Population-Based Studies on Incidence, Survival Rates, and Genetic Alterations in Astrocytic and Oligodendroglial Gliomas

Choline-PET/CT in the Differential Diagnosis Between Cystic Glioblastoma and Intraparenchymal Hemorrhage

OBJECTIVE

Glioblastoma multiforme (GBM) represents the most common and malignant glioma, accounting for 45%-50% of all gliomas. The median survival time for patients with glioblastoma is only 12-15 months after surgical, chemioterapic and radiotherapic treatment; a correct diagnosis is naturally fundamental to establish a rapid and correct therapy. Non-invasive imaging plays a pivotal role in each phase of the diagnostic workup of patients with suspected for diagnosis. The aim of this case report was to describe the potential clinical impact of 18F-fluorocholine (FCH) PET/CT in the assessment of a cystic GBM mimicking a spontaneous hemorrhage.

METHODS

a 57 years-old male with intraparenchymal hemorrhage at CT imaging initially in reduction ad serial imaging and suspected right fronto-temporo-parietal lesion at MRI underwent dynamic and static (60' after tracer injection) FCH PET/CT of the brain.

RESULTS

FCH PET/CT showed rapid tracer uptake after few second from injection at dynamic acquisition and consequent incremental mild uptake at static imaging after 60 minutes at the level of oval formation in the right cerebral hemisphere characterized by annular and peripheral high metabolic activity. The central region of the lesion was characterized by the absence 18F-FCH uptake most likely due to blood component. The patient underwent surgery for tumor removal; the histopathological examination confirmed the suspect of GBM. Chemo-radiotherapic adjuvant protocol according to Stupp protocol was therefore administrated; to date the patient is alive without any progression disease at 5 months from treatment.

CONCLUSION

In this case report FCH PET/CT represented the final diagnostic technique to confirm the suspicious of a cystic GBM. Our case demonstrated the potential role of 18F-FCH PET/CT for discrimination of higher proliferation area over intraparenchymal hemorrhage, supporting the potential use of this imaging biomarker in surgical or radiosurgical approach. Obviously, further prospective studies are needed to confirm this role and to exactly define possible routinely applications.

Reduced Neoantigen Expression Revealed by Longitudinal Multiomics as a Possible Immune Evasion Mechanism in Glioma

Immune-based therapies have shown limited efficacy in glioma thus far. This might be at least in part due to insufficient numbers of neoantigens, thought to be targets of immune attack. In addition, we hypothesized that dynamic genetic and epigenetic tumor evolution in gliomas might also affect the mutation/neoantigen landscape and contribute to treatment resistance through immune evasion. Here, we investigated changes in the neoantigen landscape and immunologic features during glioma progression using exome and RNA-seq of paired primary and recurrent tumor samples obtained from 25 WHO grade II-IV glioma patients (glioblastoma, IDH-wild-type, n = 8; grade II-III astrocytoma, IDH-mutant, n = 9; and grade II-III oligodendroglioma, IDH-mutant, 1p/19q-codeleted, n = 8). The number of missense mutations, predicted neoantigens, or expressed neoantigens was not significantly different between primary and recurrent tumors. However, we found that in individual patients the ratio of expressed neoantigens to predicted neoantigens, designated the "neoantigen expression ratio," decreased significantly at recurrence (P = 0.003). This phenomenon was particularly pronounced for "high-affinity," "clonal," and "passenger gene-derived" neoantigens. Gene expression and IHC analyses suggested that the decreased neoantigen expression ratio was associated with intact antigen presentation machinery, increased tumor-infiltrating immune cells, and ongoing immune responses. Our findings imply that decreased expression of highly immunogenic neoantigens, possibly due to persistent immune selection pressure, might be one of the immune evasion mechanisms along with tumor clonal evolution in some gliomas.

Long-term outcomes and late adverse effects of a prospective study on proton radiotherapy for patients with low-grade glioma

BACKGROUND

Patients with low-grade gliomas (LGG) can survive years with their illness. Proton radiotherapy (PRT) can reduce off-target dose and decrease the risk of treatment-related morbidity. We examined long-term morbidity following proton therapy in this updated prospective cohort of patients with LGG.

METHODS

Twenty patients with LGG were enrolled prospectively and received PRT to 54 Gy(RBE) in 30 fractions. Comprehensive baseline and longitudinal assessments of toxicity, neurocognitive and neuroendocrine function, quality of life, and survival outcomes were performed up to 5 years following treatment.

RESULTS

Six patients died (all of disease) and six had progression of disease. Median follow-up was 6.8 years for the 14 patients alive at time of reporting. Median progression-free survival (PFS) was 4.5 years. Of tumors tested for molecular markers, 71% carried the IDH1-R132H mutation and 29% had 1p/19q co-deletion. There was no overall decline in neurocognitive function; however, a subset of five patients with reported cognitive symptoms after radiation therapy had progressively worse function by neurocognitive testing. Six patients developed neuroendocrine deficiencies, five of which received Dmax ≥20 Gy(RBE) to the hypothalamus-pituitary axis (HPA). Most long-term toxicities developed within 2 years after radiation therapy.

CONCLUSIONS

The majority of patients with LGG who received proton therapy retained stable cognitive and neuroendocrine function. The IDH1-R132H mutation was present in the majority, while 1p/19q loss was present in a minority. A subset of patients developed neuroendocrine deficiencies and was more common in those with higher dose to the HPA.

Pontine tumor in a neonate: case report and analysis of the current literature

Tumors of the central nervous system represent the largest group of solid tumors found in pediatric patients. Pilocytic astrocytoma is the most common pediatric glioma, mostly located in the posterior fossa. The majority of brainstem tumors, however, are classified as highly aggressive diffuse intrinsic pontine gliomas (DIPGs) and their prognosis is dismal.The authors report on the case of a neonate in whom MRI and neuropathological assessment were used to diagnose DIPG. Before initiation of the planned chemotherapy, the tumor regressed spontaneously, and the newborn exhibited a normal neurological development. Meanwhile, Illumina Human Methylation450 BeadChip analysis reclassified the tumor as pilocytic astrocytoma of the posterior fossa.In conclusion, the authors advocate not initiating immediate intensive therapy in newborns with brain tumors, even with classical appearance of a DIPG; rather, they would like to encourage a biopsy to define the best individual therapeutic approach and avoid ineffective chemotherapy.

Leptomeningeal metastases in glioma: The Memorial Sloan Kettering Cancer Center experience

OBJECTIVE

To perform a retrospective analysis examining the incidence and prognosis of glioma patients with leptomeningeal disease (LMD) at Memorial Sloan Kettering Cancer Center over a 15-year period and correlate these findings with clinicopathologic characteristics.

METHODS

We conducted a retrospective review of glioma patients with LMD at Memorial Sloan Kettering Cancer Center diagnosed from 2001 to 2016. Patients were identified through a keyword search of their electronic medical record and by ICD-9 codes.

RESULTS

One hundred three patients were identified with disseminated LMD and 85 patients with subependymal spread of disease, 4.7% of all patients with glioma. These cohorts were analyzed separately for time to development of disseminated LMD/subependymal LMD, median overall survival, and survival from LMD diagnosis. Patients were pooled for subsequent analyses (n = 188) because of comparable clinical behavior. LMD was present at glioma diagnosis in 10% of patients. In the remaining 90% of patients diagnosed at recurrence, time to LMD diagnosis, survival after LMD diagnosis, and overall survival varied by original histology. Patients with oligodendroglioma had a median survival of 10.8 (range 1.8-67.7) months, astrocytoma 6.5 (0.1-28.5) months, and glioblastoma 3.8 (0.1-32.6) months after LMD diagnosis. In addition, we found that treatment of LMD was associated with superior performance status and increased survival.

