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Purpose To comprehensively investigate prognostic factors, including clinical and molecular factors and treatment modalities, in adult glioma patients with leptomeningeal metastases (LM). Methods Total 226 patients with LM (from 2001 to 2021 among 1495 grade 2 to 4 glioma patients, 88.5% of LM patients being IDH-wildtype) with complete information on IDH mutation, 1p/19q codeletion, and MGMT promoter methylation status were enrolled. Predictors of overall survival (OS) of entire patients were determined by time-dependent Cox analysis, including clinical, molecular, and treatment data. Subgroup analyses were performed for patients with LM at initial diagnosis and LM diagnosed at recurrence (herein, initial and recurrent LM). Identical analyses were performed in IDH-wildtype glioblastoma patients. Results Median OS was 17.0 (IQR 9.7–67.1) months, with shorter median OS in initial LM than recurrent LM patients (12.2 vs 20.6 months, P Conclusion Active chemotherapy and antiangiogenic therapy demonstrated survival benefit in glioma patients with LM. There is consistent female survival advantage, whereas longer interval between initial glioma diagnosis and LM development suggests longer OS in recurrent LM.

Introduction The importance of fatty acid oxidation (FAO) in the bioenergetics of glioblastoma (GBM) is being realized. Etomoxir (ETO), a carnitine palmitoyltransferase 1 (CPT1) inhibitor exerts cytotoxic effects in GBM, which involve interrupting the FAO pathway. We hypothesized that FAO inhibition could affect the outcomes of current standard temozolomide (TMZ) chemotherapy against GBM. Methods The FAO-related gene expression was compared between GBM and the tumor-free cortex. Using four different GBM tumorspheres (TSs), the effects of ETO and/or TMZ was analyzed on cell viability, tricarboxylate (TCA) cycle intermediates and adenosine triphosphate (ATP) production to assess metabolic changes. Alterations in tumor stemness, invasiveness, and associated transcriptional changes were also measured. Mouse orthotopic xenograft model was used to elucidate the combinatory effect of TMZ and ETO. Results GBM tissues exhibited overexpression of FAO-related genes, especially CPT1A, compared to the tumor-free cortex. The combined use of ETO and TMZ further inhibited TCA cycle and ATP production than single uses. This combination treatment showed superior suppression effects compared to treatment with individual agents on the viability, stemness, and invasiveness of GBM TSs, as well as better downregulation of FAO-related gene expression. The results of in vivo study showed prolonged survival outcomes in the combination treatment group. Conclusion ETO, an FAO inhibitor, causes a lethal energy reduction in the GBM TSs. When used in combination with TMZ, ETO effectively reduces GBM cell stemness and invasiveness and further improves survival. These results suggest a potential novel treatment option for GBM.

Background The brainstem has the critical role of regulating cardiac and respiratory function and it also provides motor and sensory function to the face via the cranial nerves. Despite the observation of a brainstem lesion in a radiological examination, it is difficult to obtain tissues for a pathological diagnosis because of the location and small volume of the brainstem. Thus, we aimed to share our 6‐year experience with stereotactic biopsies from brainstem lesions and confirm the value and safety of stereotactic biopsy on this highly eloquent area in this study. Methods We retrospectively reviewed the medical records of 42 adult patients who underwent stereotactic biopsy on brainstem lesions from 2015 to 2020. The radiological findings, surgical records, pathological diagnosis, and postoperative complications of all patients were analyzed. Results Histopathological diagnoses were made in 40 (95.2%) patients. Astrocytic tumors were diagnosed in 29 (69.0%) patients, diffuse large B cell lymphoma in 5 (11.9%) patients, demyelinating disease in 4 (9.5%) patients, germinoma in 1 (2.4%) patient, and radiation necrosis in 1 (2.4%) patient. In the 40 patients with successful stereotactic biopsy, 10 (25.0%) patients had inconsistent preoperative radiological diagnosis and postoperative pathological diagnosis. In addition, there was a difference between the treatments prescribed by the radiological and pathological diagnoses in 8 out of 10 patients whose diagnoses changed after biopsy. There was no operative mortality among the 42 patients. Conclusions A pathological diagnosis can be made safely and efficiently in brainstem lesions using stereotactic biopsy. This pathological diagnosis will enable patients to receive appropriate treatment., Three approaches to stereotactic biopsy for brainstem and a Venn diagram showing the location of 42 brainstem lesion that performed stereotactic biopsy.

Limited treatment options are currently available for glioblastoma (GBM), an extremely lethal type of brain cancer. For a variety of tumor types, bioenergetic deprivation through inhibition of cancer-specific metabolic pathways has proven to be an effective therapeutic strategy. Here, we evaluated the therapeutic effects and underlying mechanisms of dual inhibition of carnitine palmitoyltransferase 1A (CPT1A) and glucose-6-phosphate dehydrogenase (G6PD) critical for fatty acid oxidation (FAO) and the pentose phosphate pathway (PPP), respectively, against GBM tumorspheres (TSs).Therapeutic efficacy against GBM TSs was determined by assessing cell viability, neurosphere formation, and 3D invasion. Liquid chromatography-mass spectrometry (LC-MS) and RNA sequencing were employed for metabolite and gene expression profiling, respectively. Anticancer efficacy in vivo was examined using an orthotopic xenograft model.CPT1A and G6PD were highly expressed in GBM tumor tissues. Notably, siRNA-mediated knockdown of both genes led to reduced viability, ATP levels, and expression of genes associated with stemness and invasiveness. Similar results were obtained upon combined treatment with etomoxir and dehydroepiandrosterone (DHEA). Transcriptome analyses further confirmed these results. Data from LC-MS analysis showed that this treatment regimen induced a considerable reduction in the levels of metabolites associated with the TCA cycle and PPP. Additionally, the combination of etomoxir and DHEA inhibited tumor growth and extended survival in orthotopic xenograft model mice.Our collective findings support the utility of dual suppression of CPT1A and G6PD with selective inhibitors, etomoxir and DHEA, as an efficacious therapeutic approach for GBM.

Advancements in photodynamic diagnosis (PDD) and photodynamic therapy (PDT) as a standard care in cancer therapy have been limited. This study is aimed to investigate the clinical availability of 5-aminolevulinic acid (5-ALA)-based PDD and PDT in glioblastoma (GBM) patient-derived tumorspheres (TSs) and mouse orthotopic xenograft model.PDT was performed using a 635 nm light-emitting diode (LED). Transcriptome profiles were obtained from microarray data. For knockdown of C5α, siRNA was transfected into tumor mesenchymal stem-like cells (tMSLCs). The invasiveness of TSs was quantified using collagen-based 3D invasion assays.Treatment with 1 mM 5 ALA induced distinct protoporphyrin IX (PpIX) fluorescence in GBM TSs, but not in non-tumor cells or tissues, including tMSLCs. These observations were negatively correlated with the expression levels of FECH, which catalyzes the conversion of accumulated PpIX to heme. Furthermore, the 5-ALA-treated GBM TSs were sensitive to PDT, thereby significantly decreasing cell viability and invasiveness. Notably, the effects of PDT were abolished by culturing TSs with tMSLC-conditioned media. Transcriptome analysis revealed diverse tMSLC-secreted chemokines, including C5α, and their correlations with the expression of stemness- or mesenchymal transition-associated genes. By adding or inhibiting C5α, we confirmed that acquired resistance to PDT was induced via tMSLC-secreted C5α.Our results show substantial therapeutic effects of 5-ALA-based PDT on GBM TSs, suggesting C5α as a key molecule responsible for PDT resistance. These findings could trigger PDT as a standard clinical modality for the treatment of GBM.

ObjectiveCavernous sinus (CS) invasion is frequently encountered in the management of skull base tumors. Surgical treatment of tumors in the CS is technically demanding, and selection of an optimal surgical approach is critical for maximal tumor removal and patient safety. We aimed to evaluate the feasibility of an endoscopic transorbital approach (ETOA) to the CS based on a cadaveric study.MethodsFive cadaveric heads were used for dissection under the ETOA in the comparison with the endoscopic endonasal approach (EEA) and the microscopic transcranial approach (TCA). The CS was exposed, accessed, and explored, first using the ETOA, followed by the EEA and TCA. A dedicated endoscopic system aided by neuronavigation guidance was used for the procedures. During the ETOA, neurovascular structures inside the CS were approached through different surgical triangles.ResultsAfter completing the ETOA with interdural dissection, the lateral wall of the CS was fully exposed. The lateral and posterior compartments of the CS, of which accessibility is greatly limited under the EEA, were effectively approached and explored under the ETOA. The anteromedial triangle was the largest window via which most of the lateral compartment was freely approached. The internal carotid artery and abducens nerve were also observed through the anteromedial triangle and just behind V1. During the ETOA, the approaching view through the supratrochlear and infratrochlear triangles was more directed towards the posterior compartment. After validation of the feasibility and safety based on the cadaveric study, ETOA was successfully performed in a patient with a pituitary adenoma with extensive CS invasion.ConclusionsBased on the cadaveric study, we demonstrated that the lateral CS wall was reliably accessed under the ETOA. The lateral and posterior compartments of the CS were effectively explored via surgical triangles under the ETOA. ETOA provides a unique and valuable surgical route to the CS with a promising synergy when used with EEA and TCA. Our experience with a clinical case convinces us of the efficacy of the ETOA during surgical management of skull base tumors with CS-invasion.

