Early presentation of primary glioblastoma

Initial cognitive impairment predicts shorter survival of patients with glioblastoma

OBJECTIVES

Seizures as presenting symptom of glioblastoma (GBM) are known to predict prolonged survival, whereas the clinical impact of other initial symptoms is less known. Our main objective was to evaluate the influence of different presenting symptoms on survival in a clinical setting. We also assessed lead times, tumour size and localization.

METHODS

Medical records of 189 GBM patients were reviewed regarding the first medical appointment, presenting symptom/s, date of diagnostic radiology and survival. Tumour size, localization and treatment data were retrieved. Overall survival was calculated using Kaplan-Meier and Mann-Whitney U test. Cox regression was used for risk estimation.

RESULTS

Cognitive impairment as the initial symptom was often misinterpreted in primary health care leading to a delayed diagnosis. Initial global symptoms (66% of all patients) were associated with reduced survival compared to no global symptoms (median 8.4 months vs. 12.6 months). Those with the most common cognitive dysfunctions: change of behaviour, memory impairment and/or disorientation had a reduced median survival to 6.4 months. In contrast, seizures (32%) were associated with longer survival (median 11.2 months vs. 8.3 months). Global symptoms were associated with larger tumours than seizures, but tumour size had no linear association with survival. The setting of the first medical appointment was evenly distributed between primary health care and emergency units.

CONCLUSION

Patients with GBM presenting with cognitive symptoms are challenging to identify, have larger tumours and reduced survival. In contrast, epileptic seizures as the first symptom are associated with longer survival and smaller tumours.

Circular RNA circNF1 siRNA Silencing Inhibits Glioblastoma Cell Proliferation by Promoting the Maturation of miR-340

It has been reported that circNF1, a type of circular RNA (circRNA), promotes gastric cancer. This study aimed to analyze the role of circNF1 in glioblastoma (GBM). The expression of circNF1, mature miR-340, and miR-340 precursor in paired GBM and non-cancer tissues from GBM patients (n = 50) was analyzed by RT-qPCR. GBM cells were transfected with circNF1 siRNA, followed by the analysis of the expression of mature miR-340 and miR-340 precursor, to study the effects of circNF1 knockdown on the maturation of miR-340. The CCK-8 assay was carried out to explore the role of circNF1 and miR-340 in the proliferation of GBM cells. circNF1 expression was found to be upregulated in GBM and was correlated with patient survival. In glioma tissue, circNF1 was inversely correlated with mature miR-340, but not with the miR-340 precursor. In GBM cells, circNF1 siRNA silencing resulted in the upregulation of mature miR-340, but not the miR-340 precursor. The cell proliferation assay showed that circNF1 siRNA silencing and miR-340 overexpression decreased the proliferation of GBM cells. In addition, the miR-340a inhibitor suppressed the role of circNF1 siRNA silencing in cell proliferation. Therefore, circNF1 siRNA silencing may inhibit GBM cell proliferation by promoting the maturation of miR-340.

Nanoribbon-Based Electronic Detection of a Glioma-Associated Circular miRNA

Nanoribbon chips, based on “silicon-on-insulator” structures (SOI-NR chips), have been fabricated. These SOI-NR chips, whose surface was sensitized with covalently immobilized oligonucleotide molecular probes (oDNA probes), have been employed for the nanoribbon biosensor-based detection of a circular ribonucleic acid (circRNA) molecular marker of glioma in humans. The nucleotide sequence of the oDNA probes was complimentary to the sequence of the target oDNA. The latter represents a synthetic analogue of a glioma marker—NFIX circular RNA. In this way, the detection of target oDNA molecules in a pure buffer has been performed. The lowest concentration of the target biomolecules, detectable in our experiments, was of the order of ~10⁻¹⁷ M. The SOI-NR sensor chips proposed herein have allowed us to reveal an elevated level of the NFIX circular RNA in the blood of a glioma patient.