CONCLUSION

Patients with LMD diagnosed at relapse may not have decreased overall survival as compared to historical controls with parenchymal relapse and may benefit from treatment.

A young man with visual disturbances and a mild headache

Headaches are common presenting complaints in EDs throughout the United States. Most are benign and should be treated symptomatically. Certain historical risk factors and physical examination findings increase the likelihood of a secondary cause of headache and warrant further investigation with neuroimaging. Gross visual field testing is a critical component of the physical examination and should not be overlooked as a potential manifestation of a neurologic deficit. This article describes a patient whose headache and unilateral vision loss prompted neuroimaging that uncovered a pilocytic astrocytoma.

Molecular Biomarkers of Brain and Spinal Cord Astrocytomas

Spinal cord astrocytomas are rare diseases of the central nervous system. The localization of these tumors and their infiltrative growth complicate their surgical resection, increase the risk of postoperative complications, and require more careful use of radio- and chemotherapy. The information on the genetic mutations associated with the onset and development of astrocytomas provides a more accurate neoplasm diagnosis and classification. In some cases, it also allows one to determine the optimal methods for treating the neoplasm, as well as to predict the treatment outcomes and the risks of relapse. To date, a number of molecular markers that are associated with brain astrocytomas and possess prognostic value have been identified and described. Due to the significantly lower incidence of spinal cord astrocytomas, the data on similar markers are much more sparse and are presented with a lesser degree of systematization. However, due to the retrospective studies of clinical material that have been actively conducted abroad in recent years, the formation of statistically significant genetic landscapes for various types of tumors, including intradural spinal cord tumors, has begun. In this regard, the purpose of this review is to analyze and systematize the information on the most significant genetic mutations associated with various types of astrocytomas, as well as discuss the prospects for using the corresponding molecular markers for diagnostic and prognostic purposes.

Characteristics, survival and incidence rates and trends of pilocytic astrocytoma in children in the United States; SEER-based analysis

INTRODUCTION

Pilocytic astrocytoma (PA) is a neurological neoplasm and a common neurological tumor among children. No recent reports have studied the recent demographic characteristics of PA cases in the US.

METHODOLOGY

We used the Surveillance, Epidemiology, and End Results (SEER) Program to retrieve data on children diagnosed with PA between 2000 and 2015. We calculated the incidence, annual percentage changes (APC), and survival.

RESULTS

Our study included 3084 children with PA, with an incidence of 8.227 per 1,000,000 person-years, being highest among whites (9.062), and children aged 1-4 year (11.175). Overall incidence in children increased significantly over the study period, with an APC of 0.825% (95% CI[0.027-1.630], P = .044). Moreover, incidence among blacks increased significantly over the study period (APC = 3.466%, 95% CI[0.342-6.688], P = .032), but did not change among other races. The relative 5-year survival of included patients was 95.3%, with patients younger than 1 year having the worst survival.

CONCLUSIONS

Overall PA incidence and incidence among blacks has been increasing last decade. Additionally, PA survival was found to be worse among infants. Further studies are also needed to investigate the effect of the age and race on the incidence and survival of PA.

The Coincidence Between Increasing Age, Immunosuppression, and the Incidence of Patients With Glioblastoma

Background: Glioblastoma (GBM) is the most aggressive primary brain tumor in adults and is associated with a median overall survival (mOS) of 16-21 months. Our previous work found a negative association between advanced aging and the survival benefit after treatment with immunotherapy in an experimental brain tumor model. Given the recent phase III clinical success of immunotherapy in patients with many types of cancer, but not for patients with GBM, we hypothesize that aging enhances immunosuppression in the brain and contributes to the lack of efficacy for immunotherapy to improve mOS in patients with malignant glioma. Herein, we compare epidemiological data for the incidence and mortality of patients with central nervous system (CNS) cancers, in addition to immune-related gene expression in the normal human brain, as well as peripheral blood immunological changes across the adult lifespan. Methods: Data were extracted from the National Cancer Institute's surveillance, epidemiology, and end results (SEER)-, the Broad Institute's Genotype Tissue Expression project (GTEx)-, and the University of California San Francisco's 10k Immunomes-databases and analyzed for associations with aging. Results: The proportion of elderly individuals, defined as ≥65 years of age, has predominantly increased for more than 100 years in the United States. Over time, the rise in elderly United States citizens has correlated with an increased incidence and mortality rate associated with primary brain and other CNS cancer. With advanced aging, human mRNA expression for factors associated with immunoregulation including immunosuppressive indoleamine 2,3 dioxygenase 1 (IDO) and programmed death-ligand 1 (PD-L1), as well as the dendritic cell surface marker, CD11c, increase in the brain of normal human subjects, coincident with increased circulating immunosuppressive Tregs and decreased cytolytic CD8⁺ T cells in the peripheral blood. Strikingly, these changes are maximally pronounced in the 60-69 year old group; consistent with the median age of a diagnosis for GBM. Conclusion: These data demonstrate a significant association between normal human aging and increased immunosuppression in the circulation and CNS; particularly late in life. Our data raise several hypotheses including that, aging: (i) progressively suppresses normal immunosurveillance and thereby contributes to GBM cell initiation and/or outgrowth; (ii) decreases immunotherapeutic efficacy against malignant glioma.

Podoplanin Positive Myeloid Cells Promote Glioma Development by Immune Suppression

The dynamic and interactive tumor microenvironment is conceived as a considerable parameter in tumor development and therapy response. Implementing this knowledge in the development of future cancer treatments could provide novel options in the combat of highly aggressive and difficult-to-treat tumors such as gliomas. One compartment of the tumor microenvironment that has gained growing interest is the immune system. As endogenous defense machinery the immune system has the capacity to fight against cancer cells. This, however, is frequently circumvented by tumor cells engaging immune-regulatory mechanisms that disable tumor-directed immune responses. Thus, in order to unlock the immune system against cancer cells, it is crucial to characterize in great detail individual tumor-associated immune cell subpopulations and dissect whether and how they influence immune evasion. In this study we investigated the function of a tumor-associated myeloid cell subpopulation characterized by podoplanin expression on the development of high-grade glioma tumors. Here, we show that the deletion of podoplanin in myeloid cells results in increased (CD8⁺) T-cell infiltrates and significantly prolonged survival in an orthotopic transplantation model. In vitro co-cultivation experiments indicate a podoplanin-dependent transcriptional regulation of arginase-1, a well-known player in myeloid cell-mediated immune suppression. These findings identify podoplanin positive myeloid cells as one novel mediator of the glioma-induced immune suppression. Thus, the targeted ablation of podoplanin positive myeloid cells could be included in combinatorial cancer therapies to enhance immune-mediated tumor elimination.

Construction of Potential Glioblastoma Multiforme-Related miRNA-mRNA Regulatory Network

Background: Glioblastoma multiforme (GBM), the most common and aggressive human malignant brain tumor, is notorious for its limited treatment options and poor prognosis. MicroRNAs (miRNAs) are found to be involved in tumorigenesis of GBM. However, a comprehensive miRNA-mRNA regulatory network has still not been established.

