tbuckley/cabot-search huggingface dataset:
MDB-11. DOES THE INTRAOPERATIVE ASSESSMENT OF SITE OF ORIGIN OF MEDULLOBLASTOMA ALLOW FOR A TAILORING OF THE NEUROSURGICAL STRATEGY? DATA FROM A RETROSPECTIVE SINGLE-CENTER ASSESSMENT AND PROPOSAL OF A PROSPECTIVE MULTICENTER STUDY
Authors: Olga Ciobanu-Caraus, Thomas Czech, Andreas Peyrl, Christine Haberler, Gregor Kasprian, Julia Furtner, Marcel Kool, Martin Sill, Josa Frischer, Anna Cho, Irene Slavc, Karl Rössler, Johannes Gojo, Christian Dorfer
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Developmental gene expression data from medulloblastoma (MB) suggest that WNT-MB originate from the region of the embryonic lower rhombic lip (LRL), whereas SHH-MB and non-WNT/non-SHH MB arise from cerebellar precursor matrix regions. This study aims to analyze detailed intraoperative data with regard to the site of origin (STO) and compare these findings with the hypothesized regions of origin associated with the molecular group. METHODS A review of the institutional database identified 58 out of 72 pediatric patients who were operated on a MB at our department between 1996 and 2020 that had a detailed operative report, surgical video as well as clinical and genetic classification data available for analysis. The STO was assessed based on intraoperative findings. RESULTS Using the intraoperatively defined STO, “correct” prediction of molecular groups was feasible in 20% of WNT-MB, 60% of SHH-MB and 71% of non-WNT/non-SHH MB. The positive predictive values of the neurosurgical inspection to detect the molecular group were 0.21 (95% CI 0.08–0.48) for WNT-MB, 0.86 (95% CI 0.49–0.97) for SHH-MB and 0.73 (95% CI 0.57–0.85) for non-WNT/non-SHH MB. CONCLUSION In our series of 58 well-documented cases, the intraoperative assessment of the STO could not reliably predict the molecular group. Thus, the current evidence does still not allow for intraoperative group-specific risk stratification that would enable tailoring the neurosurgical strategy to the prognostic and predictive profile of the patient. Prospective multicenter assessments are necessary to systematically evaluate the growth pattern and site of origin of medulloblastoma. Accordingly, a study protocol of an international cohort study will be presented.
BIOM-13. THE MIR-17/92 CO-EXPRESSED NETWORK IS ENRICHED IN AGGRESSIVE PEDIATRIC BRAIN TUMORS
Authors: Shehbeel Arif, Komal S Rathi, Ammar S Naqvi, Anne M Coyle, Madison L Hollawell, Phillip B Storm, Adam C Resnick, Peter J Madsen, Mateusz P Koptyra
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Over the past two decades, the understanding of miRNA biology has drastically increased as miRNAs have been found to pervade most aspects of molecular biology–from cellular growth to apoptosis. Nevertheless, there has been little understanding of the role of miRNAs in pediatric brain tumors. In this study, we sought to correlate miRNA expression with pediatric brain tumor histologies. METHODS Weighted gene co-expression network analysis (WGCNA) was performed to determine co-expressed miRNA networks that correlated with distinct brain tumor histologies. Our study cohort consisted of miRNA-sequencing of 262 pediatric brain tumor histologies consisting of Atypical Teratoid/Rhabdoid tumors, Craniopharyngioma, Ependymomas, Ganglioglioma, Low-grade astrocytic tumors, High-grade astrocytic tumors, and Medulloblastoma. We utilized associated multi-omics data from the Open Pediatric Brain Tumor Atlas to validate the results. RESULTS WGCNA analysis revealed a distinct miRNA network consisting of 32 miRNAs with miR-17-5p as the hub miRNA that was markedly upregulated in the aggressive brain tumor group (p&amp;lt;0.001). Interestingly, the majority of the miRNA network consisted of the miR-17/92 family of miRNAs, which are known for their oncogenic role in various cancers. To determine the transcriptional regulatory mechanism of miR-17/92 miRNAs, we first looked at sample-matched RNA-sequencing data. The gene encoding for the miR-17/92 miRNAs, MIR17HG, was significantly overexpressed (p&amp;lt;0.001). Further upstream, we observed that E2F1/2/3, known transcriptional regulators of MIR17HG, gene and protein expressions were significantly overexpressed (p&amp;lt;0.01). Sample-matched phospho-proteomics data indicated the E2F regulator, RB1, being hyperphosphorylated–additionally supporting the E2F activity in these samples. CONCLUSION These findings reveal a network of oncogenic miRNAs consisting of the miR-17/92 family that are distinctly overexpressed in aggressive pediatric brain tumors. Moreover, we suggest that the E2F-RB1 axis is the upstream regulator of the miR-17/92 family of miRNAs.
