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BackgroundDespite recent advances in the biology of IDH-wildtype glioblastoma, it remains a devastating disease with median survival of less than 2 years. However, the molecular underpinnings of the heterogeneous response to the current standard-of-care treatment regimen consisting of maximal safe resection, adjuvant radiation, and chemotherapy with temozolomide remain unknown.MethodsComprehensive histopathologic, genomic, and epigenomic evaluation of paired initial and recurrent glioblastoma specimens from 106 patients was performed to investigate the molecular evolution and cellular phenotypes underlying differential treatment responses.ResultsWhile TERT promoter mutation and CDKN2A homozygous deletion were early events during gliomagenesis shared by initial and recurrent tumors, most other recurrent genetic alterations (eg, EGFR, PTEN, and NF1) were commonly private to initial or recurrent tumors indicating acquisition later during clonal evolution. Furthermore, glioblastomas exhibited heterogeneous epigenomic evolution with subsets becoming more globally hypermethylated, hypomethylated, or remaining stable. Glioblastoma that underwent sarcomatous transformation had shorter interval to recurrence and were significantly enriched in NF1, TP53, and RB1 alterations and the mesenchymal epigenetic class. Patients who developed somatic hypermutation following temozolomide treatment had significantly longer interval to disease recurrence and prolonged overall survival, and increased methylation at 4 specific CpG sites in the promoter region of MGMT was significantly associated with this development of hypermutation. Finally, an epigenomic evolution signature incorporating change in DNA methylation levels across 347 critical CpG sites was developed that significantly correlated with clinical outcomes.ConclusionsGlioblastoma undergoes heterogeneous genetic, epigenetic, and cellular evolution that underlies prognostically different treatment responses.

Glioblastoma is a clinically and molecularly heterogeneous disease, and new predictive biomarkers are needed to identify those patients most likely to respond to specific treatments. Through prospective genomic profiling of 459 consecutive primary treatment-naïve IDH-wildtype glioblastomas in adults, we identified a unique subgroup (2%, 9/459) defined by somatic hypermutation and DNA replication repair deficiency due to biallelic inactivation of a canonical mismatch repair gene. The deleterious mutations in mismatch repair genes were often present in the germline in the heterozygous state with somatic inactivation of the remaining allele, consistent with glioblastomas arising due to underlying Lynch syndrome. A subset of tumors had accompanying proofreading domain mutations in the DNA polymerase POLE and resultant "ultrahypermutation". The median age at diagnosis was 50 years (range 27-78), compared with 63 years for the other 450 patients with conventional glioblastoma (p

IntroductionTumor Treating Fields (TTFields, 200 kHz) therapy is a noninvasive, locoregional cancer treatment approved for use in newly diagnosed glioblastoma (GBM), recurrent GBM, and malignant pleural mesothelioma. GBM patients with hydrocephalus may require implantation of a ventriculoperitoneal (VP) shunt, however, the current TTFields therapy label does not include the use of VP shunts in GBM patients due to insufficient safety data. This analysis evaluates the safety of TTFields therapy use in this population.MethodsUnsolicited post-marketing global surveillance data from patients with GBM and a VP shunt (programmable/non-programmable) who received TTFields therapy between November 2012-April 2021 were retrospectively analyzed. Adverse events (AEs) were assessed using the Medical Dictionary for Regulatory Activities version 24.0.ResultsOverall, 156 patients with VP shunts were identified and included in this analysis. In total, 77% reported  ≥ 1 AE; the most common TTFields therapy-related AEs were non-serious and localized, beneath-array skin AEs (43%). The incidence and categories of AEs were comparable between patients with or without VP shunts. Six patients with VP shunts experienced seven serious TTFields therapy-related AEs: skin erosion at the shunt site (n = 3); wound dehiscence at the shunt site (n = 2) and at the resection scar (n = 2). No shunt malfunctions were deemed related to TTFields therapy.ConclusionsIn the real-world setting, TTFields therapy in GBM patients with VP shunts demonstrated good tolerability and a favorable safety profile. There was no evidence that TTFields therapy disrupted VP shunt effectiveness. These results suggest TTFields therapy may be safely used in patients with VP shunts.

