EXTH-46. MRS BASED BIOMARKERS OF IDH1 MUTANT GLIOMA RESPONSE TO THE IDH INHIBITOR BAY-1436032

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi173-vi173
Author(s):  
Donghyun Hong ◽  
Noriaki Minami ◽  
Céline Taglang ◽  
Georgios Batsios ◽  
Anne Marie Gillespie ◽  
...  
Keyword(s):  
Animal Models ◽  
Animal Studies ◽  
Response To Treatment ◽  
Resonance Spectroscopy ◽  
Low Grade ◽  
Isocitrate Dehydrogenase 1 ◽  
1H Mrs ◽  
Hyperpolarized 13C ◽  
13C Mrs ◽  
Mutant Idh1

Abstract Gliomas are the most prevalent type of brain tumor in the central nervous system. Mutations in the cytosolic enzyme isocitrate dehydrogenase 1 (IDH1) are a common feature of primary low-grade gliomas, catalyzing the conversion of α-ketoglutarate (αKG) to the oncometabolite 2-hydroxyglutarate (2HG), and mutant IDH1 is a therapeutic target for these tumors. Several mutant IDH inhibitors are currently in clinical trials, nonetheless, complementary non-invasive early biomarkers to assess drug delivery and potential therapeutic response are still needed. The goal of this study was therefore to determine the potential of 1H and hyperpolarized 13C magnetic resonance spectroscopy (MRS)-based biomarkers as indicators of mutant IDH1 low-grade glioma response to treatment with the clinically-relevant IDH1 inhibitor BAY-1436032 in cells and animal models. Immortalized human astrocytes engineered to express mutant IDH1 were treated with 500nM (IC50 value) of BAY-1436032 and BT257 tumors implanted in rats were treated with 150mg/kg of BAY-1436032. To assess steady-state metabolite levels, 1H MRS spectra were acquired on a 500 MHz MRS cancer for cells and a 3 T scanner for animal studies. To assess metabolic fluxes, we used hyperpolarized 13C MRS and probed the fate of hyperpolarized [1-13C]αKG. 1H MRS showed a significant decrease in 2HG as well as a significant increase in glutamate (Glu) and phosphocholine (PCh) following BAY-1436032 treatment in both cell and animal models compared to controls. Furthermore, hyperpolarized 13C MRS showed that hyperpolarized 2HG production from hyperpolarized [1-13C]αKG was decreased and hyperpolarized glutamate production from hyperpolarized [1-13C]αKG was increased in the BAY-1436032 treated groups compared to controls. These findings are consistent with our previous study, which investigated the MRS-detectable consequences of two other mutant IDH inhibitors: AG120 and AG881. Collectively, our work identifies translatable MRS-based metabolic biomarkers of mutant IDH1 inhibition.

scholarly journals EXTH-20. HYPERPOLARIZED [2-13C] PYRUVATE TO [5-13C] GLUTAMATE AS BIOMARKERS OF IDH1 MUTANT GLIOMA RESPONSE TO TEMOZOLOMIDE THERAPY

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi86-vi86 ◽  
Author(s):  
Elavarasan Subramani ◽  
Chloe Najac ◽  
Georgios Batsios ◽  
Pavithra Viswanath ◽  
Marina Radoul ◽  
...  
Keyword(s):  
Tca Cycle ◽  
Response To Therapy ◽  
Response To Treatment ◽  
Metabolic Imaging ◽  
Imaging Biomarkers ◽  
Resonance Spectroscopy ◽  
Low Grade ◽  
1H Mrs ◽  
Hyperpolarized 13C ◽  
13C Mrs