Methods: A miRNA microarray dataset (GSE90603) was obtained from GEO database. Then, we employed GEO2R tool to perform differential expression analysis. Potential transcription factors and target genes of screened differentially expressed miRNAs (DE-miRNAs) were predicted. The GBM mRNA dataset were downloaded from TCGA database for identifying differentially expressed genes (DEGs). Next, GO annotation and KEGG pathway enrichment analysis was conducted. PPI network was then established, and hub genes were identified via Cytoscape software. The expression and prognostic roles of hub genes was further evaluated.

Results: Total 33 DE-miRNAs, consisting of 10 upregulated DE-miRNAs and 23 downregulated DE-miRNAs, were screened. SP1 was predicted to potentially regulate most of screened DE-miRNAs. Three thousand and twenty seven and 3,879 predicted target genes were obtained for upregulated and downregulated DE-miRNAs, respectively. Subsequently, 1,715 upregulated DEGs and 1,259 downregulated DEGs were identified. Then, 149 and 295 potential downregulated and upregulated genes commonly appeared in target genes of DE-miRNAs and DEGs were selected for GO annotation and KEGG pathway enrichment analysis. The downregulated genes were significantly enriched in cGMP-PKG signaling pathway and calcium signaling pathway whereas the upregulated genes were enriched in pathways in cancer and PI3K-Akt signaling pathway. Construction and analysis of PPI network showed that STXBP1 and TP53 were recognized as hub genes with the highest connectivity degrees. Expression analytic result of the top 20 hub genes in GBM using GEPIA database was generally identical with previous differential expression analysis for TCGA data. EGFR, PPP3CB, and MYO5A expression was significantly associated with patients' OS.

Conclusions: In this study, we established a potential GBM-related miRNA-mRNA regulatory network, which explores a comprehensive understanding of the molecular mechanisms and provides key clues in seeking novel therapeutic targets for GBM. In the future, more experiments need to be performed to validate our current findings.

The Utility of Whole Body Imaging in the Evaluation of Solitary Brain Tumors

BACKGROUND

Solitary brain tumors can propose a diagnostic dilemma owing to the difficulty in differentiating between primary brain tumors and metastatic disease. The similar radiologic appearance on routine magnetic resonance imaging will necessitate the need for additional noninvasive testing. We sought to determine the clinical utility of preoperative whole body screening with computed tomography (CT) to detect metastatic disease in patients with solitary brain tumors.

METHODS

A prospectively maintained surgical database for a large quaternary care academic institution was retrospectively reviewed for all patients undergoing craniotomy for a new diagnosis of enhancing solitary brain lesion from January 2011 to January 2016. Patients were excluded if the imaging findings had demonstrated multiple brain tumors, they had a known diagnosis of malignancy, or they had undergone previous craniotomy. The demographic and radiographic information and clinical and histopathologic data were collected and tallied.

RESULTS

A total of 218 patients with solitary brain tumors met the inclusion criteria and were included in the present study. Histopathologic analysis confirmed primary central nervous system tumors in 152 patients (74.4%) and metastatic disease in 66 (25.6%). Preoperative screening with whole body CT had a sensitivity of 0.92 and specificity of 0.95 for detecting systemic metastases in the patients. Preoperative whole body CT correctly identified systemic malignancy in 88% of the patients ultimately diagnosed with metastasis (positive predictive value, 88%). Of those with negative whole body imaging findings, 97% had a diagnosis of a primary central nervous system neoplasm (negative predictive value, 97%).

CONCLUSIONS

Preoperative whole body CT had a positive predictive value of 88% and negative predictive value of 97% in the present study and was both sensitive (92%) and specific (95%) for the detection of extracranial tumors. The identification of extracranial tumors on whole body CT screening might alter management.

C-type lectin domain family 5, member A (CLEC5A, MDL-1) promotes brain glioblastoma tumorigenesis by regulating PI3K/Akt signalling

OBJECTIVES

Glioblastoma is the most common malignant glioma of all brain tumours. It is difficult to treat because of its poor response to chemotherapy and radiotherapy and high recurrence rate after treatment. The aetiology of glioblastoma is a result of disorders of multiple factors. Depending on cell signal transduction, these glioblastoma-associated factors lead to cell proliferation, differentiation and apoptosis. Therefore, investigation of the potential factors which involved in the development of glioblastoma could provide a new target for the treatment of glioblastoma.

MATERIALS AND METHODS

We analysed the transcript expression of CLEC5A in glioblastoma by accessing The Cancer Genome Atlas (TCGA). qRT-PCR was performed to detect the RNA expression of genes in cells and tissues, and Western blot was used to measure the protein levels (Cyclin D1, Bcl-2, BAX, PCNA, MMP2, MMP9, Akt and Akt phosphorylation) in tissues and cells. Cell proliferation, migration, invasion, cycle and apoptosis were measured by CCK-8, transwell and flow cytometry assays, respectively. Ki67 level and lung metastasis were determined by immunochemistry and H&E staining.

RESULTS

In this study, we found that CLEC5A was highly upregulated in glioblastoma compared to normal brain tissues, which had an opposite relation with the overall patient survival. Downregulation of CLEC5A could inhibit cell proliferation, migration and invasion via promoting apoptosis and G1 arrest. In contrast, overexpression of CLEC5A stimulated cell proliferation, migration and invasion. In addition, we found that CLEC5A level was positively correlated with Akt phosphorylation level. Akt inhibitor or agonist could reverse the modulation effects of CLEC5A in glioblastoma. Moreover, In vivo results suggested that inhibition of CLEC5A significantly reduced tumour size, weight, cell proliferation ability and lung metastasis via inhibition of phosphorylation Akt.

CONCLUSION

Both in vitro and in vivo evidences supported that CLEC5A was involved in glioblastoma pathogenesis via regulation of PI3K/Akt pathway. Thus, CLEC5A might serve as a potential therapeutic target in the treatment of glioblastoma in the future.

Neurosurgical patterns of care for diffuse low-grade gliomas in Sweden between 2005 and 2015

BACKGROUND

In the last decade, increasing evidence has evolved for early and maximal safe resection of diffuse low-grade gliomas (LGGs) regarding survival. However, changes in clinical practice are known to occur slowly and we do not know if the scientific evidence has yet resulted in changes in neurosurgical patterns of care.

METHODS

The Swedish Brain Tumor Registry was used to identify all patients with a first-time histopathological diagnosis of LGG between 2005 and 2015. For analysis of surgical treatment patterns, we subdivided assessed time periods into 2005-2008, 2009-2012, and 2013-2015. Population-based data on patient and disease characteristics, surgical management, and outcomes were extracted.

RESULTS

A total of 548 patients with diffuse World Health Organization grade II gliomas were identified: 142 diagnosed during 2005-2008, 244 during 2009-2012, and 162 during 2013-2015. Resection as opposed to biopsy was performed in 64.3% during 2005-2008, 74.2% during 2009-2012, and 74.1% during 2013-2015 (P = .08). There was no difference among the 3 periods regarding overall survival (P = .11). However, post hoc analysis of data from the 4 (out of 6) centers that covered all 3 time periods demonstrated a resection rate of 64.3% during 2005-2008, 77.4% during 2009-2012, and 75.4% during 2013-2015 (P = .02) and longer survival of patients diagnosed 2009 and onward (P = .04).

CONCLUSION

In this nationwide, population-based study we observed a shift over time in favor of LGG resection. Further, a positive correlation between the more active surgical strategy and longer survival is shown, although no causality can be claimed because of possible confounding factors.

Update on amino acid PET of brain tumours

PURPOSE OF REVIEW

The aim of this study was to give an update on the emerging role of PET using radiolabelled amino acids in the diagnostic workup and management of patients with cerebral gliomas and brain metastases.

