemispheric location (p = 0.0010), and intratumoral hemorrhage (p = 0.0149).

CONCLUSIONS

HGG in young children is heterogeneous and best defined by integrating histopathological and molecular features. Patients with IHG have relatively good outcomes, yet they endure significant deficits, making them good candidates for therapy de-escalation and trials of molecular targeted therapy.

[11C]-methionine positron emission tomography in the evaluation of pediatric low-grade gliomas

Background

[11C]-Methionine positron emission tomography (PET; [11C]-MET-PET) is principally used for the evaluation of brain tumors in adults. Although amino acid PET tracers are more commonly used in the evaluation of pediatric brain tumors, data on [11C]-MET-PET imaging of pediatric low-grade gliomas (pLGG) is scarce. This study aimed to investigate the roles of [11C]-MET-PET in the evaluation of pLGGs.

Methods

Eighteen patients with newly diagnosed pLGG and 26 previously treated pLGG patients underwent [11C]-MET-PET met the inclusion and exclusion criteria. Tumor-to-brain uptake ratio (TBR) and metabolic tumor volumes were assessed for diagnostic performances (newly diagnosed, 15; previously treated 26), change with therapy (newly diagnosed, 9; previously treated 7), and variability among different histology (n = 12) and molecular markers (n = 7) of pLGGs.

Results

The sensitivity of [11C]-MET-PET for diagnosing pLGG, newly diagnosed, and previously treated combined was 93% for both TBRmax and TBRpeak, 76% for TBRmean, and 95% for qualitative evaluation. TBRmax showed a statistically significant reduction after treatment, while other PET parameters showed a tendency to decrease. Median TBRmax, TBRpeak, and TBRmean values were slightly higher in the BRAFV600E mutated tumors compared to the BRAF fused tumors. Median TBRmax, and TBRpeak in diffuse astrocytomas were higher compared to pilocytic astrocytomas, but median TBRmean, was slightly higher in pilocytic astrocytomas. However, formal statistical analysis was not done due to the small sample size.

Conclusions

Our study shows that [11C]-MET-PET reliably characterizes new and previously treated pLGGs. Our study also shows that quantitative parameters tend to decrease with treatment, and differences may exist between various pLGG types.

Pediatric diencephalic tumors: a constellation of entities and management modalities

The diencephalon is a complex midline structure consisting of the hypothalamus, neurohypophysis, subthalamus, thalamus, epithalamus, and pineal body. Tumors arising from each of these diencephalic components differ significantly in terms of biology and prognosis. The aim of this comprehensive review is to describe the epidemiology, clinical symptoms, imaging, histology, and molecular markers in the context of the 2021 WHO classification of central nervous system neoplasms. We will also discuss the current management of each of these tumors.

Outcomes of SARS-CoV-2 infection in 126 children and adolescents with central nervous system tumors

BACKGROUND

The Global Registry of COVID-19 in Childhood Cancer (GRCCC) seeks to describe the natural history of SARS-CoV-2 in children with cancer across the world. Here, we report the disease course and management of coronavirus disease 2019 (COVID-19) infection in the subset of children and adolescents with central nervous system (CNS) tumors who were included in the GRCCC until February 2021, the first data freeze.

PROCEDURE

The GRCCC is a deidentified web-based registry of patients less than 19 years of age with cancer or recipients of a hematopoietic stem cell transplant and laboratory-confirmed SARS-CoV-2 infection. Demographic data, cancer diagnosis, cancer-directed therapy, and clinical characteristics of SARS-CoV-2 infection were collected. Outcomes were collected at 30 and 60 days post infection.

RESULTS

The GRCCC included 1500 cases from 45 countries, including 126 children with CNS tumors (8.4%). Sixty percent of the cases were from middle-income countries, while no cases were reported from low-income countries. Low-grade gliomas, high-grade gliomas, and CNS embryonal tumors were the most common CNS cancer diagnoses (67%, 84/126). Follow-up at 30 days was available for 107 (85%) patients. Based on the composite measure of severity, 53.3% (57/107) of reported SARS-CoV-2 infections were asymptomatic, 39.3% (42/107) were mild/moderate, and 6.5% (7/107) were severe or critical. One patient died from SARS-CoV-2 infection. There was a significant association between infection severity and absolute neutrophil count less than 500 (p = .04). Of 107 patients with follow-up available, 40 patients (37.4%) were not receiving cancer-directed therapy. Thirty-four patients (50.7%) had a modification to their treatment due to withholding of chemotherapy or delays in radiotherapy or surgery.

CONCLUSION

In this cohort of patients with CNS tumors and COVID-19, the frequency of severe infection appears to be low, although severe disease and death do occur. We found that greater severity was seen in patients with severe neutropenia, although treatment modifications were not associated with infection severity or cytopenias. Additional analyses are needed to further describe this unique group of patients.

The role of neurosurgery in advancing pediatric CNS tumor care worldwide

Introduction

There is substantial inequity in survival outcomes for pediatric brain tumor patients residing in high-income countries (HICs) compared to low- and middle-income countries (LMICs). To address disparities in pediatric cancer survival, the World Health Organization (WHO) established the Global Initiative for Childhood Cancer (GICC) to expand quality care for children with cancer.

Research question

To provide an overview of pediatric neurosurgical capacity and detail the burden of neurosurgical diseases impacting children.

Material and methods

A narrative review of the current context of global pediatric neurosurgical capacity as it relates to neurooncology and other diseases relevant to children.

Results

In this article, we provide an overview of pediatric neurosurgical capacity and detail the burden of neurosurgical diseases impacting children. We highlight concerted advocacy and legislative efforts aimed at addressing unmet neurosurgical needs in children. Finally, we discuss the potential implications of advocacy efforts on treating pediatric CNS tumors and outline strategies to improve global outcomes for children with brain tumors worldwide in the context of the WHO GICC.

Discussion and conclusion

With both global pediatric oncology and neurosurgical initiatives converging on the treatment of pediatric brain tumors, significant strides toward decreasing the burden of pediatric neurosurgical diseases will hopefully be made.

Survival trends for patients with retinoblastoma between 2000 and 2018: What has changed?

INTRODUCTION

Retinoblastoma (RB) is the most common primary intraocular cancer of childhood. Over the last few decades, a variety of techniques and treatment modalities emerged that improved the survival and ocular salvage rate of patients with RB. We investigated the relative survival trends of patients with RB from 2000 to 2018 by using the Surveillance, Epidemiology, and End Results (SEER) database.

DESIGN

Retrospective database review.

METHODS

We extracted data from SEER 18 from 2000 to 2018. All patients with clinically diagnosed RB during the study period were included. We utilized SEER*Stat 8.3.9 and JPSurv software to estimate relative 5- and 10-year survival rates and trends and generated descriptive analyses with IBM SPSS.

MAIN OUTCOME MEASURES

Patient survival rates at 5- and 10-year after RB diagnosis.

RESULTS

RB was diagnosed in 1479 patients within the SEER 18 Program during our study period. The cohort comprised 776 (52.5%) males, 615 (41.6%) non-Hispanic whites, 487(32.9%) Hispanics, 1030 (69.6%) patients with unilateral disease, and 1087 (73.5%) patients with localized disease. Relative survival trends at 5- and 10-year significantly declined over the study periods (-0.42%, and -0.50% annually, respectively) but the decline was not significant in unilateral and bilateral RB cases separately.

CONCLUSIONS

Five- and ten-year relative survival trends declined from 2000 to 2018 and were significantly decreasing. Further studies that include more patients are needed to identify the factors contributing to reduced survival of patients with RB over time.

An exploratory study of sleep habits in school-aged survivors of retinoblastoma

OBJECTIVE/BACKGROUND

Retinoblastoma is an ocular cancer diagnosed in early childhood. Previous research has indicated the impact of cancer treatment on sleep, but little is known about how sleep is impacted among survivors of retinoblastoma. The current study aimed to describe sleep habits of school-age survivors of retinoblastoma, to examine associations between sleep and quality of life, and to examine concordance between parent and child reports of sleep habits.

PATIENTS/METHODS

Sixty-nine survivors of retinoblastoma (Mage = 10.89, SD = 1.07, 50.7% female; 56.5% unilateral disease) and their caregivers participated, providing information on both self- and parent-reported sleep habits, quality of life, and demographic data.

RESULTS

Greater sleep concerns than national norms were reported by parents (bedtime resistance (t(58) = 2.69, p = .009), greater sleep onset delay (t(66) = 2.46, p = .017), shorter sleep duration (t(57) = 2.12, p = .038), increased daytime sleepiness (t(53) = 6.45, p= <.001)) and children (sleep location (t(61) = 2.39, p = .02), restless legs syndrome (t(62) = -2.21, p = .03), parasomnias (t(64) = 19.19, p=<.001)) . Both children and parents of children who received enucleation endorsed greater sleep concerns across several domains (e.g., electronic use before bed, sleep-disordered breathing). Child- and parent-reported sleep concerns were generally associated with decreased quality of life. Finally, child- and parent-report of sleep habits appeared generally consistent.