BackgroundMonitoring lower-grade gliomas (LrGGs) for disease progression is made difficult by the limits of anatomical MRI to distinguish treatment related tissue changes from tumor progression. MR spectroscopic imaging (MRSI) offers additional metabolic information that can help address these challenges. The goal of this study was to compare longitudinal changes in multiparametric MRI, including diffusion weighted imaging, perfusion imaging, and 3D MRSI, for LrGG patients who progressed at the final time-point and those who remained clinically stable.MethodsForty-one patients with LrGG who were clinically stable were longitudinally assessed for progression. Changes in anatomical, diffusion, perfusion and MRSI data were acquired and compared between patients who remained clinically stable and those who progressed.ResultsThirty-one patients remained stable, and 10 patients progressed. Over the study period, progressed patients had a significantly greater increase in normalized choline, choline-to-N-acetylaspartic acid index (CNI), normalized creatine, and creatine-to-N-acetylaspartic acid index (CRNI), than stable patients. CRNI was significantly associated with progression status and WHO type. Progressed astrocytoma patients had greater increases in CRNI than stable astrocytoma patients.ConclusionsLrGG patients in surveillance with tumors that progressed had significantly increasing choline and creatine metabolite signals on MRSI, with a trend of increasing T2 FLAIR volumes, compared to LrGG patients who remained stable. These data show that MRSI can be used in conjunction with anatomical imaging studies to gain a clearer picture of LrGG progression, especially in the setting of clinical ambiguity.

Abstract BACKGROUND Epigenetic inhibition of the O6-methylguanine-DNA-methyltransferase (MGMT) gene has emerged as a clinically relevant prognostic marker in glioblastoma (GBM). Methylation of the MGMT promoter has been shown to increase chemotherapy efficacy. While traditionally reported as a binary marker, recent methodological advancements have led to quantitative approaches that measure methylation, providing clearer insights into methylation’s functional relationship with survival. METHODS A CLIA assay and bisulfite sequencing was utilized to develop a quantitative, 17-point MGMT promoter methylation index derived from the number of methylated CpG sites. Retrospective review of 240 newly diagnosed GBM patients was performed in order to discern how risk for mortality transforms as promoter methylation increases. Non-linearities were captured by fitting splines to Cox proportional hazard models, plotting smoothed residuals, and creating survival plots. Covariates included age, KPS, IDH1 mutation, and extent of resection. RESULTS Median follow-up time and progression free survival were 16 and 9 months, respectively. 176 subjects experienced death. A one-unit increase in CpG methylation on a scale of 1-17 resulted in a 4% reduction in hazard (95% CI 0.93–0.99, P< 0.005). Moreover, GBM patients with low-levels of methylation (1-6 CpG sites) fared markedly worse (HR=1.62, 95% CI 1.03-2.54, P< 0.036) than individuals who were unmethylated (reference group). Subjects with medium-levels of methylation (7-12 CpG sites) had the greatest reduction in hazard (HR=0.48, 95% CI 0.29-0.80, P< 0.004), followed by individuals in the highest methylation tertile (HR=0.62, 95% CI 0.40-0.97, P< 0.035). CONCLUSION This novel approach offers greater bisulfite conversion efficiency when compared to alternative methods, reducing the likelihood of false positives. Analysis of the resulting methylation index scores demonstrates a non-linear relationship between MGMT methylation and survival, suggesting conformation of the marker’s protective effect. These findings challenge the current understanding of MGMT’s functional form and underline why implementing an “optimal cutoff point” may be disadvantageous.

Abstract BACKGROUND The prognosis of WHO grade II low-grade gliomas (LGG) is varied with potential for long survival.Given their relatively intact immune system and slow growth rate, vaccines are an attractive treatment strategy for LGG in an attempt to defer more toxic treatments. The goals of this pilot study were to evaluate safety and immunological effects of vaccination with GBM6-AD, an allogeneic glioblastoma stem cell line lysate, with poly-ICLC in LGG. METHODS Eligible patients were ≥ 18 years old, ≥ 70 KPS, with recurrent LGG or imaging consistent with LGG, and amenable to resection. Patients were randomized to vaccine prior to surgery (Arm 1) or not (Arm 2) and all received adjuvant vaccine. Co-primary outcomes were safety and immune response in the tumor, with exploratory outcomes of survival and immunologic effects in peripheral blood. RESULTS A total of 17 eligible patients were evaluable – nine into Arm 1 and eight into Arm 2. Median age was 33 years, with median time from initial diagnosis of 4.7 years (0 – 20). Two patients (11.8%) previously received radiotherapy and seven (41.2%) prior systemic therapy. No dose limiting toxicities or grade 3 AEs were observed. Neoadjuvant vaccination induced up regulation of type-1 cytokines and chemokines in peripheral blood, and CD8+ T cell clones that reacted to the vaccine were also detected in the tumor. Median follow-up time from first post-operative vaccine was 20.8 months with median PFS of 11.0 months and time to change in therapy of 23.7 months. Of the six patients to receive additional treatment, three had second surgery only one confirming malignant progression to anaplastic oligodendroglioma. CONCLUSION Treatment was well-tolerated with no regimen-limiting toxicity. GBM6-AD plus poly-ICLC induced effector CD8+ T cell response in peripheral blood and enables some vaccine-reactive CD8+ T cells to migrate into the TME. Further investigation is warranted.

