Radiation plus Temozolomide in Patients with Glioblastoma

Disturbed meningeal lymphatic function associated with malignancy and progression in patients with intracranial malignant tumors

BACKGROUND

Meningeal lymphatic vessels (mLVs) have proven to bear a relationship with tumor immunity and therapeutic efficacy of intracranial malignant tumors in pre-clinical animal studies. We aimed to explore the association between mLV function and intracranial malignant tumors in clinical participants.

METHODS

The participants were allocated to a control group or a group of patients with intracranial tumors. Dynamic enhanced magnetic resonance was used to evaluate the wash-in and wash-out functions of mLVs around the superior sagittal sinus and the sigmoid sinus.

FINDINGS

A total of 246 individuals were recruited for our study. The area under curve and wash-in rate of mLVs in the intracranial tumor group were higher than in the control group (2,749 vs. 2,110, p < 0.001 and 3.72 vs. 2.87, p < 0.001, respectively). The wash-out ratio of mLVs was lower in the intracranial tumor group than in the control group (0.65 vs. 0.73, p < 0.001). Decreased wash-out of mLVs was associated with tumor progression (β = -0.118; p < 0.001). High-grade glioma and isocitrate dehydrogenase wild type were associated with a lower mLV wash-out function (β = -0.057, p = 0.044 and β = -0.069, p = 0.047, respectively).

CONCLUSIONS

Intracranial malignant tumors were associated with elevated wash-in function and decreased wash-out function of mLVs. High-grade glioma and isocitrate dehydrogenase wild type were associated with low mLV wash-out function, and long-term decreased mLV wash-out function was a risk factor for tumor progression.

FUNDING

There was no funding.

[18F]-fluoroethyl-L-tyrosine (FET) in glioblastoma (FIG) TROG 18.06 study: protocol for a prospective, multicentre PET/CT trial

INTRODUCTION

Glioblastoma is the most common aggressive primary central nervous system cancer in adults characterised by uniformly poor survival. Despite maximal safe resection and postoperative radiotherapy with concurrent and adjuvant temozolomide-based chemotherapy, tumours inevitably recur. Imaging with O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) positron emission tomography (PET) has the potential to impact adjuvant radiotherapy (RT) planning, distinguish between treatment-induced pseudoprogression versus tumour progression as well as prognostication.

METHODS AND ANALYSIS

The FET-PET in Glioblastoma (FIG) study is a prospective, multicentre, non-randomised, phase II study across 10 Australian sites and will enrol up to 210 adults aged ≥18 years with newly diagnosed glioblastoma. FET-PET will be performed at up to three time points: (1) following initial surgery and prior to commencement of chemoradiation (FET-PET1); (2) 4 weeks following concurrent chemoradiation (FET-PET2); and (3) within 14 days of suspected clinical and/or radiological progression on MRI (performed at the time of clinical suspicion of tumour recurrence) (FET-PET3). The co-primary outcomes are: (1) to investigate how FET-PET versus standard MRI impacts RT volume delineation and (2) to determine the accuracy and management impact of FET-PET in distinguishing pseudoprogression from true tumour progression. The secondary outcomes are: (1) to investigate the relationships between FET-PET parameters (including dynamic uptake, tumour to background ratio, metabolic tumour volume) and progression-free survival and overall survival; (2) to assess the change in blood and tissue biomarkers determined by serum assay when comparing FET-PET data acquired prior to chemoradiation with other prognostic markers, looking at the relationships of FET-PET versus MRI-determined site/s of progressive disease post chemotherapy treatment with MRI and FET-PET imaging; and (3) to estimate the health economic impact of incorporating FET-PET into glioblastoma management and in the assessment of post-treatment pseudoprogression or recurrence/true progression. Exploratory outcomes include the correlation of multimodal imaging, blood and tumour biomarker analyses with patterns of failure and survival.

ETHICS AND DISSEMINATION

The study protocol V.2.0 dated 20 November 2020 has been approved by a lead Human Research Ethics Committee (Austin Health, Victoria). Other clinical sites will provide oversight through local governance processes, including obtaining informed consent from suitable participants. The study will be conducted in accordance with the principles of the Declaration of Helsinki and Good Clinical Practice. Results of the FIG study (TROG 18.06) will be disseminated via relevant scientific and consumer forums and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ANZCTR ACTRN12619001735145.

