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Importance: The prognosis for patients with glioblastoma is poor following standard therapy with surgical resection, radiation, temozolomide, and tumor-treating fields., Objectives: To evaluate the combination of veliparib and temozolomide in glioblastoma based on preclinical data demonstrating significant chemosensitizing effects of the polyadenosine diphosphate-ribose polymerase 1/2 inhibitor veliparib when combined with temozolomide., Design, Setting, and Participants: Patients with newly diagnosed glioblastoma with MGMT promoter hypermethylation who had completed concomitant radiation and temozolomide were enrolled between December 15, 2014, and December 15, 2018, in this Alliance for Clinical Trials in Oncology trial. The data for this analysis were locked on April 21, 2023., Interventions: Patients were randomized and treated with standard adjuvant temozolomide (150-200 mg/m2 orally, days 1-5) combined with either placebo or veliparib (40 mg orally, twice daily, days 1-7) for 6 cycles., Main Outcomes and Measures: The primary end point for the phase 3 portion of the trial was overall survival (OS)., Results: There were 322 patients randomized during the phase 2 accrual period and an additional 125 patients randomized to complete the phase 3 accrual, for a total of 447 patients in the final phase 3 analysis. The median (range) age for patients was 60 (20-85) years and 190 patients (42.5%) were female. The median OS was 24.8 months (90% CI, 22.6-27.7) for the placebo arm and 28.1 months (90% CI, 24.3-33.3) for the veliparib arm (P = .17). The difference in survival did not meet the prespecified efficacy end point. However, there was a separation of the survival curves that favored the veliparib arm over 24 to 48 months of follow-up. The experimental combination was well tolerated with an acceptable elevation in grade 3 or 4 hematologic toxic effects., Conclusions and Relevance: This trial found that adding veliparib to adjuvant temozolomide did not significantly extend OS in patients with newly diagnosed, MGMT-hypermethylated glioblastoma., Trial Registration: ClinicalTrials.gov Identifier: NCT02152982.

The extracellular microenvironment modulates glioma behaviour. It remains unknown if blood-brain barrier disruption merely reflects or functionally supports glioma aggressiveness. We utilised intra-operative microdialysis to sample the extracellular metabolome of radiographically diverse regions of gliomas and evaluated the global extracellular metabolome via ultra-performance liquid chromatography tandem mass spectrometry. Among 162 named metabolites, guanidinoacetate (GAA) was 126.32x higher in enhancing tumour than in adjacent brain. 48 additional metabolites were 2.05-10.18x more abundant in enhancing tumour than brain. With exception of GAA, and 2-hydroxyglutarate in IDH-mutant gliomas, differences between non-enhancing tumour and brain microdialysate were modest and less consistent. The enhancing, but not the non-enhancing glioma metabolome, was significantly enriched for plasma-associated metabolites largely comprising amino acids and carnitines. Our findings suggest that metabolite diffusion through a disrupted blood-brain barrier may largely define the enhancing extracellular glioma metabolome. Future studies will determine how the altered extracellular metabolome impacts glioma behaviour., (© 2023. The Author(s).)