Abstract BACKGROUND Gliomas are devastating primary tumors of the central nervous system that often present with difficult to manage symptoms in addition to the antineoplastic tumor itself. Due to recent increase in popularity and societal acceptance of cannabis products, their use by glioma patients has increased. METHODS We conducted a single center, prospective study: patients with glioma answered a locally validated survey to inquire about their cannabis use at baseline and every three months. Quality of Life was measured using the EORTC QLQ-C30, its complementary module BN-20 and the EQ-5D-5L instrument. Eligible participants were classified as cannabis users or non-users. We performed linear regression clustered by subjects to see differences by user group and trends overtime. RESULTS To date, 89 patients agreed to participate, enrolled, and answered the baseline questionnaires, and 64 have answered the 3 month follow up survey. The mean age was 49.7(SD 13.74), 55 were male, 55 were cannabis users at baseline (61.8%) and 34 at 3 months (53.13%). Patients who were cannabis users scored 11.73 lower points at baseline when compared to non-users (79.65 [SD 18.93] vs 67.92 [SD 19.22]) in the QLQ-C30 instrument. Similarly, cannabis users recorded 9.624 lower points at 3 months compared to non-users (70.1 [SD 21.33] vs 79.72 [SD13.95]). The difference-in-difference estimator was 2.108 (p< 0.7). CONCLUSION Although we observed cannabis users scoring lower QoL measurements (p< 0.05) at baseline and 3 months, we observed a slight improvement in QoL of cannabis users while observing no change or decline (in some measures) among non-users. Our findings provide insight to the impact that cannabis has in QoL over time. While not conclusive, these preliminary results need to be studied on a longer-term basis with a larger sample size in order to detect trends on quality of life among patients with different tumor types.

Abstract INTRODUCTION Mutations in isocitrate dehydrogenase (IDH) have been investigated as a prognostic biomarker in glioma. The presence of the IDH mutation (IDHm) is associated with 2-hydroxyglutarate (2HG) production and inhibition of glutamate synthesis (McBrayer, Cell 2018). Hyperpolarized carbon-13 (HP-13C) MRI enables dynamic measurements of in-vivo metabolism using a [2-13C]pyruvate labeled probe that undergoes conversion to [2-13C]lactate and [5-13C]glutamate. Here, we present HP [2-13C]pyruvate data from healthy volunteers and patients with IDHm diffuse glioma. Due to its intrinsic low signal-to-noise ratio (SNR), we demonstrate the ability of post-processing denoising to improve its utility and aid in detection of metabolic changes associated with IDHm. METHODS Dynamic HP 13C data were acquired following intravenous injection of [2-13C]pyruvate from five healthy volunteers and one patient with IDHm grade III astrocytoma. A novel multi-resolution frequency specific multislice EPI sequence was used to obtain [2-13C]pyruvate, [5-13C]glutamate, and downfield and upfield [2-13C]lactate signals (3s temporal resolution, pyruvate/lactate/glutamate spatial resolutions = 0.75x0.75cm2/ 2.25x2.25cm2/ 2.25x2.25cm2, 5 slices 3cm thick). Following phase correction, patch-based tensor decomposition denoising was applied to metabolite images. Metabolite differences between normal-appearing white matter (NAWM) and T2 lesion were examined for the patient data. RESULTS HP [2-13C]pyruvate imaging is able to simultaneously probe glycolytic ([2-13C]lactate) and oxidative ([5-13C]glutamate) metabolism. Denoised pyruvate/lactate/glutamate signals achieved a 4-9/3-6/3-7 fold increase in SNR. T2 lesion exhibited decreased glutamate-to-pyruvate and glutamate-to-lactate AUC ratios versus contralateral NAWM (p< 0.018, p < 1.5e-5), consistent with IDH mutant status. CONCLUSION We successfully demonstrated the feasibility of applying variable resolution HP [2-13C]pyruvate metabolic imaging to detect IDHm specific metabolism. This technique addresses a major hurdle in HP 13C MRI by improving SNR while permitting robust metabolism quantification. Future studies will optimize methods for acquiring and processing data to evaluate further data acquired from IDHm glioma patients. Supported by NIH T32 CA151022, P01 CA118816, and NICO.