Abstract Low-grade gliomas, driven by mutations in the cytosolic isocitrate dehydrogenase 1 (IDH1) gene, are less aggressive than primary glioblastoma, but nonetheless always recur and ultimately lead to patient death. The treatment of IDH1 mutant patients with Temozolomide (TMZ) improves survival, but there remains a need for complementary imaging methods to assess response to therapy at an early time point. The goal of this study was, therefore, to determine the value of magnetic resonance spectroscopy (MRS)-based metabolic imaging biomarkers for detection of response to treatment. To this end we investigated NHA and U87 cells expressing IDH1 R132H mutant gene (NHAIDHmut and U87IDHmut) and first used 1H MRS combined with chemometrics to examined the metabolic alterations that occurred following treatment with the IC50 value of TMZ. We observed a significant increase in 2-hydroxyglutarate (2-HG), glutamate, and glutamine, and metabolic pathway analysis showed tricarboxylic acid (TCA) cycle and pyruvate metabolism to be significantly altered pathways following TMZ treatment compared to DMSO control. To confirm changes in TCA cycle flux and to assess the metabolic pathways contributing to the increase in 2-HG and glutamate/glutamine, cells were then labelled with [1-13C] glucose and [3-13C] glutamine. Our data indicated that both glucose flux via the TCA to glutamate and 2HG, and the contribution of glutamine to glutamate and 2HG were increased following TMZ treatment. Finally, we used hyperpolarized 13C-MRS to dynamically probe the metabolism of hyperpolarized [2-13C] pyruvate and its conversion to hyperpolarized [5-13C] glutamate via the TCA cycle. Consistent with our previous findings, we observed that hyperpolarized [5-13C] glutamate synthesis was significantly higher in TMZ-treated cells compared to controls. Collectively, our findings identify 1H MRS-detectable elevation of 2-HG and glutamate/glutamine as well as hyperpolarized 13C-MRS-detectable [5-13C] glutamate production from [2-13C] pyruvate as potentially translatable metabolic biomarkers of response to TMZ therapy in mutant IDH1 glioma.

scholarly journals Early Noninvasive Metabolic Biomarkers of Mutant IDH Inhibition in Glioma

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 109
Author(s):  
Marina Radoul ◽  
Donghyun Hong ◽  
Anne Marie Gillespie ◽  
Chloé Najac ◽  
Pavithra Viswanath ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Genetically Engineered ◽  
Response To Treatment ◽  
Driver Mutations ◽  
Resonance Spectroscopy ◽  
Low Grade ◽  
Isocitrate Dehydrogenase 1 ◽  
1H Mrs ◽  
Metabolic Biomarkers

Approximately 80% of low-grade glioma (LGGs) harbor mutant isocitrate dehydrogenase 1/2 (IDH1/2) driver mutations leading to accumulation of the oncometabolite 2-hydroxyglutarate (2-HG). Thus, inhibition of mutant IDH is considered a potential therapeutic target. Several mutant IDH inhibitors are currently in clinical trials, including AG-881 and BAY-1436032. However, to date, early detection of response remains a challenge. In this study we used high resolution 1H magnetic resonance spectroscopy (1H-MRS) to identify early noninvasive MR (Magnetic Resonance)-detectable metabolic biomarkers of response to mutant IDH inhibition. In vivo 1H-MRS was performed on mice orthotopically-implanted with either genetically engineered (U87IDHmut) or patient-derived (BT257 and SF10417) mutant IDH1 cells. Treatment with either AG-881 or BAY-1436032 induced a significant reduction in 2-HG. Moreover, both inhibitors led to a significant early and sustained increase in glutamate and the sum of glutamate and glutamine (GLX) in all three models. A transient early increase in N-acetylaspartate (NAA) was also observed. Importantly, all models demonstrated enhanced animal survival following both treatments and the metabolic alterations were observed prior to any detectable differences in tumor volume between control and treated tumors. Our study therefore identifies potential translatable early metabolic biomarkers of drug delivery, mutant IDH inhibition and glioma response to treatment with emerging clinically relevant therapies.

scholarly journals CBMT-10. MUTANT ISOCITRATE DEHYDROGENASE 1 INHIBITION INDUCES A UNIQUE MRS-DETECTABLE METABOLIC SIGNATURE IN LOW-GRADE GLIOMAS

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi34-vi35
Author(s):  
Abigail Molloy ◽  
Aliya Lakhani ◽  
Chloé Najac ◽  
Elavarasan Subramani ◽  
Anne Marie Gillespie ◽  
...  
Keyword(s):  
Cell Lines ◽  
Isocitrate Dehydrogenase ◽  
Phase 1 ◽  
Genetically Engineered ◽  
Resonance Spectroscopy ◽  
Low Grade ◽  
Isocitrate Dehydrogenase 1 ◽  
1H Mrs ◽  
Low Grade Gliomas ◽  
Non Invasive