Isocitrate dehydrogenase (IDH) 1 or 2 mutations confer a favorable prognosis compared to IDH-wildtype in astrocytoma, frequently denoting a lower grade malignancy. However, recent molecular profiling has identified specific aggressive tumor subgroups with clear clinical prognostic implications that are independent of histologic grading. The homozygous deletion of CDKN2A/B is the strongest implicated independent indicator of the poor prognosis within IDH-mutant astrocytoma, and the identification of this alteration in these lower histologic grade tumors transforms their biology toward an aggressive grade 4 phenotype clinically. CDKN2A/B homozygous deletion is now sufficient to define a grade 4 tumor in IDH-mutant astrocytomas regardless of histologic appearance, yet there are currently no effective molecularly informed targeted therapies for these tumors. The biological impact of CDKN2A/B homozygous deletion in IDH-mutant tumors and the optimal treatment strategy for this molecular subgroup remains insufficiently explored. Here we review the current understanding of the translational significance of homozygous deletion of CDKN2A/B gene expression in IDH-mutant astrocytoma and associated diagnostic and therapeutic implications., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: Pineal parenchymal tumor of intermediate differentiation (PPTID) is a neoplasm of pinealocyte origin and of intermediate differentiation (WHO grade 2 or 3). Treatment selection and prognostication is challenging for this rare, recently characterized tumor. In this single study, we review our clinical experience in patients with PPTID as well as pooled data from two other institutions., Methods: This is a retrospective analysis of patients seen at Mayo Clinic, with additional data pooled from two similar studies at outside institutions for comparison and further analysis., Results: Ten adult patients (6 male) were identified. Median age at diagnosis was 36 years (range 13-73 years). Patients were followed between 3 and 88 months with no reported deaths. The most common presenting symptom was headache, followed by nausea. Nine patients had local disease without neuroaxial dissemination at diagnosis, one of which had tumor recurrence at 36 months. Two patients underwent gross total resection (GTR) without adjuvant radiation without recurrence (PFS 4 and 46 months). In our combined analysis, we reviewed 36 patients from three different institutions. Four patients presented with disseminated disease. GTR was achieved for 16 patients. Twenty-eight patients received adjuvant radiation therapy and 16 patients experienced disease recurrence. Median overall survival was 44 months., Conclusion: Our single institution experience and combined multi-institution analysis suggest GTR is associated with improved outcomes. The role of adjuvant radiation therapy and utility of CSI compared to focal RT is less unclear. Prospective study is required to identify optimal adjuvant therapy selection., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: The presence of necrosis or microvascular proliferation was previously the hallmark for glioblastoma (GBM) diagnosis. The 2021 WHO classification now considers IDH-wildtype diffuse astrocytic tumors without the histological features of glioblastoma (that would have otherwise been classified as grade 2 or 3) as molecular GBM (molGBM) if they harbor any of the following molecular abnormalities: TERT promoter mutation, EGFR amplification, or chromosomal + 7/-10 copy changes. We hypothesize that these tumors are early histological GBM and will eventually develop the classic histological features., Methods: Medical records from 65 consecutive patients diagnosed with molGBM at three tertiary-care centers from our institution were retrospectively reviewed from November 2017-October 2021. Only patients who underwent reoperation for tumor recurrence and whose tissue at initial diagnosis and recurrence was available were included in this study. The detailed clinical, histopathological, and radiographic scenarios are presented., Results: Five patients were included in our final cohort. Three (60%) patients underwent reoperation for recurrence in the primary site and 2 (40%) underwent reoperation for distal recurrence. Microvascular proliferation and pseudopalisading necrosis were absent at initial diagnosis but present at recurrence in 4 (80%) patients. Radiographically, all tumors showed contrast enhancement, however none of them showed the classic radiographic features of GBM at initial diagnosis., Conclusions: In this manuscript we present preliminary data for a hypothesis that molGBMs are early histological GBMs diagnosed early in their natural history of disease and will eventually develop necrosis and microvascular proliferation. Further correlative studies are needed in support of this hypothesis., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: In-field high-grade glioma (HGG) recurrence is a common challenge with limited treatment options, including re-irradiation. The radiotracer 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine ( 18 F-DOPA) crosses the blood brain barrier and demonstrates high uptake in tumor, but low uptake in normal tissue. This study investigated whether 18 F-DOPA positron emission tomography (PET) and MRI guided re-irradiation for recurrent HGG may improve progression free survival (PFS)., Methods: Adults with recurrent or progressive HGG previously treated with radiation were eligible. The primary endpoint was a 20% improvement from the historical control PFS at 3 months (PFS3) of 20% with systemic therapy alone. Re-RT dose was 35 Gy in 10 fractions. The target volume was MRI T1 contrast-enhancement defined tumor plus 18 F-DOPA PET defined tumor., Results: Twenty patients completed treatment per protocol. Diagnosis was most commonly glioblastoma, IDH-wildtype (60%). MRI-defined volumes were expanded by a median 43% (0-436%) by utilizing 18 F-DOPA PET. PFS3 was 85% (95% CI 63.2-95.8%), meeting the primary endpoint of PFS3 ≥ 40%. With 9.7 