NFS-27. SELUMETINIB FOR SYMPTOMATIC, INOPERABLE PLEXIFORM NEUROFIBROMAS IN NEUROFIBROMATOSIS TYPE 1: A SINGLE-INSTITUTION EXPERIENCE
Authors: Felisa Vázquez-Gómez, Marta Perez-Somarriba, Serafin Castellano, José Luis Moreno, Susana Cartas, Verónica Cantarín, Anna Duat, Pedro Borrego, Inés Solís, Isabel Valls, Ángela Hernández, Antonio Torrelo, Borja Esteso, Amalia Tamariz-Martel, Rosa María Egea, Luis Blasco, Isabel Colmenero, Begoña Arce, Belén Rivero, Luis Madero, Álvaro Lassaletta
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Half of patients with Neurofibromatosis type 1 (NF1) develop plexiform neurofibromas (PNs). PNs may grow during childhood causing significant complications, including pain, functional impairment, and disfigurement. Treatment options are limited, given their tendency to regrow following surgery and their propensity to transform into malignant tumors following radiation. Selumetinib is an oral selective inhibitor of RAS-mitogen activated protein kinase (MAPK) 1 and 2, which has shown efficacy for tumor shrinkage/ stabilisation and symptom improvement. METHODS Single-institution retrospective review of patients with NF1 treated with selumetinib for symptomatic PNs between 2020 and 2023. Clinical data were abstracted from medical records. Treatment consisted of selumetinib 25 mg/m2 BID. Patient follow-up included monthly complete physical examination, evaluation of treatment adherence, blood analysis, echocardiogram, ophthalmologic assessment every 3 months, and MRI every 6 months. Response evaluation criteria in solid tumors (RECIST) was used for assessment. RESULTS Ten patients were treated with selumetinib during the period indicated. Mean age 13.9 years (range 7-21). Predominant target locations were head and neck (60%), and abdomen-pelvis (30%). The most important comorbidities were disfigurement (50%) and pain (50%). The mean follow-up time was 519 days (range 45–1460). None of the patients presented grade 3-4 toxicities; all of them had associated grade 1-2 skin toxicity. None presented cardiac or ophthalmologic alterations. All the patients with pain had sustained clinical improvement in the first 35–60 days of treatment. At one year of treatment 6/8 patients showed stable disease and 2/8 partial response on MRI. In one patient, treatment was discontinued after 270 days (lack of clear benefit).Another patient has not reached one year of therapy yet. CONCLUSIONS In this study we expose that selumetinib for symptomatic, inoperable plexiform neurofibromas in NF1 was associated with clinical and radiological response. Our study also confirms the safety and good tolerance of this drug.