BackgroundPrognostic markers for meningioma are needed to risk-stratify patients and guide postoperative surveillance and adjuvant therapy.ObjectiveTo identify a prognostic gene signature for meningioma recurrence and mortality after resection using targeted gene-expression analysis.MethodsTargeted gene-expression analysis was used to interrogate a discovery cohort of 96 meningiomas and an independent validation cohort of 56 meningiomas with comprehensive clinical follow-up data from separate institutions. Bioinformatic analysis was used to identify prognostic genes and generate a gene-signature risk score between 0 and 1 for local recurrence.ResultsWe identified a 36-gene signature of meningioma recurrence after resection that achieved an area under the curve of 0.86 in identifying tumors at risk for adverse clinical outcomes. The gene-signature risk score compared favorably to World Health Organization (WHO) grade in stratifying cases by local freedom from recurrence (LFFR, P

Paragangliomas are neuroendocrine tumors of the autonomic nervous system that are variably clinically functional and have a potential for metastasis. Up to 40% occur in the setting of a hereditary syndrome, most commonly due to germline mutations in succinate dehydrogenase (SDHx) genes. Immunohistochemically, paragangliomas are characteristically GATA3-positive and cytokeratin-negative, with loss of SDHB expression in most hereditary cases. In contrast, the rare paragangliomas arising in the cauda equina (CEP) or filum terminale region have been shown to be hormonally silent, clinically indolent, and have variable keratin expression, suggesting these tumors may represent a separate pathologic entity. We retrospectively evaluated 17 CEPs from 11 male and 6 female patients with a median age of 38 years (range 21-82), none with a family history of neuroendocrine neoplasia. Six of the 17 tumors demonstrated prominent gangliocytic or ganglioneuromatous differentiation. By immunohistochemistry, none of the CEPs showed GATA3 positivity or loss of SDHB staining; all 17 CEPs were cytokeratin positive. Genome-wide DNA methylation profiling was performed on 12 of the tumors and compared with publicly available genome-wide DNA methylation data. Clustering analysis showed that CEPs form a distinct epigenetic group, separate from paragangliomas of extraspinal sites, pheochromocytomas, and other neuroendocrine neoplasms. Copy number analysis revealed diploid genomes in the vast majority of CEPs, whereas extraspinal paragangliomas were mostly aneuploid with recurrent trisomy 1q and monosomies of 1p, 3, and 11, none of which were present in the cohort of CEP. Together, these findings indicate that CEPs likely represent a distinct entity. Future genomic studies are needed to further elucidate the molecular pathogenesis of these tumors.

The FGFR1 gene encoding fibroblast growth factor receptor 1 has emerged as a frequently altered oncogene in the pathogenesis of multiple low-grade neuroepithelial tumor (LGNET) subtypes including pilocytic astrocytoma, dysembryoplastic neuroepithelial tumor (DNT), rosette-forming glioneuronal tumor (RGNT), and extraventricular neurocytoma (EVN). These activating FGFR1 alterations in LGNET can include tandem duplication of the exons encoding the intracellular tyrosine kinase domain, in-frame gene fusions most often with TACC1 as the partner, or hotspot missense mutations within the tyrosine kinase domain (either at p.N546 or p.K656). However, the specificity of these different FGFR1 events for the various LGNET subtypes and accompanying genetic alterations are not well defined. Here we performed comprehensive genomic and epigenomic characterization on a diverse cohort of 30 LGNET with FGFR1 alterations. We identified that RGNT harbors a distinct epigenetic signature compared to other LGNET with FGFR1 alterations, and is uniquely characterized by FGFR1 kinase domain hotspot missense mutations in combination with either PIK3CA or PIK3R1 mutation, often with accompanying NF1 or PTPN11 mutation. In contrast, EVN harbors its own distinct epigenetic signature and is characterized by FGFR1-TACC1 fusion as the solitary pathogenic alteration. Additionally, DNT and pilocytic astrocytoma are characterized by either kinase domain tandem duplication or hotspot missense mutations, occasionally with accompanying NF1 or PTPN11 mutation, but lacking the accompanying PIK3CA or PIK3R1 mutation that characterizes RGNT. The glial component of LGNET with FGFR1 alterations typically has a predominantly oligodendroglial morphology, and many of the pilocytic astrocytomas with FGFR1 alterations lack the biphasic pattern, piloid processes, and Rosenthal fibers that characterize pilocytic astrocytomas with BRAF mutation or fusion. Together, this analysis improves the classification and histopathologic stratification of LGNET with FGFR1 alterations.