To investigate whether type-specific sex differences in survival exist independently of clinical and molecular factors in adult-type diffuse gliomas according to the 2021 World Health Organization (WHO) classification.A retrospective chart and imaging review of 1325 patients (mean age, 54 ± 15 years; 569 females) with adult-type diffuse gliomas (oligodendroglioma, IDH-mutant, and 1p/19q-codeleted, n = 183; astrocytoma, IDH-mutant, n = 211; glioblastoma, IDH-wildtype, n = 800; IDH-wildtype diffuse glioma, NOS, n = 131) was performed. The demographic information, extent of resection, imaging data, and molecular data including OIn patients with glioblastoma, IDH-wildtype, female sex remained as an independent predictor of better overall survival (hazard ratio = 0.91, P = 0.031), along with age, histological grade 4, MGMT promoter methylation status, and gross total resection. Female sex showed a higher prevalence of MGMT promoter methylation (40.2% vs 32.0%, P = 0.017) but there was no interaction effect between female sex and MGMT promoter methylation status (P-interaction = 0.194), indicating independent role of female sex. The median OS for females were 19.2 months (12.3-35.0) and 16.2 months (10.5-30.6) for males. No sex difference in survival was seen in other types of adult-type diffuse gliomas.There was a female survival advantage in glioblastoma, IDH-wildtype, independently of clinical data or MGMT promoter methylation status. There was no sex difference in survival in other types of adult-type diffuse gliomas, suggesting type-specific sex effects solely in glioblastoma, IDH-wildtype.

Background: Gastric adenocarcinoma (GAC) is heterogeneous lethal disease in genomic and clinical level. Although the clinical relevance of genomic and molecular subtypes of GAC has been demonstrated, their translation to the clinic has been hindered by discrepancies in classification methods. We aim to examine a consensus of genomic subtypes and correlate them with clinical outcomes. Method: We collected genomic data from 2527 GAC tumors and divided the data into discovery (n = 1427) and validation sets (n = 1100). By integrating 8 previously established genomic subtype algorithms, we identified 6 clinically and molecularly distinct genomic consensus subtypes (CGSs) in discovery set. For validation of clinical significance of new subtypes, we constructed GAC predictor of integrated consensus subtype with 120 genes (GPICS120) and applied it to validation data set. In systematic analysis of genomic and proteomic data, we estimated potential response rate of each subtype to standard and experimental treatments such as radiation therapy, target therapy, and immunotherapy and further validated their functional significance in cell line models. Results: Among identified 6 subtypes. CGS1 is characterized by poorest prognosis, very high stem cell characteristics, and high IGF1 expression, but low genomic alterations. CGS2 showed canonical epithelial gene expression patterns. CGS3 and CGS4 are characterized by high copy number alterations and low immune activity. However, CGS3 and CGS4 are different in high HER2 activation (CGS3) and SALL4 and KRAS activation (CSG4). CGS5 has highest mutation burden and moderately high immune activity that is characteristics of MSI-high tumors. Most of CGS6 tumors are EBV-positive and shows extremely high methylation and high immune activity. Most interestingly, CSG1 is most responsive to immunotherapy while CGS3 is significantly associated with benefit of chemoradiation therapy due to high basal level ferroptosis. In addition, we also identified potential therapeutic targets for each subtype. Conclusion: Consensus subtype is robust classification system and can be the basis for pre-clinical investigation of subtype-based targeted interventions and future clinical trials. Citation Format: Yun Seong Jeong, Young-Gyu Eun, Sung Hwan Lee, Sang-Hee Kang, Sun Young Yim, Eui Hyun Kim, Joo Kyung Noh, Bo Hwa Sohn, Ju-Seog Lee. Consensus genomic subtypes of gastric adenocarcinoma and their therapeutic implication. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4344.

PURPOSE Since it is known that midline located glioma with H3K27 mutation in children has a disastrous prognosis, in 2016 WHO classification, these tumors were defined as diffuse midline glioma (DMG) and classified as grade IV. A lot of papers about pediatric DMG have been published, but there are not many papers about adult DMG. In this study, we aimed to identify factors affecting the prognosis of adult midline glioma. This is the first paper to study the prognosis of adult DMG according to histological grade and is the largest study to investigate the survival of adult DMG. METHODS We reviewed the chart of adult patients diagnosed with midline glioma with H3K27M mutation after undergoing resection or biopsy among patients who visited our institution between January 2010 and December 2020. Survival analysis was performed according to tumor location, histological grading, Karnofsky Performance Scale (KPS), and age. RESULTS Among the 125 adult midline gliomas we identified, 45 (36.0%) had the H3K27M mutation. As a result of survival analysis performed on 125 adult midline gliomas, low histological grade, KPS ≥ 80, and age ≤ 60 showed significantly better survival. After adjusting for age, the difference in survival between H3K27M mutation and wildtype group was not significant. As a result of survival analysis performed on 45 DMG, low histological grade, KPS ≥ 80, total resection, and concurrent chemoradiation therapy group showed significantly better survival. CONCLUSION In adult midline glioma, disastrous prognosis due to H3K27M mutation was not observed as in children. The prognosis of adult midline gliomas is determined by histological grade, age, KPS, and extent of tumor resection. Therefore, the current WHO classification, which classifies all H3K27M mutant midline gliomas as grade IV regardless of histological diagnoses, is not suitable for adults.

An increasing number of studies indicate air pollutants infiltrate into the brain. We aimed to find the association of cumulative air pollution exposure in the main body of primary brain tumor: glioblastoma (GBM). In this double‐cohort, retrospective analysis study with a protocol, we compared the health effect of air pollution on the GBM patients from the SEER (Surveillance, Epidemiology, and End Results Program) in 27 U.S. counties from 10 states and GBM patients of Severance cohort of Korea. From 2000 to 2015, 10621 GBM patients of the SEER were individually evaluated for the cumulative average exposure for each pollutant, and 9444 (88.9%) mortality events were reported. From 2011 to 2018, 398 GBM patients of the Severance with the same protocol showed 259 (65.1%) mortality events. The multi‐pollutant models show that the association level of risk with CO is increased in the SEER (HR 1.252; 95% CI 1.141‐1.373) with an increasing linear trend of relative death rate in the spline curve. The Severance GBM data showed such a statistically significant result of the health impact of CO on GBM patients. The overall survival gain of the less exposure group against CO was 2 and 3 months in the two cohorts. Perioperative exposure to CO may increase the risk of shorter survival of GBM patients of the SEER and the Severance cohort., This retrospective observational study found that chronic exposure to ambient level of carbon monoxide is associated with a shorter survival of glioblastoma patients (2‐3 months). Such association was validated in the cohorts of the United states (N=10621, HR 1.252, 95% CI 1.141‐1.373) and Korea (N=398, HR 2.874, 95% CI 1.040‐7.944).

Objective To investigate the molecular characteristics of AGEJ compared with EAC and gastric adenocarcinoma. Summary of background data Classification of AGEJ based on differential molecular characteristics between EAC and gastric adenocarcinoma has been long-standing controversy but rarely conducted due to anatomical ambiguity and epidemiologic difference. Methods The molecular classification model with Bayesian compound covariate predictor was developed based on differential mRNA expression of EAC (N = 78) and GCFB (N = 102) from the Cancer Genome Atlas (TCGA) cohort. AGEJ/cardia (N = 48) in TCGA cohort and AGEJ/upper third GC (N = 46 pairs) in Seoul National University cohort were classified into the EAC-like or GCFB-like groups whose genomic, transcriptomic, and proteomic characteristics were compared. Results AGEJ in both cohorts was similarly classified as EAC-like (31.2%) or GCFB-like (68.8%) based on the 400-gene classifier. The GCFB-like group showed significantly activated phosphoinositide 3-kinase-AKT signaling with decreased expression of ERBB2. The EAC-like group presented significantly different alternative splicing including the skipped exon of RPS24, a significantly higher copy number amplification including ERBB2 amplification, and increased protein expression of ERBB2 and EGFR compared with GCFB-like group. High-throughput 3D drug test using independent cell lines revealed that the EAC-like group showed a significantly better response to lapatinib than the GCFB-like group (P = 0.015). Conclusions AGEJ was the combined entity of the EAC-like and GCFB-like groups with consistently different molecular characteristics in both Seoul National University and TCGA cohorts. The EAC-like group with a high Bayesian compound covariate predictor score could be effectively targeted by dual inhibition of ERBB2 and EGFR.

Purpose Glioblastoma (GBM) is the most aggressive type of brain tumor and has poor survival outcomes, even after a combination of surgery, radiotherapy, and chemotherapy. Temozolomide is the only agent that has been shown to be effective against GBM, suggesting that combination of temozolomide with other agents may be more effective. Niclosamide, an FDA approved anthelmintic agent, has shown anti-cancer effects against human colon, breast, prostate cancers as well as GBM. However, the efficacy of the combination of niclosamide with temozolomide against GBM tumorspheres (TSs) has not been determined. We hypothesized that the combined treatment could effectively suppress GBM TSs. Methods GBM TSs (TS15-88, GSC11) were treated with niclosamide and/or temozolomide. Combined effects of two drugs were evaluated by measuring viability, neurosphere formation, and 3D-invasion in collagen matrix. Transcriptional profiles of GBM TS were analyzed using RNA sequencing. In vivo anticancer efficacy of combined drugs was tested in a mouse orthotopic xenograft model. Results Combination treatment of niclosamide and temozolomide significantly inhibited the cell viability, stemness, and invasive properties of GBM TSs. This combined treatment significantly down-regulated the expression of epithelial mesenchymal transition-related markers, Zeb1, N-cadherin, and β-catenin. The combined treatment also significantly decreased tumor growth in orthotopic xenograft models. Conclusion The combination of niclosamide and temozolomide effectively decreased the stemness and invasive properties of GBM TSs, suggesting that this regimen may be therapeutically effective in treating patients with GBM.

Esthesioneuroblastoma as a source of ectopic Cushing's syndrome is rare, and to the best of our knowledge, only 20 cases have been reported worldwide. A 46-year-old healthy man visited a local clinic for general weakness and hyposmia, and underwent examination with serial endocrinological workup and brain imaging. 68Gallium-DOTA-TOC positron emission tomography scan was helpful where diagnosis of sellar MRI and inferior petrosal sinus sampling were discordant. Combined transcranial and endoscopic endonasal approach surgery was performed, and a diagnosis of esthesioneuroblastoma was given.