months median follow-up, 17 (85%) had progressed and 15 (75%) had died. Median OS from re-RT was 8.8 months. Failure following re-RT was within both the MRI and PET tumor volumes in 75%, MRI only in 13%, PET only in 0%, and neither in 13%. Four (20%) patients experienced grade 3 toxicity, including CNS necrosis (n = 2, both asymptomatic with bevacizumab initiation for radiographic findings), seizures (n = 1), fatigue (n = 1), and nausea (n = 1). No grade 4-5 toxicities were observed., Conclusion: 18 F-DOPA PET-guided re-irradiation for progressive high-grade glioma appears safe and promising for further investigation., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Diffuse midline gliomas (DMG) with the H3 K27M-mutation are a well-described entity with most DMG harboring this mutation, with notable heterogeneity in adults. No therapy has been proven to improve survival in this tumor type. Panobinostat is a histone deacetylase inhibitor that may have therapeutic benefit., Methods: We report our retrospective experience with use of panobinostat in adults (> 18 years) with H3 K27M-mutant DMG treated at Mayo Clinic (Rochester) from January 2016 to August 2020, with follow-up until October 2021. Survival was calculated using the Kaplan-Meier method., Results: 4 patients with H3 K27M-mutant glioma were treated with panobinostat as compassionate use. Patients had a median age of 40 years (range 22-62 years) and 2 were female. Tumor location was midline for all patients, spinal cord (n = 2), brainstem (n = 1), and thalamus (n = 1). All tumors were IDH1/IDH2 wildtype. 3 patients received radiotherapy followed by adjuvant panobinostat. All patients had no other pharmacologic therapy utilized prior to or during panobinostat therapy aside from concurrent dexamethasone utilized in 3 patients. No patient experienced a grade 2 or higher (per CTCAE grade) adverse effect. The median overall survival was 42 months, median progression free survival of 19 months, 2 patients were alive at last follow up (both with spinal cord tumors and received radiation). The best response was stable disease in 2 patients and a partial response in 1 patient., Conclusions: This is the first report of clinical outcomes of panobinostat in adults with H3 K27M-mutant DMG. We showed that it is well-tolerated at the dosage schedule that we describe, with no serious adverse effects throughout the study period., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: Histological diagnosis of glioblastoma (GBM) was determined by the presence of necrosis or microvascular proliferation (histGBM). The 2021 WHO classification now considers IDH-wildtype diffuse astrocytic tumors without the histological features of glioblastoma (that would have otherwise been classified as grade 2 or 3) as molecular GBM (molGBM, WHO grade 4) if they harbor any of the following molecular abnormalities: TERT promoter mutation, EGFR amplification, or chromosomal + 7/- 10 copy changes. The objective of this study was to explore and compare the survival outcomes between histGBM and molGBM., Methods: Medical records for patients diagnosed with GBM at the three tertiary care academic centers of our institution from November 2017 to October 2021. Only patients who underwent adjuvant chemoradiation were included. Patients without molecular feature testing or with an IDH mutation were excluded. Univariable and multivariable analyses were performed to evaluate progression-free (PFS) and overall- survival (OS)., Results: 708 consecutive patients were included; 643 with histGBM and 65 with molGBM. Median PFS was 8 months (histGBM) and 13 months (molGBM) (p = 0.0237) and median OS was 21 months (histGBM) versus 26 months (molGBM) (p = 0.435). Multivariable analysis on the molGBM sub-group showed a worse PFS if there was contrast enhancement on MRI (HR 6.224 [CI 95% 2.187-17.714], p < 0.001) and a superior PFS on patients with MGMT methylation (HR 0.026 [CI 95% 0.065-0.655], p = 0.007)., Conclusions: molGBM has a similar OS but significantly longer PFS when compared to histGBM. The presence of contrast enhancement and MGMT methylation seem to affect the clinical behavior of this subset of tumors., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Tesevatinib is a potent oral brain penetrant EGFR inhibitor currently being evaluated for glioblastoma therapy. Tesevatinib distribution was assessed in wild-type (WT) and Mdr1a/b (-/-) Bcrp (-/-) triple knockout (TKO) FVB mice after dosing orally or via osmotic minipump; drug-tissue binding was assessed by rapid equilibrium dialysis. Two hours after tesevatinib dosing, brain concentrations in WT and TKO mice were 0.72 and 10.03 μg/g, respectively. Brain-to-plasma ratios (Kp) were 0.53 and 5.73, respectively. With intraperitoneal infusion, brain concentrations were 1.46 and 30.6 μg/g (Kp 1.16 and 25.10), respectively. The brain-to-plasma unbound drug concentration ratios were substantially lower (WT mice, 0.03-0.08; TKO mice, 0.40-1.75). Unbound drug concentrations in brains of WT mice were 0.78 to 1.59 ng/g. In vitro cytotoxicity and EGFR pathway signaling were evaluated using EGFR -amplified patient-derived glioblastoma xenograft models (GBM12, GBM6). In vivo pharmacodynamics and efficacy were assessed using athymic nude mice bearing either intracranial or flank tumors treated by oral gavage. Tesevatinib potently reduced cell viability [IC 50 GBM12 = 11 nmol/L (5.5 ng/mL), GBM6 = 102 nmol/L] and suppressed EGFR signaling in vitro However, tesevatinib efficacy compared with vehicle in intracranial (GBM12, median survival: 23 vs. 18 days, P = 0.003) and flank models (GBM12, median time to outcome: 41 vs. 33 days, P = 0.007; GBM6, 44 vs. 33 days, P = 0.007) was modest and associated with partial inhibition of EGFR signaling. Overall, tesevatinib efficacy in EGFR -amplified PDX GBM models is robust in vitro but relatively modest in vivo , despite a high brain-to-plasma ratio. This discrepancy may be explained by drug-tissue binding and compensatory signaling., (©2021 American Association for Cancer Research.)