Abstract Mutations in isocitrate dehydrogenase 1/2 (IDHmut) are reported in 70–90% of low-grade gliomas and secondary glioblastomas. IDHmut catalyzes the reduction of a-ketoglutarate (a-KG) to 2-hydroxyglutarate (2-HG), an oncometabolite that drives tumorigenesis. Inhibition of IDHmut is therefore a rapidly emerging therapeutic approach and IDHmut inhibitors such as AG-120 and AG-881 have shown promising results in phase 1 and 2 clinical studies. The goal of this study was to identify early non-invasive metabolic biomarkers of IDHmut inhibition that can serve to moniter response to these therapies. We used 1H and 13C magnetic resonance spectroscopy (MRS) to investigate the response of two genetically-engineered IDHmut cell lines (U87-based and normal human astrocyte-based) to AG-120 and AG-881 treatment. As expected, in both cell lines, our 1H-MRS data indicated that AG-120 and AG-881 induced a significant decrease in 2-HG. Interestingly however, we also observed a significant increase in phosphocholine and glutamate, pointing to broader changes in the metabolism of treated cells and a unique MRS signature. To further investigate the increase in glutamate induced by AG-120 and AG-881 in our models, we used 13C-MRS and quantified the flux of [1-13C] glucose and [3-13C] glutamine to 13C-labeled glutamate. Our results indicate that both AG-120 and AG-881 significantly increase the flux of 13C-labeled glutamine to 13C glutamate, while the flux of 13C-labeled glucose to 13C glutamate remained unchanged. Further studies are currently underway to explore the utility of using hyperpolarized [1-13C]-glutamine and hyperpolarized [1-13C]-a-KG for monitoring flux to glutamate and 2-HG, and to validate these probes as additional biomarkers of response to IDHmut inhibition. Taken together, our studies indicate that IDHmut inhibition induces a unique MRS-detectable metabolic profile that can potentially be exploited for early non-invasive, clinically translatable detection of response to emerging IDHmut inhibitors.

TAMI-40. PEDIATRIC H3K27M MUTANT GLIOMAS UNDERGO METABOLIC REPROGRAMMING THAT CAN BE LEVERAGED FOR NON-INVASIVE METABOLIC IMAGING

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi206-vi207
Author(s):  
Meryssa Tran ◽  
Georgios Batsios ◽  
Céline Taglang ◽  
Anne Marie Gillespie ◽  
Javad Nazarian ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Phospholipid Metabolism ◽  
Metabolic Reprogramming ◽  
Metabolic Imaging ◽  
Resonance Spectroscopy ◽  
1H Mrs ◽  
Hyperpolarized 13C ◽  
Non Invasive ◽  
13C Mrs

Abstract Diffuse midline gliomas (DMGs) are a universally lethal form of childhood cancer. The infiltrative nature of DMGs makes them difficult to visualize by conventional magnetic resonance imaging. Genomics studies indicate that DMGs are driven by unique histone H3K27M mutations that result in broad epigenetic dysregulation. Many of the resulting changes in gene expression have the potential to induce metabolic reprogramming, which has been identified as a hallmark of cancer. The goal of this study was to dissect metabolic reprogramming in preclinical DMG models in order to identify novel magnetic resonance spectroscopy (MRS)-detectable metabolic biomarkers that can be exploited for non-invasive imaging. First, we used 1H-MRS, which reports on steady-state metabolism, to examine H3K27M mutant SF7761 cells and H3 wild-type normal human astrocytes (NHA). Lactate, glutathione and phosphocholine, which are involved in glycolysis, redox and phospholipid metabolism respectively, were elevated in SF7761 cells relative to NHAs. Mechanistically, these metabolic alterations were associated with upregulation of key enzymes including hexokinase 2, glutamate cysteine ligase and choline kinase a. Importantly, in vivo 1H-MRS showed elevated lactate, glutathione and total choline (combined signal from choline, phosphocholine and glycerophosphocholine) in mice bearing orthotopic SF7761 tumors relative to tumor-free controls. We then examined alterations in dynamic metabolic pathways in our models. Using thermally-polarized 13C-MRS, we identified elevated production of [2-13C]-lactate from [2-13C]-glucose in SF7761 cells relative to NHAs. Hyperpolarized 13C-MRS is a method of enhancing the 13C-MR signal such that metabolic fluxes can be interrogated with high sensitivity. Hyperpolarized [1-13C]-pyruvate flux to [1-13C]-lactate non-invasively monitors glycolysis and is in clinical trials in adult glioma patients. Importantly, hyperpolarized [1-13C]-pyruvate metabolism to lactate was elevated in SF7761 cells relative to NHAs. Collectively, our studies suggest that H3K27M mutant DMGs undergo reprogramming of glucose, redox and phospholipid metabolism that can be leveraged for non-invasive 1H- and hyperpolarized 13C-MRS-based imaging.