CONCLUSIONS

Survivors of retinoblastoma experience sleep difficulties. As such, assessment and targeted intervention is important to mitigate any effects on quality of life. Future research should examine sleep habits of survivors of retinoblastoma across cultures and developmental periods.

An international multicenter survey reveals health care providers' knowledge gap in childhood central nervous system tumors

Childhood central nervous system (CNS) tumors have longer delays in diagnosis than do other pediatric malignancies because health care providers (HCPs) lack awareness about clinical presentation of these tumors. To evaluate the knowledge gap among HCPs, we conducted a global cross-sectional survey. The survey consisted of a set of CNS tumor knowledge questions focused on symptoms, signs, and imaging indications. The survey was disseminated to HCPs via email (November 2018-March 2020). Participants had to complete a pre-test survey, attend an education seminar on CNS tumors, and complete a post-test survey. The knowledge gap was evaluated using pre-test and post-test scores. We received 889 pre-test and 392 post-test responses. Most respondents were from Asia (73.1% of pre-test responses; 87.5% of post-test responses). The median pre-test score was 40.0% (range: 13.1-92.9%). A high percentage of correct answers were given in post-test responses (median score: 77.1%, range: 14.9-98.2%). In the pre-test, 18.7% of participants accurately responded that Cushing's triad was a less common symptom, and 15.0% recognized that children aged > 10 years are at risk of late diagnosis. Surprisingly, 21.9% falsely reported that patients with malignancy experienced the longest pre-diagnostic symptom interval, and 54.5% of respondents wrongly selected medulloblastoma as the most common CNS tumor. Overall, pediatricians demonstrated a greater knowledge gap on both surveys than did other specialties.  Conclusion: Pre- and post-test surveys revealed significant knowledge gaps in childhood CNS tumors among HCPs. Thus, raising professional awareness on clinical presentations of CNS tumors through educational strategies is important to address this knowledge deficit. What is Known: • Diagnostic delay in childhood central nervous system (CNS) tumors continues to be a significant problem that negatively impacts the quality of life and treatment sequelae. • Lack of medical education on CNS tumors is a contributing factor to this problem. What is New: • Most health care providers do not realize that low-grade tumors are the most common neoplasm in children. • Health care providers fail to recognize that teenagers and adolescents are a vulnerable age group for diagnostic delays, with the longest pre-diagnostic symptom interval.

Psychosocial outcomes and quality of life among school-age survivors of retinoblastoma

BACKGROUND

Retinoblastoma is the most common intraocular childhood cancer and is typically diagnosed in young children. With increasing number of survivors and improved medical outcomes, long-term psychosocial impacts need to be explored. Thus, the current study sought to assess functioning in school-aged survivors of retinoblastoma.

PROCEDURE

Sixty-nine survivors of retinoblastoma underwent a one-time evaluation of psychosocial functioning. Survivors (Mage = 10.89 years, SD = 1.07 years; 49.3% male; 56.5% unilateral disease) and parents completed measures of quality of life (QoL; PedsQL) and emotional, behavioral, and social functioning (PROMIS [patient-reported outcome measurement information system] Pediatric Profile, BASC-2 parent report). Demographic and medical variables were also obtained.

RESULTS

On the whole, both survivors and caregivers indicated QoL and behavioral and emotional health within the typical range of functioning. Survivors reported better physical QoL compared to both parent report and a national healthy comparison sample, whereas caregivers reported that survivors experienced lower social, school, and physical QoL than a healthy comparison. Regarding behavioral and emotional health, survivors indicated more anxiety than a nationally representative sample. Parents of female survivors endorsed lower adaptive scores than parents of male survivors.

CONCLUSIONS

Results indicated that survivors of retinoblastoma reported QoL and behavioral and emotional health within normal limits, although parents appear to perceive greater impairment across several assessed domains. Understanding both survivor and parent reports remains important for this population. Future research should explore psychosocial functioning of these survivors as they transition to adolescence and early adulthood, given the increased independence and behavioral and emotional concerns during these developmental periods.

The Greatest Healthcare Disparity: Addressing Inequities in the Treatment of Childhood Central Nervous System Tumors in Low- and Middle-Income Countries

The antithesis between childhood cancer survival rates in low- and middle-income countries (LMIC) and high-income countries (HIC) represents one of healthcare's most significant disparities. In HICs, the 5-year survival rate for children with cancer, including most brain tumors, exceeds 80%. Unfortunately, children in LMICs experience far worse outcomes with 5-year survival rates as low as 20%. To address inequities in the treatment of childhood cancer and disease burden globally, the World Health Organization (WHO) launched the Global Initiative for Childhood Cancer. Within this initiative, pediatric low-grade glioma (LGG) represents a unique opportunity for the neurosurgical community to directly contribute to a paradigm shift in the survival outcomes of children in LMICs, as many of these tumors can be managed with surgical resection alone. In this chapter, we discuss the burden of pediatric LGG and outline actions the neurosurgical community might consider to improve survival for children with LGG in LMICs.

Pediatric Neurosurgical Capacity for the Care of Children With CNS Tumors Worldwide: A Cross-Sectional Assessment

PURPOSE

Efforts to address inequities in the treatment of pediatric CNS tumors and the burden of childhood cancer globally have prompted the designation of low-grade glioma as one of six index cancers for the World Health Organization Global Initiative for Childhood Cancer. Understanding the importance of neurosurgical interventions and evaluating pediatric neurosurgical capacity may identify critical interventions to improve outcomes for children with low-grade glioma and other CNS tumors.

METHODS

An online, cross-sectional survey assessing pediatric neurosurgical practice and capacity was distributed to members of the International Society of Pediatric Neurosurgery. The survey included 36 items covering domains including patient volume, available infrastructure, scope of practice, case distribution, and multidisciplinary care.

RESULTS

Responses from 196 individuals from 61 countries, spanning all WHO regions, were included. Ninety-six (49.0%) were from high-income countries, 57 (29.1%) were from upper-middle-income countries, 42 (21.4%) were from lower-middle-income countries (LMICs), and 1 was (0.5%) from a low-income country. Most respondents had a catchment population of ≥ 1 million and indicated the availability of basic neurosurgical resources such as a dedicated neurosurgical operating theater and surgical microscope. The presence of a neurosurgical intensive care unit, inpatient rehabilitation services, and infection monitoring showed similar availability across country groups. Quantitative scoring of 13 infrastructure and service items established that fewer resources were available in low-income countries/LMICs and upper-middle-income countries compared with high-income countries. The volume of pediatric CNS tumor cases and case distribution did not vary according to World Bank country groups.

CONCLUSION

This study provides a comprehensive evaluation of pediatric neurosurgical capacity across the globe, establishing variability of resources on the basis of the country income level. Our findings suggest that pediatric neurosurgeons in LMICs may benefit from key neurosurgical instrumentation and increased support for multidisciplinary brain tumor programs and childhood cancer research efforts.

The clinical and molecular characteristics of progressive hypothalamic/optic pathway pilocytic astrocytoma

BACKGROUND

Unresectable hypothalamic/optic pathway pilocytic astrocytoma (PA) often progresses despite multiple therapies. Identifying clinical and molecular characteristics of progressive tumors may aid in prognostication and treatment.

METHODS

We collected 72 unresectable, non-NF1-associated hypothalamic/optic pathway PA to identify clinical and biologic factors associated with tumor progression. Tumors that progressed after therapy, metastasized, or resulted in death were categorized into Cohort B; those that did not meet these criteria were categorized into Cohort A. DNA methylation and transcriptome analyses were performed on treatment-naïve tumors, and the findings were validated by immunohistochemistry (IHC).

RESULTS

The median follow-up of the entire cohort was 12.3 years. Cohort B was associated with male sex (M:F = 2.6:1), younger age at diagnosis (median 3.2 years vs. 6.7 years, P = 0.005), and high incidence of KIAA1549-BRAF fusion (81.5% vs. 38.5%, P = 0.0032). Cohort B demonstrated decreased CpG methylation and increased RNA expression in mitochondrial genes and genes downstream of E2F and NKX2.3. Transcriptome analysis identified transcription factor TBX3 and protein kinase PIM1 as common downstream targets of E2F and NKX2.3. IHC confirmed increased expression of TBX3 and PIM1 in Cohort B tumors. Gene enrichment analysis identified enrichment of MYC targets and MAPK, PI3K/AKT/mTOR, and p53 pathways, as well as pathways related to mitochondrial function.

CONCLUSIONS

We identified risk factors associated with progressive PA. Our results support the model in which the p53-PIM1-MYC axis and TBX3 act alongside MAPK and PI3K/AKT/mTOR pathways to promote tumor progression, highlighting potential new targets for combination therapy and refining disease prognostication.

Outcomes of Children With Low-Grade Gliomas in Low- and Middle-Income Countries: A Systematic Review

PURPOSE

Pediatric CNS tumors are increasingly a priority, particularly with the WHO designation of low-grade glioma (LGG) as one of six index childhood cancers. There are currently limited data on outcomes of pediatric patients with LGGs in low- and middle-income countries (LMICs).