We present a case of bilateral synchronous orbital muscle infiltration of extra-neural glioblastoma metastases with evidence of focal treatment response. The orbital infiltration was preceded by evidence of leptomeningeal disease, and followed by further symptomatic perineural spread of tumor along the second and third division of the trigeminal nerve and into the masticator space., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The treatment of metastatic lesions in the brain represents a serious unmet medical need in the field of neuro-oncology. Even though many effective compounds have demonstrated success in treating peripheral (non-CNS) tumors with targeted agents, one aspect of this lack of success in the brain may be related to poor delivery of otherwise effective compounds. Many factors can influence the brain delivery of these agents, but one key barrier is a heterogeneously "leaky" BBB that expresses efflux transporters that limit the BBB permeability for many targeted agents. Future success in therapeutics for brain metastases must take into account the adequate delivery of "active, free drug" to the target, and may include combinations of targeted drugs that are appropriate to address each individual patient's tumor type. This review discusses some issues that are pertinent to precision medicine for brain metastases, using specific examples of tumor types that have a high incidence of brain metastases.

The blood-brain barrier (BBB) excludes the vast majority of cancer therapeutics from normal brain. However, the importance of the BBB in limiting drug delivery and efficacy is controversial in high-grade brain tumors, such as glioblastoma (GBM). The accumulation of normally brain impenetrant radiographic contrast material in essentially all GBM has popularized a belief that the BBB is uniformly disrupted in all GBM patients so that consideration of drug distribution across the BBB is not relevant in designing therapies for GBM. However, contrary to this view, overwhelming clinical evidence demonstrates that there is also a clinically significant tumor burden with an intact BBB in all GBM, and there is little doubt that drugs with poor BBB permeability do not provide therapeutically effective drug exposures to this fraction of tumor cells. This review provides an overview of the clinical literature to support a central hypothesis: that all GBM patients have tumor regions with an intact BBB, and cure for GBM will only be possible if these regions of tumor are adequately treated., (© The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Seizures in patients with glioblastoma are associated with worse quality of life. However, their incidence, clinical characteristics, and prognostic implications are less well characterized., Objective: This study was undertaken to provide a contemporary experience along with benchmark data relevant to the above in patients with glioblastoma. It also sought to reexplore improved survival with seizures, as observed by others., Methods: In this single-institution study, patients with glioblastoma from 2010 through 2014 had their medical records reviewed in detail., Results: Among 122 patients, 58 (48%) had a seizure history. Of these, 67% had more than 1, 41% had generalized seizures, and most received antiseizure medication (most commonly levetiracetam). The median survival for patients with seizures was 1.66 years and 0.87 years for those without (hazard ratio for risk of death with seizures: 0.72; 95% confidence interval: 0.43, 1.21; P = .22 by the log-rank test)., Conclusion: Seizures are common in patients with glioblastoma and, in contrast to earlier reports, are not associated with a statistically significant improvement in survival.

