Epidemiological characteristics and genetic alterations in adult diffuse glioma in East Asian populations

Management and survival trends for diffuse gliomas diagnosed at a single neurooncology center in China during 2000 to 2020

Currently reported survival outcomes for gliomas exhibit significant variability and controversy. In this study, we aim to provide survival data in Chinese populations by conducting a retrospective analysis of management and survival trends in a large cohort of glioma patients from a single institute in China. A total of 1206 patients with newly diagnosed gliomas treated between 2000 and 2020 were enrolled, including 537 glioblastoma (WHO grade 4), 450 astrocytomas (grade 2/3) and 219 oligodendroglial tumors (grade 2/3). The estimated overall survival at 5 years was 18.9% for glioblastoma, 58.8% for astrocytomas, and 80.7% for oligodendroglial tumors, while median survival was 17.2 months, 82.8 months, and not reached, respectively. The survival trend has increased over the past decades for all types of gliomas. Additionally, similar survival trends were observed between grade 2 and 3 IDH-mutant gliomas. Rising trends were observed in patients undergoing postsurgical radiation and chemotherapy. Multivariate analysis identified adjuvant radiochemotherapy as an independent factor for better prognosis in glioblastoma and astrocytomas. In summary, despite its retrospective nature, this cohort of glioma patients exhibits favorable survival outcomes compared to global statistics, indicating a geographical disparity in glioma prognosis. The promotion of adjuvant chemoradiotherapy contributes to improved prognosis.

18F-FET PET/CT can aid in diagnosing patients with indeterminate MRI findings for brain tumors: a prospective study

OBJECTIVE

This prospective study aimed to evaluate the diagnostic value of fluorine-18-labeled fluoroethyltyrosine (18F-FET) positron emission tomography (PET)/computed tomography (CT) in diagnosing brain tumors within an Asian patient population.

METHODS

Patients suspected of having primary or recurrent brain tumors were prospectively recruited. Each patient underwent 18F-FET and fluorine-18 fluorodeoxyglucose (18F-FDG) PET/CT on separate days within 1 week. We calculated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy to compare the diagnostic performance of the two PET scans. The standardized uptake value (SUV) and tumor-to-background ratio (TBR) of the lesions were determined using static images. Additionally, time-activity curves (TACs) and time-to-peak (TTP) were generated from the dynamic PET images.

RESULTS

From September 2019 to December 2023, 33 subjects were enrolled for reasons including suspected brain tumors (n = 20) or suspicious glioma recurrence (n = 8) on magnetic resonance imaging (MRI) and restaging for glioma (n = 5). Among the patients with suspected brain tumors or glioma recurrence on MRI, 25% had false-positive results. 18F-FET PET/CT accurately identified 86% of these false positives. The sensitivity, specificity, PPV, NPV, and accuracy of visual interpretation of 18F-FET PET/CT were 96.2%, 85.7%, 96.2%, 85.7%, and 93.9%, respectively. The corresponding 18F-FDG PET/CT values were 73.1%, 71.4%, 90.5%, 41.7%, and 72.7%. 18F-FET PET/CT demonstrated significantly higher sensitivity and accuracy than 18F-FDG PET (p = 0.031 and p = 0.030, respectively). Using TBRmean as an adjunct reference index enhanced the diagnostic accuracy of 18F-FET PET/CT, achieving a sensitivity and NPV of 100%. Wash-out TAC or TTP < 20 min was associated with a PPV of 100% for brain tumors.

CONCLUSIONS

18F-FET PET/CT appears to be a valuable tool for assessing brain tumors with indeterminate MRI findings in this Asian cohort. 18F-FET PET/CT offers benefits over 18F-FDG PET in differentiating brain tumors from nontumor brain lesions, particularly when using semiquantitative analysis with TBR. This study was registered on CinicalTrial.gov (NCT06563024).

Efficient discovery of robust prognostic biomarkers and signatures in solid tumors

Recent advancements in multi-omics and big-data technologies have facilitated the discovery of numerous cancer prognostic biomarkers and gene signatures. However, their clinical application remains limited due to poor reproducibility and insufficient independent validation. Despite the availability of high-quality datasets, achieving reliable biomarker identification across multiple cohorts continues to be a significant challenge. To address these issues, we developed a comprehensive platform, SurvivalML, designed to support the discovery and validation of prognostic biomarkers and gene signatures using large-scale and harmonized data from 21 cancer types. Through SurvivalML, we identified DCLRE1B as a novel prognostic biomarker for hepatocellular carcinoma, with experimental confirmation of its role in promoting tumor progression. Additionally, we developed the Chinese glioblastoma prognostic signature (CGPS) and its simplified version, SCGPS, a three-gene model. Both demonstrated superior predictive performance compared to other glioblastoma signatures in our in-house cohort and five independent Chinese datasets. The SCGPS model was further validated in 109 clinical samples using multiplex immunofluorescence, showing strong consistency with the original CGPS model. Overall, SurvivalML provides a robust platform for the identification and validation of prognostic biomarkers and gene signatures, offering a valuable resource for advancing cancer research and clinical application.