PurposeWe aimed to compare the outcomes of adjuvant radiotherapy (ART) and surveillance in patients with grade 2 meningiomas (MNG2) who underwent surgical resection.Materials and MethodsData from four hospitals, in which patients aged ≥18 years underwent Simpson grade 1−4 surgical resection for newly diagnosed MNG2 between 1998 and 2018, were examined in this multicenter retrospective cohort study. Patients receiving ART with conventional fractionation were compared with those undergoing surveillance. Progression-free survival (PFS), progression/recurrence (P/R) were evaluated.ResultsThis study included 518 patients, 158 of whom received ART. The median follow-up duration was 64.9 months. In the total cohort, ART was independently associated with significantly improved PFS (HR, 0.35; 95% CI, 0.23–0.55; PConclusionsART significantly improved PFS and P/R in patients with MNG2, irrespective of the surgical extent, and can be recommended after gross total resection. A prognostic model may guide decision-making for the use of ART.

BACKGROUND To evaluate the impact of extent of resection (EOR) of contrast-enhancing (CE) and nonenhancing (NE) tumors in the types of adult-type diffuse gliomas according to the 2021 WHO classification. METHODS Total 1,196 adult-type diffuse glioma patients diagnosed between 2001 and 2021 from a single institution were enrolled (183 patients with isocitrate dehydrogenase [IDH]-mutant and 1p/19q codeleted oligodendroglioma [herein oligodendroglioma], 211 patients with IDH-mutant astrocytoma, and 802 patients with IDH-wildtype glioblastoma). Analyses were performed within each type to assess predictors of overall survival, including clinical, imaging data, histological grade, O6-methylguanine-methyltransferase (MGMT) promoter methylation status, adjuvant treatment, and EOR of CE and NE tumors. Subgroup analyses were performed in patients with CE tumor. RESULTS Among 1,196 patients, 926 (77.4%) patients had CE tumors. In oligodendrogliomas, gross total removal (GTR) of CE tumor was associated with survival (hazard ratio [HR]=0.09, P< 0.001), whereas GTR of NE tumor was not associated with survival (HR=0.41, P=0.088). In 81 (43.3%) oligodendroglioma patients with CE tumor, GTR of CE tumor was the only independent predictor of survival (HR=0.20, P=0.092) in multivariable analysis. GTR of CE and NE tumors was independently associated with better survival in IDH-mutant astrocytoma and IDH-wildtype glioblastoma (all Ps< 0.05). CONCLUSIONS GTR of both CE and NE tumors may significantly improve survival within all types of adult-type diffuse gliomas except oligodendrogliomas. In oligodendrogliomas, the EOR of CE tumor may be crucial in survival; aggressive GTR of NE tumor may be unnecessary, whereas GTR of the CE tumor is recommended.

Human glioblastoma (GBM), originating from the subventricular zone (SVZ), occurs due to molecular disruptions in chromosomes. Most GBM tissues exhibit definitive chromosomal patterns: copy-number-variations (CNV) in chromosome 7 (gain) and 10 (loss), known as the earliest molecular events. Herein, we hypothesised that the origin-cells in SVZ of GBM patients can provide clues regarding these chromosomal alterations. We compared bulk RNA sequencing (RNAseq) data of GBM tumor tissue (n=126), tumour free GBM SVZ (n=40), and tumor-free control SVZ of non-glial tumor (n=9). Paired single-cell-level RNAseq samples of tumor free GBM SVZ (n=7) and GBM tumor tissue (n=10), were done to see cell specific CNVs. Using human SVZ and GBM samples as a background, we generated origin-cell and origin-cell-derived tumour cell using CRISPR/Cas9. In this work, we identified two GBM-origin-cell types with stem-cell signatures during single-cell level analyses of 60 SVZ tissue samples obtained from tumor-free regions of GBM patients. Furthermore, single-cell level analysis revealed that two origin-cell types in SVZ harbor ongoing patterns of CNV alterations. Among the origin-cells found in the SVZ of GBM patients, NO-like cells showed neural progenitor plus oligodendrocyte progenitor (NO) signature, while AN-like cells showed astrocyte plus neural stem cell (AN) signature. For the interconnectedness, we subjected single-cell-level RNA-seq data to ligand-receptor connection analysis. In the stem cell mode, NO-like cells was connected to AN-like cells in SVZ samples and while in the tumor samples, cycling cell was connected to AN-like cells. NO-like cells was common in TERT promoter wildtype GBM and AN-like cells was more common in TERT promoter mutant GBM. CRISPR/Cas9 models revealed accumulation copy-number alterations from non-tumorigenic origin-cells to tumor cells. These two origin-cells (NO-like cells and AN-like cells) derived from the SVZ of the adult human brain will facilitate the understanding of GBM genesis and development of potential novel therapeutic targets.

BACKGROUND To compare the outcomes between adjuvant radiotherapy (ART) and surveillance in patients with grade 2 intracranial meningiomas (MNG2s) after surgical resection.Materials and METHODS This multicenter study included 518 patients with newly diagnosed MNG2 who underwent resection between 1998–2018. Patients receiving ART with conventional fractionation (n = 158) were compared with those undergoing surveillance (n = 360). Progression-free survival (PFS) and progression/recurrence (P/R) rates were evaluated. Propensity score matching was performed to adjust for covariables (n = 43 in each group). RESULTS The median follow-up was 64.9 months. The median ART dose was 60 Gy in 30 fractions. Patients receiving ART had larger tumors (median, 5.0 vs. 4.5 cm, P < 0.001) and less frequent gross total resection (69.6% vs. 85.3%, P < 0.001). In multivariable analysis, ART was associated with significantly improved PFS (HR, 0.34; 95% CI, 0.22–0.53; P< 0.001) and P/R (HR, 0.29; 95% CI, 0.18–0.46; P< 0.001). In the propensity score matched cohort, the 5-year PFS rates were 80.8% vs 57.7% (P = 0.020) in the ART and surveillance group, respectively. Even in patients receiving gross total resection, the 5-year PFS (85.0% vs. 64.7%; HR, 0.50; 95% CI, 0.27–0.91; P = 0.023) and P/R rates (15.2% vs. 32.0%; HR, 0.50; 95% CI, 0.25–0.96; P = 0.038) were significantly improved by ART. Using recursive partitioning analysis in patients undergoing surveillance, we classified patients to low-, intermediate-, or high-risk of P/R based on surgical extent, tumor size, and Ki-67 index. The 5-year P/R rates in the low-, intermediate-, and high-risk groups were 18.6%, 37.9%, and 65.3%, respectively. CONCLUSION ART significantly improved PFS and P/R in MNG2s irrespective of surgical extent and should be recommended after both gross total and partial resection. A recursive partitioning analysis model for P/R may guide clinicians for decision making in resected MNG2s.

OBJECTIVE In glioblastoma (GBM) patients, controlling the microenvironment around the tumor using various treatment modalities, including surgical intervention, is essential in determining the outcome of treatment. This study was conducted to elucidate whether recurrence patterns differ according to the extent of resection (EOR) and whether this difference affects prognosis. METHODS This single-center study included 358 eligible patients with histologically confirmed isocitrate dehydrogenase (IDH)-wild-type GBM from November 1, 2005, to December 31, 2018. Patients were assigned to one of three separate groups according to EOR: supratotal resection (SupTR), gross-total resection (GTR), and subtotal resection (STR) groups. The patterns of recurrence were classified as local, marginal, and distant based on the range of radiation. The relationship between EOR and recurrence pattern was statistically analyzed. RESULTS Observed tumor recurrence rates for each group were as follows: SupTR group, 63.4%; GTR group, 75.3%; and STR group, 80.5% (p = 0.072). Statistically significant differences in patterns of recurrences among groups were observed with respect to local recurrence (SupTR, 57.7%; GTR, 76.0%; STR, 82.8%; p = 0.036) and distant recurrence (SupTR, 50.0%; GTR, 30.1%; STR, 23.2%; p = 0.028). Marginal recurrence showed no statistical difference between groups. Both overall survival and progression-free survival were significantly increased in the SupTR group compared with the STR and GTR groups (p < 0.0001). CONCLUSIONS In this study, the authors investigated the association between EOR and patterns of recurrence in patients with IDH-wild-type GBM. The findings not only show that recurrence patterns differ according to EOR but also provide clinical evidence supporting the hypothesized mechanism by which distant recurrence occurs.

BACKGROUND Hippo/YAP signaling pathway has emerged as an important driver of GBM. However, the clinical significance and expression correlation of YAP in GBM is still unknown. The purpose of this study is to elucidate the regulatory functions of YAP in response to tumorspheres (TS) in GBM. Material and METHODS In GBM-tumorspheres (TS), mRNA levels of Yap1 and TAZ were determined by RNA-Seq, and nuclear YAP1 expression level and its correlation with tumor aggressiveness were assessed through nucleus cytosolic fractionation, quantitative confocal microscopy, western blot, and TEAD4 reporter assay. Cell proliferation, stemness, and invasive properties were also measured using YAP siRNA and its inhibitor Verteporfin to reveal the effect of YAP on glioma progression. In orthotopic xenograft models, the inhibition of YAP function were tested. RESULTS All GBM-TS exhibited various phosphorylation states of YAP but no significant differences regarding the expression of YAP. Among them, TS15-88 cell line showed relatively low YAP phosphorylation in the quantified immunoblot results. Indeed, TS with reduced YAP phosphorylation was associated with aggressive cancer phenotypes. Predominant nuclear localization of YAP and binding of YAP/TAZ to TEAD in the nucleus was evident in the TS15-88 cells. The YAP knockdown (KD) by siRNA significantly resulted decrease in TS proliferation through WST and ATP assay and values were validated again through YAP inhibitor, Verteporfin (VP). YAP KD attenuated not only the invasion and stemness of TS but also caused a reduction in tumor volume and prolonged the overall survival of mice. CONCLUSION We showed alteration of gene activities by YAP and nuclear localization of YAP/TAZ complex contributes to GBM progression. Moreover, thus tuning of Yap activity results a marked suppression in aggressive phenotypes of cancer. These associations emphasize that the YAP signaling network highly suggests new therapeutic opportunities in diagnosing and treating GBM.