RECENT FINDINGS

Numerous studies have demonstrated the potential of PET using radiolabelled amino acids for differential diagnosis of brain tumours, delineation of tumour extent for treatment planning and biopsy guidance, differentiation between tumour progression and recurrence versus treatment-related changes, and for monitoring of therapy. The Response Assessment in Neuro-Oncology (RANO) working group - an international effort to develop new standardized response criteria for clinical trials in brain tumours - has recently recommended the use of amino acid PET imaging for brain tumour management in addition to MRI at every stage of disease. With the introduction of F-18 labelled amino acids, a broader clinical application has become possible, but is still hampered by the lack of regulatory approval and of reimbursement in many countries.

SUMMARY

PET using radiolabelled amino acids is a rapidly evolving method that can significantly enhance the diagnostic value of MRI in brain tumours. Current developments suggest that this imaging technique will become an indispensable tool in neuro-oncological centres in the near future.

Neuro-oncology: Implications of the molecular era

The field of neuro-oncology has recently experienced a renaissance in the understanding of the molecular underpinnings and pathophysiology of glioma. Genetic markers have significant implications regarding treatment responsiveness and prognosis and are now the primary basis for classification. This article gives an updated understanding of the pathogenesis and mechanisms of resistance of glioma via discussion of 4 molecular and genetic markers: MGMT, IDH, 1p/19q, and TERT.

DNA demethylation is associated with malignant progression of lower-grade gliomas

To elucidate the mechanisms of malignant progression of lower-grade glioma, molecular profiling using methylation array, whole-exome sequencing, and RNA sequencing was performed for 122, 36 and 31 gliomas, respectively. This cohort included 24 matched pairs of initial lower-grade gliomas and recurrent tumors, most of which showed malignant progression. Nearly half of IDH-mutant glioblastomas that had progressed from lower-grade gliomas exhibited characteristic partial DNA demethylation in previously methylated genomic regions of their corresponding initial tumors, which had the glioma CpG island methylator phenotype (G-CIMP). In these glioblastomas, cell cycle-related genes, RB and PI3K-AKT pathway genes were frequently altered. Notably, late-replicating domain was significantly enriched in the demethylated regions that were mostly located in non-regulatory regions, suggesting that the loss of DNA methylation during malignant transformation may involve mainly passive demethylation due to a delay in maintenance of methylation during accelerated cell division. Nonetheless, a limited number of genes including IGF2BP3, which potentially drives cell proliferation, were presumed to be upregulated due to demethylation of their promoter. Our data indicated that demethylation of the G-CIMP profile found in a subset of recurrent gliomas reflects accelerated cell divisions accompanied by malignant transformation. Oncogenic genes activated by such epigenetic change represent potential therapeutic targets.

Outcome of Bevacizumab Therapy in Patients with Recurrent Glioblastoma Treated with Angiotensin System Inhibitors

PURPOSE

Antihypertensive therapy may improve bevacizumab efficacy in cancer patients. We examined efficacy and toxicity of angiotensin system inhibitors (ASI) and other antihypertensive drugs in bevacizumab treated recurrent glioblastoma patients.

METHODS

We retrospectively combined a national prescription registry with a clinical database with recurrent glioblastoma patients (n = 243).

RESULTS

Patients who initiated ASI after bevacizumab (n = 26) showed a tendency towards improved progression-free survival and overall survival (OS) with hazard rate (HR) reductions (HR = 0.70 and HR = 0.79, respectively). Calcium antagonists during bevacizumab therapy significantly improved OS (HR = 0.57).

CONCLUSIONS

Overall the study supports a potential beneficial effect of antihypertensive treatment on prognosis of bevacizumab treated glioblastoma patients.

[Gemistocytic astrocytomas]

Gemistocytic astrocytomas (GA) are a variant of diffuse astrocytomas GII (WHO, 2016). Like all diffuse astrocytomas, GA recur with time, which is often accompanied by malignant degeneretion into the anaplastic astrocytoma GIII or to the secondary glioblastoma GIV. However, the progression-free survival and overall survival in patients with GA is less than in patients with diffuse astrocytomas. Given that this group of patients, according to the WHO classification (2016), is classified as GII, patients with GA usually do not receive comprehensive treatment. We have conducted a thorough analysis of research on this problem for the period from 1956 to 2017. Differences in the histological pattern, immunohistochemical and molecular-genetic profiles, survival of patients with GA and diffuse astrocytomas GII are shown there. A clinical case of a patient with transformation of a diffuse astrocytoma in GA (GIII) and then into a secondary glioblastoma is presented.

Understanding and exploiting cell signalling convergence nodes and pathway cross-talk in malignant brain cancer

In cancer, complex intracellular and intercellular signals constantly evolve for the advantage of the tumour cells but to the disadvantage of the whole organism. Decades of intensive research have revealed the critical roles of cellular signalling pathways in regulating complex cell behaviours which influence tumour development, growth and therapeutic response, and ultimately patient outcome. Most studies have focussed on specific pathways and the resulting tumour cell function in a rather linear fashion, partly due to the available methodologies and partly due to the traditionally reductionist approach to research. Advances in cancer research, including genomic technologies have led to a deep appreciation of the complex signals and pathway interactions operating in tumour cells. In this review we examine the role and interaction of three major cell signalling pathways, PI3K, MAPK and cAMP, in regulating tumour cell functions and discuss the prospects for exploiting this knowledge to better treat difficult to treat cancers, using glioblastoma, the most common and deadly malignant brain cancer, as the example disease.

The Myeloid Cell Compartment-Cell by Cell

Myeloid cells are a major cellular compartment of the immune system comprising monocytes, dendritic cells, tissue macrophages, and granulocytes. Models of cellular ontogeny, activation, differentiation, and tissue-specific functions of myeloid cells have been revisited during the last years with surprising results; for example, most tissue macrophages are yolk sac derived, monocytes and macrophages follow a multidimensional model of activation, and tissue signals have a significant impact on the functionality of all these cells. While these exciting results have brought these cells back to center stage, their enormous plasticity and heterogeneity, during both homeostasis and disease, are far from understood. At the same time, the ongoing revolution in single-cell genomics, with single-cell RNA sequencing (scRNA-seq) leading the way, promises to change this. Prevailing models of hematopoiesis with distinct intermediates are challenged by scRNA-seq data suggesting more continuous developmental trajectories in the myeloid cell compartment. Cell subset structures previously defined by protein marker expression need to be revised based on unbiased analyses of scRNA-seq data. Particularly in inflammatory conditions, myeloid cells exhibit substantially vaster heterogeneity than previously anticipated, and work performed within large international projects, such as the Human Cell Atlas, has already revealed novel tissue macrophage subsets. Based on these exciting developments, we propose the next steps to a full understanding of the myeloid cell compartment in health and diseases.