A pilot study on metabolomic characterization of human glioblastomas and patient plasma

Purpose

To determine whether recurrent GBMs are metabolically distinct from primary GBM, and whether patient plasma can be used as a liquid biopsy to reflect this difference.

Methods

In a single center cohort study, tissue and blood samples from 15 patients with glioblastoma (9 glioblastoma tissues at diagnosis, 3 pairs of tissue, and 6 pairs of plasma specimens at diagnosis and at recurrence) were analyzed.

Results

Several metabolites had significant alternations in both tumor and plasma specimens. In the tissue, the following representative metabolites had a significant increase in peak intensity at recurrence compared to diagnosis: N-alpha-methylhistamine (p = 0.037), glycerol-3-phosphate (p = 0.029), phosphocholine (p = 0.045), and succinic acid (p = 0.025). In patient plasma, metabolites that significantly increased at recurrence included: 2,4-difluorotoluene (p = 0.031), diatrizoic acid (p = 0.032), indole-3-acetate with (p = 0.029), urea (P = 0.025), pseudouridine (p = 0.042), and maltose (p = 0.035). Metabolites that significantly decreased in plasma at recurrence were: eicosenoic acid (p = 0.017), glucose-1-phosphate (p = 0.017), FA 18:2 (linoleic acid) (p = 0.017), arginine (p = 0.036), fatty acids 20:3 (homo-gamma-linolenic acid (p = 0.036), galactosamine (p = 0.007), and FA 18:3 (linolenic acid) (P = 0.012). Principal component analysis showed that the metabolomic profiles differ between tumor tissue and patient plasma.

Conclusions

Our data suggest that metabolomic profiles of human GBM tissue and patient plasma differ at diagnosis and at recurrence. Many metabolites involved in tumorigenesis and metabolomic flexibility were identified. A larger study using targeted metabolomic assay is warranted to measure the levels of these metabolites, which will help identify the metabolomic signatures in both GBM tissue and patient plasma for risk stratification, clinical outcome prediction, and development of new adjuvant metabolomic-targeting therapy.

Network pharmacological analysis of active components of Xiaoliu decoction in the treatment of glioblastoma multiforme

Background: Glioblastoma multiforme (GBM) is the most aggressive primary nervous system brain tumor. There is still a lack of effective methods to control its progression and recurrence in clinical treatment. It is clinically found that Xiaoliu Decoction (XLD) has the effect of treating brain tumors and preventing tumor recurrence. However, its mechanism is still unclear.

Methods: Search the Traditional Chinese Medicine System Pharmacology Database (TCSMP) for efficient substances for the treatment of XLD in the treatment of GBM, and target the targeted genes of the effective ingredients to construct a network. At the same time, download GBM-related gene expression data from the TCGA and GTEX databases, screen differential expression bases, and establish a drug target disease network. Through bioinformatics analysis, the target genes and shared genes of the selected Chinese medicines are analyzed. Finally, molecular docking was performed to further clarify the possibility of XLD in multiple GBMs.

Results: We screened 894 differentially expressed genes in GBM, 230 XLD active ingredients and 169 predicted targets of its active compounds, of which 19 target genes are related to the differential expression of GBM. Bioinformatics analysis shows that these targets are closely related to cell proliferation, cell cycle regulation, and DNA synthesis. Finally, through molecular docking, it was further confirmed that Tanshinone IIA, the active ingredient of XLD, was tightly bound to key proteins.

Conclusion: To sum up, the results of this study suggest that the mechanism of XLD in the treatment of GBM involves multiple targets and signal pathways related to tumorigenesis and development. This study not only provides a new theoretical basis for the treatment of glioblastoma multiforme with traditional Chinese medicine, but also provides a new idea for the research and development of targeted drugs for the treatment of glioblastoma multiforme.