Seizures occur in most patients with primary malignant tumors and are associated with poor quality of life. To our knowledge, no previous studies have sought descriptions of quality of life in patients' own words. Patients with a history of a malignant primary brain tumor and seizures participated in semi-structured interviews, which were analyzed with qualitative methodology. Twenty-seven patients participated, most with high grade brain tumors. Most were receiving anti-seizure medication. Three distinct themes emerged: (1) the first seizure as a sentinel event, as manifested in part by how patients described their first seizure in remarkable detail ("I clearly remember the date…"); (2) seizures as inextricably tied to the brain tumor itself; for example, one patient explained how he "always wondered what was happening with my brain tumor" with each seizure; and (3) adaptation and acceptance-or lack therefore-to seizures. With respect to this third theme, patients conveyed frustration from an inability to work, to drive, and to take care of their children ("It's like you are 15 all over again.") Others described frustration with taking antiseizure medications ("I felt like an 80 year old, now taking her pills every day"). However, some patients had adapted or resigned themselves ("…so much of life is out of control-you just gotta take what you get."). These findings have future research implications but should also serve to make healthcare providers more aware of the heavy emotional burden that seizures thrust upon brain tumor patients.

This study assesses the controversial role of temozolomide (TMZ) concurrent with adjuvant radiation (RT) in patients with anaplastic astrocytoma (AA). The impact of isocitrate dehydrogenase (IDH) status on therapy and outcomes is also examined. All adult patients diagnosed with AA from 2001 to 2011 and treated with standard doses of adjuvant RT were identified retrospectively for clinical data extraction. IDH status was determined by IDH1-R132H immunostain and sequencing for other mutations in IDH1/IDH2. Cumulative survival probabilities were estimated using the Kaplan-Meier method. Cox proportional hazards regression models were fit for univariable/multivariable analyses. 136 patients had received concurrent TMZ while 29 had not. Of these, IDH status was determined on 114 and 27 patients, respectively. On univariable analysis, improved five-year survival was independently associated with concurrent TMZ (46.2 vs. 29.3%, p = 0.02) and IDH mutation (78.9 vs. 22.0%, p < 0.001). IDH mutation was additionally associated with a greater likelihood of extensive resection possibly secondary to a more favorable tumor location. Gross total/subtotal resections also led to improved survival when compared to biopsy alone on univariable analysis. On multivariable analysis, the association with five-year survival persisted for both concurrent TMZ and IDH mutation, but not with extent of surgery. Both IDH mutation and concurrent TMZ are associated with improved five-year survival in patients with AA who are receiving adjuvant RT. Secondarily, the association between five-year survival and extent of resection is lost on multivariable analysis. This suggests a possible association between IDH mutation, tumor location and consequent resectability.

Purpose: Effective sensitizing strategies potentially can extend the benefit of temozolomide (TMZ) therapy in patients with glioblastoma (GBM). We previously demonstrated that robust TMZ-sensitizing effects of the [poly (ADP-ribose) polymerase] (PARP) inhibitor veliparib (ABT-888) are restricted to TMZ-sensitive GBM xenografts. The focus of this study is to provide an understanding for the differential sensitization in paired TMZ-sensitive and -resistant GBM models., Experimental Design: The impact of veliparib on TMZ-induced cytotoxicity and DNA damage was evaluated in vitro and in vivo in models of acquired TMZ resistance (GBM12TMZ-mgmt(High), GBM12TMZ-mgmt(Low), and U251TMZ), inherent TMZ resistance (T98G), and TMZ-sensitive (U251 and GBM12). In vivo drug efficacy, pharmacokinetics, and pharmacodynamics were analyzed using clinically relevant dosing regimens., Results: Veliparib enhanced TMZ cytotoxicity and DNA-damage signaling in all GBM models in vitro with more pronounced effects in TMZ-resistant lines at 3 to 10 μmol/L veliparib. In vivo, combined TMZ/veliparib, compared with TMZ alone, significantly delayed tumor growth and enhanced DNA-damage signaling and γH2AX levels in the sensitive GBM12 xenograft line but not in the resistant GBM12TMZ lines. The pharmacokinetic profile of veliparib was similar for GBM12 and GBM12TMZ tumors with Cmax (∼1.5 μmol/L) in tissue significantly lower than concentrations associated with optimal in vitro sensitizing effects for resistant tumors. In contrast, robust suppression of PARP-1 expression by shRNA significantly increased TMZ sensitivity of U251TMZ in vitro and in vivo., Conclusions: In vitro cytotoxicity assays do not adequately model the therapeutic index of PARP inhibitors, as concentrations of veliparib and TMZ required to sensitize TMZ-resistant cancer cells in vivo cannot be achieved using a tolerable dosing regimen., (©2014 American Association for Cancer Research.)