scholarly journals Non-Invasive Differentiation of M1 and M2 Activation in Macrophages Using Hyperpolarized 13C MRS of Pyruvate and DHA at 1.47 Tesla

Metabolites ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 410
Author(s):  
Kai Qiao ◽  
Lydia M. Le Page ◽  
Myriam M. Chaumeil
Keyword(s):  
Macrophage Activation ◽  
Dehydroascorbic Acid ◽  
Metabolic Reprogramming ◽  
Metabolic Imaging ◽  
Alternative Activation ◽  
Resonance Spectroscopy ◽  
1H Mrs ◽  
Central Process ◽  
Hyperpolarized 13C ◽  
13C Mrs

Macrophage activation, first generalized to the M1/M2 dichotomy, is a complex and central process of the innate immune response. Simply, M1 describes the classical proinflammatory activation, leading to tissue damage, and M2 the alternative activation promoting tissue repair. Given the central role of macrophages in multiple diseases, the ability to noninvasively differentiate between M1 and M2 activation states would be highly valuable for monitoring disease progression and therapeutic responses. Since M1/M2 activation patterns are associated with differential metabolic reprogramming, we hypothesized that hyperpolarized 13C magnetic resonance spectroscopy (HP 13C MRS), an innovative metabolic imaging approach, could distinguish between macrophage activation states noninvasively. The metabolic conversions of HP [1-13C]pyruvate to HP [1-13C]lactate, and HP [1-13C]dehydroascorbic acid to HP [1-13C]ascorbic acid were monitored in live M1 and M2 activated J774a.1 macrophages noninvasively by HP 13C MRS on a 1.47 Tesla NMR system. Our results show that both metabolic conversions were significantly increased in M1 macrophages compared to M2 and nonactivated cells. Biochemical assays and high resolution 1H MRS were also performed to investigate the underlying changes in enzymatic activities and metabolite levels linked to M1/M2 activation. Altogether, our results demonstrate the potential of HP 13C MRS for monitoring macrophage activation states noninvasively.

scholarly journals From genomics to the clinic: biological and translational insights of mutant IDH1/2 in glioma

2013 ◽  
Vol 34 (2) ◽  
pp. E2 ◽  
Author(s):  
Gavin P. Dunn ◽  
Ovidiu C. Andronesi ◽  
Daniel P. Cahill
Keyword(s):  
Hypoxia Inducible Factor ◽  
Diagnostic Tools ◽  
Low Grade ◽  
Isocitrate Dehydrogenase 1 ◽  
Treatment Algorithms ◽  
Recurrent Mutations ◽  
Molecular Landscape ◽  
Mutant Idh1 ◽  
And Function

The characterization of the genomic alterations across all human cancers is changing the way that malignant disease is defined and treated. This paradigm is extending to glioma, where the discovery of recurrent mutations in the isocitrate dehydrogenase 1 (IDH1) gene has shed new light on the molecular landscape in glioma and other IDH-mutant cancers. The IDH1 mutations are present in the vast majority of low-grade gliomas and secondary glioblastomas. Rapidly emerging work on the consequences of mutant IDH1 protein expression suggests that its neomorphic enzymatic activity catalyzing the production of the oncometabolite 2-hydroxyglutarate influences a range of cellular programs that affect the epigenome, transcriptional programs, hypoxia-inducible factor biology, and development. In the brief time since its discovery, knowledge of the IDH mutation status has had significant translational implications, and diagnostic tools are being used to monitor its expression and function. The concept of IDH1-mutant versus IDH1-wild type will become a critical early distinction in diagnostic and treatment algorithms.

scholarly journals Inhibitor potency varies widely among tumor-relevant human isocitrate dehydrogenase 1 mutants

2018 ◽  
Vol 475 (20) ◽  
pp. 3221-3238 ◽  
Author(s):  
Diego Avellaneda Matteo ◽  
Grace A. Wells ◽  
Lucas A. Luna ◽  
Adam J. Grunseth ◽  
Olga Zagnitko ◽  
...  
Keyword(s):  
Isocitrate Dehydrogenase ◽  
Resistance Mutation ◽  
Poor Response ◽  
Fold Increase ◽  
Structural Features ◽  
Low Grade ◽  
Wild Type ◽  
Isocitrate Dehydrogenase 1 ◽  
Dynamics Simulations ◽  
Mutant Idh1