RADT-01. TUMOR VOLUME INCREASE AND NEED FOR RADIOTHERAPY PLAN ADAPTATION IN PEDIATRIC HIGH-GRADE GLIOMA AND DIFFUSE MIDLINE GLIOMA DURING A SIX-WEEK COURSE OF RADIOTHERAPY
Authors: Bianca A W Hoeben, Max Peters, Enrica Seravalli, Mirjam Willemsen-Bosman, Fasco van Ommen, Jasper van der Lugt, Rutger A J Nievelstein, Sabine Mueller, Esther Hulleman, Eelco W Hoving, Geert O Janssens
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Pediatric High-Grade Glioma/ diffuse midline glioma (pHGG/DMG) growth during a six-week course of radiotherapy may precipitate geographical miss of target volumes and early disease progression. In a patient cohort, we retrospectively evaluated the evolution of tumor volumes during radiotherapy, the clinical need for plan adaptation, and potential correlation with local disease progression. METHODS Twenty-four pHGG/DMG patients (12M/12F, ages 4-20 years) with gross tumor volume (GTV) after debulking (n=7) or biopsy (n=17) received 30 fractions of Volumetric Modulated Arc Therapy within an adaptive radiotherapy-protocol. The GTV was defined by combined T1+FLAIR MRI sequence abnormalities. A 1-cm margin was applied for Clinical Target Volume (CTV). MRI-based target volume re-evaluation was performed at fraction 10 and 20, defining GTV increase &amp;gt;1mL as growth. The clinical need for plan adaptation was based on tumor volume changes. GTV increase and need for plan adaptation were evaluated against local progression-free survival (LPFS). RESULTS Median time between baseline MRI and radiotherapy start was 10 days (range 3-29). From baseline, GTV growth was observed in 7/24 patients at fraction 10, and in an additional 7/24 patients at fraction 20 (cumulative 14/24), corresponding to a mean volume increase of 21%/3.7mL (range [-7%/-2.7mL] to [+185%/24.4mL]) and 40%/8.7mL (range [-18%/-8.1mL] to [+329%/115.1mL]) after 10 and 20 fractions, respectively. At fraction 10 and 20, respectively 6 and 6 plans needed adaptation in a total of 11 patients. Baseline tumor volumes between patients with/without plan adaptation were equivalent. Median LPFS was 8.3 months (95%CI 8.0-12.7). No significant difference in LPFS was observed between patients with versus without GTV increase or plan adaptation. CONCLUSIONS Between MRI at baseline and at fractions 10 and 20, this adaptive radiotherapy protocol using 1-cm CTV margins demonstrated pHGG/DMG tumor volume increase with a clinical need for plan adaptations in 11/24 patients.
LGG-47. VINBLASTINE TO PREVENT TUMOUR REBOUND AFTER BEVACIZUMAB/IRINOTECAN IN CHILDREN AND ADOLESCENTS WITH MULTIPLY RELAPSED LOW-GRADE GLIOMAS: THE SOUTH LONDON PAEDIATRIC &amp; TYA NEURO-ONCOLOGY NETWORK EXPERIENCE
Authors: Annette Weiser, Julia V Cockle, Paola Angelini, Elwira Szychot, Kavitha Srivatsa, Henry C Mandeville, Sucheta Vaidya, Lynley Marshall, Fernando Carceller
Journal: Neuro-Oncology (2024)

Abstract INTRODUCTION Low-grade gliomas (LGG) present 10-year overall survival rates of 90%. However, many require multiple lines of treatment. Bevacizumab/Irinotecan is the standard third line treatment for recurrent LGG in the UK; with targeted therapies being accessible only as a fourth or subsequent line for most cases. Access to targeted therapies may also be limited by the need for tumour tissue, which isn’t always available for LGG cases. Bevacizumab is effective in LGG, but between 65 and 90% regrow within 5-8 months from treatment discontinuation [Hwang 2013; Green 2023]. In this context and based on preliminary evidence from the group in Marseille (France) [Heng, 2016; Roux 2021], we explored if Vinblastine could extend the progression-free survival (PFS) after Bevacizumab. METHODS Institutional review of patients aged 1-25 years with relapsed LGG treated between 2018 and 2022 with Bevacizumab/Irinotecan followed by Vinblastine (24 weekly doses) at the discretion of the treating physician. The primary endpoint was PFS post-Bevacizumab (PFS-pB) measured at 8 months from last dose of Bevacizumab to allow for comparison with the results of a recently published national case series of paediatric LGG treated with Bevacizumab-based regimes [Green 2023]. RESULTS Ten LGG cases received Bevacizumab/Irinotecan. One progressed on treatment, leaving 9 evaluable (8 completed 12 cycles, 1 discontinued treatment due to toxicity): of which 6 received Vinblastine. The PFS-pB at 8 months was 66% (4/6) with Vinblastine vs 35% in the national UK case series. CONCLUSIONS In this limited case series, Vinblastine delayed tumour progression following completion of Bevacizumab-based regimes compared to a national UK case series. Vinblastine could be considered as a holding strategy after Bevacizumab where targeted therapies are not readily available. Further prospective studies are required to validate this hypothesis.