BNIP3 contributes to silibinin-induced DNA double strand breaks in glioma cells via inhibition of mTOR

BNIP3 is found to eliminate cancer cells via causing mitochondrial damage and endoplasmic reticulum stress, but it remains elusive of its role in regulating DNA double strand breaks (DSBs). In this study, we find that silibinin triggers DNA DSBs, ROS accumulation and expressional upregulation of BNIP3 in glioma cells. Mitigation of ROS with antioxidant GSH significantly inhibits silibinin-induced DNA DSBs and glioma cell death. Then, we find knockdown of BNIP3 with SiRNA obviously prevents silibinin-induced DNA DSBs and ROS accumulation. Mechanistically, BNIP3 knockdown not only reverses silibinin-triggered depletion of cysteine and GSH via maintaining xCT level, but also abrogates catalase decrease. Notably, silibinin-induced dephosphorylation of mTOR is also prevented when BNIP3 is knocked down. Given that activated mTOR could promote xCT expression and inhibit autophagic degradation of catalase, our data suggest that BNIP3 contributes to silibinin-induced DNA DSBs via improving intracellular ROS by inhibition of mTOR.

Opportunities and challenges of glioma organoids

Glioma is the most common primary brain tumor and its prognosis is poor. Despite surgical removal, glioma is still prone to recurrence because it grows rapidly in the brain, is resistant to chemotherapy, and is highly aggressive. Therefore, there is an urgent need for a platform to study the cell dynamics of gliomas in order to discover the characteristics of the disease and develop more effective treatments. Although 2D cell models and animal models in previous studies have provided great help for our research, they also have many defects. Recently, scientific researchers have constructed a 3D structure called Organoids, which is similar to the structure of human tissues and organs. Organoids can perfectly compensate for the shortcomings of previous glioma models and are currently the most suitable research platform for glioma research. Therefore, we review the three methods currently used to establish glioma organoids. And introduced how they play a role in the diagnosis and treatment of glioma. Finally, we also summarized the current bottlenecks and difficulties encountered by glioma organoids, and the current efforts to solve these difficulties.

Combining MGMT promoter pyrosequencing and protein expression to optimize prognosis stratification in glioblastoma

Pyrosequencing (PSQ) represents the golden standard for MGMT promoter status determination. Binary interpretation of results based on the threshold from the average of several CpGs tested would neglect the existence of the “gray zone”. How to define the gray zone and reclassify patients in this subgroup remains to be elucidated. A consecutive cohort of 312 primary glioblastoma patients were enrolled. CpGs 74‐81 in the promoter region of MGMT were tested by PSQ and the protein expression was assessed by immunohistochemistry (IHC). Receiver operating characteristic curves were constructed to calculate the area under the curves (AUC). Kaplan‐Meier plots were used to estimate the survival rate of patients compared by the log‐rank test. The optimal threshold of each individual CpG differed from 5% to 11%. Patients could be separated into the hypomethylated subgroup (all CpGs tested below the corresponding optimal thresholds, n = 126, 40.4%), hypermethylated subgroup (all CpGs tested above the corresponding optimal thresholds, n = 108, 34.6%), and the gray zone subgroup (remaining patients, n = 78, 25.0%). Patients in the gray zone harbored an intermediate prognosis. The IHC score instead of the average methylation levels could successfully predict the prognosis for the gray zone (AUC for overall survival, 0.653 and 0.519, respectively). Combining PSQ and IHC significantly improved the efficiency of survival prediction (AUC: 0.662, 0.648, and 0.720 for PSQ, IHC, and combined, respectively). Immunohistochemistry is a robust method to predict prognosis for patients in the gray zone defined by PSQ. Combining PSQ and IHC could significantly improve the predictive ability for clinical outcomes.

Parenteral high‑dose ascorbate - A possible approach for the treatment of glioblastoma (Review)

For glioblastoma, the treatment with standard of care therapy comprising resection, radiation, and temozolomide results in overall survival of approximately 14-18 months after initial diagnosis. Even though several new therapy approaches are under investigation, it is difficult to achieve life prolongation and/or improvement of patient's quality of life. The aggressiveness and progression of glioblastoma is initially orchestrated by the biological complexity of its genetic phenotype and ability to respond to cancer therapy via changing its molecular patterns, thereby developing resistance. Recent clinical studies of pharmacological ascorbate have demonstrated its safety and potential efficacy in different cancer entities regarding patient's quality of life and prolongation of survival. In this review article, the actual glioblastoma treatment possibilities are summarized, the evidence for pharmacological ascorbate in glioblastoma treatment is examined and questions are posed to identify current gaps of knowledge regarding accessibility of ascorbate to the tumor area. Experiments with glioblastoma cell lines and tumor xenografts have demonstrated that high-dose ascorbate induces cytotoxicity and oxidative stress largely selectively in malignant cells compared to normal cells suggesting ascorbate as a potential therapeutic agent. Further investigations in larger cohorts and randomized placebo-controlled trials should be performed to confirm these findings as well as to improve delivery strategies to the brain, through the inherent barriers and ultimately to the malignant cells.