Mutations in isocitrate dehydrogenase 1 (IDH1) drive most low-grade gliomas and secondary glioblastomas and many chondrosarcomas and acute myeloid leukemia cases. Most tumor-relevant IDH1 mutations are deficient in the normal oxidization of isocitrate to α-ketoglutarate (αKG), but gain the neomorphic activity of reducing αKG to D-2-hydroxyglutarate (D2HG), which drives tumorigenesis. We found previously that IDH1 mutants exhibit one of two reactivities: deficient αKG and moderate D2HG production (including commonly observed R132H and R132C) or moderate αKG and high D2HG production (R132Q). Here, we identify a third type of reactivity, deficient αKG and high D2HG production (R132L). We show that R132Q IDH1 has unique structural features and distinct reactivities towards mutant IDH1 inhibitors. Biochemical and cell-based assays demonstrate that while most tumor-relevant mutations were effectively inhibited by mutant IDH1 inhibitors, R132Q IDH1 had up to a 16 300-fold increase in IC50 versus R132H IDH1. Only compounds that inhibited wild-type (WT) IDH1 were effective against R132Q. This suggests that patients with a R132Q mutation may have a poor response to mutant IDH1 therapies. Molecular dynamics simulations revealed that near the NADP+/NADPH-binding site in R132Q IDH1, a pair of α-helices switches between conformations that are more wild-type-like or more mutant-like, highlighting mechanisms for preserved WT activity. Dihedral angle changes in the dimer interface and buried surface area charges highlight possible mechanisms for loss of inhibitor affinity against R132Q. This work provides a platform for predicting a patient's therapeutic response and identifies a potential resistance mutation that may arise upon treatment with mutant IDH inhibitors.

scholarly journals RDNA-06. TARGETING IDH1/2-MUTANT GLIOMAS WITH UNIQUE COMBINATIONS OF DNA REPAIR INHIBITORS

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi208-vi208
Author(s):  
Amrita Sule ◽  
Ranjit Bindra
Keyword(s):  
Clinical Trials ◽  
Dna Repair ◽  
Myeloid Leukemia ◽  
Parp Inhibitors ◽  
Low Grade ◽  
High Fidelity ◽  
Isocitrate Dehydrogenase 1 ◽  
Dna Repair Inhibitors ◽  
Mutant Idh1 ◽  
Tumor Types

Abstract Mutations in the Isocitrate Dehydrogenase-1 and -2 (IDH1/2) genes occur in the vast majority of low-grade and secondary high-grade gliomas. These neomorphic mutations occur early on in gliomagenesis leading to the production of 2-Hydroxyglutarate (2HG). 2HG has been implicated in tumorigenesis via inhibiting α-ketoglutarate (αKG)-dependent dioxygenases. Our group recently demonstrated that the production of 2HG suppresses the high-fidelity homologous recombination (HR) DNA repair pathway, resulting in a state of “BRCAness”. We initially found that mutant IDH1/2-induced BRCAness confers exquisite sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors, a finding which now has been replicated by multiple independent laboratories. Although IDH1/2 mutations were first identified in gliomas and acute myeloid leukemia (AML) cells, multiple other tumor types have subsequently been shown to harbor these mutations. Current clinical trials are testing the efficacy of PARP inhibitors as a monotherapy, as well as in combination with other DNA repair inhibitors. Here, we demonstrate that novel combinations of DNA repair inhibitors can be utilized to synergistically target IDH1/2-mutant glioma cells. In particular, we demonstrate potent synergy with ATRi and PARPis, a finding which was validated in multiple structurally unique drugs within these classes. As this combination is active in BRCA1/2-mutant cancers, in particular after the emergence of PARPi resistance, these data suggest are consistent with an underlying HR defect in IDH1/2-mutant gliomas. These preclinical investigations will provide a blueprint for future clinical trials combining PARP and ATR inhibitors in the treatment of glioblastoma.

Vorasidenib (VOR; AG-881), an inhibitor of mutant IDH1 and IDH2, in patients (pts) with recurrent/progressive glioma: Updated results from the phase I non-enhancing glioma population.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 2504-2504 ◽  
Author(s):  
Ingo K. Mellinghoff ◽  
Katherine B. Peters ◽  
Timothy Francis Cloughesy ◽  
Howard A. Burris III ◽  
Elizabeth Anne Maher ◽  
...  
Keyword(s):  
Phase 1 ◽  
Objective Response ◽  
Low Grade ◽  
Isocitrate Dehydrogenase 1 ◽  
Eligibility Criteria ◽  
Dual Inhibitor ◽  
Study Results ◽  
Grade 3 ◽  
Mutant Idh1 ◽  
Favorable Safety