Understanding Neovascularization in Glioblastoma: Insights from the Current Literature

Glioblastomas (GBMs), among the most aggressive and resilient brain tumors, characteristically exhibit high angiogenic potential, leading to the formation of a dense yet aberrant vasculature, both morphologically and functionally. With these premises, numerous expectations were initially placed on anti-angiogenic therapies, soon dashed by their limited efficacy in concretely improving patient outcomes. Neovascularization in GBM soon emerged as a complex, dynamic, and heterogeneous process, hard to manage with the classical standard of care. Growing evidence has revealed the existence of numerous non-canonical strategies of angiogenesis, variously exploited by GBM to meet its ever-increasing metabolic demand and differently involved in tumor progression, recurrence, and escape from treatments. In this review, we provide an accurate description of each neovascularization mode encountered in GBM tumors to date, highlighting the molecular players and signaling cascades primarily involved. We also detail the key architectural and functional aspects characteristic of the GBM vascular compartment because of an intricate crosstalk between the different angiogenic networks. Additionally, we explore the repertoire of emerging therapies against GBM that are currently under study, concluding with a question: faced with such a challenging scenario, could combined therapies, tailored to the patient's genetic signatures, represent an effective game changer?

Voagafries A-E, undescribed indole alkaloids with anti-glioma activity from Voacanga africana

Voagafries A-E, five undescribed monoterpenoid indole alkaloids (MIAs), were isolated from the stem bark of Voacanga africana. Voagafrie A (1) has a unique 6/5/5/6/6 spiral ring skeleton with an indolone-fused 9-oxo-3-aza-tricyclo[6,3,1,03,7]-12-alkane-10-carbonyllactone. Voagafrie B (2) is a rare 5,6-seco diazine scaffold, whereas voagafrie C (3) possesses an octahydropyrrolo[2,3-b] pyrrole-fused 2,8-diazabicyclo[3.3.1] nonane. In addition, voagafrie D (4) represents an additional 3C ibogamine-type MIA. Their structures were elucidated using extensive spectroscopic and computational analyses and a plausible biosynthetic pathway originating from conopharyngine was proposed. Furthermore, voagafries B (2) and E (5) exhibited significant cytotoxicity against SH-SY5Y at 10 μmol/L with cell viabilities of 72.7 ± 3.8 and 79.5 ± 2.1, respectively, which were comparable to that of the positive drug paclitaxel (64.1 ± 0.9). Based on the research on several cell death-related factors, these compounds may be involved in apoptosis; therefore, it is necessary to advance our understanding of them through future studies.

Epidemiology of glioblastoma in Pakistan: a secondary analysis of the Pakistan Brain Tumor Epidemiology Study (PBTES)

PURPOSE

The incidence and outcomes of glioblastoma (GBM) patients in Pakistan remain unassessed owing to a lack of cancer registries and the absence of population-based studies. For any specific population-based oncological intervention, epidemiology must be studied. Therefore, this study aims to examine the epidemiological characteristics of glioblastoma patients in Pakistan, as part of a secondary analysis of a nationwide epidemiological study.

METHODS

Data comprising of sociodemographic, tumor and treatment characteristics of 2750 patients from the Pakistan Brain Tumor Epidemiology Study were extracted and analyzed for cases between January 1, 2019, and December 31, 2019. Chi-square tests identified outcome and treatment differences. Data analysis was performed using SPSS version 26.

RESULTS

A total of 260 GBM cases were analyzed, with a mean diagnosis age of 45 years. Males accounted for 68.8%. Most patients were from a middle- (39.6%) or lower-income (42.7%) socioeconomic background and received care from a public institution (63.8%). GBM tumors were mainly located in the frontal lobe with similar proportions of right and left laterality. A median distance of 119 km was traveled for oncological care, and the mean time to surgery from the initial radiological diagnosis was 72 days. Gross total resection was achieved in 47.3% of first surgeries, with 23 reoperations for recurrence. At the end of the study period, 33% of the GBM cohort was recorded as alive with 47% being lost to follow-up.