METHODS

To better understand the outcomes of LGGs in LMICs, this systematic review interrogated nine literature databases.

RESULTS

The search identified 14,977 publications. Sixteen studies from 19 countries met the selection criteria and were included for data abstraction and analysis. Eleven studies (69%) were retrospective reviews from single institutions, and one (6%) captured institutional data prospectively. The studies captured a total of 957 patients with a median of 49 patients per study. Seven (44%) of the studies described the treatment modalities used. Of 373 patients for whom there was information, 173 (46%) had a gross total or near total resection, 109 (29%) had a subtotal resection, and 91 (24%) had only a biopsy performed. Seven studies, with a total of 476 patients, described the frequency of use of radiotherapy and/or chemotherapy in the cohorts: 83 of these patients received radiotherapy and 76 received chemotherapy. The 5-year overall survival ranged from 69.2% to 93.5%, although lower survival rates were reported at earlier time points. We identified limitations in the published studies with respect to the cohort sizes and methodologies.

CONCLUSION

The included studies reported survival rates frequently exceeding 80%, although the ultimate number of studies was limited, pointing to the paucity of studies describing the outcomes of children with LGGs in LMICs. This study underscores the need for more robust data on outcomes in pediatric LGG.

Molecular classification and outcome of children with rare CNS embryonal tumors: results from St. Jude Children's Research Hospital including the multi-center SJYC07 and SJMB03 clinical trials

Methylation profiling has radically transformed our understanding of tumors previously called central nervous system primitive neuro-ectodermal tumors (CNS-PNET). While this marks a momentous step toward defining key differences, reclassification has thrown treatment into disarray. To shed light on response to therapy and guide clinical decision-making, we report outcomes and molecular features of children with CNS-PNETs from two multi-center risk-adapted studies (SJMB03 for patients ≥ 3 years; SJYC07 for patients < 3 years) complemented by a non-protocol institutional cohort. Seventy patients who had a histological diagnosis of CNS-PNET or CNS embryonal tumor from one of the new categories that has supplanted CNS-PNET were included. This cohort was molecularly characterized by DNA methylation profiling (n = 70), whole-exome sequencing (n = 53), RNA sequencing (n = 20), and germline sequencing (n = 28). Clinical characteristics were detailed, and treatment was divided into craniospinal irradiation (CSI)-containing (SJMB03 and SJMB03-like) and CSI-sparing therapy (SJYC07 and SJYC07-like). When the cohort was analyzed in its entirety, no differences were observed in the 5-year survival rates even when CSI-containing therapy was compared to CSI-sparing therapy. However, when analyzed by DNA methylation molecular grouping, significant survival differences were observed, and treatment particulars provided suggestions of therapeutic response. Patients with CNS neuroblastoma with FOXR2 activation (CNS-NB-FOXR2) had a 5-year event-free survival (EFS)/overall survival (OS) of 66.7% ± 19.2%/83.3% ± 15.2%, and CIC rearranged sarcoma (CNS-SARC-CIC) had a 5-year EFS/OS both of 57.1% ± 18.7% with most receiving regimens that contained radiation (focal or CSI) and multidrug chemotherapy. Patients with high-grade neuroepithelial tumor with BCOR alteration (HGNET-BCOR) had abysmal responses to upfront chemotherapy-only regimens (5-year EFS = 0%), but survival extended with salvage radiation after progression [5-year OS = 53.6% ± 20.1%]. Patients with embryonal tumor with multilayered rosettes (ETMR) or high-grade glioma/glioblastoma multiforme (HGG/GBM) did not respond favorably to any modality (5-year EFS/OS = 10.7 ± 5.8%/17.9 ± 7.2%, and 10% ± 9.0%/10% ± 9.0%, respectively). As an accompaniment, we have assembled this data onto an interactive website to allow users to probe and query the cases. By reporting on a carefully matched clinical and molecular cohort, we provide the needed insight for future clinical management.

Torticollis as a presenting symptom of pediatric CNS tumors: A systematic review

To assess the frequency of torticollis as a presenting symptom of pediatric CNS tumors and its impact on pre-diagnostic symptom intervals (PSIs) and patient outcomes. We performed a systematic review of studies reporting torticollis in children with various CNS tumors. We searched PubMed for studies published from January 1972 to March 2021 in English. Case reports were included in the analysis if the following criteria were met (1) torticollis was the presenting symptom secondary to a CNS tumor (2) children <18 years of age, (3) underwent imaging intervention and (4) outcome data provided. Of 1,365 relevant articles, 45 were eligible for analysis according to our inclusion criteria representing 95 patients. Two independent investigators extracted the data, and a third investigator arbitrated discrepancies. We found that 38.9% of CNS tumors exhibited torticollis as the only presenting symptom. PSI lengths ranged from 0 to 4 years (median, 5 months) for low-grade tumors, and patient age and PSI length were inversely associated. Of patients with low-grade tumors, 23.8% received physiotherapy, in contrast with 0% of patients with high-grade tumors. PSI length also increased for patients who received rehabilitation, and 39.3% and 7.1% of patients with high-grade and low-grade tumors, respectively, died of their disease. Patients with low-grade tumors and torticollis as a primary presenting symptom were more likely to have a prolonged PSI. Therefore, CNS tumors should be considered in the differential diagnosis of acquired torticollis in children.

EPID-05. A novel, clinically-relevant classification of pediatric CNS tumors for cancer registries using a clustering analysis

To accurately evaluate the burden of pediatric central nervous system (CNS) tumors, estimate resources for cancer control, and monitor outcomes, a classification system that segregates tumors into clinically relevant groups is essential. The current classification of CNS tumors included in the third revision of the International Childhood Cancer Classification does not identify key clinical groups, such as low- and high-grade gliomas. To address this need, a novel classification was embarked upon using ICD-O-3 codes, CBTRUS grouping, incidence, survival, and treatment modalities as inputs. For each ICD-O-3 code with &gt;50 new cases/year in CBTRUS from 2000 to 2016, 2 clinicians reached consensus defining the efficacy of three treatment modalities: surgical resection, radiotherapy, and chemotherapy. Then, patient level 5-year overall survival (OS) times were simulated based on total incidence and 5-year OS for each code. Subsequently, 5 factors were included as potential classifiers: tumor behavior, CBTRUS sub-group, and efficacy of the three treatment modalities. A “survival tree” was developed by using partitioning. Starting with the patient cohort (root), univariate cox proportional hazards model was used to identify statistically significant (P &lt; 0.05) factors. The factors with the largest hazard ratio were selected manually to create child nodes. Within each child node, the partitioning process was repeated on remaining factors until no statistically significant factor remained. This clustering yielded 4 main groups (low-, intermediate-, high-, and very high-risk tumors) and 11 subgroups, including “embryonal tumors” and “low-risk glial and glioneuronal tumors”. Further validation of the classification will be sought through a structured consensus process using multidisciplinary experts. This systematic method to develop a classification for pediatric CNS tumors will allow for more relevant estimations of outcomes and better estimation of resource utilization. Furthermore, this strategy could be replicated for other disease groups.

LGG-13. The clinical and molecular characteristics of progressive hypothalamic/optic pathway pilocytic astrocytoma

Unresectable hypothalamic/optic pathway pilocytic astrocytoma (PA) can be challenging to manage due to repeated progressions despite multiple lines of therapy. To identify clinical and biologic factors associated with tumor progression, we retrospectively identified 72 unresectable non-NF1-associated hypothalamic/optic pathway PA. Tumors were classified as high-risk (50%) if they progressed after three or more lines of chemotherapy/targeted therapy, progressed after radiation, developed metastatic disease, or died of disease. DNA methylation profiling and transcriptome analysis (RNA sequencing) were performed on treatment-naïve tumors with available tissue (n=40), and the findings were validated by immunohistochemistry (IHC) on additional tumor tissue. The median follow-up of the entire cohort was 12.3 years. High-risk tumors were associated with male sex (M:F = 2.6:1), younger age at diagnosis (median 3.2 years vs. 6.7 years, P = 0.005), and high incidence of KIAA1549-BRAF fusion (81.5% vs. 38.5%, P = 0.0032). High-risk tumors demonstrated decreased CpG methylation and increased RNA expression in many mitochondrial genes and genes downstream of E2F and NKX2.3 transcription factors. Transcriptome analysis identified transcription factor TBX3 and proto-oncogene serine/threonine protein kinase PIM1 as common downstream targets of both E2F and NKX2.3 and potential drivers of tumor progression. IHC confirmed increased expression of TBX3 and PIM1 in high-risk tumors. PIM1 is known to increase the stability and transcriptional activity of MYC, and gene enrichment analysis identified enrichment of MYC targets. Signaling pathways known to be implicated in PA, such as MAPK and PI3K/AKT/mTOR, were also enriched, in addition to pathways related to mitochondrial biogenesis and oxidative phosphorylation. Our results support the model in which the p53-PIM1-MYC axis and TBX3 act alongside MAPK and PI3K/AKT/mTOR pathways to promote tumor progression, highlighting potential new targets for combination therapy and refining disease prognosis.