Effects of Long Form of CAPON Overexpression on Glioma Cell Proliferation are Dependent on AKT/mTOR/P53 Signaling

Background: CAPON has two isoforms in human brain: long form of CAPON (CAPON-L) and short form of CAPON (CAPON-S). Recent studies have indicated the involvement of CAPON in tumor cell growth. We aimed to reveal the role of the two CAPON isoforms in the proliferation of glioma cells in this study. Materials and Methods: Lentivirus-mediated stable cell lines with CAPON-L or CAPON-S overexpression were established in U87 and U251 glioma cells. Cell counting kit-8 and colony formation assays were used to evaluate cell proliferation. Western blot analysis of cell cycle-related proteins and flow cytometry were performed to analyze cell cycle progression. Some important molecules of the AKT/mTOR pathway and P53 were also measured by Western blot analysis. Results: Overexpression of CAPON-L showed a significantly inhibitory role in U251 cells, while it exhibited a promoting role in U87 cells. Consistently, overexpressing CAPON-L impeded the cell cycle progression and down-regulated the expression levels of Cyclin D1, CDK4 and CDK6 in U251 cells, whereas it up-regulated the CDK6 level in U87 cells. The overexpression of CAPON-L significantly decreased the phosphorylation and/or total levels of AKT, mTOR and S6 in U251 cells, while it did not affect these signaling molecules in U87 cells, except for a significant increase in the phosphorylation of AKT at Thr-308 site. Transfecting constitutively active AKT (myr-AKT) partially reversed the decreased phosphorylation of AKT and S6 in the CAPON-L-overexpressing U251 cells. In addition, we found a significant decrease in the wild-type P53 level in the CAPON-L-overexpressing U87 cells. The overexpression of CAPON-S also inhibited cell proliferation, blocked cell cycle progression, and decreased the AKT/mTOR pathway activity in U251 cells. Conclusion: The effects of CAPON-L overexpression on glioma cell proliferation are dependent on the AKT/mTOR/P53 activity. The overexpression of CAPON inhibits U251 cell proliferation through the AKT/mTOR signaling pathway, while overexpressing CAPON-L promoted U87 cell proliferation, possibly through down-regulating the P53 level.

Comments on the US National Toxicology Program technical reports on toxicology and carcinogenesis study in rats exposed to whole-body radiofrequency radiation at 900 MHz and in mice exposed to whole-body radiofrequency radiation at 1,900 MHz

During the use of handheld mobile and cordless phones, the brain is the main target of radiofrequency (RF) radiation. An increased risk of developing glioma and acoustic neuroma has been found in human epidemiological studies. Primarily based on these findings, the International Agency for Research on Cancer (IARC) at the World Health Organization (WHO) classified in May, 2011 RF radiation at the frequency range of 30 kHz‑300 GHz as a 'possible' human carcinogen, Group 2B. A carcinogenic potential for RF radiation in animal studies was already published in 1982. This has been confirmed over the years, more recently in the Ramazzini Institute rat study. An increased incidence of glioma in the brain and malignant schwannoma in the heart was found in the US National Toxicology Program (NTP) study on rats and mice. The NTP final report is to be published; however, the extended reports are published on the internet for evaluation and are reviewed herein in more detail in relation to human epidemiological studies. Thus, the main aim of this study was to compare earlier human epidemiological studies with NTP findings, including a short review of animal studies. We conclude that there is clear evidence that RF radiation is a human carcinogen, causing glioma and vestibular schwannoma (acoustic neuroma). There is some evidence of an increased risk of developing thyroid cancer, and clear evidence that RF radiation is a multi‑site carcinogen. Based on the Preamble to the IARC Monographs, RF radiation should be classified as carcinogenic to humans, Group 1.

Lidocaine induces protective autophagy in rat C6 glioma cell line

Malignant glioma is the most common type of brain cancer with poor prognosis. Surgical resection, chemotherapy and radiotherapy are the main therapeutic options; however, in addition to their insufficient efficacy, they are associated with the pain experienced by patients. To relieve pain, local anesthetics, such as lidocaine can be used. In the present study, the effects of lidocaine on the C6 rat glioma cell line were investigated. An MTT assay and Annexin V/propidium iodide analysis indicated the increase in the percentage of apoptotic and necrotic cells in response to lidocaine. Furthermore, light microscopy analysis on the ultrastructural level presented the occurrence of vacuole-like structures associated with autophagy, which was supported by the analysis of autophagy markers (microtubule-associated protein 1A/1B-light chain 3, acridine orange and Beclin-1). Additionally, reorganization of the cytoskeleton was observed following treatment with lidocaine, which serves an important role in the course of autophagy. To determine the nature of autophagy, an inhibitor, bafilomycin A1 was applied. This compound suppressed the fusion of autophagosomes with lysosomes and increased the percentage of apoptotic cells. These results demonstrated that lidocaine may induce cytoprotective autophagy and that manipulation of this process could be an alternative therapeutic strategy in the treatment of cancer.

The Emerging Role of Amino Acid PET in Neuro-Oncology

Imaging plays a critical role in the management of the highly complex and widely diverse central nervous system (CNS) malignancies in providing an accurate diagnosis, treatment planning, response assessment, prognosis, and surveillance. Contrast-enhanced magnetic resonance imaging (MRI) is the primary modality for CNS disease management due to its high contrast resolution, reasonable spatial resolution, and relatively low cost and risk. However, defining tumor response to radiation treatment and chemotherapy by contrast-enhanced MRI is often difficult due to various factors that can influence contrast agent distribution and perfusion, such as edema, necrosis, vascular alterations, and inflammation, leading to pseudoprogression and pseudoresponse assessments. Amino acid positron emission tomography (PET) is emerging as the method of resolving such equivocal lesion interpretations. Amino acid radiotracers can more specifically differentiate true tumor boundaries from equivocal lesions based on their specific and active uptake by the highly metabolic cellular component of CNS tumors. These therapy-induced metabolic changes detected by amino acid PET facilitate early treatment response assessments. Integrating amino acid PET in the management of CNS malignancies to complement MRI will significantly improve early therapy response assessment, treatment planning, and clinical trial design.

Survivorship in adults with malignant brain and other central nervous system tumor from 2000-2014

Background

The goal of this study was to provide up-to-date and comprehensive statistics on incidence, survival, and prevalence rates for selected malignant brain and other CNS tumors in adults.

Methods

The current study used data from the Central Brain Tumor Registry of the United States, provided by the Centers for Disease Control and Prevention, to examine incidence and data from the Surveillance, Epidemiology, and End Results program to examine survival and prevalence in 16 distinct malignant brain and other CNS histologies in adults (aged 20 y and older at diagnosis) from 2000-2014 overall and by sex, age group, race, and ethnicity.

Results

Glioblastoma had the highest incidence (4.40 per 100000) and prevalence (9.23 per 100000). Ependymal tumors had the highest 5- and 10-year relative survivals (87.8% and 84.5%, respectively), while glioblastoma had the lowest 5- and 10-year relative survivals (5.4% and 2.7%, respectively). Females generally had better survival and lower prevalence than males. Younger adults tended to have better survival than older adults, and prevalence varied greatly by age and histology. While survival did not vary significantly by race, white adults had higher prevalence than the other race groups. Hispanics generally had better survival rates and lower prevalence than non-Hispanics.

Conclusions

Survival varied greatly by age and ethnicity. Prevalence differed by sex, age, race, and ethnicity.

Thermal and non-thermal health effects of low intensity non-ionizing radiation: An international perspective

Exposure to low frequency and radiofrequency electromagnetic fields at low intensities poses a significant health hazard that has not been adequately addressed by national and international organizations such as the World Health Organization. There is strong evidence that excessive exposure to mobile phone-frequencies over long periods of time increases the risk of brain cancer both in humans and animals. The mechanism(s) responsible include induction of reactive oxygen species, gene expression alteration and DNA damage through both epigenetic and genetic processes. In vivo and in vitro studies demonstrate adverse effects on male and female reproduction, almost certainly due to generation of reactive oxygen species. There is increasing evidence the exposures can result in neurobehavioral decrements and that some individuals develop a syndrome of "electro-hypersensitivity" or "microwave illness", which is one of several syndromes commonly categorized as "idiopathic environmental intolerance". While the symptoms are non-specific, new biochemical indicators and imaging techniques allow diagnosis that excludes the symptoms as being only psychosomatic. Unfortunately standards set by most national and international bodies are not protective of human health. This is a particular concern in children, given the rapid expansion of use of wireless technologies, the greater susceptibility of the developing nervous system, the hyperconductivity of their brain tissue, the greater penetration of radiofrequency radiation relative to head size and their potential for a longer lifetime exposure.