Prognostic relevance of adding MRI data to WHO 2016 and cIMPACT-NOW updates for diffuse astrocytic tumors in adults. Working toward the extended use of MRI data in integrated glioma diagnosis

Assess the contribution of preoperative MRI data in improving grading of adult astrocytomas reclassified according to the WHO 2016 and cIMPACT-NOW update 3. Retrospective unicentric cohort study of 679 adult patients treated for newly diagnosed diffuse astrocytic and oligodendroglial tumors (January 2006-December 2016). We first systematically compared radiological (contrast enhancement present [CE+] vs. absent [CE-]) and histopathological findings (microvascular proliferation present [MPV+] vs. absent [MPV-]) to validate whether this comparing step of neoangiogenesis represents an efficient method to appreciate the representativity of the tumoral sampling. We focused on 629 cases of astrocytomas for radio-histological integrated analyses. In 598 cases (95.1%), neoangiogenesis evaluated by MRI or histology (CE+/MPV+ or CE-/MPV-) was identical. For the CE+/MPV- and CE-/MPV+ groups (23 cases), the radio-histological face-to-face evaluation allowed us to assess that for 13 cases (56.5%) the reason for this discrepancy was an undersampled tumor. We analyzed the group of CE+/MPV- (n = 8) and CE-/MPV+ (n = 2) in verified image-guided tumoral samples. Finally, we identified three new prognostic subgroups for molecular glioblastomas: (1) "non-representative sampling" (n = 9), (2) "Non neoangiogenic glioblastoma at the time of diagnosis, without contrast enhancement and microvascular proliferation" (n = 8), and (3) "contrast enhancing glioblastoma but without microvascular proliferation in a representative sample" (n = 4). Neoangiogenesis processes should be assessed to improve the prognosis accuracy of the current integrated diagnosis. We suggest adding imaging analyses during the neuropathological analysis of astrocytomas in adults.

Behavior-Oriented Nomogram for the Stratification of Lower-Grade Gliomas to Improve Individualized Treatment

Secondary glioblastomas (sGBM) are derived from previously lower-grade [World Health Organization (WHO) grades II or III] gliomas. Lower-grade benign-behaving gliomas may retain their former grade following recurrence, or may become malignant higher-grade glioblastomas. Prediction of tumor behavior in lower-grade gliomas is critical for individualized glioma therapy. A total of 89 patients were included between January 2000 and January 2019 in the present study to establish a nomogram via univariate and multivariate logistic regression analyses. Nomogram predictive performance was tested in the validation group. We then analyzed 36 O-6-methylguanine-DNA methyltransferase (MGMT) unmethylated lower-grade gliomas from patients seen at West China Hospital of Sichuan University. Survival statistics were calculated with the Kaplan-Meier method. Two clinical factors (molecular diagnosis and WHO grade), five radiological factors (location, cortical involvement, multicentricity, uniformity, and margin enhancement), one biomarker (1p19q codeletion), and a combination of three biomarkers (IDH+/ATRX-/TP53-) were associated with glioma upgrading. Nomograms positive for these prognostic factors had an AUC of 0.880 in the derivation group and 0.857 in the validation group. The calibration and score-stratified survival curves for the derivation group and validation group were good. An operational nomogram was published at https://warrenwrl.shinyapps.io/DynNomapp/. The overall survival of secondary gliomas in the MGMT-unmethylated cohort were influenced independently by the use of temozolomide during the treatment of formerly low-grade gliomas (p=0.00096). Clinical and radiological factors and biomarker-based behavior-oriented nomograms may offer a feasible identification tool for the detection of sGBM precursors. This method may further assist neurosurgeons with the stratification of lower-grade glioma cases and thus the development of better, more individualized treatment plans.

The efficacy and toxicity of ATM inhibition in glioblastoma initiating cells-driven tumor models

The Ataxia Telangiectasia Mutated (ATM)-mediated DNA damage response (DDR) is a major mechanism of resistance of glioblastoma (GB) - initiating cells (GICs) to radiotherapy. The closely related Ataxia Telangiectasia and Rad3-related protein (ATR) is also involved in tumor resistance to radio- and chemotherapy. It has been shown that pharmacological inhibition of ATM protein may overcome the DDR-mediated resistance in GICs and significantly radiosensitize GIC-driven GB. Albeit not essential for life as shown by the decade-long lifespan of AT patients, the ATM protein may be involved in a number of important functions other than the response to DNA damage. We discuss our current knowledge about the toxicity of pharmacologic inhibition of ATM and ATR proteins.