BackgroundEmerging data suggest that a subset of patients with diffuse isocitrate dehydrogenase (IDH)-mutant low-grade glioma (LGG) who receive adjuvant temozolomide (TMZ) recur with hypermutation in association with malignant progression to higher-grade tumors. It is currently unclear why some TMZ-treated LGG patients recur with hypermutation while others do not. MGMT encodes O6-methylguanine-DNA methyltransferase, a DNA repair protein that removes cytotoxic and potentially mutagenic lesions induced by TMZ. Here, we hypothesize that epigenetic silencing of MGMT by promoter methylation facilitates TMZ-induced mutagenesis in LGG patients and contributes to development of hypermutation at recurrence.MethodsWe utilize a quantitative deep sequencing assay to characterize MGMT promoter methylation in 109 surgical tissue specimens from initial tumors and post-treatment recurrences of 37 TMZ-treated LGG patients. We utilize methylation arrays to validate our sequencing assay, RNA sequencing to assess the relationship between methylation and gene expression, and exome sequencing to determine hypermutation status.ResultsMethylation level at the MGMT promoter is significantly higher in initial tumors of patients that develop hypermutation at recurrence relative to initial tumors of patients that do not (45.7% vs 34.8%, P = 0.027). Methylation level in initial tumors can predict hypermutation at recurrence in univariate models and multivariate models that incorporate patient age and molecular subtype.ConclusionsThese findings reveal a mechanistic basis for observed differences in patient susceptibility to TMZ-driven hypermutation. Furthermore, they establish MGMT promoter methylation level as a potential biomarker to inform clinical management of LGG patients, including monitoring and treatment decisions, by predicting risk of hypermutation at recurrence.

IntroductionTumor Treating Fields (TTFields; antimitotic treatment) delivers low-intensity, intermediate-frequency, alternating electric fields through skin-applied transducer arrays. TTFields (200 kHz) was FDA-approved in glioblastoma (GBM), based on the phase 3 EF-11 (recurrent GBM, rGBM) and EF-14 (newly diagnosed GBM, ndGBM) trials. The most common TTFields-related adverse event (AE) in both trials was array-associated skin irritation. We now report on TTFields-related AEs in the real-world, clinical practice setting.MethodsUnsolicited, post-marketing surveillance data from TTFields-treated patients (October 2011-February 2019) were retrospectively analyzed using MedDRA v21.1 preferred terms, stratified by region (US, EMEA [Europe, Middle East, Africa], Japan), diagnosis (ndGBM, rGBM, anaplastic astrocytoma/oligodendroglioma, other brain tumors), and age ( 11,000 patients revealed no new safety concerns, with a favorable safety profile comparable with published TTFields/GBM trials. The safety profile remained consistent among subgroups, suggesting feasibility in multiple populations, including elderly patients.

BackgroundPrimary CNS tumors constitute a heterogeneous group of neoplasms that share a considerable morbidity and mortality rate. To help control tumor growth and clinical outcomes (overall survival, progression-free survival, quality of life) symptoms, patients often resort to alternative therapies, including the use of cannabis. Despite rapidly growing popularity, cannabis and its impact on patients with primary malignant CNS tumors is understudied.MethodsTo shed light on the lack of scientific evidence in this field, in November 2018 we conducted a search and examination of cannabis in neuro-oncology in major journal databases and bibliographies of selected articles, and through abstracts of annual meetings using prespecified criteria in line with the Cochrane Collaboration guidelines.ResultsWe identified 45 publications, of which 9 were selected. Five studies were included. Publication dates ranged from 2004 to 2018 and included varying histologies of primary brain tumors. The average survival at 1 year was 56.09% (95% CI: 48.28-63.9). There was no difference in risk ratio (RR) for death at 1 year between groups (RR: 1.069 [95% CI: 0.139-8.25]). We found strong evidence of heterogeneity (Q = 74.0%; P = .021). We found no statistical evidence of publication bias (P = .117; SD = 1.91).ConclusionsThere was limited moderate-quality evidence that supports the use of cannabinoids as adjuvant to the standard of care in the treatment of brain and CNS tumors. There was very low-quality evidence suggesting that cannabinoids were associated with adult-onset gliomas. Further prospective clinical trials are necessary to adequately evaluate the impact of cannabinoids on CNS tumors, specifically on survival and quality of life.

"Myxoid glioneuronal tumor, PDGFRA p.K385-mutant" is a recently described tumor entity of the central nervous system with a predilection for origin in the septum pellucidum and a defining dinucleotide mutation at codon 385 of the PDGFRA oncogene replacing lysine with either leucine or isoleucine (p.K385L/I). Clinical outcomes and optimal treatment for this new tumor entity have yet to be defined. Here, we report a comprehensive clinical, radiologic, and histopathologic assessment of eight cases. In addition to its stereotypic location in the septum pellucidum, we identify that this tumor can also occur in the corpus callosum and periventricular white matter of the lateral ventricle. Tumors centered in the septum pellucidum uniformly were associated with obstructive hydrocephalus, whereas tumors centered in the corpus callosum and periventricular white matter did not demonstrate hydrocephalus. While multiple patients were found to have ventricular dissemination or local recurrence/progression, all patients in this series remain alive at last clinical follow-up despite only biopsy or subtotal resection without adjuvant therapy in most cases. Our study further supports "myxoid glioneuronal tumor, PDGFRA p.K385-mutant" as a distinct CNS tumor entity and expands the spectrum of clinicopathologic and radiologic features of this neoplasm.