CONCLUSION

Our analysis is the first population-based analysis of GBM in Pakistan. This epidemiologic study can serve as a basis for future research in etiology, treatment, and outcomes for glioblastoma in the Pakistani population.

Identification of Brain Cell Type-Specific Therapeutic Targets for Glioma From Genetics

BACKGROUND

Previous research has demonstrated correlations between the complex types and functions of brain cells and the etiology of glioma. However, the causal relationship between gene expression regulation in specific brain cell types and glioma risk, along with its therapeutic implications, remains underexplored.

METHODS

Utilizing brain cell type-specific cis-expression quantitative trait loci (cis-eQTLs) and glioma genome-wide association study (GWAS) datasets in conjunction with Mendelian randomization (MR) and colocalization analyses, we conducted a systematic investigation to determine whether an association exists between the gene expression of specific brain cell types and the susceptibility to glioma, including its subtypes. Additionally, the potential pathogenicity was explored utilizing mediation and bioinformatics analyses. This exploration ultimately led to the identification of a series of brain cell-specific therapeutic targets.

RESULTS

A total of 110 statistically significant and robust associations were identified through MR analysis, with most genes exhibiting causal effects exclusively in specific brain cell types or glioma subtypes. Bayesian colocalization analysis validated 36 associations involving 26 genes as potential brain cell-specific therapeutic targets. Mediation analysis revealed genes indirectly influencing glioma risk via telomere length. Bioinformatics analysis highlighted the involvement of these genes in glioma pathogenesis pathways and supported their enrichment in specific brain cell types.

CONCLUSIONS

This study, employing an integrated approach, demonstrated the genetic susceptibility between brain cell-specific gene expression and the risk of glioma and its subtypes. Its findings offer novel insights into glioma etiology and underscore potential therapeutic targets specific to brain cell types.

Efficient and Accurate Brain Tumor Classification Using Hybrid MobileNetV2-Support Vector Machine for Magnetic Resonance Imaging Diagnostics in Neoplasms

BACKGROUND/OBJECTIVES

Magnetic Resonance Imaging (MRI) plays a vital role in brain tumor diagnosis by providing clear visualization of soft tissues without the use of ionizing radiation. Given the increasing incidence of brain tumors, there is an urgent need for reliable diagnostic tools, as misdiagnoses can lead to harmful treatment decisions and poor outcomes. While machine learning has significantly advanced medical diagnostics, achieving both high accuracy and computational efficiency remains a critical challenge.

METHODS

This study proposes a hybrid model that integrates MobileNetV2 for feature extraction with a Support Vector Machine (SVM) classifier for the classification of brain tumors. The model was trained and validated using the Kaggle MRI brain tumor dataset, which includes 7023 images categorized into four types: glioma, meningioma, pituitary tumor, and no tumor. MobileNetV2's efficient architecture was leveraged for feature extraction, and SVM was used to enhance classification accuracy.

RESULTS

The proposed hybrid model showed excellent results, achieving Area Under the Curve (AUC) scores of 0.99 for glioma, 0.97 for meningioma, and 1.0 for both pituitary tumors and the no tumor class. These findings highlight that the MobileNetV2-SVM hybrid not only improves classification accuracy but also reduces computational overhead, making it suitable for broader clinical use.

CONCLUSIONS

The MobileNetV2-SVM hybrid model demonstrates substantial potential for enhancing brain tumor diagnostics by offering a balance of precision and computational efficiency. Its ability to maintain high accuracy while operating efficiently could lead to better outcomes in medical practice, particularly in resource limited settings.

Serum exosomal miRNA promote glioma progression by targeting SOS1 via abscopal effect of radiation

INTRODUCTION

Local exposure to ionizing radiation (IR) can induce changes in biological processes in distant tissues and organs. Exosomes are nanoscale vesicles that transport biomolecules, mediate communication between cells and tissues, and can affect the abscopal effects of radiotherapy.

METHODS

Mice were treated with 8.0 Gy doses of chest and abdomen IR, after which serum samples were taken 24 h after exposure. Their serum exosomes were then isolated via ultracentrifugation and the small RNA portions were extracted for sequencing and bioinformatic analysis. Exosomes were injected intravenously into the mice to assess their ability to cross the blood-brain barrier (BBB). Glioma cells and glioma stem cells (GSCs) were examined for malignant biological behaviors, stemness, and tumorigenic capacity after co-culturing with different groups of exosomes.

