Citations

Isocitrate dehydrogenase (IDH) mutant gliomas are a primary malignancy of the central nervous system (CNS) malignancies, most commonly affecting adults under the age of 55. Standard of care therapy for IDH-mutant gliomas involves maximal safe resection, radiotherapy, and chemotherapy. However, despite good initial responses to multimodality treatment, recurrence is virtually universal. IDH-mutant gliomas represent a life-limiting prognosis. For this reason, there is a great need for novel treatments that can prolong survival. Uniquely for IDH-mutant gliomas, the IDH mutation is the direct driver of oncogenesis through its oncometabolite 2-hydroxygluterate. Inhibition of this mutated IDH with a corresponding reduction in 2-hydroxygluterate offers an attractive treatment target. Researchers have tested several IDH inhibitors in glioma through preclinical and early clinical trials. A phase III clinical trial of an IDH1 and IDH2 inhibitor vorasidenib yielded promising results among patients with low-grade IDH-mutant gliomas who had undergone initial surgery and no radiation or chemotherapy. However, many questions remain regarding optimal use of IDH inhibitors in clinical practice. In this review, we discuss the importance of IDH mutations in oncogenesis of adult-type diffuse gliomas and current evidence supporting the use of IDH inhibitors as therapeutic agents for glioma treatment. We also examine unresolved questions and propose potential directions for future research.

Introduction: Glioblastoma is a uniformly lethal primary central nervous system neoplasm. Despite the increased understanding of its pathophysiology and treatment advancements, median overall survival for patients with glioblastoma, IDH-wild type remains 14 to 21 months from diagnosis. Case Report: We present the case of a 48-year-old female who presented with a focal seizure and was found to have a right frontal lobe mass on the brain magnetic resonance imaging. She underwent gross total resection and received a histological diagnosis of glioblastoma. She received radiotherapy and 6 cycles of carmustine (BCNU). Seventeen months later, she developed left hemiparesis. Imaging was concerning for tumor progression, and she was treated with 1 cycle of mechlorethamine, vincristine (oncovin), procarbazine, and prednisone (MOPP). Subsequent surveillance imaging demonstrated a therapeutic response. Twenty-seven years after her glioblastoma diagnosis, she developed status epilepticus and died from respiratory failure. Neuropathology on autopsy demonstrated extensive treatment-related changes but no evidence of recurrent glioblastoma. Genomic testing performed over 30 years after her original diagnosis revealed a profile diagnostic of glioblastoma, IDH-wild type per 2021 World Health Organization criteria. Conclusions: This patient is one of the longest-known survivors of glioblastoma, IDH-wild type, with pathologic confirmation of glioblastoma at the time of her resection and no evidence of residual disease 26 years after her last treatment. She presented with multiple factors associated with long-term glioblastoma survivorship, including female sex, young age, high Karnofsky score, and multimodal therapy. This case shows that long-term survival after glioblastoma diagnosis is possible and likely mediated through a combination of individual, tumor, and treatment factors.