Ependymomas exist within distinct genetic subgroups, but the molecular diversity within individual ependymomas is unknown. We perform multiplatform molecular profiling of 6 spatially distinct samples from an ependymoma with C11orf95-RELA fusion. DNA methylation and RNA sequencing distinguish clusters of samples according to neuronal development gene expression programs that could also be delineated by differences in magnetic resonance blood perfusion. Exome sequencing and phylogenetic analysis reveal epigenomic intratumor heterogeneity and suggest that chromosomal structural alterations may precede accumulation of single-nucleotide variants during ependymoma tumorigenesis. In sum, these findings shed light on the oncogenesis and intratumor heterogeneity of ependymoma.

Background"Diffuse midline glioma (DMG), H3 K27M-mutant" is a new tumor entity established in the 2016 WHO classification of Tumors of the Central Nervous System that comprises a set of diffuse gliomas arising in midline structures and is molecularly defined by a K27M mutation in genes encoding the histone 3 variants H3.3 or H3.1. While this tumor entity is associated with poor prognosis in children, clinical experience in adults remains limited.MethodsPatient demographics, radiologic and pathologic characteristics, treatment course, progression, and patient survival were collected for 60 adult patients with DMG, H3 K27M-mutant. A subset of tumors also underwent next-generation sequencing. Analysis of progression-free survival and overall survival was conducted using Kaplan-Meier modeling, and univariate and multivariate analysis.ResultsMedian patient age was 32 years (range 18-71 years). Tumors were centered in the thalamus (n = 34), spinal cord (10), brainstem (5), cerebellum (4), or other midline sites (4), or were multifocal (3). Genomic profiling revealed p.K27M mutations exclusively in the H3F3A gene and an absence of mutations in HIST1H3B or HIST1H3C, which are present in approximately one-third of pediatric DMGs. Accompanying mutations in TP53, PPM1D, FGFR1, NF1, and ATRX were frequently found. The overall survival of this adult cohort was 27.6 months, longer than historical averages for both H3 K27M-mutant DMG in children and IDH-wildtype glioblastoma in adults.ConclusionsTogether, these findings indicate that H3 K27M-mutant DMG represents a heterogeneous disease with regard to outcomes, sites of origin, and molecular pathogenesis in adults versus children.

BackgroundOptimal techniques and patient selection for salvage reirradiation of high-grade glioma (HGG) are unclear. In this study, we identify prognostic factors for freedom from progression (FFP) and overall survival (OS) after reirradiation, risk factors for high-grade toxicity, and validate clinical prognostic scores.MethodsA total of 116 patients evaluated between 2000 and 2018 received reirradiation for HGG (99 WHO grade IV, 17 WHO grade III). Median time to first progression after initial therapy was 10.6 months. Salvage therapies before reirradiation included surgery (31%) and systemic therapy (41%). Sixty-five patients (56%) received single-fraction stereotactic radiosurgery (SRS) as reirradiation. The median biologically effective dose (BED) was 47.25 Gy, and the median planning target volume (PTV) was 4.8 cc for SRS and 95.0 cc for non-SRS treatments. Systemic therapy was given concurrently to 52% and adjuvantly to 74% of patients.ResultsMedian FFP was 4.9 months, and median OS was 11.0 months. Significant multivariable prognostic factors for FFP were performance status, time to initial progression, and BED; for OS they were age, time to initial progression, and PTV volume at recurrence. High-grade toxicity was correlated to PTV size at recurrence. Three-level prognostic scores were generated for FFP and OS, with cross-validated receiver operating characteristic area under the curve (AUC) of 0.640 and 0.687, respectively.ConclusionsClinical variables at the time of reirradiation for HGG can be used to prognosticate FFP and OS.