OTHR-06. Knowledge gap among health care providers in childhood central nervous system tumors: Result from an international multicenter survey

BACKGROUND: Central nervous system (CNS) tumors in children are associated with a longer delay in diagnosis. One of the contributing factors is the lack of awareness regarding childhood CNS tumors presentation among health care providers. To evaluate the knowledge gap among health care providers, we conducted a cross-sectional survey that was distributed globally. METHODS: The survey was disseminated to health care practitioners via electronic mail in November 2018 and it was closed in March 2020. The participants were asked to complete a pre-test survey, requested to view a CNS tumor education seminar, and subsequently complete a post-test survey. The survey had nine questions focusing on CNS tumor symptoms, pre-diagnosis symptom interval (PSI), and imaging indication. The knowledge gap was evaluated with pre-test and post-test scores. RESULTS: 889 pre-test and 392 post-test responses were received. The majority of the respondents were from Asia, with a percentage of 73.1% and 87.5% in pre-test and post-test respectively. For the pre-test, the median score for accurate answers was 40.0% (range:13.1-92.9%). Interestingly, a high rate of correctness was achieved in the post-test with a median score of 77.1% (14.9-98.2%). In the pre-test, only 18.7% of the participants responded precisely that Cushing’s triad is a less common symptom and just 15.0% recognized that older children &gt;10 years old are at risk for late diagnosis. Surprisingly, 21.9% falsely reported that patients with malignant tumors experience the longest PSI, and 54.5% of the respondents wrongly selected medulloblastoma as the commonest CNS tumor. Overall, the pre-test scores among pediatricians and professionals with &gt;10 years of experience did not demonstrate improved knowledge when compared to other specialties. CONCLUSIONS: The survey analysis showed a significant knowledge gap regarding childhood CNS tumors among health care providers. Therefore, raising professional awareness is very important and can be achieved through targeted educational strategies.

Comprehensive global collaboration in the care of 1182 pediatric oncology patients over 12 years: The Iraqi-Italian experience

BACKGROUND

Iraq's health care system has gradually declined after several decades of wars, terrorism, and UN economic sanctions. The Oncology Unit at Children's Welfare Teaching Hospital (CWTH) in Baghdad was lacking basic facilities and support. To address this shortcoming, a humanitarian and educational partnership was established between CWTH and Sapienza University of Rome (SUR).

METHODS

We investigated the outcomes of 80 online and 16 onsite educational sessions and 142 teleconsultation sessions from 2006 to 2014. We also determined the outcomes of pathology reviews by SUR of 1216 tissue specimens submitted by CWTH from 2007 until 2019 for second opinions. The primary outcomes were discordance, concordance, and changes among clinical diagnoses and pathology review findings. The measures included the frequency of teleconsultation and tele-education sessions, the topics discussed in these sessions, and the number of pathology samples requiring second opinions.

FINDINGS

A total of 500 cases were discussed via teleconsultations during the study period. The median patient age was 7 years (range, 24 days to 16·4 years), and the cases comprised 79 benign tumors, 299 leukemias, 120 lymphomas, and 97 solid tumors. The teleconsultation sessions yielded 27 diagnostic changes, 123 confirmed diagnoses, and 13 equivocal impacts. The pathology reviews by SUR were concordant for 996 (81·9%) cases, discordant for 186 (15·3%), and inconclusive for 34 (2·8%). The major cause of discordance was inadequate immunohistochemical staining. The percentage of discordance markedly decreased over time (from 40% to 10%). The cause of the improvement is multifactorial: training of two CWTH pathologists at SUR, better immunohistochemical staining, and the ongoing clinical and pathologic telemedicine activities. The partnership yielded 12 publications, six posters, and three oral presentations by CWTH investigators.

INTERPRETATION

The exchange of knowledge and expertise across continental boundaries meaningfully improved the diagnoses and management of pediatric cancer at CWTH.

LINC-21. PROGNOSTIC FACTORS AND SURVIVAL OF LOW-GRADE GLIOMAS IN CHILDREN AND ADOLESCENTS – A MULTICENTER STUDY IN PERU

BACKGROUND: Low-grade gliomas (LGG) are the most common central nervous system (CNS) tumors in children. Peru is an index country for the Global Initiative for Childhood Cancer (GICC). As part of the Initiative, a multidisciplinary brain tumor team was formed in 2020 that includes five national reference centers: National Institute of Neoplastic Diseases, National Children’s Health Institute-San Borja, National Children’s Health Institute-Breña, Edgardo Rebagliati Martins National Hospital and Guillermo Almenara Irigoyen National Hospital. This multicenter study sought to evaluate the survival and prognostic factors of patients younger than 18 years diagnosed with LGG, an index cancer for the GICC. METHODS: A retrospective study included all patients diagnosed with LGG in the five centers between 2014 and 2018. We analyzed clinical characteristics, histology, and treatment modalities. We used the Kaplan-Meier method for survival. RESULTS: 194 patients were registered; 136 patients were included. M/F ratio was 1.2, mean age 7 years old. The most frequent location was infratentorial (42.2%), supratentorial (34.9%), optic/chiasm/sellar (11%) and brainstem (11.9%). The most frequent histological types were pilocytic astrocytoma (61%), diffuse astrocytoma (10.3%), oligodendroglioma (5.2%), and other low-grade neoplasms (23.5%). Surgery was performed in 109 patients (83.2%). Chemotherapy alone was used in 17 (12.5%), while radiotherapy in 20 (14.7%). Overall survival at 5 years was 82.9% (95% CI 73.3 - 89.4). Age younger than 3 years (p=0.002), diffuse histological type (p=0.04), and location in the brainstem (p=0.001) were factors associated with a worse prognosis. CONCLUSIONS: Within the framework of the GICC, this work is one of the first steps to understand the current context of pediatric CNS tumor care in Peru. Although the reported survival rate is about the GICC goal of 60%, further improvements in care are needed to increase survival to level closer to high-resource setting and decrease long term morbidity.

Correlation of clinical and radiological predictors of retinoblastoma with high-risk histopathological features

INTRODUCTION

Retinoblastoma (RB) tumors having high-risk histopathologic features (HRFs) have an increased risk of metastasis and disease relapse. However, RB has not been studied widely in Pakistan. Therefore, we evaluated the association of clinical, histopathologic, and radiological findings with HRFs in patients with RB who were treated at the Indus Health & Hospital Network in Karachi, Pakistan.

METHODS

We enrolled treatment-naïve patients with RB who received upfront enucleation from September 2017 to February 2021. We evaluated enucleated eyes with the Intraocular Classification of Retinoblastoma system and classified HRFs as invasion of the anterior chamber, including the iris and ciliary body, or massive invasion of the choroid, sclera, or optic nerve (postlaminar and/or up to the transection line).

RESULTS

Of 117 patients with RB treated at our institution during the study period, 54 received upfront enucleation. Unilateral disease was present in 92.6% of cases. The most frequent disease signs and symptoms included the presence of vitreous seeds (30.6%) and leukocoria (100%), respectively. The most frequent HRFs and radiological findings comprised massive choroidal invasion (15.1%) and anterior chamber enhancement (66.7%), respectively. The majority (62.9%) of patients did not exhibit any HRFs. Female sex, pseudohypopyon, iris neovascularization, buphthalmos, and glaucoma had significant predictive ability for HRF occurrence.

CONCLUSION

Pseudohypopyon, iris neovascularization, buphthalmos, and glaucoma are important clinical factors that should be taken into consideration before the management of RB. Early recognition of high-risk histopathological and radiological features is essential for appropriate treatment of RB.

Psychiatric symptoms in children with low-grade glioma and craniopharyngioma: A systematic review

The presentation of psychiatric symptoms in pediatric low-grade brain tumors is challenging because this can delay proper diagnosis and treatment. We performed a systematic review of psychiatric presenting symptoms of low-grade brain tumors in pediatric patients. We searched the PubMed and Web of Science databases of studies published in English from 1977 until 2019 reporting patients aged ≤21 years at the time of tumor diagnosis who exhibited psychiatric/behavioral symptoms before diagnosis of low-grade glioma (LGG), pilocytic astrocytoma (PA), or craniopharyngioma (CP). Our systematic search strategy coupled each tumor type with patient age and presenting symptoms by using different variations of the search terms "childhood" and "psychiatric symptoms" or "behavioral symptoms." We identified six unique articles that met our inclusion criteria in the LGG search, 27 in the PA search, and 32 in the CP search. Six patients were included in the LGG articles (age range, 3-16 years), 75 in the PA articles (age range, 0.5-21 years), and 87 in the CP articles (age range, 0.67-21 years). The most common presenting symptoms included eating disorders (n = 64) and behavioral changes (n = 49). Our findings demonstrate the need to establish clear criteria for neuroimaging indications for pediatric patients exhibiting eating disorders.

A Proposal for Future Modifications on Clinical TNM Staging System of Retinoblastoma Based on the American Joint Committee on Cancer Staging Manual, 7th and 8th Editions

Importance: The 8^th edition of the American Joint Committee on Cancer (AJCC) staging manual incorporated new changes from its 7^th edition for classifying retinoblastoma (RB).