BACKGROUND: Cancer cells depended on cytosolic nicotinamide adenine dinucleotide (NADH) transported into mitochondria via the malate-aspartate shuttle (MAS) for ATP production. KN612 (N-phenylmaleimide), a MAS inhibitor, is known to interfere with cancer growth by reducing ATP production, supported by several studies except on glioblastoma (GBM). Therefore, this study was designed to elucidate whether MAS could be an aimable target in GBM. METHODS: We compared expression levels of MAS conforming enzymes between normal and GBM samples. Gene expression profiles were analyzed using RNA-sequencing. Mitochondrial activity was measured by oxygen consumption (OCR), tetramethylrhodamine-ethylester (TMRE) staining, and liquid chromatograph-tandem mass spectrometer (LC-MS/MS). Also, biological functions were measured by cell viability, ATP levels, NADH levels, stemness, and invasiveness. In vivo efficacies were confirmed using a mouse orthotopic xenograft model. RESULTS: An analysis of the microarray database revealed that expression levels of several MAS enzymes including OGC (SLC25A11) were elevated in GBM. Through RNA sequencing, it was confirmed that KN612 accurately targeted SLC25A11 and decreased its expression. KN612-treated cells showed decreased viability, ATP production, and NADH levels compared with control cells. Under the same conditions, a significant decrease in stemness, invasion, and MMP was confirmed. In addition, KN612 confirmed remarkable therapeutic responses in a mouse orthotopic xenograft model. CONCLUSION: Our results show that KN612 effectively inhibits cancer cells both at the cellular level and at the in vivo level. This shows that targeting MAS could be a potential treatment option in addition to the currently limited standard GBM therapy.

BackgroundThe new World Health Organization (WHO) classification system proposed a cell lineage-based classification scheme for pituitary adenomas in which transcription factors (TFs) play a major role as key classifiers. We aimed to evaluate clinical relevance of the new classification system in a clinical setting.MethodsTF staining was retrospectively performed for 153 clinically and histologically well characterized pituitary adenomas. Then, 484 pituitary adenomas were prospectively stained for TFs and then for relevant pituitary hormones. TF and hormone stain-based diagnoses were compared, and differences in clinical manifestations were evaluated.ResultsThe accuracies of antibodies for three TFs were successfully validated and had an overall matching rate was 89.6%. We identified 50 (10.4%) cases with discrepancies between TF and pituitary hormone stains. Gonadotroph adenomas lacking follicle-stimulating hormone and luteinizing hormone stains account for most discrepancies. Null cell adenomas may be more prevalent than reported and may be clinically more aggressive than gonadotroph adenomas.ConclusionThe new WHO classification is mostly well matched with the traditional classification. However, until the new classification is further validated and interpreted in the context of long-term clinical outcomes, routine histological examination should include full slate of immunostains for pituitary hormones as well as TFs.

Purpose: Immune checkpoint inhibitors (ICI) are used for the treatment of various cancers, but clinical trials of anti-programmed cell death protein 1 (PD-1) with patients with recurrent glioblastoma (GBM) have failed to show clinical benefits. In this study, we examined the differentiation status of CD8+ tumor-infiltrating lymphocytes (TIL) from patients with primary GBM and their reinvigoration by ICIs to understand the nature of T-cell exhaustion in GBM. Experimental Design: We isolated TILs from 98 patients with newly diagnosed GBM and examined the expression of immune checkpoint receptors and T-cell transcription factors using flow cytometry. TILs were ex vivo stimulated with anti-CD3 in the presence of anti-PD-1 and/or anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) and their proliferation assessed. Results: CD8+ TILs had significantly increased expression of immune checkpoint receptors, including PD-1 and CTLA-4, compared with peripheral blood CD8+ T cells. Among CD8+ TILs, PD-1+ cells exhibited more terminally differentiated phenotypes (i.e., EomeshiT-betlo) than PD-1− cells. These data were confirmed by analyzing NY-ESO-1157–specific CD8+ TILs. Evaluating the proliferation of CD8+ TILs after ex vivo stimulation with anti-CD3 and anti-PD-1, we found that proliferation inversely correlated with the percentage of EomeshiT-betlo cells among PD-1+CD8+ TILs. When anti-CTLA-4 was used in combination with anti-PD-1, an additional increase in CD8+ TIL proliferation was observed in patients with low percentages of EomeshiT-betlo CD8+ TILs, who responded well to anti-PD-1 in ex vivo assays, but not in patients with high percentages of EomeshiT-betlo CD8+ TILs, who did not respond to anti-PD-1. Conclusions: In primary GBM, the differentiation status of CD8+ TILs determines their reinvigoration ability upon ICI treatment.

Previous studies have revealed that PHLDB1 single-nucleotide polymorphisms (SNPs) are associated with glioma risk. Nonetheless, the association between PHLDB1 SNPs and the risk of pituitary adenoma has not been studied. The present study evaluated the association of PHLDB1 SNPs with the risk of pituitary adenomas. We genotyped 27 PHLDB1 tagging and exon SNPs in a case–control study that included 148 patients who got a diagnosis of nonfunctional pituitary adenoma (NFPA) and 375 normal controls within the Korean population. Statistical analyses of the association between PHLDB1 SNPs and the NFPA risk were conducted using logistic regression. We detected an association between a PHLDB1 SNP and the risk of NFPA in the Korean population. Rs67307131 in intron 2 was significantly associated with NFPA (odds ratio [OR] = 2.15, 95% confidence interval [CI] 1.44–3.20; P = 0.0002 in the dominant model). In the referent analysis, a higher OR and stronger association (lower P value) were observed among patients with the “C/T” genotype (OR = 2.39, 95% CI 1.60–3.58; P = 0.00002). In a functional analysis with a SNP annotation tool, this SNP was predicted to be a CpG site and copy number variant; these properties are associated with susceptibility to diseases. Our findings suggest that genetic variation of PHLDB1 may be associated with the risk of NFPA. This is the first report of an association between PHLDB1 variants and NFPA. Further research is needed to confirm the impact of this SNP on NFPA susceptibility.

We aimed to evaluate the utility of diffusion tensor imaging (DTI), dynamic contrast-enhanced (DCE), and dynamic susceptibility contrast (DSC) imaging for stratifying bevacizumab treatment outcomes in patients with recurrent high-grade glioma. Fifty-three patients with recurrent high-grade glioma who underwent baseline magnetic resonance imaging including DTI, DCE, and DSC before bevacizumab treatment were included. The mean apparent diffusion coefficient, fractional anisotropy, normalized cerebral blood volume, normalized cerebral blood flow, volume transfer constant, rate transfer coefficient (Kep), extravascular extracellular volume fraction, and plasma volume fraction were assessed. Predictors of response status, progression-free survival (PFS), and overall survival (OS) were determined using logistic regression and Cox proportional hazard modeling. Responders (n = 16) showed significantly longer PFS and OS (P < 0.001) compared with nonresponders (n = 37). Multivariable analysis revealed that lower mean Kep (odds ratio = 0.01, P = 0.008) was the only independent predictor of favorable response after adjustment for age, isocitrate dehydrogenase (IDH) mutation status, and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. Multivariable Cox proportional hazard modeling showed that a higher mean Kep was the only variable associated with shorter PFS (hazard ratio [HR] = 7.90, P = 0.006) and OS (HR = 9.71, P = 0.020) after adjustment for age, IDH mutation status, and MGMT promoter methylation status. Baseline mean Kep may be a useful biomarker for predicting response and stratifying patient outcomes following bevacizumab treatment in patients with recurrent high-grade glioma.

PURPOSE Glioblastoma (GBM) is the most common and lethal brain tumor with the median survival between 10 and 14 months. Since current treatments including surgical resection, radiation and chemotherapy fail to cure GBM, a new strategy to maximize the efficacy is needed. Here, etomoxir, an inhibitor of fatty acid oxidation, has been combined with temozolomide, a standard treatment for GBM, to examine its anti-tumor effects. Etomoxir has shown anti-cancer effects against human bladder, prostate cancers as well as GBM. We hypothesize that etomoxir inhibits fatty acid metabolism in cancer cell to suppress tumor progression while temozolomide causes cancer cell death. METHOD Four kinds of human GBM tumorspheres (TSs) were treated with temozolomide or etomoxir alone, or in combination with each other. Therapeutic effects of two drugs were evaluated by measuring cell viability, apoptosis, neurosphere formation, 3D-invasion using collagen/matrigel matrix, and LC/MS analysis of energy metabolism. Protein and mRNA expression profiles after drug treatment were evaluated by western blotting and RNA-sequencing. RESULTS Combination treatment of temozolomide and etomoxir significantly inhibited the cell viability, stemness, and invasiveness in GBM TSs. Expression levels of stemness-, invasiveness-associated markers were also decreased by the combined treatment. The combined treatment also significantly inhibited ATP production in TCA cycle. CONCLUSIONS Our findings suggest that combined treatment of etomoxir and TMZ may be therapeutically effective in the treatment GBM

OBJECTIVES To assess the predictive role of quantitative MRI parameters from DTI, dynamic susceptibility contrast (DSC), and dynamic contrast-enhanced (DCE) imaging in determining the epidermal growth factor receptor (EGFR) amplification and telomerase reverse transcriptase promoter (TERTp) mutation status of isocitrate dehydrogenase-wildtype (IDHwt) lower-grade gliomas (LGGs). METHODS A total of 49 patients with IDHwt LGGs with either known EGFR amplification (39 EGFR non-amplified, 10 EGFR-amplified) or TERTp mutation (19 TERTp wildtype, 21 TERTp mutant) statuses underwent preoperative MRI. The mean apparent diffusion coefficient (ADC), fractional anisotropy (FA), normalized cerebral blood volume (nCBV), normalized cerebral blood flow (nCBF), volume transfer constant (Ktrans), rate transfer coefficient (Kep), extravascular extracellular volume fraction (Ve), and plasma volume fraction (Vp) values were assessed. Univariate and multivariate logistic regression models were constructed to predict EGFR amplification and TERTp status. RESULTS EGFR-amplified tumors showed lower mean ADC values than EGFR non-amplified tumors (p = 0.019). Mean ADC was an independent predictor of EGFR amplification, with an AUC of 0.75. TERTp mutant tumors showed higher mean nCBV (p = 0.020), higher mean nCBF (p = 0.017), and higher mean Vp (p = 0.002) than TERTp wildtype tumors. With multivariate logistic regression, mean Vp was the only independent predictor of TERTp mutation status, with an AUC of 0.85. CONCLUSION Lower ADC values may be a useful marker for the prediction of EGFR amplification, whereas higher Vp values may be a useful marker for the prediction of the TERTp mutation status of IDHwt LGGs.