2504 Background: Isocitrate dehydrogenase 1 and 2 mutations (m IDH1/2) occur in approximately 70% and 4% of low-grade gliomas (LGGs), respectively, promoting oncogenesis via increased production of D-2-hydroxyglutarate. In this ongoing phase 1 trial, VOR, a potent, oral, reversible, brain-penetrant, first-in-class dual inhibitor of mIDH1/2, is being evaluated in advanced m IDH1/2 solid tumors, including gliomas. Safety and preliminary results were presented previously (Mellinghoff et al., J Clin Oncol 2018). Here, we report updated data for the non-enhancing glioma pt population. Methods: Pts with recurrent/progressive m IDH1/2 glioma received VOR daily (continuous 28-day cycles). Key eligibility criteria included: ≥18 years; histologically or cytologically confirmed glioma with documented m IDH1/2; ECOG 0-2; and evaluable disease by RANO-LGG criteria. Dose escalation cohorts enrolled using a Bayesian logistic regression model (BLRM) escalation guided by the overdose control (EWOC). Tumor response was evaluated by MRI every 8 weeks using RANO-LGG criteria by local assessment. Results: As of 28 Nov 2019, 22 pts with non-enhancing glioma had received VOR and 8 (36%) remain on treatment. M/F, 8/14; grade 2/3, 17/5; median age, 47 years; m IDH1/2, 20/1; 1p19q intact, 9/22; median (range) number of prior systemic therapies, 2 (1–4). Common (≥5 pts) treatment-emergent adverse events (AEs) of any grade and regardless of causality included increased ALT/AST (63.6%/59.1%), headache (45.5%), nausea (40.9%), neutropenia (31.8%), fatigue and hyperglycemia (27.3% each), and seizures and decreased white blood cell count (22.7% each). Transaminase elevations were grade 1 in severity at dose levels < 100mg and were less frequent (5 [38.5%] of 13 pts). Three subjects had related grade ≥3 AEs; 2 discontinued due to AEs. Objective response rate was 13.6% (1 partial response, 2 minor responses), and 17 (77.3%) pts achieved stable disease. 60.5% of pts were progression free and alive at 24 months. Conclusions: In this previously treated population with non-enhancing glioma, VOR was associated with a favorable safety profile. The study results also show encouraging preliminary activity within that population, with PFS duration extending to 24 months or longer in 60% of participants. A global randomized phase 3 study of VOR in grade 2 non-enhancing glioma pts who have had surgery only is currently enrolling (NCT04164901). Clinical trial information: NCT02481154 .

scholarly journals Molecular features assisting in diagnosis, surgery, and treatment decision making in low-grade gliomas

2015 ◽  
Vol 38 (3) ◽  
pp. E2 ◽  
Author(s):  
Ricky Chen ◽  
Vijay M. Ravindra ◽  
Adam L. Cohen ◽  
Randy L. Jensen ◽  
Karen L. Salzman ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Molecular Genetic ◽  
Treatment Decision ◽  
Resonance Spectroscopy ◽  
Low Grade ◽  
Isocitrate Dehydrogenase 1 ◽  
Genetic Event ◽  
Surgical Interventions ◽  
Low Grade Gliomas ◽  
Molecular Features

The preferred management of suspected low-grade gliomas (LGGs) has been disputed, and the implications of molecular changes for medical and surgical management of LGGs are important to consider. Current strategies that make use of molecular markers and imaging techniques and therapeutic considerations offer additional options for management of LGGs. Mutations in the isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) genes suggest a role for this abnormal metabolic pathway in the pathogenesis and progression of these primary brain tumors. Use of magnetic resonance spectroscopy can provide preoperative detection of IDH-mutated gliomas and affect surgical planning. In addition, IDH1 and IDH2 mutation status may have an effect on surgical resectability of gliomas. The IDH-mutated tumors exhibit better prognosis throughout every grade of glioma, and mutation may be an early genetic event, preceding lineage-specific secondary and tertiary alterations that transform LGGs into secondary glioblastomas. The O6-methylguanine-DNAmethyltransferase (MGMT) promoter methylation and 1p19q codeletion status can predict sensitivity to chemotherapy and radiation in low- and intermediate-grade gliomas. Thus, these recent advances, which have led to a better understanding of how molecular, genetic, and epigenetic alterations influence the pathogenicity of the different histological grades of gliomas, can lead to better prognostication and may lead to specific targeted surgical interventions and medical therapies.

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