DIPG-53. AN EXCEPTIONALLY RARE CASE OF A DIFFUSE MIDLINE GLIOMA WITH CONCOMITANT H3.1 K27M AND G34R MUTATIONS IN THE<i>HIST1H3C (H3C3)</i> GENE
Authors: Zita Reisz, Rita Pereira, Smitha Nevis, Alan Mackay, Leena Bhaw, Yura Grabovska, Ross Laxton, Valeria Molinari, Anna Burford, Barnaby Clark, Cristina Bleil, Bassel Zebian, Annette Weiser, Fernando Carceller, Lynley Marshall, Andrew King, Istvan Bodi, Safa Al-Sarraj, Chris Jones, Matthew Clarke
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Histone mutations (H3 K27M, H3 G34R/V) define subtypes of paediatric-type diffuse high-grade gliomas (HGG) (diffuse midline glioma (DMG), H3 K27-altered, diffuse hemispheric glioma (DHG), H3 G34-mutant). The WHO classification recognises exceptional cases where these mutations co-occur. We report one such case of a 2-year-old female presenting with neurological symptoms and lethargy. METHODS MRI imaging identified a brainstem lesion; a stereotactic needle biopsy was undertaken, followed by standard diagnostic neuropathology workflows including histology review, panel immunohistochemistry, DNA methylation profiling (Illumina EPIC BeadArrays, brain tumour classifier (MNP v12.5 R package)) and WES/WGS. Patient-derived in vitro cell cultures were established allowing further characterisation using RNAseq and chromatin immunoprecipitation assays with sequencing (ChIP-seq). RESULTS Histology showed diffusely infiltrating pleomorphic astrocytes, multinucleated cells, and conspicuous mitotic activity; the diagnosis was DMG, H3 K27-altered (immunohistochemistry: H3K27me3 loss, H3K27M positivity). DNA methylation profiling classified the tumour as ‘DMG, H3 K27-altered’ (calibrated score=0.99). WES/WGS revealed concurrent H3.1 K27M and G34R mutations (clonal, in the same reads) of HIST1H3C (H3C3), somatic variants in FGF11 and PIK3CA, and a pathogenic germline NBN variant. The RNAseq profile of the primary tumour and cell cultures clustered with H3 K27M-mutant tumours. Unbiased in vitro drug screening showed no selective sensitivities. ChIP-seq (H3K27ac, H3K27me3, H3K36me3, RNApol2 marks) showed features in keeping with DMG H3 K27M-mutant tumours (H3K27ac loci including OLIG2, IRX1/2, PKDCC). The patient was treated with adjuvant radiotherapy and everolimus, but progressed and passed away 13 months post-diagnosis. CONCLUSION This case is an exceptionally rare, complex variant of histone-mutant paediatric HGG, and the first reported occurrence in HIST1H3C (H3C3). It illustrates that in cis, the H3.1 K27M mutation demonstrates a dominance over molecular and clinical profiles compared to G34R, and highlights the importance of broad molecular profiling to identify such examples for further study.