RESULTS

We found that serum exosomes crossed the BBB in mice after local IR exposure-which induced decreases in the expression of BBB tight-junction proteins and increased brain endothelial cell apoptosis. Exosomes from the exposed groups promoted malignant biological behaviors, stemness, and tumorigenic capacity in glioma cells and GSCs by upregulating the expression of SOS1. Phospho-MEK1/2 and Phospho-ERK1/2, of the MAPK signaling pathway, were found to be up-regulated in cells that were co-cultured with the exposing groups of the exosomes. Further analyses demonstrated that differentially expressed levels of miR-93-5p in mouse serum exosomes regulated the cellular expression of SOS1.

CONCLUSION

Following local IR exposure, serum exosomes cross the BBB to promote the progression of distant gliomas. Exosomal microRNAs play an important role in this process.

Comparative analysis of molecular and histological glioblastomas: insights into prognostic variance

PURPOSE

Whether molecular glioblastomas (GBMs) identify with a similar dismal prognosis as a "classical" histological GBM is controversial. This study aimed to compare the clinical, molecular, imaging, surgical factors, and prognosis between molecular GBMs and histological GBMs.

METHODS

Retrospective chart and imaging review was performed in 983 IDH-wildtype GBM patients (52 molecular GBMs and 931 histological GBMs) from a single institution between 2005 and 2023. Propensity score-matched analysis was additionally performed to adjust for differences in baseline variables between molecular GBMs and histological GBMs.

RESULTS

Molecular GBM patients were substantially younger (58.1 vs. 62.4, P = 0.014) with higher rate of TERTp mutation (84.6% vs. 50.3%, P < 0.001) compared with histological GBM patients. Imaging showed higher incidence of gliomatosis cerebri pattern (32.7% vs. 9.2%, P < 0.001) in molecular GBM compared with histological GBM, which resulted in lesser extent of resection (P < 0.001) in these patients. The survival was significantly better in molecular GBM compared to histological GBM (median OS 30.2 vs. 18.4 months, P = 0.001). The superior outcome was confirmed in propensity score analyses by matching histological GBM to molecular GBM (P < 0.001).

CONCLUSION

There are distinct clinical, molecular, and imaging differences between molecular GBMs and histological GBMs. Our results suggest that molecular GBMs have a more favorable prognosis than histological GBMs.

The role of NPC2 gene in glioma was investigated based on bioinformatics analysis

Glioblastoma (GBM) is one of the most malignant primary brain tumors in adults. The NPC2 gene (Niemann-Pick type C intracellular cholesterol transporter 2) is a protein-coding gene with a lipid recognition domain. The NPC2 gene was found to be significantly increased in gliomas (LGG and GBM), and it is now thought to be a risk factor. COX analysis demonstrated that NPC2 was a significant risk factor for glioma. Functional enrichment analysis of genes that were differentially expressed between high and low expression groups revealed that genes were primarily enriched in the regulation of trans-synaptic signaling, Retrograde endocannabinoid signaling and other pathways. According to the findings of the immunoinfiltration investigation, the NPC2 gene and macrophage, DC, etc. have a strong positive association. In addition, patients with high NPC2 expression had higher levels of immune cell expression. Medication sensitivity research revealed that NPC2's differential expression had some bearing on patients' medication sensitivity. There was a strong correlation between the prognosis of glioma patients and the gene sets NUDT19 and NUME. In brief, the NPC2 gene was identified to be a possible biomarker of glioma, and preliminary analysis was done on the role of the NPC2 gene in immunological microenvironment of glioma.

Advancements in Glioma Care: Focus on Emerging Neurosurgical Techniques

BACKGROUND

Despite significant advances in understanding the molecular pathways of glioma, translating this knowledge into effective long-term solutions remains a challenge. Indeed, gliomas pose a significant challenge to neurosurgical oncology because of their diverse histopathological features, genetic heterogeneity, and clinical manifestations. Relevant sections: This study focuses on glioma complexity by reviewing recent advances in their management, also considering new classification systems and emerging neurosurgical techniques. To bridge the gap between new neurosurgical approaches and standards of care, the importance of molecular diagnosis and the use of techniques such as laser interstitial thermal therapy (LITT) and focused ultrasound (FUS) are emphasized, exploring how the integration of molecular knowledge with emerging neurosurgical approaches can personalize and improve the treatment of gliomas.