Trends and challenges in modeling glioma using 3D human brain organoids

The human brain organoids derived from pluripotent cells are a new class of three-dimensional tissue systems that recapitulates several neural epithelial aspects. Brain organoids have already helped efficient modeling of crucial elements of brain development and disorders. Brain organoids’ suitability in modeling glioma has started to emerge, offering another usefulness of brain organoids in disease modeling. Although the current state-of-the organoids mostly reflect the immature state of the brain, with their vast cell diversity, human brain-like cytoarchitecture, feasibility in culturing, handling, imaging, and tractability can offer enormous potential in reflecting the glioma invasion, integration, and interaction with different neuronal cell types. Here, we summarize the current trend of employing brain organoids in glioma modeling and discuss the immediate challenges. Solving them might lay a foundation for using brain organoids as a pre-clinical 3D substrate to dissect the glioma invasion mechanisms in detail.

ELAVL1 Role in Cell Fusion and Tunneling Membrane Nanotube Formations with Implication to Treat Glioma Heterogeneity

Homotypic and heterotypic cell fusions via permanent membrane fusions and temporal tunneling nanotube formations in the glioma microenvironment were recently documented in vitro and in vivo and mediate glioma survival, plasticity, and recurrence. Chronic inflammation, a hypoxic environment, aberrant mitochondrial function, and ER stress due to unfolded protein accumulation upregulate cell fusion events, which leads to tumor heterogeneity and represents an adaptive mechanism to promote tumor cell survival and plasticity in cytotoxic, nutrient-deprived, mechanically stressed, and inflammatory microenvironments. Cell fusion is a multistep process, which consists of the activation of the cellular stress response, autophagy formation, rearrangement of cytoskeletal architecture in the areas of cell-to-cell contacts, and the expression of proinflammatory cytokines and fusogenic proteins. The mRNA-binding protein of ELAV-family HuR is a critical node, which orchestrates the stress response, autophagy formation, cytoskeletal architecture, and the expression of proinflammatory cytokines and fusogenic proteins. HuR is overexpressed in gliomas and is associated with poor prognosis and treatment resistance. Our review provides a link between the HuR role in the regulation of cell fusion and tunneling nanotube formations in the glioma microenvironment and the potential suppression of these processes by different classes of HuR inhibitors.

Identification of Aberrantly Expressed Genes in Murine Glioblastoma During Radiotherapy via Bioinformatic Data Mining

Objective

Glioblastoma (GBM) is an aggressive tumor with a fast growth rate. Radioresistance of GBM can lead to high recurrence. In general, due to the protection of the blood-brain barrier, the immune environment of the central nervous system is unique. The immune response induced by radiotherapy is weak in GBM. In the present study, aberrantly expressed genes during radiotherapy were assessed in murine models based on microarray RNA data.

Methods

The microarray data were extracted from the Intergovernmental Group on Earth Observations and differentially expressed genes (DEGs) screened out. Gene expression profiles of 115 samples in GSE56113 were analyzed and 104 genes were identified as aberrantly expressed based on GEO2R 8 d after radiotherapy. Then, the Database for Annotation, Visualization, and Integrated Discovery was used to analyze Genome Kyoto Encyclopedia of Gene pathways and Gene Ontology (GO) terms. The 20 core candidate genes were identified using protein-protein interaction network analysis and Cytoscape software with Molecular Complex Detection plug-in.

Results

Post-irradiated tumor tissues expressed significantly more immune-associated genes than contralateral brain tissues. GO and pathway analyses showed core DEGs were mainly enriched in the chemokine signaling and IL-6 signaling pathways, which could lead to immunosuppressive inflammatory monocyte infiltration and radioresistance. Chemokine signaling and IL-6 signaling pathway-associated genes were increased in the irradiated U87 cell strain.

Conclusion

Chemokine signaling and IL-6 signaling pathways were activated after radiation in murine glioma and human glioma cell lines which could lead to changes in the immune microenvironment and treatment failure. The results of the present study could provide potential therapeutic targets especially when immune therapy and radiotherapy are combined to treat GBM patients.