This study was conducted to assess whether levetiracetam (LEV) affects the survival of patients with glioblastoma (GBM) treated with concurrent temozolomide (TMZ) chemotherapy. To this end, from 2004 to 2016, 322 patients with surgically resected and pathologically confirmed isocitrate dehydrogenase (IDH)-wildtype GBM who received TMZ-based chemoradiotherapy were analysed. The patients were divided into two groups based on whether LEV was used as an anticonvulsant both at the time of surgery and the first visit thereafter. The median overall survival (OS) and progression-free survival (PFS) were compared between the groups. The OS was 21.1 and 17.5 months in the LEV (+) and LEV (−) groups, respectively (P = 0.003); the corresponding PFS was 12.3 and 11.2 months (P = 0.017). The other prognostic factors included age, extent of resection, O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status, and Karnofsky Performance Status (KPS) score. The multivariate analysis showed age (hazard ratio [HR], 1.02; P MGMT promoter methylation (HR 0.75; P

Purpose The aim of this study is to evaluate the survival rate and prognostic factors of anaplastic gliomas according to the 2016 World Health Organization classification, including extent of resection (EOR) as measured by contrast-enhanced T1-weighted magnetic resonance imaging (MRI) and the T2-weighted MRI. Materials and methods The records of 113 patients with anaplastic glioma who were newly diagnosed at our institute between 2000 and 2013 were retrospectively reviewed. There were 62 cases (54.9%) of anaplastic astrocytoma isocitrate dehydrogenase (IDH) wild-type (AAw), 18 cases (16.0%) of anaplastic astrocytoma, IDH-mutant, and 33 cases (29.2%) of anaplastic oligodendroglioma, IDH-mutant and 1p/19q-codeleted. Results The median overall survival (OS) was 48.4 months in the whole anaplastic glioma group and 21.5 months in AAw group. In multivariate analysis, age, preoperative Karnofsky Performance Scale score, O6-methylguanine-DNA methyltransferase (MGMT) methylation status, postoperative tumor volume, and EOR measured from the T2 MRI sequence were significant prognostic factors. The EOR cut-off point for OS measured in contrast-enhanced T1-weighted MRI and T2-weighted MRI were 99.96% and 85.64%, respectively. Conclusions We found that complete resection of the contrast-enhanced portion (99.96%) and more than 85.64% resection of the non-enhanced portion of the tumor have prognostic impacts on patient survival from anaplastic glioma.

Purpose To investigate whether radiomic features at MRI improve survival prediction in patients with glioblastoma multiforme (GBM) when they are integrated with clinical and genetic profiles. Materials and Methods Data in patients with a diagnosis of GBM between December 2009 and January 2017 (217 patients) were retrospectively reviewed up to May 2017 and allocated to training and test sets (3:1 ratio). Radiomic features (n = 796) were extracted from multiparametric MRI. A random survival forest (RSF) model was trained with the radiomic features along with clinical and genetic profiles (O-6-methylguanine-DNA-methyltransferase promoter methylation and isocitrate dehydrogenase 1 mutation statuses) to predict overall survival (OS) and progression-free survival (PFS). The RSF models were validated on the test set. The incremental values of radiomic features were evaluated by using the integrated area under the receiver operating characteristic curve (iAUC). Results The 217 patients had a mean age of 57.9 years, and there were 87 female patients (age range, 22-81 years) and 130 male patients (age range, 17-85 years). The median OS and PFS of patients were 352 days (range, 20-1809 days) and 264 days (range, 21-1809 days), respectively. The RSF radiomics models were successfully validated on the test set (iAUC, 0.652 [95% confidence interval {CI}, 0.524, 0.769] and 0.590 [95% CI: 0.502, 0.689] for OS and PFS, respectively). The addition of a radiomics model to clinical and genetic profiles improved survival prediction when compared with models containing clinical and genetic profiles alone (P = .04 and .03 for OS and PFS, respectively). Conclusion Radiomic MRI phenotyping can improve survival prediction when integrated with clinical and genetic profiles and thus has potential as a practical imaging biomarker. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Jain and Lui in this issue.

Objectives Heterogeneity of head and neck squamous cell carcinomas (HNSCCs) results in unpredictable outcomes for patients with similar stages of cancer. Beyond the role of human papilloma virus (HPV), no validated molecular marker of HNSCCs has been established. Thus, clinically relevant molecular subtypes are needed to optimize HNSCC therapy. The purpose of this study was to identify subtypes of HNSCC that have distinct biological characteristics associated with clinical outcomes and to characterize genomic alterations that best reflect the biological and clinical characteristics of each subtype. Materials and methods We analyzed gene expression profiling data from pan-SCC tissues including cervical SCC, esophageal SCC, lung SCC, and HNSCC (n = 1346) to assess the similarities and differences among SCCs and to identify molecular subtypes of HNSCC associated with prognosis. Subtype-specific gene expression signatures were identified and used to construct predictive models. The association of the subtypes with prognosis was validated in two independent cohorts of patients. Results Pan-SCC analysis identified three novel subtypes of HNSCC. Subtype 1 had the best prognosis and was similar to cervical SCC, whereas subtype 3 had the worst prognosis and was similar to lung SCC. Subtype 2 had a moderate prognosis. The 600-gene signature associated with the three subtypes significantly predicted prognosis in two independent validation cohorts. These three subtypes also were associated with potential benefit of immunotherapy. Conclusion We identified three clinically relevant HNSCC molecular subtypes. Independent prospective studies to assess the clinical utility of the subtypes and associated gene signature are warranted.

Simple Summary Predicting dopamine agonist resistance in patients with macroprolactinoma is essential for clinicians to prevent treatment failure and subsequent complications such as medication–induced cerebrospinal fluid (CSF) rhinorrhea. In this retrospective cross-sectional study that included 140 patients with newly diagnosed and cabergoline-treated prolactinoma with prolactin levels ≥1000 ng/mL, non-responders and patients with CSF rhinorrhea included a significantly higher number of patients receiving hormone replacement therapy than responders. Hormone deficiency was associated with a greater odds ratio for the risk of non-responders (adjusted odds ratio = 5.13, 95% CI 1.96–13.46, p = 0.001). Cabergoline was effective in bioactive macroprolactinoma and initial cabergoline dose in long-term responsiveness and development of CSF rhinorrhea was not significantly different. Hypopituitarism was independently associated with an increased risk of cabergoline resistance and CSF rhinorrhea. Abstract Predicting dopamine agonist resistance in patients with macroprolactinoma is essential for clinicians to prevent treatment failure and subsequent complications such as medication-induced cerebrospinal fluid (CSF) rhinorrhea. We evaluated the features of patients with cabergoline resistance and CSF rhinorrhea in patients with prolactinomas with prolactin levels ≥1000 ng/mL. A total of 140 patients who were newly diagnosed with prolactinoma secreting only prolactin ≥1000 ng/mL and treated with cabergoline for the first time were included in this study. Based on the hormonal and radiologic response of the prolactinoma, the patients were divided into responders and non-responders. Non-responders (36/140, 25.8%) included a higher number of patients receiving hormone replacement than responders (responders, n (%) = 12(11.5) vs. non-responders = 13(36.1), p = 0.001). In propensity score matching analysis, patients who developed CSF rhinorrhea presented more frequent hormone deficiency than responders regardless of initial cabergoline dose. Hormone deficiency was associated with a greater odds ratio for the risk of non-responders (adjusted odds ratio = 5.13, 95% CI 1.96–13.46, p = 0.001). Cabergoline was effective in bioactive macroprolactinoma. Furthermore, initial cabergoline dose was not significantly associated with long-term responsiveness and development of CSF rhinorrhea but the hypopituitarism was independently associated with an increased risk of cabergoline resistance and CSF rhinorrhea.

// Young-Gyu Eun 1, 2 , Dongjin Lee 1, 3 , Young Chan Lee 2 , Bo Hwa Sohn 1 , Eui Hyun Kim 1, 4 , Sun Young Yim 1, 5 , Kee Hwan Kwon 3 and Ju-Seog Lee 1 1 Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA 2 Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Kyung Hee University, Seoul, Republic of Korea 3 Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Hallym University, Seoul, Republic of Korea 4 Department of Neurosurgery, Severance Hospital, Brain Tumor Center, Yonsei University College of Medicine, Seoul, Republic of Korea 5 Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea Correspondence to: Ju-Seog Lee, email: jlee@mdanderson.org Keywords: YAP1; gene signature; head and neck cancer; prognosis Received: February 27, 2017 Accepted: July 18, 2017 Published: November 27, 2017 ABSTRACT By analyzing the genomic data of head and neck squamous cell cancer (HNSCC), we investigated clinical significance of YAP1 activation. Copy number and mRNA expression of YAP1 were analyzed together to assess clinical relevance of YAP1 activation in HNSCC. The clinical significance of YAP1 activation was further validated in four independent test cohorts. We also assessed the correlation of YAP1 activation with genomic alterations such as copy number alteration, somatic mutation, and miRNA expression. The YAP1-activated (YA) subgroup showed worse prognosis for HNSCC as tested and validated in five cohorts. In a multivariate risk analysis, the YAP1 signature was the most significant predictor of overall survival. The YAP1-inactivated (YI) subgroup was associated with HPV-positive status. In multiplatform analysis, YA tumors had gain of EGFR and SNAI2; loss of tumor-suppressor genes such as CSMD1, CDKN2A, NOTCH1, and SMAD4; and high mutation rates of TP53 and CDKN2A. YI tumors were characterized by gain of PIK3CA, SOX2, and TP63; deletion of 11q23.1; and high mutation rates of NFE2L2, PTEN, SYNE1, and NSD1. YA tumors also showed weaker immune activity as reflected in low IFNG composite scores and YAP1 activity is negatively associated with potential response to treatment of pembrolizumab. In conclusion, activation of YAP1 is associated with worse prognosis of patients with HNSCC and potential resistance to immunotherapy.