Objective: We assessed the comparative prognostic values of the 7^th and 8^th editions of the AJCC clinical (cTNM) staging manuals for RB and suggested modifications for future edition accordingly.

Design: A retrospective, observational study.

Setting: King Hussein Cancer Centre.

Participants: A cohort of 478 patients and 565 eyes with RB.

Main Outcomes and Measures: Main outcome measures included demographics; tumor features, AJCC cTNM stage, and eye salvage rates. The prognostic performance of the different staging systems was assessed with the concordance index (C-index) and likelihood ratio χ² tests.

Results: The overall eye salvage rate was 65%. Stage migration occurred for 330 (48%) eyes with the AJCC Staging Manual, 8^th edition. Based on the 7^th edition AJCC staging, the eye salvage rate was 94% (n=177) for T1 tumors (98% for T1a, 93%for T1b, and 90%for T1c), 69% (n=204) for T2 tumors (73% for T2a and 62%for T2b), and 51% (n=40) for T3 tumors. Based on the 8^th edition AJCC staging, the eye salvage rate was 95% (n=139) for T1 tumors (98% for T1a and 93% for T1b), 68% (n=281) for T2 tumors (90%for T2a and 66%for T2b), and 12% (n=1) for T3 tumors. With our proposed cTNM modifications, the eye salvage rate was 94% (n=177) for T1 tumors (98%for T1a, 93%for T1b, and 90% for T1c), 66% (n=243) for T2 tumors (73% for T2a, 62% for T2b, and 55% for T2c), and 12% (n=1) for T3 tumors. As estimated by odds ratios, more advanced cTNM stage (regardless of the cTNM staging system) was significantly associated with an increased chance of treatment failure (P < .0001). The C-index for both the 8^th edition and the proposed modifications were approximately equal, and both were higher than that of the 7^th edition. However, the proposed modifications had the highest likelihood ratio χ² value and the best bootstrap 95% confidence interval.

Conclusions and Relevance: Our proposed modifications on the clinical TNM Staging System for RB harbor more detailed subgroup classification criteria that provides better prognostic value for eye globe salvage than the published similar (but not identical) AJCC Staging Manual, 7^th and 8^th editions, furthermore these modifications may resolve the discrepancies in the previously published different classification systems for RB.

Barriers to Care and Outcomes of Pediatric Acute Lymphoblastic Leukemia Treatment in the Gaza Strip

BACKGROUND

Childhood acute lymphoblastic leukemia (ALL) is the most common pediatric cancer worldwide. Although children in high-income countries enjoy survival rates of ~90%, children in countries with limited resources suffer from survival rates of <35%. No published data on pediatric cancer incidence, management, or outcomes in the Gaza Strip are available.

METHODS

A retrospective cohort study was undertaken for pediatric (below 12 y of age) ALL diagnoses admitted to the only pediatric cancer ward in the Gaza Strip between 2010 and 2015. Outcomes included event-free survival (EFS) and overall survival (OS) calculated by Kaplan-Meier estimates. Events were defined as induction failure, relapse, and death.

RESULTS

The 3-year EFS estimate was 80% (95% confidence interval [CI], 66%-89%). The EFS at 1 and 3 years for high-risk ALL was 55% (95% CI, 27%-76%) and 23% (95% CI, 4%-51%), respectively. The 3-year OS was 93% (95% CI, 82%-97%). The 3-year OS for high-risk ALL was 69% (95% CI, 30%-90%). All 84 (100%) patients required referral to an outside hospital for definitive ALL diagnoses and induction therapy. Forty-four (52%) patients required at least one additional referral.

CONCLUSIONS

The overall outcomes demonstrated relatively high survival rates at 3 years which may be artificially elevated due to exclusion of adolescents, limited follow up, and deceased patient charts unavailable. Structural determinants of health in Gaza lead to limited diagnostic and treatment capabilities, limited access to advanced medical training, and reliance on out-of-territory transfers for care. These barriers impact the access to comprehensive pediatric care within the Gaza Strip.

Treatment and outcomes of pediatric patients with cancer and COVID-19 at MAHAK pediatric cancer treatment and research center, Tehran, Iran

The COVID-19 pandemic has been particularly devastating for Iran. Children with cancer are generally immunosuppressed and especially vulnerable to SARS-CoV-2 infections. We report the treatment and outcomes of pediatric oncology patients with COVID-19 at the MAHAK Pediatric Cancer Treatment and Research Center (MPCTRC) in Tehran. We enrolled pediatric oncology patients who experienced SARS-CoV-2 infections from March 18, 2020, to January 28, 2021. The COVID-19 diagnostic criteria at MPCTRC were based on imaging and clinical presentation because of specific challenges diagnosing SARS-CoV-2 infections with molecular testing, which was locally developed and conducted at centers other than MPCTRC. We enrolled nine outpatients and eight inpatients (mean age = 9 years), seven of whom had a diagnosis of leukemias, and five who had brain tumors. COVID-19 symptoms were mild in fourteen patients, and three patients were asymptomatic. Of twelve patients who received molecular testing for SARS-CoV-2 infection, eight were negative and four were positive. Of nine patients tested for IgG and IgM antibodies, one was positive. Three patients died of COVID-19, all of whom were hospitalized. Mild COVID-19 symptoms did not appear to affect the outcomes of the pediatric patients with cancer who received treatment at MPCTRC during the study period.

Follow-up evaluation of a web-based pediatric brain tumor board in Latin America

BACKGROUND

Since 2013, pediatric oncologists from Central and South America discuss neuro-oncology cases with experts from North America and Europe in a web-based "Latin American Tumor Board" (LATB). Here, we evaluate the feasibility of recommendations rendered by the Board.

METHODS

An electronic questionnaire was distributed to physicians who had received recommendations between October 2017 and October 2018. Physicians were asked regarding the feasibility of each recommendation given during the LATB discussion. Baseline case characteristics of all presented cases were obtained from anonymized minutes.

RESULTS

Of the 142 patients discussed, data on 103 patients from 15 countries were available, corresponding to 283 recommendations. Physicians followed 60% of diagnostic procedural recommendations and 69% of therapeutic recommendations. The most difficult recommendations to follow were genetic and molecular testing, pathology review, chemotherapy, surgery, and molecular targeted therapies. Histological diagnoses changed in eight of 18 cases in which a pathology review was undertaken. Fifty-four percent of the recommendations that could not be implemented were considered not feasible in the specific context of the patient, while 31% were not implemented due to a decision of the medical staff or the parents (15% not specified). However, 96% of respondents considered the recommendations useful.

CONCLUSION

Recommendations were frequently perceived as useful, and were applicable in the participating institutions. Nevertheless, limitations in availability of diagnostic procedures and treatment modalities affected the feasibility of some recommendations. Tele-oncology tumor boards offer physicians from low- and middle-income countries access to real-time, high-level subspecialist expertise and provide a valuable platform for worldwide information exchange.

[11C]-Methionine PET for Identification of Pediatric High-Grade Glioma Recurrence

Differentiating tumor recurrence or progression from pseudoprogression during surveillance of pediatric high-grade gliomas (PHGGs) using MRI, the primary imaging modality for evaluation of brain tumors, can be challenging. The aim of this study was to evaluate whether ¹¹C-methionine PET, a molecular imaging technique that detects functionally active tumors, is useful for further evaluating MRI changes concerning for tumor recurrence during routine surveillance. Methods: Using ¹¹C-methionine PET during follow-up visits, we evaluated 27 lesions in 26 patients with new or worsening MRI abnormalities for whom tumor recurrence was of concern. We performed quantitative and qualitative assessments of both ¹¹C-methionine PET and MRI data to predict the presence of tumor recurrence. Further, to assess for an association with overall survival (OS), we plotted the time from development of the imaging changes against survival. Results: Qualitative evaluation of ¹¹C-methionine PET achieved 100% sensitivity, 60% specificity, and 93% accuracy to correctly predict the presence of tumors in 27 new or worsening MRI abnormalities. Qualitative MRI evaluation achieved sensitivity ranging from 86% to 95%, specificity ranging from 40% to 60%, and accuracy ranging from 85% to 89%. The interobserver agreement for ¹¹C-methionine PET assessment was 100%, whereas the interobserver agreement was only 50% for MRI (P < 0.01). Quantitative MRI and ¹¹C-methionine PET evaluation using receiver-operating characteristics demonstrated higher specificity (80%) than did qualitative evaluations (40%–60%). Postcontrast enhancement volume, metabolic tumor volume, tumor-to-brain ratio, and presence of tumor as determined by consensus MRI assessment were inversely associated with OS. Conclusion:¹¹C-methionine PET has slightly higher sensitivity and accuracy for correctly predicting tumor recurrence, with excellent interobserver agreement, than does MRI. Quantitative ¹¹C-methionine PET can also predict OS. These findings suggest that ¹¹C-methionine PET can be useful for further evaluation of MRI changes during surveillance of previously treated PHGGs.