First statement on preparation for the COVID-19 pandemic in large German Speaking University-based radiation oncology departments

The COVID-19 pandemic is challenging modern radiation oncology. At University Hospitals, we have a mandate to offer high-end treatments to all cancer patients. However, in times of crisis we must learn to prioritize resources, especially personnel. Compromising oncological outcome will blur all statistics, therefore all measures must be taken with great caution. Communication with our neighboring countries, within societies and between departments can help meet the challenge. Here, we report on our learning system and preparation measures to effectively tackle the COVID-19 challenge in University-Based Radiation Oncology Departments.

Image-based metric of invasiveness predicts response to adjuvant temozolomide for primary glioblastoma

Background

Temozolomide (TMZ) has been the standard-of-care chemotherapy for glioblastoma (GBM) patients for more than a decade. Despite this long time in use, significant questions remain regarding how best to optimize TMZ therapy for individual patients. Understanding the relationship between TMZ response and factors such as number of adjuvant TMZ cycles, patient age, patient sex, and image–based tumor features, might help predict which GBM patients would benefit most from TMZ, particularly for those whose tumors lack O⁶–methylguanine–DNA methyltransferase (MGMT) promoter methylation.

Methods and findings

Using a cohort of 90 newly–diagnosed GBM patients treated according to the standard of care, we examined the relationships between several patient and tumor characteristics and volumetric and survival outcomes during adjuvant chemotherapy. Volumetric changes in MR imaging abnormalities during adjuvant therapy were used to assess TMZ response. T1Gd volumetric response is associated with younger patient age, increased number of TMZ cycles, longer time to nadir volume, and decreased tumor invasiveness. Moreover, increased adjuvant TMZ cycles corresponded with improved volumetric response only among more nodular tumors, and this volumetric response was associated with improved survival outcomes. Finally, in a subcohort of patients with known MGMT methylation status, methylated tumors were more diffusely invasive than unmethylated tumors, suggesting the improved response in nodular tumors is not driven by a preponderance of MGMT methylated tumors.

Conclusions

Our finding that less diffusely invasive tumors are associated with greater volumetric response to TMZ suggests patients with these tumors may benefit from additional adjuvant TMZ cycles, even for those without MGMT methylation.

Outcomes of presumed malignant glioma treated without pathological confirmation: a retrospective, single-center analysis

Background

Tissue diagnosis is essential in the usual management of high-grade glioma. In rare circumstances, due to patient preference, performance status, comorbidities, or tumor location, biopsy is not feasible. Sometimes a biopsy is nondiagnostic. Many neuro-oncology clinics have patients like this, but these patients' outcomes and responses to treatment are not known.

Methods

We retrospectively reviewed records from adult patients diagnosed with presumed high-grade glioma of the brain without definitive pathology, diagnosed between 2004 and 2016. We recorded several clinical variables including date of first diagnostic imaging and date of death.

Results

We identified 61 patients and subclassified them to brainstem glioma (n = 32), supratentorial presumed glioblastoma (n = 24), presumed thalamic diffuse midline glioma (n = 2), gliomatosis cerebri (n = 2), and cerebellar glioma (n = 1). Most brainstem glioma patients had no biopsy because of tumor location. Supratentorial presumed glioblastoma patients had no biopsy predominantly because of comorbidities. Median survival, from first diagnostic imaging, was 3.2 months (95% CI: 2.9 to 6.3 months) in the supratentorial glioblastoma group and 18.5 months (95% CI: 13.0 to 44.1 months) in the brainstem group. Treatment with radiation or chemotherapy did not alter the median survival of the supratentorial glioblastoma group (hazard ratio 1.41, uncorrected P = .5).

Conclusions

Patients with imaging diagnoses of high-grade glioma have similar, if not worse, survival than those with pathological confirmation. Based on these uncontrolled data, it is unclear how effective radiation or chemotherapy is in this population.