Treatment of Glioblastoma in the Elderly

Clinical research in neuro-oncology frequently classifies patients over 60-70 years of age as 'elderly', a designation intended to identify patients with the disease characteristics, psychosocial changes, and susceptibility to treatment toxicities associated with advancing age. The elderly account for a large proportion of patients diagnosed with glioblastoma (GBM), and this population is projected to increase. Their prognosis is inferior to that of GBM patients as a whole, and concerns over treatment toxicity may limit the aggressiveness with which they are treated. Recent clinical studies have assisted with therapeutic decision making in this cohort. Hypofractionated radiation with concurrent and adjuvant temozolomide has been shown to increase survival without worsened quality of life in elderly patients with good functional status. Single modality radiation therapy or temozolomide therapy are frequently used in this population, and while neither has demonstrated superiority, O⁶-methylguanine-DNA methyltransferase (MGMT) methylation status is predictive of improved survival with temozolomide over radiation therapy. Despite these advances, ambiguity as to how to best define, assess, and treat this population remains. The specific response of elderly patients to emerging therapies, such as immunotherapies, is unclear. Advancing outcomes for elderly patients with GBM requires persistent efforts to include them in translational and clinical research endeavors, and concurrent dedication to the preservation of function and quality of life in this population.

TERT promoter wild-type glioblastomas show distinct clinical features and frequent PI3K pathway mutations

TERT promoter (TERTp) mutations are found in the majority of World Health Organization (WHO) grade IV adult IDH wild-type glioblastoma (IDH-wt GBM). Here, we characterized the subset of IDH-wt GBMs that do not have TERTp mutations. In a cohort of 121 adult grade IV gliomas, we identified 109 IDH-wt GBMs, after excluding 11 IDH-mutant cases and one H3F3A -mutant case. Within the IDH-wt cases, 16 cases (14.7%) were TERTp wild-type (TERTp-wt). None of the 16 had BRAF V600E or H3F3A G34 hotspot mutations. When compared to TERTp mutants, patients with TERTp-wt GBMs, were significantly younger at first diagnosis (53.2 years vs. 60.7 years, p = 0.0096), and were more frequently found to have cerebellar location (p = 0.0027). Notably, 9 of 16 (56%) of TERTp-wt GBMs contained a PIK3CA or PIK3R1 mutation, while only 16/93 (17%) of TERTp-mutant GBMs harbored these alterations (p = 0.0018). As expected, 8/16 (50%) of TERTp-wt GBMs harbored mutations in the BAF complex gene family (ATRX, SMARCA4, SMARCB1, and ARID1A), compared with only 8/93 (9%) of TERTp-mutant GBMs (p = 0.0003). Mutations in BAF complex and PI3K pathway genes co-occurred more frequently in TERTp-wt GBMs (p = 0.0002), an association that has been observed in other cancers, suggesting a functional interaction indicative of a distinct pathway of gliomagenesis. Overall, our finding highlights heterogeneity within WHO-defined IDH wild-type GBMs and enrichment of the TERTp-wt subset for BAF/PI3K-altered tumors, potentially comprising a distinct clinical subtype of gliomas.

Arterial spin labeling MR imaging for differentiation between high- and low-grade glioma-a meta-analysis

Background

Arterial spin labeling is an MR imaging technique that measures cerebral blood flow (CBF) non-invasively. The aim of the study is to assess the diagnostic performance of arterial spin labeling (ASL) MR imaging for differentiation between high-grade glioma and low-grade glioma.

Methods

Cochrane Library, Embase, Medline, and Web of Science Core Collection were searched. Study selection ended November 2017. This study was prospectively registered in PROSPERO (CRD42017080885). Two authors screened all titles and abstracts for possible inclusion. Data were extracted independently by 2 authors. Bivariate random effects meta-analysis was used to describe summary receiver operating characteristics. Trial sequential analysis (TSA) was performed.

Results

In total, 15 studies with 505 patients were included. The diagnostic performance of ASL CBF for glioma grading was 0.90 with summary sensitivity 0.89 (0.79-0.90) and specificity 0.80 (0.72-0.89). The diagnostic performance was similar between pulsed ASL (AUC 0.90) with a sensitivity 0.85 (0.71-0.91) and specificity 0.83 (0.69-0.92) and pseudocontinuous ASL (AUC 0.88) with a sensitivity 0.86 (0.79-0.91) and specificity 0.80 (0.65-0.87). In astrocytomas, the diagnostic performance was 0.89 with sensitivity 0.86 (0.79 to 0.91) and specificity 0.79 (0.63 to 0.89). Sensitivity analysis confirmed the robustness of the findings. TSA revealed that the meta-analysis was adequately powered.

Conclusion

Arterial spin labeling MR imaging had an excellent diagnostic accuracy for differentiation between high-grade and low-grade glioma. Given its low cost, non-invasiveness, and efficacy, ASL MR imaging should be considered for implementation in the routine workup of patients with glioma.

Duplications of KIAA1549 and BRAF screening by Droplet Digital PCR from formalin-fixed paraffin-embedded DNA is an accurate alternative for KIAA1549-BRAF fusion detection in pilocytic astrocytomas

Pilocytic astrocytomas represent the most common glioma subtype in young patients and account for 5.4% of all gliomas. They are characterized by alterations in the RAS-MAP kinase pathway, the most frequent being a tandem duplication on chromosome 7q34 involving the BRAF gene, resulting in oncogenic BRAF fusion proteins. BRAF fusion involving the KIAA1549 gene is a hallmark of pilocytic astrocytoma, but it has also been recorded in rare cases of gangliogliomas, 1p/19q co-deleted oligodendroglial tumors, and it is also a common feature of disseminated oligodendroglial-like leptomeningeal neoplasm. In some difficult cases, evidence for KIAA1549-BRAF fusion is of utmost importance for the diagnosis. Moreover, because the KIAA1549-BRAF fusion constitutively activates the MAP kinase pathway, it represents a target for drugs such as MEK inhibitors, and therefore, the detection of this genetic abnormality is highly relevant in the context of clinical trials applying such new approaches. In the present study, we aimed to use the high sensitivity of Droplet Digital PCR (DDPCR™) to predict KIAA1549-BRAF fusion on very small amounts of formalin-fixed paraffin-embedded tissue in routine practice. Therefore, we analyzed a training cohort of 55 pilocytic astrocytomas in which the KIAA1549-BRAF fusion status was known by RNA sequencing used as our gold standard technique. Then, we analyzed a prospective cohort of 40 pilocytic astrocytomas, 27 neuroepithelial tumors remaining difficult to classify (pilocytic astrocytoma versus ganglioglioma or diffuse glioma), 15 dysembryoplastic neuroepithelial tumors, and 18 gangliogliomas. We could demonstrate the usefulness and high accuracy (100% sensitivity and specificity when compared to RNA sequencing) of DDPCR™ to assess the KIAA1549-BRAF fusion from very low amounts of DNA isolated from formalin-fixed paraffin-embedded specimens. BRAF duplication is both necessary and sufficient to predict this fusion in most cases and we propose that this single analysis could be used in routine practice to save time, money, and precious tissue.