Purpose: The Cancer Genome Atlas (TCGA) project recently uncovered four molecular subtypes of gastric cancer: Epstein–Barr virus (EBV), microsatellite instability (MSI), genomically stable (GS), and chromosomal instability (CIN). However, their clinical significances are currently unknown. We aimed to investigate the relationship between subtypes and prognosis of patients with gastric cancer. Experimental Design: Gene expression data from a TCGA cohort (n = 262) were used to develop a subtype prediction model, and the association of each subtype with survival and benefit from adjuvant chemotherapy was tested in 2 other cohorts (n = 267 and 432). An integrated risk assessment model (TCGA risk score) was also developed. Results: EBV subtype was associated with the best prognosis, and GS subtype was associated with the worst prognosis. Patients with MSI and CIN subtypes had poorer overall survival than those with EBV subtype but better overall survival than those with GS subtype (P = 0.004 and 0.03 in two cohorts, respectively). In multivariate Cox regression analyses, TCGA risk score was an independent prognostic factor [HR, 1.5; 95% confidence interval (CI), 1.2–1.9; P = 0.001]. Patients with the CIN subtype experienced the greatest benefit from adjuvant chemotherapy (HR, 0.39; 95% CI, 0.16–0.94; P = 0.03) and those with the GS subtype had the least benefit from adjuvant chemotherapy (HR, 0.83; 95% CI, 0.36–1.89; P = 0.65). Conclusions: Our prediction model successfully stratified patients by survival and adjuvant chemotherapy outcomes. Further development of the prediction model is warranted. Clin Cancer Res; 23(15); 4441–9. ©2017 AACR.

The purpose of this study was to identify independent prognostic factors among preoperative imaging features in elderly glioblastoma patients and to evaluate whether these imaging features, in addition to clinical features, could enhance the predictive power of survival models. This retrospective study included 108 patients ≥65 years of age with newly diagnosed glioblastoma. Preoperative clinical features (age and KPS), postoperative clinical features (extent of surgery and postoperative treatment), and preoperative MRI features were assessed. Univariate and multivariate cox proportional hazards regression analyses for overall survival were performed. The integrated area under the receiver operating characteristic curve (iAUC) was calculated to evaluate the added value of imaging features in the survival model. External validation was independently performed with 40 additional patients ≥65 years of age with newly diagnosed glioblastoma. Eloquent area involvement, multifocality, and ependymal involvement on preoperative MRI as well as clinical features including age, preoperative KPS, extent of resection, and postoperative treatment were significantly associated with overall survival on univariate Cox regression. On multivariate analysis, extent of resection and ependymal involvement were independently associated with overall survival and preoperative KPS showed borderline significance. The model with both preoperative clinical and imaging features showed improved prediction of overall survival compared to the model with preoperative clinical features (iAUC, 0.670 vs. 0.600, difference 0.066, 95% CI 0.021-0.121). Analysis of the validation set yielded similar results (iAUC, 0.790 vs. 0.670, difference 0.123, 95% CI 0.021-0.260), externally validating this observation. Preoperative imaging features, including eloquent area involvement, multifocality, and ependymal involvement, in addition to clinical features, can improve the predictive power for overall survival in elderly glioblastoma patients.

Glioblastoma (GBM) is one of the most lethal human tumors with a highly infiltrative phenotype. Although invasiveness is related to poor prognosis, no therapeutic intervention targeting invasion is available for treatment of GBM patient, partially due to the diversity and redundancy of invasion machinery genes. In this regard, additional identification of deterministic and causative targets for invasion is required. Invasiveness of GBM patients and matched tumorspheres (TSs) was quantified using MR images and collagen-based 3D invasion assays, respectively. Transcriptome of GBM samples were obtained using microarrays. The knockdown effects of invasion-deterministic transcription factors (TFs) were evaluated using western blot and mouse orthotopic xenograft model. This study is aimed to identify novel transcriptional regulatory networks, which can collectively modulate invasion-involved genes in GBM. After classification of 23 GBM patient-derived TSs into low and high invasion groups, we applied single sample gene set enrichment analysis using TF target gene sets. According to enrichment scores, TFs responsible for low (PCBP1) and high (STAT3 and SRF) invasiveness were identified. Consistently with computational prediction, knockdown of PCBP1 significantly increased invasion area, whereas knockdown of STAT3 or SRF significantly suppressed invasive properties in all tested TSs. Notably, MR images showed coherent patterns with invasion of originated TS, and high invasiveness was associated with poor prognosis. In addition, mouse orthotopic xenograft model using TSs with down-regulated STAT3 or SRF showed significantly prolonged survival time compared to control. We identified invasion-deterministic TFs in glioblastoma using integrative transcriptome analysis. Owing to relationship among these transcriptional regulatory networks, invasive phenotype, and prognosis, we suggest that these TFs as novel drug targets for GBM.

INTRODUCTION Patterns of failure in patients with olfactory neuroblastoma (ONB) according to two surgical approaches, craniofacial resection (CFR) and endoscopic surgery (ENDO), have yet to be analyzed. METHODS We retrospectively reviewed 30 patients with surgically treated ONB between January 1995 and October 2018. Sixteen (53.3%) patients underwent CFR (9 CFR alone, 7 ENDO-assisted CFR) and 14 (46.7%) underwent ENDO. Twenty-one (70.0%) patients underwent post-operative radiotherapy (RT). RESULTS At a median follow-up of 53.8 months (range 10.4–195.3), the 5-year progression-free survival (PFS) and 10-year overall survival were 37.3% and 57.5%, respectively. Patients with adjuvant RT had a 5-year PFS of 46.7%, whereas those treated with surgery alone had a 5-year PFS of 19.4% (p = 0.01). Locoregional failure (LRF) occurred in ten patients (median 59.6 months after initial diagnosis; range 12.7–59.7). Neck node metastasis occurred in 23.3% (7 of 30). Five patients with ENDO showed LRF and underwent proper subsequent treatments with either surgery or adjuvant RT. Approximately 31.3% patients (five patients) in the CFR group experienced distant metastasis in the intracranial dura region (median 116.4 months after initial diagnosis; range 2.6–142.4). Three of four patients who developed LRF after CFR developed dura-based metastasis. CONCLUSIONS Both dura-based and neck node metastasis in the delayed phase were distinct patterns of failure in ONB. Patterns of recurrence differed based on surgical approach; dura-based metastases were common after CFR. LRF was the distinct failure pattern in ENDO, but could be successfully salvaged. Treatment outcome was improved considerably with RT following surgical resection.

Background There was no practical guideline for the management of patients with central nervous system tumor in Korea in the past. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, developed the guideline for glioblastoma successfully and published it in Brain Tumor Research and Treatment, the official journal of KSNO, in April 2019. Recently, the KSNO guideline for World Health Organization (WHO) grade III cerebral glioma in adults has been established. Methods The Working Group was composed of 35 multidisciplinary medical experts in Korea. References were identified by searches in PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL databases using specific and sensitive keywords as well as combinations of keywords. Scope of the disease was confined to cerebral anaplastic astrocytoma and oligodendroglioma in adults. Results Whenever radiological feature suggests high grade glioma, maximal safe resection if feasible is globally recommended. After molecular and histological examinations, patients with anaplastic astrocytoma, isocitrate dehydrogenase (IDH)-mutant should be primary treated by standard brain radiotherapy and adjuvant temozolomide chemotherapy whereas those with anaplastic astrocytoma, NOS, and anaplastic astrocytoma, IDH-wildtype should be treated following the protocol for glioblastomas. In terms of anaplastic oligodendroglioma, IDH-mutant and 1p19q-codeletion, and anaplastic oligodendroglioma, NOS should be primary treated by standard brain radiotherapy and neoadjuvant or adjuvant PCV (procarbazine, lomustine, and vincristine) combination chemotherapy. Conclusion The KSNO's guideline recommends that WHO grade III cerebral glioma of adults should be treated by maximal safe resection if feasible, followed by radiotherapy and/or chemotherapy according to molecular and histological features of tumors.