Malignant Evaluation and Clinical Prognostic Values of m6A RNA Methylation Regulators in Glioblastoma

N6-methyladenosine (m6A) RNA methylation, the most common form of mRNA modification and regulated by the m6A RNA methylation regulators ("writers," "erasers," and "readers"), has been reported to be associated with the progression of the malignant tumor. However, its role in glioblastoma (GBM) has been poorly known. This study aimed to identify the expression, potential functions, and prognostic values of m6A RNA methylation regulators in GBM. Here, we revealed that the 13 central m6A RNA methylation regulators were firmly related to the clinical and molecular phenotype of GBM. Taking advantage of consensus cluster analysis, we obtained two categories of GBM samples and found malignancy-related processes of m6A methylation regulators and compounds that specifically targeted the malignant processes. Besides, we also obtained a list of genes with poor prognosis in GBM. Finally, we derived a risk-gene signature with three selected m6A RNA methylation regulators, which allowed us to extend the in-depth study and dichotomized the OS of patients with GBM into high- and low-risk subgroups. Notably, this risk-gene signature could be used as independent prognostic markers and accurate clinicopathological parameter predictors. In conclusion, m6A RNA methylation regulators are a type of vital participant in the malignant progression of GBM, with a critical potential in the prognostic stratification and treatment strategies of GBM.

Validation of the Comprehensive Geriatric Assessment as a Predictor of Mortality in Elderly Glioblastoma Patients

Background: Treatment of elderly glioblastoma patients (EGP) is a challenge in neuro-oncology. The comprehensive geriatric assessment (CGA) is currently used to assess geriatric oncological patients with other types of tumors. We performed a large retrospective study to analyze its predictive role in EGP. Methods: Patients aged ≥65 years with histologically confirmed diagnosis of glioblastoma were enrolled. CGA included the following tests: the Cumulative Illness Rating Scale-Comorbidity and Severity Index, Activities of Daily Living, Instrumental Activities of Daily Living, the Mini Mental State Examination, and the Geriatric Depression Scale. Based on CGA results, each patient was categorized as fit, vulnerable, or frail. Results: We enrolled 113 patients. According to the CGA scores, 35% of patients were categorized as "fit", 30% as "vulnerable", and 35% as "frail" patients. Median overall survival was 16.5, 12.1, and 10.3 months in fit, vulnerable, and frail patients (p = 0.1), respectively. On multivariate analysis, the CGA score resulted an independent predictor of survival; indeed, vulnerable and frail patients had a hazard ratio of 1.5 and 2.2, respectively, compared to fit patients (p = 0.04). No association between CGA and progression-free survival (PFS) was demonstrated. Conclusions: The CGA score proved to be a significant predictor of mortality in EGP, and it could be a useful treatment decision tool.

Super-early initiation of temozolomide prolongs the survival of glioblastoma patients without gross-total resection: a retrospective cohort study

OBJECTIVE

The optimal timing of chemoradiotherapy in patients with newly diagnosed glioblastoma (GBM) remains unclear. In this study, we explored the clinical efficacy of super-early initiation of temozolomide (TMZ) in the treatment interval from surgery to radiotherapy.

METHODS

We retrospectively reviewed the clinical data of 375 patients with GBM in our institution from 2012 to 2018. One hundred and sixty-three patients received super-early TMZ within 7 days after craniotomy based on standard Stupp protocol (super-early group, SEG), while two hundred and twelve patients underwent standard Stupp protocol alone (control group, CG). We performed propensity score matching (PSM) to reduce patient selection bias between the two groups.

RESULTS

Before PSM, both median progression-free survival (PFS) and overall survival (OS) of patients in SEG were longer than those in CG (PFS 11.5 vs. 9.0 months, P = 0.0384 and OS 23.0 vs. 17.0 months, P = 0.0014). After PSM, the clinical efficacy of super-early initiation of TMZ only remained significant in term of OS, which was further validated in Cox hazard proportional model (HR = 0.583, 95% CI 0.384-0.884, P = 0.011). In the subgroup analysis, patients without gross total resection (GTR) or with O⁶-methylguanine DNA methyltransferase promoter methylation could benefit from super-early initiation of TMZ in both PFS and OS (P < 0.05). No significant difference of treatment emerging adverse events was observed between the two groups (P > 0.05).

CONCLUSIONS

This retrospective study highlights that super-early initiation of TMZ in newly diagnosed GBM may confer to survival benefit, especially for those without GTR.