Background: The compensatory reserve metric (CRM) provides a novel marker of hemodynamic status in prediction of sudden cardiovascular decompensation during central hypovolemia. The CRM has previously been calculated using arterial waveforms obtained from a photoplethysmographic volume-clamp technique. However, the in-field use of pulse oximetry is becoming more prominent in research and medicine. To improve in-field applicability of the CRM, this project aimed to validate pulse-oximetry derived CRM values relative to physiologic data during simulated hemorrhage through application of lower body negative pressure (LBNP). Methods: Forty-nine healthy adults (25 females) underwent a graded LBNP protocol with the following 5-minute stages: -0, -15, -30, -45, -60, -70, -80, -90, and 100 mmHg, or until the onset of pre-syncopal symptoms (tolerance) was reached. Arterial waveforms were sampled using pulse oximetry (Massimo Radical 7). The CRM was calculated using a validated one-dimensional convolutional neural network. A brachial artery catheter was used to measure intraarterial pressure. A 3-lead ECG was used to measure heart rate. SpO2 was measured using pulse oximetry. Cardiac output and stroke volume were estimated using the photoplethysmographic volume-clamp. Data were binned for the last thirty seconds of each completed stage, and at tolerance. Fixed-effect linear mixed models with repeated measures were used to examine the association between CRM values and physiologic variables. A priori significance was set at P<0.05. Results: The median LBNP stage reached was 70 mmHg (Range: 45-100 mmHg). Relative to baseline, at tolerance there was a 50±12% ( P<0.001) mean reduction in stroke volume, 65±27% ( P<0.001) increase in heart rate, 18±8% ( P<0.001) reduction in mean arterial pressure, 21±7% ( P<0.001) systolic blood pressure, 8±9% ( P<0.001) diastolic blood pressure, and 39±12% ( P<0.001) pulse pressure. The CRM obtained using pulse oximetry was significantly associated with a reduction in stroke volume ( P<0.001), increase in heart rate ( P<0.001), and reductions in systolic ( P=0.033), diastolic ( P=0.036), and pulse pressure ( P=0.002). There was no statistically significant association between CRM and cardiac output ( P=0.421), SpO2 ( P=0.408), or mean arterial pressure ( P=0.214). Conclusion: The CRM obtained using pulse oximetry may be a valid, reliable marker of hemodynamic status with promising in-field applications. Future studies warrant investigation of feasibility and applicability within various contexts ranging from the operating room to the battlefield. The presented work was funded in part by the Congressionally Directed Medical Research Program (Award No. DM180240) and Offce of Naval Research (Awards No. N00014-18-D-7001 and N00014-19-C-2017). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Congenital facial weakness (CFW) encompasses a heterogenous set of rare disorders presenting with decreased facial movement from birth, secondary to impaired function of the facial musculature. The aim of the present study is to provide an analysis of subject-reported oral health-related quality of life (OHRQoL) in congenital facial weakness (CFW) disorders. Forty-four subjects with CFW and age- and sex- matched controls were enrolled in an Institutional Review Board (IRB)-approved study. Demographic data, medical and surgical history, comprehensive oral examination, and the Oral Health Impact Profile (OHIP-14) were obtained. Compared to unaffected controls, subjects with CFW had higher OHIP-14 scores overall (mean ± SD: 13.11 ± 8.11 vs. 4.46 ± 4.98, p < 0.0001) and within five of seven oral health domains, indicating decreased OHRQoL. Although subjects with Moebius syndrome (MBS) were noted to have higher OHIP-14 scores than those with Hereditary Congenital Facial Paresis (HCFP), there was no significant correlation in OHIP-14 score to age, sex, or specific diagnosis. An increase in OHIP-14 scores in subjects was detected in those who had undergone reanimation surgery. In conclusion, subjects with CFW had poorer OHRQoL compared to controls, and subjects with MBS had poorer OHRQoL than subjects with HCFP. This study provides better understanding of oral health care needs and quality of life in a CFW cohort and suggests that guidelines for dental treatment are required.

Introduction: Hydrochlorothiazide (HCTZ) is among the most commonly prescribed antihypertensives in the US, yet <50% of HCTZ treated patients achieve blood pressure (BP) control. Hypothesis: Integrating metabolomic and genomic profiles of HCTZ treated patients could identify novel pathways/biomarkers for optimizing the use of HCTZ. Methods: Primary analysis included 228 white hypertensives treated with HCTZ from the Pharmacogenomic Evaluation of Antihypertensive Response (PEAR) study. Genotyping was determined via Illumina Omni 1M-Quad Chip and untargeted metabolomics was performed on baseline fasting plasma samples using a GC-TOF MS platform. Pathway analysis was used to integrate metabolites significantly associated with HCTZ BP response (FDR<.05) and genetic signals at p<5x10-5 from HCTZ BP genome-wide analysis. Replication was conducted in another 212 white HCTZ treated patients. Replicated genetic signals were used to create a BP response score by summing their BP lowering alleles. We validated this score by testing it in 196 white HCTZ treated patients in the Genetic Epidemiology of Responses to Antihypertensives (GERA) study. Results: Thirteen metabolites were significantly associated with HCTZ systolic BP (SBP) and diastolic BP (DBP) responses (FDR<.05). Metabolomics-genomics integration revealed significant metabolites along with rs2727563 PRKAG2, rs12604940 DCC, and rs13262930 EPHX2, in the netrin signalling pathway (p=1x10-5), as potential markers significantly influencing HCTZ BP response. We successfully replicated those 3 genetic signals and added their alleles to create a response score which explained 11.3% and 11.9% of the variability to HCTZ SBP and DBP responses, respectively. We found that patients carrying one “response” allele had a significantly worse response than carriers of six alleles (ΔSBP/ΔDBP: -1.5/1.2 vs -16.3/-10.4 mmHg, respectively, SBP score p=1x10-8 and DBP score p=3x10-9). We further validated this response score by testing it in the GERA (DBP score p=0.03, SBP score p=0.07). Conclusion: This study highlights the power of using different omics to identify novel pathways/biomarkers of drug response, and suggests that PRKAG2, DCC and EPHX2 might be important determinants of HCTZ BP response.