Background Although surgical resection is the first line therapy for acromegaly, many patients do not achieve biochemical remission after surgery and require the adjuvant therapy including medical treatment (somatostatin analogues; SSA, GH antagonist, and dopamine agonist), conventional radiotherapy, and gamma-knife surgery (GKS). Due to the limitations of rare disease, there are few studies evaluating the efficacy of each adjuvant treatment. In this study, we investigated clinical course and disease control after initiation of adjuvant treatment. Method We performed a single-center retrospective study including acromegalic patients treated with SSA at least for 6 months from January 1, 2005 to June 30, 2018. Age, gender, fasting GH, IGF-1 levels, 75 g oral glucose tolerance tests and tumor size were measured before/after operation, medical treatments, or radiotherapy. The patients were considered biochemically controlled/cured if fasting mean GH levels were less than 2.5ng/ml or nadir GH after oral glucose loading was less than 1 ng/ml together with age- and sex-matched normalized IGF-1. Result We analyzed 72 patients for median 62.9 months (40.0-111.5). The median age was 46 (37-53) years. The median duration of SSA use was 31.5 months (12.6-53.0). The median GH level was 30.5 (17.6-47.3) ng/ml, IGF-1 was 694.7 (600.0-862.8) ng/ml, initial tumor size was 24 (17.2-32.2) mm. Of 72 patients, 59 patients (81%) underwent surgical resection and 40 patients (55.6%) underwent GKS. Of the 40 patients who underwent GKS, 16 (40%) discontinued the medication after 26 (10.3-35.2) months. After treatment, 54 patients (75%) were biochemically controlled. Before initiation of SSA treatment, biochemically controlled group had significantly lower GH (3.63 vs 15.35ng/ml, p

To optimize and validate a current (NRG [a newly constituted National Clinical Trials Network group through National Surgical Adjuvant Breast and Bowel Project [NSABP], the Radiation Therapy Oncology Group [RTOG] and the Gynecologic Oncology Group (GOG)]) nomogram for glioblastoma patients as part of continuous validation. We identified patients newly diagnosed with glioblastoma who were treated with temozolomide-based chemoradiotherapy between 2006 and 2016 at three large-volume hospitals. The extent of resection was determined via postoperative MRI. The discrimination and calibration abilities of the prediction algorithm were assessed; if additional factors were identified as independent prognostic factors, updated models were developed using the data from two hospitals and were externally validated using the third hospital. Models were internally validated using cross-validation and bootstrapping. A total of 837 patients met the eligibility criteria. The median overall survival (OS) was 20.0 (95% CI 18.5–21.5) months. The original nomogram was able to estimate the 6‑, 12-, and 24-month OS probabilities, but it slightly underestimated the OS values. In multivariable Cox regression analysis, MRI-defined total resection had a greater impact on OS than that shown by the original nomogram, and two additional factors—IDH1 mutation and tumor contacting subventricular zone—were newly identified as independent prognostic values. An updated nomogram incorporating these new variables outperformed the original nomogram (C-index at 6, 12, 24, and 36 months: 0.728, 0.688, 0.688, and 0.685, respectively) and was well calibrated. External validation using an independent cohort showed C‑indices of 0.787, 0.751, 0.719, and 0.702 at 6, 12, 24, and 36 months, respectively, and was well calibrated. An updated and validated nomogram incorporating the contemporary parameters can estimate individual survival outcomes in patients with glioblastoma with better accuracy.

BACKGROUND There has been no practical guidelines for the management of patients with central nervous system (CNS) tumors in Korea for many years. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, started to prepare guidelines for CNS tumors from February 2018. METHODS The Working Group was composed of 35 multidisciplinary medical experts in Korea. References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of keywords. RESULTS First, the maximal safe resection if feasible is recommended. After the diagnosis of a glioblastoma with neurosurgical intervention, patients aged ≤70 years with good performance should be treated by concurrent chemoradiotherapy with temozolomide followed by adjuvant temozolomide chemotherapy (Stupp's protocol) or standard brain radiotherapy alone. However, those with poor performance should be treated by hypofractionated brain radiotherapy (preferred)±concurrent or adjuvant temozolomide, temozolomide alone (Level III), or supportive treatment. Alternatively, patients aged >70 years with good performance should be treated by hypofractionated brain radiotherapy+concurrent and adjuvant temozolomide or Stupp's protocol or hypofractionated brain radiotherapy alone, while those with poor performance should be treated by hypofractionated brain radiotherapy alone or temozolomide chemotherapy if the patient has methylated MGMT gene promoter (Level III), or supportive treatment. CONCLUSION The KSNO's guideline recommends that glioblastomas should be treated by maximal safe resection, if feasible, followed by radiotherapy and/or chemotherapy according to the individual comprehensive condition of the patient.

High metabolic activity, reflected in increased glucose uptake, is one of the hallmarks of many cancers including breast cancer. However, not all cancers avidly take up glucose, suggesting heterogeneity in their metabolic demand. Thus, we aim to generate a genomic signature of glucose hypermetabolism in breast cancer and examine its clinical relevance. To identify genes significantly associated with glucose uptake, gene expression data were analyzed together with the standardized uptake values (SUVmax) of (18)F-fluorodeoxy-glucose on positron emission tomography (PET) for 11 breast cancers. The resulting PET signature was evaluated for prognostic significance in four large independent patient cohorts (n = 5417). Potential upstream regulators accountable for the high glucose uptake were identified by gene network analysis. A PET signature of 242 genes was significantly correlated with SUVmax in breast cancer. In all four cohorts, high PET signature was significantly associated with poorer prognosis. The prognostic value of this PET signature was further supported by Cox regression analyses (hazard ratio 1.7, confidential interval 1.48–2.02; P

Purpose To investigate the incremental prognostic value of apparent diffusion coefficient (ADC) histogram analysis over oxygen 6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in patients with glioblastoma and the correlation between ADC parameters and MGMT status. Materials and Methods This retrospective study was approved by institutional review board, and informed consent was waived. A total of 112 patients with glioblastoma were divided into training (74 patients) and test (38 patients) sets. Overall survival (OS) and progression-free survival (PFS) was analyzed with ADC parameters, MGMT status, and other clinical factors. Multivariate Cox regression models with and without ADC parameters were constructed. Model performance was assessed with c index and receiver operating characteristic curve analyses for 12- and 16-month OS and 12-month PFS in the training set and validated in the test set. ADC parameters were compared according to MGMT status for the entire cohort. Results By using ADC parameters, the c indices and diagnostic accuracies for 12- and 16-month OS and 12-month PFS in the models showed significant improvement, with the exception of c indices in the models for PFS (P.05 for all) in the training set. In the test set, the diagnostic accuracy was improved by using ADC parameters and was significant, with the 25th and 50th percentiles of ADC for 16-month OS (P = .040 and P = .047) and the 25th percentile of ADC for 12-month PFS (P = .026). No significant correlation was found between ADC parameters and MGMT status. Conclusion ADC histogram analysis had incremental prognostic value over MGMT promoter methylation status in patients with glioblastoma. (©) RSNA, 2016 Online supplemental material is available for this article.

During 5-aminolevulinic acid (ALA)-guided glioblastoma multiforme (GBM) surgery, we encountered fluorescence in ventricular walls that lacked enhancement on magnetic resonance (MR) images and were free of macroscopic invasion of tumor cells. However, the meaning of ventricular wall fluorescence during 5-ALA-guided surgery is still unknown. The aim of this study was to investigate the relationship between intraoperative 5-ALA fluorescence and histopathological findings of ventricular walls free of enhancement on MR images. Nineteen patients with newly diagnosed GBM located near the lateral ventricle underwent 5‑ALA fluorescence‑guided surgery. During the surgery, the ventricle wall was opened and investigated with the aid of a surgical microscope equipped with optical filters to examine 5‑ALA fluorescence of the ventricular wall. Twenty‑five ventricular wall tissues that were apparently free of tumor involvement by MR imaging and macroscopic observation were obtained during surgery. Among the 19 cases with brightly fluorescing tumor masses, 11 patients (57.9%) exhibited 5‑ALA‑induced fluorescence in the ventricular wall. Of the 25 ventricular wall samples, 11 exhibited 5‑ALA‑induced fluorescence; upon pathologic examination, tumors were present in 5 samples (45.5%), but the remaining 6 (54.5%) were free of tumor cells. A pathologic examination revealed no tumor cells in the 14 samples that lacked 5‑ALA‑induced fluorescence. Our data suggest the possibility that glioma cells exhibiting 5‑ALA fluorescence are present in the ventricle wall, despite no signs of tumor involvement in MR images. Further investigation of non‑tumor cells from tissues with 5‑ALA fluorescence is needed to understand the nature of this unexpected ventricular wall fluorescence.

PURPOSE The purpose of this study was to investigate the feasibility and survival benefits of combined treatment with radiotherapy and adjuvant temozolomide (TMZ) in a Korean sample. MATERIALS AND METHODS A total of 750 Korean patients with histologically confirmed glioblastoma multiforme, who received concurrent chemoradiotherapy with TMZ (CCRT) and adjuvant TMZ from January 2006 until June 2011, were analyzed retrospectively. RESULTS After the first operation, a gross total resection (GTR), subtotal resection (STR), partial resection (PR), biopsy alone were achieved in 388 (51.7%), 159 (21.2%), 96 (12.8%), and 107 (14.3%) patients, respectively. The methylation status of O6-methylguanine-DNA methyltransferase (MGMT) was reviewed retrospectively in 217 patients. The median follow-up period was 16.3 months and the median overall survival (OS) was 17.5 months. The actuarial survival rates at the 1-, 3-, and 5-year OS were 72.1%, 21.0%, and 9.0%, respectively. The median progression-free survival (PFS) was 10.1 months, and the actuarial PFS at 1-, 3-, and 5-year PFS were 42.2%, 13.0%, and 7.8%, respectively. The patients who received GTR showed a significantly longer OS and PFS than those who received STR, PR, or biopsy alone, regardless of the methylation status of the MGMT promoter. Patients with a methylated MGMT promoter also showed a significantly longer OS and PFS than those with an unmethylated MGMT promoter. Patients who received more than six cycles of adjuvant TMZ had a longer OS and PFS than those who received six or fewer cycles. Hematologic toxicity of grade 3 or 4 was observed in 8.4% of patients during the CCRT period and in 10.2% during the adjuvant TMZ period. CONCLUSION Patients treated with CCRT followed by adjuvant TMZ had more favorable survival rates and tolerable toxicity than those who did not undergo this treatment.