Supratentorial high-grade astrocytoma with leptomeningeal spread to the fourth ventricle: a lethal dissemination with dismal prognosis

PURPOSE

Leptomeningeal spread to the fourth ventricle (LSFV) from supratentorial high-grade astrocytoma (HGA) is rarely investigated. The incidence and prognostic merit of LSFV were analyzed in this study.

METHODS

A consecutive cohort of 175 patients with pathologically diagnosed HGA according to the 2016 WHO classification of brain tumors was enrolled. LSFV was defined as radiological occupation in the fourth ventricle at the moment of initial progression. Clinical, radiological, and pathological data were analyzed to explore the difference between HGA patients with and without LSFV.

RESULTS

There were 18 of 175 (10.3%) HGAs confirmed with LSFV. The difference of survival rate between patients with LSFV or not was significant in both overall survival (OS) (14.5 vs. 24 months, P =  0.0007) and post progression survival (PPS) (6.0 vs. 11.5 months, P = 0.0004), while no significant difference was observed in time to progression (TTP) (8.5 months vs. 9.5 months P = 0.6795). In the Cox multivariate analysis, LSFV was confirmed as an independent prognostic risk factor for OS (HR 2.06, P = 0.010). LSFV was correlated with younger age (P = 0.044), ventricle infringement of primary tumor (P < 0.001) and higher Ki-67 index (P = 0.013) in further analysis, and the latter two have been validated in the Logistic regression analysis (OR 18.16, P = 0.006; OR 4.04, P = 0.012, respectively).

CONCLUSION

LSFV was indicative of end-stage for supratentorial HGA patients, which shortened patients' PPS and OS instead of TTP. It's never too cautious to alert this lethal event when tumor harbored ventricle infringement and higher Ki-67 index in routine clinical course.

Drug Screening of Human GBM Spheroids in Brain Cancer Chip

Glioblastoma multiforme (GBM), an extremely invasive and high-grade (grade IV) glioma, is the most common and aggressive form of brain cancer. It has a poor prognosis, with a median overall survival of only 11 months in the general GBM population and 14.6 to 21 months in clinical trial participants with standard GBM therapies, including maximum safe craniotomy, adjuvant radiation, and chemotherapies. Therefore, new approaches for developing effective treatments, such as a tool for assessing tumor cell drug response before drug treatments are administered, are urgently needed to improve patient survival. To address this issue, we developed an improved brain cancer chip with a diffusion prevention mechanism that blocks drugs crossing from one channel to another. In the current study, we demonstrate that the chip has the ability to culture 3D spheroids from patient tumor specimen-derived GBM cells obtained from three GBM patients. Two clinical drugs used to treat GBM, temozolomide (TMZ) and bevacizumab (Avastin, BEV), were applied and a range of relative concentrations was generated by the microfluidic channels in the brain cancer chip. The results showed that TMZ works more effectively when used in combination with BEV compared to TMZ alone. We believe that this low-cost brain cancer chip could be further developed to generate optimal combination of chemotherapy drugs tailored to individual GBM patients.

Protein Toxin Chaperoned by LRP-1-Targeted Virus-Mimicking Vesicles Induces High-Efficiency Glioblastoma Therapy In Vivo

Glioblastoma is a most intractable and high-mortality malignancy because of its extremely low drug accessibility resulting from the blood-brain barrier (BBB). Here, it is reported that angiopep-2-directed and redox-responsive virus-mimicking polymersomes (ANG-PS) (angiopep-2 is a peptide targeting to low-density lipoprotein receptor-related protein-1 (LRP-1)) can efficiently and selectively chaperone saporin (SAP), a highly potent natural protein toxin, to orthotopic human glioblastoma xenografts in nude mice. Unlike chemotherapeutics, free SAP has a low cytotoxicity. SAP-loaded ANG-PS displays, however, a striking antitumor activity (half-maximal inhibitory concentration, IC₅₀  = 30.2 × 10^-9 m) toward U-87 MG human glioblastoma cells in vitro as well as high BBB transcytosis and glioblastoma accumulation in vivo. The systemic administration of SAP-loaded ANG-PS to U-87 MG orthotopic human-glioblastoma-bearing mice brings about little side effects, effective tumor inhibition, and significantly improved survival rate. The protein toxins chaperoned by LRP-1-targeted virus-mimicking vesicles emerge as a novel and highly promising treatment modality for glioblastoma.