Abstract The pathophysiological mechanisms driving disease progression of frontotemporal lobar degeneration (FTLD) and corresponding biomarkers are not fully understood. We leveraged aptamer-based proteomics (> 4,000 proteins) to identify dysregulated communities of co-expressed cerebrospinal fluid proteins in 116 adults carrying autosomal dominant FTLD mutations (C9orf72, GRN, MAPT) compared to 39 noncarrier controls. Network analysis identified 31 protein co-expression modules. Proteomic signatures of genetic FTLD clinical severity included increased abundance of RNA splicing (particularly in C9orf72 and GRN) and extracellular matrix (particularly in MAPT) modules, as well as decreased abundance of synaptic/neuronal and autophagy modules. The generalizability of genetic FTLD proteomic signatures was tested and confirmed in independent cohorts of 1) sporadic progressive supranuclear palsy-Richardson syndrome and 2) frontotemporal dementia spectrum syndromes. Network-based proteomics hold promise for identifying replicable molecular pathways in adults living with FTLD. ‘Hub’ proteins driving co-expression of affected modules warrant further attention as candidate biomarkers and therapeutic targets.

Abstract Background Despite the lack of proven therapies for recurrent high-grade glioma (HGG), only 8%–11% of patients with glioblastoma participate in clinical trials, partly due to stringent eligibility criteria. Prior bevacizumab treatment is a frequent exclusion criterion, due to difficulty with response assessment and concerns for rebound edema following antiangiogenic discontinuation. There are no standardized trial eligibility rules related to prior antiangiogenic use. Methods We reviewed ClinicalTrials.gov listings for glioma studies starting between May 2009 and July 2022 for eligibility rules related to antiangiogenics. We also reviewed the literature pertaining to bevacizumab withdrawal. Results Two hundred and ninety-seven studies for patients with recurrent glioma were reviewed. Most were phase 1 (n = 145, 49%), non-randomized (n = 257, 87%), evaluated a drug-only intervention (n = 223, 75%), and had a safety and tolerability primary objective (n = 181, 61%). Fifty-one (17%) excluded participants who received any antiangiogenic, one (0.3%) excluded participants who received any non-temozolomide systemic therapy. Fifty-nine (20%) outlined washout rules for bevacizumab (range 2–24 weeks, 4-week washout n = 35, 12% most common). Seventy-eight required a systemic therapy washout (range 1–6 weeks, 4-week washout n = 34, 11% most common). Nine permitted prior bevacizumab use with limitations, 18 (6%) permitted any prior bevacizumab, 5 (2%) were for bevacizumab-refractory disease, and 76 (26%) had no rules regarding antiangiogenic use. A literature review is then presented to define standardized eligibility criteria with a 6-week washout period proposed for future trial design. Conclusions Interventional clinical trials for patients with HGG have substantial heterogeneity regarding eligibility criteria pertaining to bevacizumab use, demonstrating a need for standardizing clinical trial design.

Abstract Background: Women with an inherited pathogenic variant in BRCA1 or BRCA2 have a greatly increased risk of developing ovarian cancer, but the importance of behavioral factors is less clear. We used a case-only design to compare the magnitude of associations with established reproductive, hormonal, and lifestyle risk factors between BRCA mutation carriers and noncarriers. Methods: We pooled data from five studies from the Ovarian Cancer Association Consortium including 637 BRCA carriers and 4,289 noncarriers. Covariate-adjusted generalized linear mixed models were used to estimate interaction risk ratios (IRR) and 95% confidence intervals (CI), with BRCA (carrier vs. noncarrier) as the response variable. Results: IRRs were above 1.0 for known protective factors including ever being pregnant (IRR = 1.29, 95% CI; 1.00–1.67) and ever using the oral contraceptive pill (1.30, 95% CI; 1.07–1.60), suggesting the protective effects of these factors may be reduced in carriers compared with noncarriers. Conversely, the IRRs for risk factors including endometriosis and menopausal hormone therapy were below 1.0, suggesting weaker positive associations among BRCA carriers. In contrast, associations with lifestyle factors including smoking, physical inactivity, body mass index, and aspirin use did not appear to differ by BRCA status. Conclusions: Our results suggest that associations with hormonal and reproductive factors are generally weaker for those with a pathogenic BRCA variant than those without, while associations with modifiable lifestyle factors are similar for carriers and noncarriers. Impact: Advice to maintain a healthy weight, be physically active, and refrain from smoking will therefore benefit BRCA carriers as well as noncarriers.