Long Non-Coding RNAs in Gliomas: From Molecular Pathology to Diagnostic Biomarkers and Therapeutic Targets

Gliomas are the most common malignancies of the central nervous system. Because of tumor localization and the biological behavior of tumor cells, gliomas are characterized by very poor prognosis. Despite significant efforts that have gone into glioma research in recent years, the therapeutic efficacy of available treatment options is still limited, and only a few clinically usable diagnostic biomarkers are available. More and more studies suggest non-coding RNAs to be promising diagnostic biomarkers and therapeutic targets in many cancers, including gliomas. One of the largest groups of these molecules is long non-coding RNAs (lncRNAs). LncRNAs show promising potential because of their unique tissue expression patterns and regulatory functions in cancer cells. Understanding the role of lncRNAs in gliomas may lead to discovery of the novel molecular mechanisms behind glioma biological features. It may also enable development of new solutions to overcome the greatest obstacles in therapy of glioma patients. In this review, we summarize the current knowledge about lncRNAs and their involvement in the molecular pathology of gliomas. A conclusion follows that these RNAs show great potential to serve as powerful diagnostic, prognostic, and predictive biomarkers as well as therapeutic targets.

Glioblastoma Treatments: An Account of Recent Industrial Developments

The different drugs and medical devices, which are commercialized or under industrial development for glioblastoma treatment, are reviewed. Their different modes of action are analyzed with a distinction being made between the effects of radiation, the targeting of specific parts of glioma cells, and immunotherapy. Most of them are still at a too early stage of development to firmly conclude about their efficacy. Optune, which triggers antitumor activity by blocking the mitosis of glioma cells under the application of an alternating electric field, seems to be the only recently developed therapy with some efficacy reported on a large number of GBM patients. The need for early GBM diagnosis is emphasized since it could enable the treatment of GBM tumors of small sizes, possibly easier to eradicate than larger tumors. Ways to improve clinical protocols by strengthening preclinical studies using of a broader range of different animal and tumor models are also underlined. Issues related with efficient drug delivery and crossing of blood brain barrier are discussed. Finally societal and economic aspects are described with a presentation of the orphan drug status that can accelerate the development of GBM therapies, patents protecting various GBM treatments, the different actors tackling GBM disease, the cost of GBM treatments, GBM market figures, and a financial analysis of the different companies involved in the development of GBM therapies.

Glioblastoma in the setting of prior lower grade gliomas - insights from SEER database

Introduction

Secondary glioblastomas (GBs) constitute a small subset of all GBs and tend to arise after a lower grade glioma. Though knowledge regarding this subset has gained traction in recent years, its definition continues to evolve, complicating its clinical management. Investigation of epidemiology and survival patterns may help provide needed insights.

Results

The age at GB diagnosis is significantly lower (46.22 vs 60.25 years) for group B. The distribution among type of GB (glioblastoma, giant cell glioblastoma, or gliosarcoma) was significantly different, with no diagnosis of giant cell GB in Group B. Compared to Group A, Group B exhibited a higher proportion of females, not married, smaller tumors, no GTR, and no radiation (all p < 0.05). GB-related observed survivals were comparable. Cox regression with inclusion of co-variates reveal no significant influence of GB group on observed survival. Regarding group B, mean age was 40.197 for diagnosis of initial lower grade glioma. The most common initial ICD-O-3 pathology was oligodendroglioma, NOS; astrocytoma, NOS; astrocytoma, anaplastic; and mixed glioma.

Methods

The SEER-18 registry was queried for patients with GBs. Patients were further classified into two GB groups: Group A – those with GB as the only primary tumor, and Group B – those with GB as a 2^nd primary or subsequent tumor and with history of lower grade gliomas. Demographics and clinical factors were compared between group A and B. Appropriate statistics were employed to calculate incidences and differences among factors and GB-related survivals between the groups.

Conclusions

Overall, Group B develops GBs at an earlier age, but observed survival remains similar to those with GBs as the only primary. Moreover, this subset also exhibit different proportions of the types of GBs, and well as differences in other key clinical factors (namely, gender and tumor size at presentation). Prior treatments for lower grade gliomas likely explain some of the differences noted regarding management course after diagnosis of GB.

Nuclear Factor I Represses the Notch Effector HEY1 in Glioblastoma

Glioblastomas (GBMs) are highly aggressive brain tumors with a dismal prognosis. Nuclear factor I (NFI) is a family of transcription factors that controls glial cell differentiation in the developing central nervous system. NFIs have previously been shown to regulate the expression of astrocyte markers such as glial fibrillary acidic protein (GFAP) in both normal brain and GBM cells. We used chromatin immunoprecipitation (ChIP)–on-chip to identify additional NFI targets in GBM cells. Analysis of our ChIP data revealed ~400 putative NFI target genes including an effector of the Notch signaling pathway, HEY1, implicated in the maintenance of neural stem cells. All four NFIs (NFIA, NFIB, NFIC, and NFIX) bind to NFI recognition sites located within 1 kb upstream of the HEY1 transcription site. We further showed that NFI negatively regulates HEY1 expression, with knockdown of all four NFIs in GBM cells resulting in increased HEY1 RNA levels. HEY1 knockdown in GBM cells decreased cell proliferation, increased cell migration, and decreased neurosphere formation. Finally, we found a general correlation between elevated levels of HEY1 and expression of the brain neural stem/progenitor cell marker B-FABP in GBM cell lines. Knockdown of HEY1 resulted in an increase in the RNA levels of the GFAP astrocyte differentiation marker. Overall, our data indicate that HEY1 is negatively regulated by NFI family members and is associated with increased proliferation, decreased migration, and increased stem cell properties in GBM cells.

Management of low-grade glioma: a systematic review and meta-analysis

Background

Optimum management of low-grade gliomas remains controversial, and widespread practice variation exists. This evidence-based meta-analysis evaluates the association of extent of resection, radiation, and chemotherapy with mortality and progression-free survival at 2, 5, and 10 years in patients with low-grade glioma.

Methods

A quantitative systematic review was performed. Inclusion criteria included controlled trials of newly diagnosed low-grade (World Health Organization Grades I and II) gliomas in adults. Eligible studies were identified, assigned a level of evidence for every endpoint considered, and analyzed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The relative risk of mortality and of progression at 2, 5, and 10 years was calculated for patients undergoing resection (gross total, subtotal, or biopsy), radiation, or chemotherapy.

Results

Gross total resection was significantly associated with decreased mortality and likelihood of progression at all time points compared to subtotal resection. Early radiation was not associated with decreased mortality; however, progression-free survival was better at 5 years compared to patients receiving delayed or no radiation. Chemotherapy was associated with decreased mortality at 5 and 10 years in the high-quality literature. Progression-free survival was better at 5 and 10 years compared to patients who did not receive chemotherapy. In patients with isocitrate dehydrogenase 1 gene (IDH1) R132H mutations receiving chemotherapy, progression-free survival was better at 2 and 5 years than in patients with IDH1 wild-type gliomas.

Conclusions

Results from this review, the first to quantify differences in outcome associated with surgery, radiation, and chemotherapy in patients with low-grade gliomas, can be used to inform evidence-based management and future clinical trials.