CONCLUSIONS

The choice between LITT and FUS should be tailored to each case, considering factors such as tumor characteristics and patient health. LITT is favored for larger, complex tumors, while FUS is standard for smaller, deep-seated ones. Both techniques are equally effective for small and superficial tumors. Our study provides clear guidance for treating pediatric low-grade gliomas and highlights the crucial roles of LITT and FUS in managing high-grade gliomas in adults. This research sets the stage for improved patient care and future developments in the field of neurosurgery.

IDH wild-type lower-grade gliomas with glioblastoma molecular features: a systematic review and meta-analysis

The WHO 2021 classification defines IDH wild type (IDHw) histologically lower-grade glioma (hLGG) as molecular glioblastoma (mGBM) if TERT promoter mutation (pTERTm), EGFR amplification or chromosome seven gain and ten loss aberrations are indicated. We systematically reviewed articles of IDHw hLGGs studies (49 studies, N = 3748) and meta-analyzed mGBM prevalence and overall survival (OS) according to the PRISMA statement. mGBM rates in IDHw hLGG were significantly lower in Asian regions (43.7%, 95% confidence interval [CI: 35.8-52.0]) when compared to non-Asian regions (65.0%, [CI: 52.9-75.4]) (P = 0.005) and were significantly lower in fresh-frozen specimen when compared to formalin-fixed paraffin-embedded samples (P = 0.015). IDHw hLGGs without pTERTm rarely expressed other molecular markers in Asian studies when compared to non-Asian studies. Patients with mGBM had significantly longer OS times when compared to histological GBM (hGBM) (pooled hazard ratio (pHR) 0.824, [CI: 0.694-0.98], P = 0.03)). In patients with mGBM, histological grade was a significant prognostic factor (pHR 1.633, [CI: 1.09-2.447], P = 0.018), as was age (P = 0.001) and surgical extent (P = 0.018). Although bias risk across studies was moderate, mGBM with grade II histology showed better OS rates when compared to hGBM.

Effect of OR51E1 Single Nucleotide Polymorphisms on Glioma Susceptibility in the Chinese Han Population

BACKGROUND

Glioma is one of the common primary intracranial tumors, which is heterogeneous among individuals with a low cure rate. Our study aimed to investigate the association between single nucleotide polymorphisms (SNPs) of the OR51E1 gene and glioma susceptibility in the Chinese Han population.

METHODS

A total of six SNPs on OR51E1 in 1,026 subjects (526 cases and 500 controls) were genotyped by MassARRAY iPLEX GOLD assay. The association between these SNPs and glioma susceptibility was analyzed using logistic regression, and odds ratios (ORs) and 95% confidence intervals (CIs) were also calculated. The multifactor dimensionality reduction (MDR) method was applied to detect "SNP-SNP" interactions.

RESULTS

In the overall sample, polymorphisms rs10768148, rs7102992, and rs10500608 were identified to be associated with glioma risk. In the stratified analysis based on gender, only polymorphism rs10768148 was observed to be associated with the risk of glioma. In the age-stratified analysis, rs7102992, rs74052483, and rs10500609 contributed to the risk of glioma in subjects aged > 40 years. And polymorphisms rs10768148 and rs7102992 were associated with the risk of glioma in subjects aged ≤ 40 years and subjects with astrocytoma. In addition, a strong synergistic relationship between rs74052483 and rs10768148, and a strong redundant relationship between rs7102992 and rs10768148 were identified in the study.

CONCLUSIONS

This study demonstrated the association of OR51E1 polymorphisms with glioma susceptibility, providing a basis for assessing glioma risk-associated variants in the Chinese Han population.

Expert opinion on translational research for advanced glioblastoma treatment

Malignant gliomas are known to be one of the most difficult diseases to diagnose and treat because of the infiltrative growth pattern, rapid progression, and poor prognosis. Many antitumor drugs are not ideal for the treatment of gliomas due to the blood-brain barrier. Temozolomide (TMZ) is a DNA alkylating agent that can cross the blood-brain barrier. As the only first-line chemotherapeutic drug for malignant gliomas at present, TMZ is widely utilized to provide a survival benefit; however, some patients are inherently insensitive to TMZ. In addition, patients could develop acquired resistance during TMZ treatment, which limits antitumor efficacy. To clarify the mechanism underlying TMZ resistance, numerous studies have provided multilevel solutions, such as improving the effective concentration of TMZ in tumors and developing novel small molecule drugs. This review discusses the in-depth mechanisms underlying TMZ drug resistance, thus aiming to provide possibilities for the establishment of personalized therapeutic strategies against malignant gliomas and the accelerated development and transformation of new targeted drugs.