DIPG-22. A NOVEL ROLE FOR ACVR1/ALK2 IN REGULATING CHOLESTEROL BIOSYNTHESIS PROVIDES A NEW COMBINATORIAL THERAPEUTIC APPROACH FOR PATIENTS WITH DMG
Authors: Rebecca Rogers, Yura Grabovaska, Alan Mackay, Diana Carvalho, Claire Dobinson, Rita Pereira, Drenusha Sejdiu, Anna Burford, Valeria Molinari, Ruth Ruddle, Florence Raynaud, Nicole Chew, Vanessa Tsui, Claire Sun, Ron Firestein, Chris Jones
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND The discovery of somatic mutations in ACVR1, which encodes the serine/threonine kinase ALK2, in 20-25% of diffuse midline glioma H3K27-altered (DMG-H3K27) patients has led to the development of numerous chemotypes of ALK2 inhibitor (ALK2i). However, in models of ACVR1-mutant DMG-H3K27 the efficacy of single-agent ALK2i’s has been modest and new combinatorial treatment approaches are desperately needed. METHODS We performed unbiased combinatorial genetic and drug screens in patient-derived ACVR1-mutant DMG-H3K27 cells in vitro, using multiple chemotypes of ALK2i. We also generated in vitro transcriptomic, proteomic and metabolomic profiles of three ACVR1-mutant DMG-H3K27 models following ALK2i treatment. RESULTS The top ALK2i sensitising CRISPR hits (vehicle vs. ALK2i) were analysed using gene set enrichment analysis (GSEA) which revealed specific genetic dependencies in cholesterol synthesis/regulation following both M4K2009 and TP-0184 treatment. The top CRISPR hits included multiple key nodes of cholesterol biosynthesis such as HMGCR (HMG-CoA&amp;gt;mevalonate), LSS (squalene-2-2-epoxide&amp;gt;lanosterol) and DHCR24 (lanosterol&amp;gt;cholesterol). These hits were pharmacologically mirrored in the top hits identified from the drug screen, including drugs that either directly or indirectly target cholesterol synthesis. Integration of the multi-omic data revealed a raft of changes associated with cholesterol biosynthesis/efflux. The expression of HMGCR/HMGCS1 (cholesterol synthesis) and LXR/ABCA1 (cholesterol export) were down and upregulated, respectively, with metabolomic data showing a reduction in cholesterol and it’s derivative 4-cholesten-3-one and an increase in desmosterol, an immediate precursor to cholesterol synthesis. Highly synergistic interactions were observed between multiple ALK2i and a panel of pharmacological agents targeting the cholesterol synthesis/efflux pathway, including routinely used drugs such as simvastatin and lovastatin, clinically well-tolerated and with good CNS penetrance in immuno-compromised and immune-competent mouse models, in whom in vivo combination studies are ongoing. CONCLUSIONS These data provide evidence for a previously unappreciated link between ALK2 signalling and metabolism, and identify readily translatable combination partners for ALK2i in the clinic.
NFS-29. DEVELOPMENTAL SCREENING AND MONITORING IN NEUROFIBROMATOSIS-1
Authors: Kelly Janke, Danielle Lawler, Zoe Kearns
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Pilot data showed developmental screening at Neurofibromatosis-1 (NF1) appointments is feasible to identify those needing neuropsychology or other referrals. Outcomes for this larger sample, many re-screened and/or seen for a neuropsychology visit, allow us to describe evolving clinical management. METHODS Screenings are offered annually (ages 2-17) at NF1 clinic appointments by the psychosocial team. Forty-eight early childhood patients (ages 2-5) were screened (54% male, 66.7% White,) while 35 were ineligible (e.g., recent neuropsychology visit) or experienced logistical barriers to screening. These groups did not differ in race/ethnicity, sex, glioma status, or childhood opportunity index. Parents completed well-validated measures including the PEDS: Developmental Milestones – Assessment Level (PEDS:DM), Modified Checklist for Autism in Toddlers, and/or an ADHD Rating for preschoolers. RESULTS On initial screens, 73.9% showed a delay of 25% or more on at least one PEDS:DM domain. Measures often aligned with clinical impressions (81.3%); however, when findings were contextualized with record review, there were false positives (8.3%) and negatives (10.4%). Screening identified emerging concerns in attention, fine-motor, and academic skills. Nearly half (47.9%) of patients had services at the time of screening, and new/modified recommendations were offered for 70.8%. One third were referred to our Education Coordinator or Social Worker for educational advocacy, support through Early Intervention/school evaluation, or outpatient referrals. Twenty-two (45.8%) were referred to Neuropsychology and 18 have now been seen (consultation, targeted testing, or comprehensive evaluation) to confirm or rule-out neurodevelopmental diagnoses (e.g., autism, ADHD, language or global delay) and further guide educational or intervention management. Follow-up screens (N = 21) have monitored developmental progress, previously subclinical symptoms rising to a significant level, and need for re-evaluation or additional services. CONCLUSIONS Multipronged systematic screening results in referrals for diagnostic clarity, guides transition from Early Intervention to school services, and supports dynamic management of changing concerns.