Diagnosis and Treatment of Early-Stage Glioblastoma

Early-stage glioblastoma has few identifiable findings; clinical significance of its early diagnosis and treatment remains unclear as no report has described treatment and long-term follow-up for early-stage glioblastoma. Here, we report a case of a 69-year-old woman with early-stage glioblastoma treated by microsurgical resection and chemoradiotherapy. Magnetic resonance imaging (MRI) revealed a small high-intensity lesion in the right temporal lobe on T2-weighted imaging. Contrast-enhanced T1-weighted MRI revealed ring enhancement. On magnetic resonance spectroscopy, the lesion demonstrated increased choline and reduced N-acetyl-aspartate levels compared with the normal brain. Positron emission tomography with ¹¹C-methionine (MET) revealed ¹¹C-methionine uptake in the lesion. Microsurgical resection was performed, and glioblastoma was pathologically diagnosed. The patient was treated with local radiotherapy and temozolomide chemotherapy postoperatively. Eight years postoperatively, the patient is surviving without tumor recurrence, but progressive cognitive impairment developed 6 years’ postoperatively. Aggressive treatment of early-stage glioblastoma may improve its extremely poor prognosis. Conversely, cognitive impairment may become a significant medical and social problem when effective therapies for glioblastoma are developed.

Identification of the Gene Expression Rules That Define the Subtypes in Glioma

As a common brain cancer derived from glial cells, gliomas have three subtypes: glioblastoma, diffuse astrocytoma, and anaplastic astrocytoma. The subtypes have distinctive clinical features but are closely related to each other. A glioblastoma can be derived from the early stage of diffuse astrocytoma, which can be transformed into anaplastic astrocytoma. Due to the complexity of these dynamic processes, single-cell gene expression profiles are extremely helpful to understand what defines these subtypes. We analyzed the single-cell gene expression profiles of 5057 cells of anaplastic astrocytoma tissues, 261 cells of diffuse astrocytoma tissues, and 1023 cells of glioblastoma tissues with advanced machine learning methods. In detail, a powerful feature selection method, Monte Carlo feature selection (MCFS) method, was adopted to analyze the gene expression profiles of cells, resulting in a feature list. Then, the incremental feature selection (IFS) method was applied to the obtained feature list, with the help of support vector machine (SVM), to extract key features (genes) and construct an optimal SVM classifier. Several key biomarker genes, such as IGFBP2, IGF2BP3, PRDX1, NOV, NEFL, HOXA10, GNG12, SPRY4, and BCL11A, were identified. In addition, the underlying rules of classifying the three subtypes were produced by Johnson reducer algorithm. We found that in diffuse astrocytoma, PRDX1 is highly expressed, and in glioblastoma, the expression level of PRDX1 is low. These rules revealed the difference among the three subtypes, and how they are formed and transformed. These genes are not only biomarkers for glioma subtypes, but also drug targets that may switch the clinical features or even reverse the tumor progression.

Detection of glioblastoma in biofluids

The detection of glioblastoma (GBM) in biofluids offers potential advantages over existing paradigms for the diagnosis and therapeutic monitoring of glial tumors. Biofluid-based detection of GBM focuses on detecting tumor-specific biomarkers in the blood and CSF. Current clinical research concentrates on studying 3 distinct tumor-related elements: extracellular macromolecules, extracellular vesicles, and circulating tumor cells. Investigations into these 3 biological classifications span the range of locales for tumor-specific biomarker discovery, and combined, have the potential to significantly impact GBM diagnosis, monitoring for treatment response, and surveillance for recurrence. This review highlights the recent advancements in the development of biomarkers and their efficacy for the detection of GBM.

Tumor Location and Survival Outcomes in Adult Patients with Supratentorial Glioblastoma by Levels of Toll-Like Receptor 9 Expression

BACKGROUND

Toll-like receptor 9 (TLR9) is a key immunotherapy target for glioblastoma (GBM). This study explored the correlation of TLR9 expression with tumor location and survival outcomes in patients with supratentorial GBM.