Radiotherapy improves survival for common childhood cancers such as medulloblastoma, leukemia, and germ cell tumors. Unfortunately, long-term survivors suffer sequelae that can include secondary neoplasia. Gliomas are common secondary neoplasms after cranial or craniospinal radiation, most often manifesting as high-grade astrocytomas with poor clinical outcomes. Here, we performed genetic profiling on a cohort of 12 gliomas arising after therapeutic radiation to determine their molecular pathogenesis and assess for differences in genomic signature compared to their spontaneous counterparts. We identified a high frequency of TP53 mutations, CDK4 amplification or CDKN2A homozygous deletion, and amplifications or rearrangements involving receptor tyrosine kinase and Ras-Raf-MAP kinase pathway genes including PDGFRA, MET, BRAF, and RRAS2. Notably, all tumors lacked alterations in IDH1, IDH2, H3F3A, HIST1H3B, HIST1H3C, TERT (including promoter region), and PTEN, which genetically define the major subtypes of diffuse gliomas in children and adults. All gliomas in this cohort had very low somatic mutation burden (less than three somatic single nucleotide variants or small indels per Mb). The ten high-grade gliomas demonstrated markedly aneuploid genomes, with significantly increased quantity of intrachromosomal copy number breakpoints and focal amplifications/homozygous deletions compared to spontaneous high-grade gliomas, likely as a result of DNA double-strand breaks induced by gamma radiation. Together, these findings demonstrate a distinct molecular pathogenesis of secondary gliomas arising after radiation therapy and identify a genomic signature that may aid in differentiating these tumors from their spontaneous counterparts.

Abstract BACKGROUND Chemotherapy for high grade gliomas (HGG) is limited by the blood-brain-barrier (BBB). Convection enhanced delivery (CED) improves chemotherapy delivery by utilizing fluid convection obviating the challenges of crossing the BBB while minimizing systemic toxicity. CED of nanoliposomal-irinotecan (Onivyde) showed to be a superior delivery route for anti-tumor activity in animal models. An advance of this trial is the development and use of real time CED, which utilizes MRI to visualize the CED process with the aid of co-convected contrast agents, monitoring delivery into the brain and affording for corrective action. METHODS This is a 3 + 3 single dose escalation trial with 2 cohorts: 20mg/ml and 40mg/ml. Onivyde and GAD were co-infused via the same catheters in a one-time delivery. The total volume of infusate, and consequently total dose, were personalized based on the patient’s tumor volume, and ranged from 20–680 mg of Onivyde, given via up to 4 catheters. Tumor diameters were allowed to be 1 – 4 cm, with injection volumes ranging from 2 – 17 mL of infusate. RESULTS 10 patients have been treated on this protocol, all in under 5 hours. There were 7 GBs, 2 anaplastic astrocytomas, and 1 oligoastrocytoma. Seven patients lived over a year after treatment, which is remarkable since median survival rates for multiply recurrent: GBs = 8 months, AAs = 11 months. Utilizing imaging software, we correlated pre-infusion modeling of the drug distribution with post-infusion imaging. A number of technical challenges were overcome by real time monitoring; the total volume of distribution (Vd), and the Vd to volume infused (Vi) ratio for each infusion was ~2. CONCLUSIONS Image-guided distribution allows for safe real-time placement and adjustment of CED cannula of Onivyde into patient’s brains. Such methods allow for maximum tumor coverage and warrant further studies with repeat dosing.

Abstract INTRODUCTION Diffuse low-grade gliomas (DLGG) treated with temozolomide (TMZ) can develop somatic hypermutation. We present data on the incidence and prognostic importance of somatic hypermutation in IDH-mutant DLGGs. METHODS We analyzed 120 patients treated on a phase II clinical trial of TMZ for sub-totally resected DLGGs to estimate the risk of recurrence and transformation after TMZ. To understand the prognostic significance of somatic hypermutation, we determined hypermutation status by exome or targeted sequencing on tumors from 81 patients with recurrent IDH-mutant DLGGs. 63/81 patients received TMZ before recurrence, including 28 patients treated on-trial. RESULTS With median follow-up of 8.7 years, 89 patients from the phase II trial progressed, 60 underwent 1 re-operation, and 36 had histologically confirmed transformation. The 8-year freedom from transformation was 48.2% and 59.9% for IDH-mutant astrocytomas and oligodendrogliomas, respectively; risk of transformation increased with pre-TMZ tumor volume (HR 2.5 per 100cc, p

IntroductionAlterations in the CDK4/6-RB signaling pathway are common causes of cell cycle dysregulation in many cancers, including glioblastoma. Palbociclib is an oral inhibitor of CDK4/6, which leads to phosphorylation of RB1 and cell-cycle arrest. We conducted a two-arm study evaluating efficacy and tissue pharmacokinetics/pharmacodynamics of palbociclib in patients with recurrent glioblastoma.MethodsEligibility criteria included confirmation of RB1 proficiency by IHC; ≤ 3 relapses; KPS ≥ 60; no limit on prior treatments. Arm 1 received palbociclib for 7 days prior to indicated resection followed by adjuvant palbociclib. Arm 2 received palbociclib without resection. Primary objective was PFS6; secondary included toxicity, OS, and ORR. Exploratory aims included biomarker assessment and pharmacokinetic/pharmacodynamic effects in surgical patients.ResultsTotal of 22 patients were enrolled; 6 on Arm 1 and 16 on Arm 2. Trial was stopped early secondary to lack of efficacy, with 95% of evaluable patients progressing within 6 months. Median PFS was 5.14 weeks (range 5 days-142 weeks) and median OS was 15.4 weeks (range 2-274 weeks). Two patients (10%) had related grade ≥ 3 AEs. In Arm 1, 5 patients had tissue concentrations of palbociclib felt to be sufficient for biological effect and paired samples available for RB1 IHC. There were no consistent changes in RB1 expression or cell proliferation in the paired tissue.ConclusionIn this trial, despite adequate tissue PK, palbociclib monotherapy was not an effective treatment for recurrent glioblastoma. However, these were heavily pretreated patients and targeting the CDK4/6 pathway may still deserve further exploration.