Evaluation of the Pediatric Neuro-Oncology Resources Available in Chile

PURPOSE

Pediatric neuro-oncology resources are mostly unknown in Chile. We report the human and material resources available in Chilean hospitals providing pediatric neuro-oncology services.

METHODS

A cross-sectional survey was distributed to 17 hospitals providing pediatric neuro-oncology services (Programa Infantil Nacional de Drogas Antineoplásicas [PINDA] hospitals, 11; private, 6).

RESULTS

Response rate was 71% (PINDA, 8; private, 4). Pediatric neuro-oncology services were mainly provided within general hospitals (67%). Registries for pediatric CNS tumors and chemotherapy-related toxicities were available in 100% and 67% of hospitals, respectively. CNS tumors were treated by pediatric oncologists in 92% of hospitals; none were formally trained in neuro-oncology. The most used treatment protocols were the national PINDA protocols. All WHO essential medicines for childhood cancer were available in more than 80% of the hospitals except for gemcitabine, oxaliplatin, paclitaxel, and procarbazine. The median number of pediatric neurosurgeons per hospital was two (range, 2-6). General neuroradiologists were available in 83% of the centers. Pathology specimens were sent to neuropathologists (58%), adult pathologists (25%), and pediatric pathologists (17%). Intensity-modulated radiotherapy, conformal radiotherapy, and cobalt radiotherapy were used by 67%, 58%, and 42% of hospitals, respectively. Only one private hospital performed autologous hematopoietic cell transplant for children with CNS tumors.

CONCLUSION

A wide range of up-to-date treatment modalities are available for children with CNS tumors. Our survey highlights future directions to improve the pediatric neuro-oncology services available in Chile such as the expansion of multidisciplinary clinics, palliative care services, long-term cancer survivorship programs, dedicated clinical research support teams, establishing standardized mechanism for sending pathologic specimen for second opinion to international specialized centers, and establishing specialized neuro-oncology training program.

The Predictive Value of the Eighth Edition of the Clinical TNM Staging System for the Likelihood of Eye Salvage for Intraocular Retinoblastoma by Systemic Chemotherapy and Focal Therapy

BACKGROUND

The American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) cTNM staging is emerging as a universal staging for all cancers, including retinoblastoma.

METHODS

Here we evaluated the predictive value of the eighth edition AJCC/UICC cTNM staging in comparison with the International Intraocular Retinoblastoma Classification for eye globe salvage by primary systemic chemotherapy and focal therapy (CRD) using logistic regression model for the probability of treatment failure.

RESULTS

The eye salvage rate for 565 treated eyes was 95% (n=139/147) for T1 tumors (98% for T1a and 93% for T1b), 56% (n=230/410) for T2 (81% for T2a and 53% for T2b), and 0% for T3 tumors, and was 98%, 93%, 76%, and 44% for group A, B, C, and D tumors, respectively. As estimated by odds ratios, T2 were 13.6-fold more likely to fail treatment than T1, and T1b, T2a, and T2b were 2.8-, 9.4-, and 35.1-fold more likely to fail treatment than T1a, respectively. Group B, C, and D tumors were 2.8-, 12.7-, and 50.1-fold more likely to fail treatment than group A tumors, respectively. Eye salvage rate was 62% for eyes with focal seeds (3 mm close to the tumor), and 42% for eyes with diffuse seeds (clouds more than 3 mm from tumor edge) (P<0.0001).

CONCLUSION

Both, the eighth edition cTNM classification and the International Intraocular Retinoblastoma Classification systems, can effectively predict eye salvage rates for retinoblastoma by CRD. Eyes with higher cT stages are more likely to experience treatment failure. Because the cT2b group is very heterogeneous, our findings suggest further division of this group based on the severity of vitreous/subretinal seeds, this should be revised in the next edition of cTNM system.

Patient-derived models recapitulate heterogeneity of molecular signatures and drug response in pediatric high-grade glioma

Pediatric high-grade glioma (pHGG) is a major contributor to cancer-related death in children. In vitro and in vivo disease models reflecting the intimate connection between developmental context and pathogenesis of pHGG are essential to advance understanding and identify therapeutic vulnerabilities. Here we report establishment of 21 patient-derived pHGG orthotopic xenograft (PDOX) models and eight matched cell lines from diverse groups of pHGG. These models recapitulate histopathology, DNA methylation signatures, mutations and gene expression patterns of the patient tumors from which they were derived, and include rare subgroups not well-represented by existing models. We deploy 16 new and existing cell lines for high-throughput screening (HTS). In vitro HTS results predict variable in vivo response to PI3K/mTOR and MEK pathway inhibitors. These unique new models and an online interactive data portal for exploration of associated detailed molecular characterization and HTS chemical sensitivity data provide a rich resource for pediatric brain tumor research.

Conduct of neuro-oncology multidisciplinary team meetings and closing the "gaps" in the clinical management of childhood central nervous system tumors in a middle-income country

PURPOSE

Multidisciplinary team meetings (MDTMs) are essential in the clinical management of pediatric central nervous system (CNS) tumors. Evaluations of the impact of MDTMs on childhood CNS tumors and clinicians' perspectives on their effectiveness are scarce.

METHODS

We retrospectively reviewed the clinical data of pediatric patients (aged <18 years) with CNS tumors diagnosed and treated in the Pediatric Hematology-Oncology Division at the University Malaya Medical Center from 2008 to 2019. We also conducted a web-based survey of the core members of the multidisciplinary team to evaluate the impact of the MDTMs.

RESULTS

During the pre-MDTM era (2008-2012), 29 CNS tumors were diagnosed and treated, and during the MDTM era (2014-2019), 49 CNS tumors were diagnosed and treated. The interval for histologic diagnosis was significantly shorter during the MDTM era (p=0.04), but the interval from diagnosis to chemotherapy or radiotherapy and the 5-year overall survival of the 78 patients did not improve (62.1% ± 9.0% vs. 68.8% ± 9.1%; p=0.184). However, the 5-year overall survival of patients with medulloblastoma or rare tumors significantly improved in the MDTM era (p=0.01). Key factors that contributed to delayed treatment and poor outcomes were postoperative complications, the facility's lack of infrastructure, poor parental education about early treatment, cultural beliefs in alternative medicine, and infection during chemotherapy. Eighteen clinicians responded to the survey; they felt that the MDTMs were beneficial in decision-making and enhanced the continuity of coordinated care.

CONCLUSION

MDTMs significantly reduced the diagnostic interval and improved the overall outcomes. However, delayed treatment remains a major challenge that requires further attention.

Cognitive and Adaptive Functioning in Youth With Retinoblastoma: A Longitudinal Investigation Through 10 Years of Age

PURPOSE

To describe the trajectory of cognitive and adaptive functioning in pediatric patients with retinoblastoma from diagnosis through age 10. This is an extension of a previous report that discussed findings from diagnosis through age 5.

PATIENTS AND METHODS

Ninety-eight participants with retinoblastoma completed psychological assessments as part of their enrollment on an institutional treatment protocol, with 73 completing an additional assessment at age 10. Trajectories of adaptive and cognitive functioning were determined, with data analyzed by treatment strata, and patients with 13q- analyzed separately.

RESULTS

Longitudinal trajectories identified a significant change point in trends at age 5, with functioning declining from diagnosis through age 5 and then increasing from age 5 to age 10. This pattern was observed for all strata for adaptive functioning, but only for enucleation-only patients (strata C low) for cognitive functioning. Cognitive trajectories were also influenced by laterality and enucleation status. At age 10, overall functioning was generally within the average range, although estimated intelligence quotient was significantly below the normative mean for enucleation-only (C low) patients. Patients with 13q- demonstrated very low functioning, but few analyses were significant because of small sample size.

CONCLUSION

The results generally indicate that previously demonstrated declines in functioning from diagnosis through age 5 improve by age 10. However, these early declines, as well as the continuous difficulties observed in patients treated with enucleation only, suggest the need for early intervention services for young patients with retinoblastoma. Continuous monitoring of the psychological functioning of patients with retinoblastoma, increased awareness of risk factors such as unilateral disease, enucleation, race, and surgery-only treatment plans, and referral to Early Intervention for all patients are indicated.

Risk stratification in pediatric low-grade glioma and glioneuronal tumor treated with radiation therapy: an integrated clinicopathologic and molecular analysis

BACKGROUND

Management of unresectable pediatric low-grade glioma and glioneuronal tumor (LGG/LGGNT) is controversial. There are no validated prognostic features to guide use of radiation therapy (RT). Our study aimed to identify negative prognostic features in patients treated with RT using clinicopathologic and molecular data and validate these findings in an external dataset.

METHODS

Children with non-metastatic, biopsy-proven unresectable LGG/LGGNT treated with RT at a single institution between 1997 and 2017 were identified. Recursive partitioning analysis (RPA) was used to stratify patients into low- and high-risk prognostic groups based on overall survival (OS). CNS9702 data were used for validation.