METHODS

We retrospectively identified 46 patients with supratentorial GBMs and divided them into those with high TLR9 (TRL9^High) and low TLR9 (TRL9^Low) levels. The 2 groups were compared by patients' ages, sex, preoperative Karnofsky Performance Scale (KPS) score, resection extent, tumor location, progression-free survival (PFS), and overall survival (OS).

RESULTS

The TLR9 expression percentages for the GBM specimens were TRL9^High: 72% (33/46) and TRL9^Low: 28% (13/46). The 2 groups showed no differences in patient age (P = 0.147) and sex (χ² = 0.002, P = 0.966), preoperative KPS score (χ² = 0.033, P = 0.855), or resection extent (χ² = 2.405, P = 0.121). Location differed significantly, with 85% (11/13) of TRL9^Low tumors in the left hemisphere and 45% (15/33) of TRL9^High tumors on the same side (χ² = 5.82, P = 0.016). The TRL9^Low group had a median PFS of 612 days (range, 77-926 days), significantly longer than the TRL9^High group (355 days; range, 105-861 days; P = 0.042). Median OS of the TRL9^Low group (733 days; range, 163-969 days) was also significantly longer than in the TRL9^High group (396 days; range, 135-1024 days; P = 0.020).

CONCLUSIONS

Patients with TRL9^Low supratentorial GBM tend to have longer survival than those with higher TLR9 expression. Such tumors show a location preference for the left hemisphere.

Limited advances in therapy of glioblastoma trigger re-consideration of research policy

Glioblastoma (GB - WHO grade IV) is the most frequent and lethal primary brain tumour with median overall survival of 7-15 months after diagnosis. As in other cancer research areas, an overwhelming amount of pre-clinical research acquisitions in the GB field have not been translated to patients' benefit, potentially due to inappropriate treatment schedules and/or trial designs in the clinical setting. The recent failure of promising anti-VEGF bevacizumab to improve GB patients' overall survival recapitulates this sense of frustration. The following measures are proposed.

Radiological and pathological features associated with IDH1-R132H mutation status and early mortality in newly diagnosed anaplastic astrocytic tumours

Background

Glioblastoma can occur either de novo or by the transformation of a low grade tumour; the majority of which harbor a mutation in isocitrate dehydrogenase (IDH1). Anaplastic tumours are high-grade gliomas that may represent the final step in the evolution of a secondary glioblastoma or the initial presentation of an early primary glioblastoma. We sought to determine whether pathological and/or radiological variables exist that can reliably distinguish IDH1-R132H-positive from IDH1-R132H-negative tumours and to identify variables associated with early mortality.

Methods

Patients diagnosed with anaplastic astrocytic tumours were included. Magnetic resonance imaging was performed and immunohistochemistry was used to identify tumours with the IDH1-R132H mutation. Survival was assessed 12 months after diagnosis. Variables associated with IDH1-R132H status were identified by univariate and ROC analysis.

Results

37 gliomas were studied; 18 were positive for the IDH1-R132H mutation. No tumours demonstrated a combined loss of chromosomes 1p/19q. Patients with IDH1-R132H-positive tumours were less likely to die within 12 months of diagnosis (17% vs. 47%; p=0.046), more likely to have tumours located in the frontal lobe (55% vs. 16%; p=0.015), and have a higher minimum apparent diffusion coefficient (1.115 x 10^-3 mm²/sec vs. 0.838 x 10^-3 mm²/sec; p=0.016), however, these variables demonstrated only moderate strength for predicting the IDH1-R132H mutation status (AUC=0.735 and 0.711, respectively). The Ki-67 index was significantly lower in IDH1-R132H-positive tumours (0.13 vs. 0.21; p=0.034). An increased risk of death was associated with contrast-enhancement ≥ 5 cm³ in patients with IDH1-R132H-positive tumours while edema ≥ 1 cm beyond the tumour margin and < 5 mitoses/mm² were associated with an increased risk of death in patients with IDH1-R132H-negative tumours.

Conclusions

IDH1-R132H-positive and -negative anaplastic tumours demonstrate unique features. Factors associated with early mortality are also dependent on IDH1-R132H status and can be used to identify patients at high risk for death.