OBJECTIVE The concept for maximal resection of glioblastoma(GBM) is changing to resect not only contrast-enhanced (CE) tumor but non-contrast-enhanced (NCE) tumor. Although maximal resection is associated with longer survival, the pattern of recurrence in glioblastoma, isocitrate dehydrogenase (IDH)-wildtype patient is poorly understood. METHODS This retrospective, single-center study included 358 eligible patients through November 1, 2005 to December 31, 2018. Those patients were grouped along extent of resection (subtotal resection (STR, n=123), gross-total resection (GTR, n=194), and supratotal resection (SupTR, n=41)). The pattern of recurrence was classified based on the range of radiation treatment, into infield gross target volume (GTV), infield clinical target volume (CTV), marginal, outfield and CSF seeding. RESULTS Tumor recurrence was observed for each group as follows: STR group, 80.5%, GTR group, 75.3%, and SupTR group, 63.4%. Statistical differences in pattern of recurrence among each group were observed in infield GTV (STR group:75.8%, GTR group: 71.9%, and SupTR group: 42.3%, p=0.003) and Outfield (STR group:11.0%, GTR group: 21.2%, SupTR group: 34.6%, p=0.012) recurrence. The survival for SupTR group was significantly longer than that for the STR and GTR in terms of both overall survival (OS) and progression free survival (PFS) (OS, STR: 15.7m, GTR: 21.6m, SupTR: 44.7m, PFS, STR: 10.4m, GTR: 14.3m, SupTR: 35.5m) CONCLUSIONS As the extent of resection increased, local recurrence decreased and distant recurrence increased. During treatment of glioblastoma, expectation

Background: Although glioblastoma (GBM) is the most common primary brain tumor, the best available treatment options are still associated with poor prognosis. Recently, the Hippo/YAP signaling pathway has emerged as an important driver of GBM. Nevertheless, extensive studies have not yet been focused on the importance of phosphorylation event in regulating endogenous YAP activity in GBM. Here, we sought to elucidate that the modulation and stabilization of YAP/TAZ in Hippo pathway promote GBM progression. Methods: A core gene expression signature reflecting Silence of Hippo pathway (SOH) was developed in GBM patient samples to determine whether SOH enhances the tumor progression. In GBM tumorsphere (TS), mRNA levels of YAP1 were determined by microarray, and nuclear YAP1 expression level and its correlation with tumor aggressiveness were assessed through nucleus cytosolic fractionation, quantitative confocal microscopy, Western blot, and TEAD4 reporter assay. Cell proliferation, stemness, and invasive properties were also measured after treatment of YAP siRNA or its inhibitor verteporfin (VP). Results: GBM patients with SOH signature associated with poor prognosis and shorter survival. GBM TSs exhibited various phosphorylation states of YAP and could be distinguished by its phosphorylation status. GBM TSs with reduced YAP phosphorylation, including TS15-88, and other GBM TSs with higher YAP phosphorylation, which includes TS13-64, showed aggressive or less-aggressive cancer phenotypes, respectively. The siRNA-mediated knockdown of YAP1 significantly suppressed proliferation of TSs, and the results were confirmed using VP. Knockdown of YAP1 not only attenuated the invasiveness and stemness of TSs. Conclusion: We showed that reduced phosphorylation of endogenous YAP contributes to GBM progression. Moreover, we found that GBM TSs can be classified into two groups based on their YAP phosphorylation. These associations emphasize the YAP signaling network as new therapeutic opportunities in diagnosing and treating GBM. Citation Format: Yoojung Oh, Eui Hyun Kim, Dongkyu Lee, Junseong Park, Ju Hyung Moon, Hyun Woo Park, Jong Hee Chang, Seok-Gu Kang. Classification of glioblastoma tumorsphere depending on the regulatory mechanisms of the Hippo pathway [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr A26.

The Hippo pathway plays a critical role in various cancers, but its role in glioblastoma (GBM) has not been properly addressed. To assess the clinical relevance of the Hippo pathway in GBM, we generated a core gene expression signature reflecting silence of the Hippo pathway (SOH), and validated it in GBM patient samples from The Cancer Genome Atlas (TCGA) and in a separate cohort, revealing that SOH signature was associated with poor prognosis in GBM in both cohorts. Expression levels of CTGF and CYR61, the most reliable and well-known downstream targets of YAP1 (a target of the Hippo pathway), were markedly increased in GBM with the SOH signature. GBM showing the SOH signature was associated with an increased Immune signature score (ISS), suggesting that these patients might be good potential candidates for immunotherapy. Genes differentially expressed between samples with the SOH signature and samples with an active Hippo signature showed that many inhibitory immune checkpoint genes, such as CTLA4, PD-1, and PD-L2, were upregulated in the SOH subgroup, suggesting that YAP1/TAZ may induce resistance of cancer cells to host immune response in GBM. Also, many M2-polarized microglial markers and innate immune pathways were activated in the SOH subgroup. The SOH signature was strongly correlated with the TGF-β signature, which was also associated with a high ISS and mesenchymal features. In summary, SOH induces protumoral immunity in various ways, which may be new immunotherapeutic targets of GBM. Note: This abstract was not presented at the conference. Citation Format: Eui Hyun Kim, Seok-Gu Kang, Ju-Seog Lee. Silence of Hippo pathway induces protumoral immunity: New therapeutic target of glioblastomas [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr B16.

BACKGROUND: Grade II glioma is a heterogeneous group of various pathologies. 2016 WHO classification defined subgroups of Grade II gliomas based on isocitrate dehydrogenase (IDH) mutation and 1p/19q codeletion status. However, implications of telomerase reverse transcriptase promoter (TERTp) mutation and alpha-thalassemia/mental retardation syndrome X-linked (ATRX) loss are not considered in the classification. METHODS: Patients (n = 191) who underwent surgery and pathologically proven for supratentorial newly diagnosed low-grade glioma (WHO grade II) were included this study. Molecular diagnoses including IDH1/2 mutation, 1p/19q codeletion, TERTp mutation, ATRX expression, O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status was evaluated. The overall survival according to TERTp mutation and ATRX loss in each 2016 WHO class were compared. RESULTS: There were 34 (17.8%) IDH-wildtype astrocytomas, 81 (42.4%) IDH-mutant astrocytomas, and 76 (39.8%) IDH-mutant and 1p/19q-codeleted oligodendrogliomas. The median overall survival (OS) of each group were 3.9, 10.4, and 18.7 years, respectively. TERTp mutation had negative impact for survival in IDH-wildtype astrocytomas (HR = 5.458, 95% confidence interval [CI] 1.771–16.826), while no significant differences were observed regarding TERTp mutation in IDH-mutant astrocytomas and oligodendrogliomas. Among IDH-wildtype/TERTp-mutant astrocytomas, ATRX loss was significantly correlated with poor outcome (2.1 vs 3.0 years, p=0.033). CONCLUSIONS: Molecular status of TERTp mutation and ATRX expression can help stratifying IDH-wildtype astrocytomas. IDH-wildtype astrocytomas which harbor TERTp mutation only without ATRX loss showed the worst outcome. Further study is needed to verify the role of TERTp mutation and ATRX in gliomas.

Two hypotheses about the origin of human glioblastoma (GBM) genesis are known to be dedifferentiation of cancer cells and orthodox differentiation of cancer stem cells. However, little is known about whether the direction of the human GBM genesis begins at the site of the tumor or at the subventricular zone (SVZ) where normal neural stem cells (NSCs) are present. Here, we describe direct molecular genetic evidence from patient brain tissue and genome-edited mouse models that show astrocyte-like NSCs in the SVZ to be the cell of origin that harbors the driver mutations of human GBM. First, we performed deep sequencing of triple-matched tissues, consisting of i) normal SVZ tissue away from the tumor mass, ii) tumor tissue, and iii) normal cortical tissue (or blood), from 28 patients with GBM, isocitrate dehydrogenase-wild type (IDH-wildtype) or other types of brain tumors. In doing so, we found that normal SVZ tissue away from the tumor in 56.3% of GBM IDH-wildtype patients contained low-level GBM driver mutations (down to ~1% of the mutational burden) that were observed at high levels in their matching tumors. Moreover, via single cell sequencing and laser microdissection analysis of patient brain tissue and genome editing of a mouse model, we discovered that astrocyte-like NSCs carrying driver mutations migrate from the SVZ and lead to the development of high-grade malignant gliomas in distant brain regions. Altogether, our results highlight NSCs in human SVZ tissue as the cell of origin that harbors the driver mutations of GBM. In addition, the origin of human glioblastoma is not the location of the tumor but the subventricular zone.

Although programmed death-1 (PD-1) blockade is effective in treating several types of cancer, the efficacy of this agent in glioblastoma (GBM) is largely unknown. We evaluated therapeutic effects of anti-PD-1, temozolomide (TMZ), and their combination in an orthotopic murine GBM model. The phenotype, number, and composition of lymphocytes were evaluated using flow cytometry. Transcriptional profiles of tumor tissues were analyzed using microarrays. Generation of antitumor immunological memory was investigated upon rechallenge. Combined treatment with anti-PD-1 and TMZ yielded synergistic antitumor efficacy in the presence of donor-originated PD-1(+)CD8(+) T cells in vitro, necessitating in vivo validation. Whereas TMZ did not rescue GBM-implanted mice, anti-PD-1 completely eradicated GBM in 44.4% of mice, and combination of anti-PD-1 and TMZ in all mice. Anti-PD-1 significantly increased the number of tumor-infiltrating lymhpocytes (TILs), and reduced frequencies of exhausted T cells and regulatory T cells. However, combining TMZ with anti-PD-1 significantly decreased the number of TILs, which was also observed with TMZ treatment alone. A transcriptome analysis of tumor tissues revealed that anti-PD-1 monotherapy perturbed immune-related genes, distinctly with combined therapy. Upon rechallenge, tumor growth was not observed in mice cured by anti-PD-1 monotherapy, whereas tumors regrew in the combination group. Furthermore, an analysis of peripheral blood revealed that antitumor memory T cells were generated in mice cured by anti-PD-1 monotherapy, not in the combination group. PD-1 blockade induces long-term therapeutic response, and combination with TMZ further enhances antitumor efficacy. However, immunological memory is provoked by anti-PD-1 monotherapy, not by combined therapy.