RESULTS

One hundred and fifty patients met inclusion criteria. Median follow-up was 11.4 years. RPA yielded low- and high-risk groups with 10-year OS of 95.6% versus 76.4% (95% CI: 88.7%-98.4% vs 59.3%-87.1%, P = 0.003), respectively. These risk groups were validated using CNS9702 dataset (n = 48) (4-year OS: low-risk vs high-risk: 100% vs 64%, P < 0.001). High-risk tumors included diffuse astrocytoma or location within thalamus/midbrain. Low-risk tumors included pilocytic astrocytoma/ganglioglioma located outside of the thalamus/midbrain. In the subgroup with known BRAF status (n = 49), risk stratification remained prognostic independently of BRAF alteration (V600E or fusion). Within the high-risk group, delayed RT, defined as RT after at least one line of chemotherapy, was associated with a further decrement in overall survival (P = 0.021).

CONCLUSION

A high-risk subgroup of patients, defined by diffuse astrocytoma histology or midbrain/thalamus tumor location, have suboptimal long-term survival and might benefit from timely use of RT. These results require validation.

Relevance of Molecular Groups in Children with Newly Diagnosed Atypical Teratoid Rhabdoid Tumor: Results from Prospective St. Jude Multi-institutional Trials

PURPOSE

Report relevance of molecular groups to clinicopathologic features, germline SMARCB1/SMARCA4 alterations (GLA), and survival of children with atypical teratoid rhabdoid tumor (ATRT) treated in two multi-institutional clinical trials.

MATERIALS AND METHODS

Seventy-four participants with newly diagnosed ATRT were treated in two trials: infants (SJYC07: age < 3 years; n = 52) and children (SJMB03: age 3-21 years; n = 22), using surgery, conventional chemotherapy (infants), or dose-dense chemotherapy with autologous stem cell rescue (children), and age- and risk-adapted radiotherapy [focal (infants) and craniospinal (CSI; children)]. Molecular groups ATRT-MYC (MYC), ATRT-SHH (SHH), and ATRT-TYR (TYR) were determined from tumor DNA methylation profiles.

RESULTS

Twenty-four participants (32%) were alive at time of analysis at a median follow-up of 8.4 years (range, 3.1-14.1 years). Methylation profiling classified 64 ATRTs as TYR (n = 21), SHH (n = 30), and MYC (n = 13), SHH group being associated with metastatic disease. Among infants, TYR group had the best overall survival (OS; P = 0.02). However, outcomes did not differ by molecular groups among infants with nonmetastatic (M0) disease. Children with M0 disease and <1.5 cm² residual tumor had a 5-year progression-free survival (PFS) of 72.7 ± 12.7% and OS of 81.8 ± 11%. Infants with M0 disease had a 5-year PFS of 39.1 ± 11.5% and OS of 51.8 ± 12%. Those with metastases fared poorly [5-year OS 25 ± 12.5% (children) and 0% (infants)]. SMARCB1 GLAs were not associated with PFS.

CONCLUSIONS

Among infants, those with ATRT-TYR had the best OS. ATRT-SHH was associated with metastases and consequently with inferior outcomes. Children with nonmetastatic ATRT benefit from postoperative CSI and adjuvant chemotherapy.

A Phase 2 Trial of Selumetinib in Children with Recurrent Optic Pathway and Hypothalamic Low-Grade Glioma without NF1: A Pediatric Brain Tumor Consortium Study

BACKGROUND

Pediatric low-grade gliomas (pLGGs) are the most common childhood brain tumor. Progression-free survival (PFS) is much lower than overall survival, emphasizing the need for alternative treatments. Sporadic (without neurofibromatosis type-1) optic pathway and hypothalamic glioma (OPHGs) are often multiply recurrent and cause significant visual deficits. Recently, there has been a prioritization of functional outcomes.

METHODS

We present results from children with recurrent/progressive OPHGs treated on a PBTC phase 2 trial evaluating efficacy of selumetinib, (AZD6244, ARRY-142886) a MEK-1/2 inhibitor. Stratum 4 of PBTC-029 included patients with sporadic recurrent/progressive OPHGs treated with selumetinib at the recommended phase 2 dose (25mg/m 2 /dose BID) for a maximum of 26 courses.

RESULTS

Twenty-five eligible and evaluable patients were enrolled with a median of 4 (1-11) previous therapies. Six of 25 (24%) had partial response, 14/25 (56%) had stable disease and 5 (20%) had progressive disease while on treatment. The median treatment courses were 26 (2-26); 14/25 patients completed all 26 courses. Two-year PFS was 78 ± 8.5%. Nineteen of 25 patients were evaluable for visual acuity which improved in 4/19 patients (21%), was stable in 13/19 (68%) and worsened in 2/19 (11%). Five of 19 patients (26%) had improved visual fields and 14/19 (74%) were stable. The most common toxicities were grade 1/2 CPK elevation, anemia, diarrhea, headache, nausea/emesis, fatigue, AST and ALT increase, hypoalbuminemia and rash.

CONCLUSIONS

Selumetinib was tolerable and led to responses and prolonged disease stability in children with recurrent/progressive OPHGs based upon radiographic response, PFS and visual outcomes.

Handedness switching as a presenting sign for pediatric low-grade gliomas: An insight into brain plasticity from a short case series

PURPOSE

To describe clinical data, rehabilitation services, and outcomes of children with handedness switching as their presenting symptom before low-grade glioma (LGG) diagnosis.

METHODS

A retrospective chart review was performed for five patients (four female and four white) with LGG and confirmed handedness switching before LGG diagnosis.

RESULTS

All children were less than 8 years at diagnosis, and two patients were less than 3 years. All children were initially right-handed and experienced loss of motor function, ranging from weakness to paresis, in their dominant hand. The median time from switching handedness to diagnosis was 1 month (range: 0.75-60 months). Rehabilitation was offered for three patients, and motor function deficits in the initial dominant hand were resolved in two of the total cohort. At long-term follow-up, hand dominance returned to the initial hand in three patients.

CONCLUSIONS

Handedness switching should be acknowledged as a potential sign of LGG in children, and early long-term rehabilitation services should be offered for these children.

LINC-35. THE ST. JUDE GLOBAL ACADEMY NEURO-ONCOLOGY TRAINING SEMINAR: A MULTIDISCIPLINARY, INTERNATIONAL EDUCATION PROGRAM

The success of the treatment of children with central nervous system (CNS) tumors relies on an effective multidisciplinary team, with up-to-date and broad knowledge and skills. The St. Jude Global Academy Neuro-Oncology Training Seminar was launched as course in globally applicable content in pediatric neuro-oncology with a focus on multidisciplinary teams in low- and middle-income countries (LMICs). To identify the content that is most relevant for the learners, a needs assessment survey that included evaluation of team dynamics, treatment capacity, existing knowledge, and educational goals was designed. Survey questions in 11 domains were answered by 24 sites in LMICs across the world. This information was used to create the course that consists of two components: a 9-week online course and a 10-day workshop at the St. Jude campus. 72 participants from 11 institutions enrolled in the online portion and 20 participants were selected based on grades to attend the workshop. A retrospective post-test evaluation established that learners improved their understanding of the barriers to care, possible solutions to improve care, understanding of diagnosis and treatment, and methodology to implement projects (p<0.01). All participating teams developed projects that are locally implemented. Those present at the workshop formed a multidisciplinary, international collaborative group (Global Alliance in Pediatric Neuro-Oncology). This experience establishes that educational programs with systematically created curricula can not only improved knowledge but be a mechanism to share experiences and create collaborative networks. Ultimately, patient outcomes will be tracked to monitor the true impact of the course.

LINC-18. FOLLOW-UP EVALUATION OF A WEB-BASED PEDIATRIC BRAIN TUMOR BOARD IN LATIN AMERICA

BACKGROUND

Since 2013, pediatric oncologists from Latin America have discussed neuro-oncology cases with experts from North America and Europe in a web-based “Latin American Tumor Board” (LATB). This descriptive study evaluates the feasibility of the recommendations rendered during the Board.

METHODS

An electronic questionnaire was distributed to physicians who received recommendations between October 2017 and October 2018, two months after their case presentation on the LATB. Physicians were asked regarding the feasibility of each recommendation given during the Board. Baseline case characteristics of all presented cases were obtained from anonymized minutes prepared after the presentations.

RESULTS

36 physicians from 15 countries answered 103 of 142 questionnaires (72.5%), containing 283 recommendations. Physicians followed 60% of diagnostic procedural recommendations and 70% of therapeutic recommendations. Overall, 96% of respondents considered the recommendations applicable and useful. The most difficult recommendations to follow were genetic and molecular testing, pathology review, locally adapted chemotherapy protocols administration, neurosurgical interventions and access to molecular targeted therapies. The most cited reasons for not implementing the recommendations were lack of resources, inapplicable recommendations to that low-to-middle income country (LMIC) setting, and lack of parental consent.

CONCLUSION

The recommendations given on the LATB are frequently applicable and helpful for physicians in LMIC. Nevertheless, limitations in availability of both diagnostic procedures and treatment modalities affected the feasibility of some recommendations. Virtual tumor boards offer physicians from LMIC access to real time, high-level subspecialist expertise and provide a valuable platform for information exchange among physicians worldwide.