MODL-13. ORGANOTYPIC BRAIN SLICE CULTURE PLATFORM AS A MODEL OF PEDIATRIC LOW GRADE GLIOMAS
Authors: Breanna Mann, Nichole Artz, Adebimpe Adefolaju, Rajaneekar Dasari, Noah Bell, Andrew Buckley, David Kram, Shawn Hingtgen, Andrew Satterlee
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Pediatric low grade glioma (pLGG), the most common subgroup of central nervous system tumors in children, suffers from a paucity of models that support pLGG biological discovery, preclinical target identification, and drug screening studies. METHODS We propose the use of an organotypic brain slice culture (OBSC) platform as a novel model in which we are able to reliably support fresh, zero-passage pLGG patient tumor tissue for preclinical testing. We performed individualized drug screening with the frequently used up-front agents: carboplatin, vincristine, trametinib, and dabrafenib. RESULTS We have collected and established on OBSCs 100% (3/3) pLGGs since 2023. With these three patient samples, we have applied our quantitative drug screening algorithm, which combines tumor killing efficacy with healthy tissue toxicity, and yielded resultant drug sensitivity scores (DSS) to quantify patient-specific treatment efficacies. CONCLUSIONS Overall, these early results suggest that the OBSC platform may serve as a novel and reliable model for pLGG, filling a critical void in representative models for this common and often highly morbid pediatric tumor.
CNSC-01. UNDERSTANDING PEDIATRIC BRAIN TUMOR CHEMOTHERAPY INDUCED LONG-TERM DEFICITS IN HIGH-ORDER NEUROCOGNITIVE AND SENSORIMOTOR FUNCTION
Authors: Anand K Singh, Renae Bertrand, Rajasekaran Mahalingam, Shungu Zimbwa, Khalil A Ahmad Kasm, Yuan Pan
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Because of major advancements in cancer treatment especially chemotherapy, 85% of children with cancer are predicted to survive for 5 years or more. However, chemotherapy can cause long-term health problems when childhood cancer survivors enter adulthood (known as late effects). The neurocognitive features of these late effects (chemobrain) include trouble in concentrating, memorizing, and decreased processing speed, and results in lower IQ and academic achievement, poor hand-eye coordination, and slower development over time. Despite such a negative impact on the quality of life of cancer-surviving children, the mechanism is poorly understood and there is no FDA-approved drug to prevent or cure these side effects. METHODS To gain a better understanding of the mechanism underlying chemotherapy-induced cognitive impairments, we developed a pre-clinical model using carboplatin in juvenile mice to study long-term neurological defects. We have tested the capacity of different doses of carboplatin and its long-term effect on cognitive and sensorimotor function and performed single nuclear RNA sequencing (snRNAseq) of the hippocampus. RESULTS Our preliminary data demonstrated dose-dependent deficits in executive and sensorimotor function 7-9 weeks after carboplatin administration in the mice of both sexes. snRNAseq of the hippocampus showed changes in the glial cell number as well as genes associated with oxidative phosphorylation and neurodegeneration at early and late time points. CONCLUSIONS This study established a preclinical model that can be leveraged to mechanistically understand the long-term neurocognitive side effects of brain tumor chemotherapy during childhood. Future studies will aim to identify potential targets to prevent and/or treat the neurotoxic effects of cancer treatment in pediatric patients.