Abstract Neurocognitive function and quality of life are important clinical outcome measures for patients with lower grade glioma. Here, we performed neurocognitive testing and quality of life assessments in radiologically and clinically stable grade 2 and 3 glioma patients who are not receiving active treatment. METHODS Patients completed a computerized battery of standardized neurocognitive tests in the NIH Toolbox and quality of life assessments with the FACT-BR. We acquired patient demographic information, current performance status, current anti-epileptic therapy, treatment history, extent of resection at diagnosis and recurrence, tumor location, and histologic and molecular tumor characteristics. Tumor volumes were measured on T2 FLAIR MRIs. RESULTS We have enrolled 15 patients. All patients had previous resection (10 partial, 5 gross total), 11 received chemotherapy, and 6 prior radiation. Median age at testing was 41 years old (range 26 – 65). As a group, patients were impaired on processing speed and fluid cognition. Two patients were impaired on picture vocabulary, 6 on list sorting, 11 on processing speed, 6 on sequence memory, 4 on inhibitory control, 2 on dimensional change, 7 on fluid cognition, and 0 on crystallized cognition. Higher age was significantly associated with poorer age-corrected oral-reading, and sequence memory. Insula and parietal lesions were associated with slower processing speed. Previous chemotherapy treatment was associated with poorer dimensional change. On imaging, larger tumor volumes were associated with poorer list sorting, processing speed, and sequence memory. On the FACT-BR, older patients, patients with prior radiation or those with higher grade were associated with poorer social/family well-being. CONCLUSION The NIH Toolbox and FACT-BR are effective, accessible tools to assess neurocognitive function and quality of life in glioma patients. By correlating these assessments with patient and tumor characteristics, it may be possible to identify patients at risk for specific deficits and provide opportunity for intervention.

Simple Summary: Dynamic hyperpolarized carbon-13 (HP-13C) MRI is a novel molecular imaging technique that allows for real-time in vivo imaging of glycolysis and oxidative phosphorylation using [1-13C]pyruvate as a non-radioactive and non-toxic metabolic probe. While HP-13C MRI has recently demonstrated the potential to capture Warburg-related metabolic dysregulation in patients with progressive/treatment-naïve high-grade gliomas, further improvement in methodologies is still necessary to help monitor disease status and evaluate early predictors of therapeutic response. To this end, a multimodal 1H/HP-13C MRI protocol was implemented in this study, which incorporated advanced brain tumor MR acquisitions and improved HP-13C metabolic imaging methodologies for the serial monitoring of patients with glioma over the course of clinical treatment. This study aimed to implement a multimodal 1H/HP-13C imaging protocol to augment the serial monitoring of patients with glioma, while simultaneously pursuing methods for improving the robustness of HP-13C metabolic data. A total of 100 1H/HP [1-13C]-pyruvate MR examinations (104 HP-13C datasets) were acquired from 42 patients according to the comprehensive multimodal glioma imaging protocol. Serial data coverage, accuracy of frequency reference, and acquisition delay were evaluated using a mixed-effects model to account for multiple exams per patient. Serial atlas-based HP-13C MRI demonstrated consistency in volumetric coverage measured by inter-exam dice coefficients (0.977 ± 0.008, mean ± SD; four patients/11 exams). The atlas-derived prescription provided significantly improved data quality compared to manually prescribed acquisitions (n = 26/78; p = 0.04). The water-based method for referencing [1-13C]-pyruvate center frequency significantly reduced off-resonance excitation relative to the coil-embedded [13C]-urea phantom (4.1 ± 3.7 Hz vs. 9.9 ± 10.7 Hz; p = 0.0007). Significantly improved capture of tracer inflow was achieved with the 2-s versus 5-s HP-13C MRI acquisition delay (p = 0.007). This study demonstrated the implementation of a comprehensive multimodal 1H/HP-13C MR protocol emphasizing the monitoring of steady-state/dynamic metabolism in patients with glioma. [ABSTRACT FROM AUTHOR]