LINC-23. PRE-OPERATIVE AND POST-OPERATIVE INTERVENTIONS REDUCE RATES OF VENTRICULITIS IN PEDIATRIC BRAIN TUMOR PATIENTS: A PILOT STUDY

BACKGROUND

The Philippine General Hospital, a public national referral center, sees 60–80 pediatric brain tumor cases per year. Historically, the rate of post-operative ventriculitis has been high, resulting in treatment delays and poor outcomes. Starting in July 2019, as a means to decrease infections, patients were provided standardized bathing and wound care kits and caregivers were trained to follow a bathing and wound care protocol.

METHODS

This quality improvement study included patients younger than 18 years who underwent craniotomy at PGH were enrolled. The type of surgery, length of surgery, existence of post-operative CNS infection, length of stay and total cost of care was collected. The outcome of these interventions are analyzed 6 months after implementation.

RESULTS

Thirty-two 32 patients were included, with mean age of 7 years (1–16). The surgeries performed were: tumor resection (n=20), ventriculo-peritoneal shunt insertion (VPS) (n=3), endoscopic third ventriculostomy (n=3), resection with tube ventriculostomy (n=3), Ommaya reservoir placement (n=2), and resection with shunt (n=1). Median surgery time was 4 hours (1–10). Three patients (9.4%) developed ventriculitis. No surgical site infections occurred. Compared to historical controls, a lower rate of infections was noted (9.4% vs. 15.5%, runchart analysis). Patients without post-operative infections had a shorter length of stay (median 14 vs 48 days, p&lt;0.05) and a lower cost of care (median $1098 vs. $2425 USD, p&lt;0.05).

CONCLUSION

Implementation of simple hygiene interventions effectively lowered post-operative CNS infections and hospital costs in a public hospital setting. Incorporation of these into standard clinical practices is urgently needed.

LINC-11. NEUROPATHOLOGY REVIEW OF LATIN AMERICAN CHILDHOOD AND ADOLESCENT BRAIN TUMOR PATIENTS: A MULTI-NATIONAL, MULTI-DISCIPLINARY PEDIATRIC NEURO-ONCOLOGY TELECONFERENCE EXPERIENCE

BACKGROUND

Pediatric brain tumor classification has undergone significant evolution over the last decade requiring a high-level of expertise and diagnostic techniques. Such advances have created challenges for pathologists particularly in low-to-middle income countries (LMIC). We conduct weekly pediatric neuro-oncology teleconferences linking global pediatric neuro-oncologists from high-income countries (HIC) to review patients with pediatric subspecialists from Latin America.

METHODS

Three to five patients are discussed weekly and second neuropathology review is offered when a high-level of suspicion emerges of a questionable diagnosis based on clinical and radiographical information. Nationwide Children’s Hospital (NCH) provides second neuropathology review at no cost to institutions in Latin America that fulfill these criteria.

RESULTS

From July 2015 to December 2019 NCH reviewed 54 pathology samples from eleven Latin American countries. Of these, 33 (61.1%) cases resulted in diagnostic changes, of which 28 (51.8%) were significant, impacting treatment plans and overall patient outcomes. The remaining 21 (38.9%) confirmed institutional diagnosis; however, in eight of these 21 cases additional molecular information and/or further tumor subtyping unavailable in their home country at the time (eg: BRAF, RELA-fusion, medulloblastoma subtyping) was provided.

CONCLUSIONS

This study highlights the importance of centralized pathology review by institutions with the proper equipment, infrastructure and expertise in pediatric neuropathology. Furthermore, this documents the beneficial impact of teleconferencing for subspecialists in LMIC who must treat a wide variety of pediatric cancers with few resources and support. Additionally, our findings underscore the need for pediatric subspecialty training in LMIC.

EPID-07. A GLOBAL PERSPECTIVE ON THE BURDEN OF PEDIATRIC CENTRAL NERVOUS SYSTEM TUMORS

Although approximately 90% of pediatric cancer cases exist in low- and middle-income countries, the magnitude of the global burden of pediatric central nervous system (CNS) tumors remains poorly quantified. METHODS: Data from International Incidence of Childhood Cancer-3 and CONCORD-3, which include observed incidence and survival from population-based cancer registries (PBCR), and from GLOBOCAN 2018 and Global Burden of Disease 2016, which produce burden estimates from observed and modelled data, were used to analyze epidemiologic characteristics and correlations for CNS tumors globally. Data from The World Bank were used for national macroeconomic variables. RESULTS: The majority of countries are not covered by PBCR, with information on incidence and survival available for 37% and 27% of countries, respectively. Survival data is not available for any low-income country. The incidence of CNS tumors varies markedly, from 0.4 to 49 x106 person-years, the greatest variability in pediatric cancer subgroups. Modelled data suggests that approximately 40,000 incident cases and 19,000 deaths occur from CNS tumors worldwide. When country-level data are segregated based on World Bank groups, a difference in incidence and survival exists (p&lt;0.05). A higher national health expenditure correlates with both an increased incidence and survival of CNS tumors, while the inverse is true for under-5 mortality (p&lt;0.05). CONCLUSIONS: Scarce facts are available, but this analysis establishes a link between national income and epidemiologic parameters for CNS tumors. In this context, carefully designed initiatives, focusing on a health-systems approach are critical to meet the global challenge of pediatric CNS tumors.

LINC-21. SURVEY ON THE RESOURCES AVAILABLE FOR PEDIATRIC NEURO-ONCOLOGY IN CHILE, SOUTH AMERICA

BACKGROUND

We report the human and material resources available in Chilean institutions providing pediatric neuro-oncology services.

METHODS

A cross-sectional survey was distributed to 17 hospitals providing pediatric neuro-oncology services (Programa Infantil Nacional de Drogas Antineoplásicas (PINDA) centers=11, Private=6).

RESULTS

Response rate was 71% (PINDA=8; Private=4). Pediatric neuro-oncology services were mainly provided within general hospitals (67%). Registries for pediatric central nervous system (CNS) tumors and chemotherapy-related toxicities were available in 100% and 67% of centers, respectively. Children with CNS tumors were treated by pediatric oncologists in 92% of institutions; none were formally trained in neuro-oncology. The most utilized treatment protocols were the national PINDA protocols followed by the Children’s Oncology Group protocols. All World Health Organization essential medicines for childhood cancer were available in more than 80% of participating institutions except for gemcitabine, oxaliplatin, paclitaxel, and procarbazine. The median number of pediatric neurosurgeons per institution was two (range,0–8). General neuro-radiologists were available in 83% of institutions. Pathology specimens were sent to pediatric neuropathologists (33%), neuropathologists (25%), adult pathologists (25%), and pediatric pathologists (16.7%). In-house pediatric radiation oncologists were available in 25% of centers. Intensity-modulated radiotherapy, conformal radiotherapy and cobalt radiotherapy were utilized by 67%, 58% and 42% of hospitals, respectively. Only one center performed autologous hematopoietic cell transplant for pediatric CNS tumors.

CONCLUSIONS

These results provide a glimpse into the pediatric neuro-oncology services available in Chile. A wide range of up-to-date treatment modalities is available for children with CNS tumors in Chile. Establishing formal pediatric neuro-oncology training may be beneficial.

LGG-04. A PHASE II RE-TREATMENT STUDY OF SELUMETINIB FOR RECURRENT OR PROGRESSIVE PEDIATRIC LOW-GRADE GLIOMA (pLGG): A PEDIATRIC BRAIN TUMOR CONSORTIUM (PBTC) STUDY

The PBTC conducted a re-treatment study (NCT01089101) evaluating selumetinib (AZD6244, ARRY-142886), a MEK I/II inhibitor, in children with recurrent/progressive pLGG. Eligible patients must have previously enrolled on PBTC-029 or PBTC-029B and progressed after coming off treatment with selumetinib. Patients must have maintained stable disease (SD) for ≥12 courses or had a sustained radiographic response (partial or complete) during their first exposure to selumetinib. Thirty-five eligible patients (median age: 13.11 years [range 7.96–25.33]) were enrolled, 57% of whom had optic pathway or hypothalamic target lesions. At the time of submission, median duration of treatment was 18 courses (range 2–48) and 21 subjects remained on therapy. Best responses reported to date are 6/35 (17%) partial response, 22/35 (63%) SD and 7/35 (20%) progressive disease with a 2-year progression-free survival of 75.7 + 8.3%, which met the design parameters for success. The most common attributable toxicities were grade 1 diarrhea, elevated AST, hypoalbuminemia, elevated CPK, maculo-papular rash, fatigue, paronychia, ALT elevation, acneiform rash and grade 2 CPK elevation. Rare grade 3 toxicities included CPK elevation (3), lymphopenia (2), paronychia (2) and ALT elevation (2). There was only one grade 4 CPK elevation. Five patients (14%) required dose reductions due to toxicity. There does not appear to be a notable difference in toxicities observed during initial selumetinib therapy versus re-treatment. In pLGG that has recurred/progressed following treatment with selumetinib, re-treatment with selumetinib appears to be effective with 80% of patients again achieving response or prolonged stable disease. Long-term follow-up is ongoing.