2016 World Health Organization Classification of Central Nervous System Tumors

PURPOSE OF REVIEW

Since 1979, the World Health Organization (WHO) has periodically published a consensus classification and grading of tumors of the central nervous system (CNS) to ensure uniform histopathologic diagnostic criteria worldwide. In 2016, the WHO published an update of the fourth edition of the classification of CNS tumors. This article summarizes the major changes in the update and discusses their impact on clinical practice.

RECENT FINDINGS

For the first time, the 2016 revision of the WHO classification uses molecular parameters in addition to traditional histology to diagnose many CNS tumors, resulting in major restructuring of the classification of many tumors, especially gliomas, ependymomas, and medulloblastomas. Accordingly, nomenclature for selected entities now includes both a histopathologic diagnosis and defining molecular features.

SUMMARY

The use of integrated phenotypic and genotypic parameters for the classification of CNS tumors introduces greater objectivity to the diagnosis but also requires more widespread availability of molecular testing. It is hoped that these changes will lead to greater diagnostic accuracy with more biologically homogeneous diagnostic entities and improved patient management and determination of prognosis.

Hydrogel-Based Drug Delivery Nanosystems for the Treatment of Brain Tumors

Chemotherapy is commonly associated with limited effectiveness and unwanted side effects in normal cells and tissues, due to the lack of specificity of therapeutic agents to cancer cells when systemically administered. In brain tumors, the existence of both physiological barriers that protect tumor cells and complex resistance mechanisms to anticancer drugs are additional obstacles that hamper a successful course of chemotherapy, thus resulting in high treatment failure rates. Several potential surrogate therapies have been developed so far. In this context, hydrogel-based systems incorporating nanostructured drug delivery systems (DDS) and hydrogel nanoparticles, also denoted nanogels, have arisen as a more effective and safer strategy than conventional chemotherapeutic regimens. The former, as a local delivery approach, have the ability to confine the release of anticancer drugs near tumor cells over a long period of time, without compromising healthy cells and tissues. Yet, the latter may be systemically administered and provide both loading and targeting properties in their own framework, thus identifying and efficiently killing tumor cells. Overall, this review focuses on the application of hydrogel matrices containing nanostructured DDS and hydrogel nanoparticles as potential and promising strategies for the treatment and diagnosis of glioblastoma and other types of brain cancer. Some aspects pertaining to computational studies are finally addressed.

Lycorine inhibits glioblastoma multiforme growth through EGFR suppression

Background

Lycorine has been revealed to inhibit the development of many kinds of malignant tumors, including glioblastoma multiforme (GBM). Although compelling evidences demonstrated Lycorine’s inhibition on cancers through some peripheral mechanism, in-depth mechanism studies of Lycotine’s anti-GBM effects still call for further exploration. Epidermal Growth Factor Receptor (EGFR) gene amplification and mutations are the most common oncogenic events in GBM. Targeting EGFR by small molecular inhibitors is a rational strategy for GBM treatment.

Methods

The molecular docking modeling and in vitro EGFR kinase activity system were employed to identify the potential inhibitory effects of Lycorine on EGFR. And the Biacore assay was used to confirm the direct binding status between Lycorine and the intracellular EGFR (696–1022) domain. In vitro assays were conducted to test the suppression of Lycorine on the biological behavior of GBM cells. By RNA interference, EGFR expression was reduced then cells underwent proliferation assay to investigate whether Lycorine’s inhibition on GBM cells was EGFR-dependent or not. RT-PCR and western blotting analysis were carried out to investigate the underlined molecular mechanism that Lycorine exerted on EGFR itself and EGFR signaling pathway. Three different xenograft models (an U251-luc intracranially orthotopic transplantation model, an EGFR stably knockdown U251 subcutaneous xenograft model and a patient-derived xenograft model) were performed to verify Lycorine’s therapeutic potential on GBM in vivo.

Results

We identified a novel small natural molecule Lycorine binding to the intracellular EGFR (696–1022) domain as an inhibitor of EGFR. Lycorine decreased GBM cell proliferation, migration and colony formation by inducing cell apoptosis in an EGFR-mediated manner. Furthermore, Lycorine inhibited the xenograft tumor growths in three animal models in vivo. Besides, Lycorine impaired the phosphorylation of EGFR, AKT, which were mechanistically associated with expression alteration of a series of cell survival and death regulators and metastasis-related MMP9 protein.

Conclusions

Our findings identify Lycorine directly interacts with EGFR and inhibits EGFR activation. The most significant result is that Lycorine displays satisfactory therapeutic effect in our patient-derived GBM tumor xenograft, thus supporting the conclusion that Lycorine may be considered as a promising candidate in clinical therapy for GBM.

Repression of Dok7 expression mediated by DNMT1 promotes glioma cells proliferation

Malignant glioma is one of the most common primary human tumors in the central nervous system. The molecular mechanisms of the progression and development of glioma have been largely unexplored. In this study, we illustrated that the expression of Dok7 was downregulation in human glioma tissues. Dok7 overexpression significantly inhibits proliferation and colony formation in vitro, and the xenograft tumor formation in vivo. In addition, 5-Aza-2'-deoxycytidine (5-Aza), a DNA methylation inhibitor, preventing the loss of Dok7 expression by decreasing aberrant hypermethylation of Dok7 promoter in glioma cells. More importantly, DNMT1 knockdown induced the demethylation of Dok7 promoter, and enhanced the expression of Dok7 in gliomas. These results suggest that epigenetic silencing of Dok7 may provide a novel glioma treatment strategy.

Survival and prognostic factors for glioblastoma multiforme: Retrospective single-institutional study

INTRODUCTION

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults. The standard management has been maximum surgical resection followed by adjuvant radiotherapy with concurrent chemotherapy followed by adjuvant chemotherapy. Although the survival rate of patients with GBM has improved with recent advancements in treatment, the prognosis remains generally poor. The median survival rates are in the range of 9-12 months and 2-year survival rates are in the range of 8%-12%.

MATERIALS AND METHODS

A single-institution retrospective review of 61 patients of GBM from 2012 to 2014. Data regarding patient factors, disease factors, and treatment factors were collected and survival has been calculated.

RESULTS

A total of 61 patients with GBM were analyzed. GBM is commonly seen in sixth decade of life. Male to female ratio is 2.6:1. The right side of the brain is commonly involved with right frontal lobe being the most common site. The median follow-up was 4.6 months. The median survival of our patients was 8 months. The 1-year and 2-year survival rates were 20% and 3.27%, respectively.

CONCLUSIONS

The overall survival and prognosis in patients with GBM remains poor despite of constant research and studies. Concurrent chemoradiotherapy followed by adjuvant chemotherapy with temozolomide should be used after maximal resection to improve the survival.

Methylation profiling of paediatric pilocytic astrocytoma reveals variants specifically associated with tumour location and predictive of recurrence

Childhood pilocytic astrocytomas (PA) are low-grade tumours with an excellent prognosis. However, a minority, particularly those in surgically inaccessible locations, have poorer long-term outcome. At present, it is unclear whether anatomical location in isolation, or in combination with underlying biological variation, determines clinical behaviour. Here, we have tested the utility of DNA methylation profiling to inform tumour biology and to predict behaviour in paediatric PA. Genome-wide DNA methylation profiles were generated for 117 paediatric PAs. Using a combination of analyses, we identified DNA methylation variants specific to tumour location and predictive of behaviour. Receiver-operating characteristic analysis was used to test the predictive utility of clinical and/or DNA methylation features to classify tumour behaviour at diagnosis. Unsupervised analysis distinguished three methylation clusters associated with tumour location (cortical, midline and infratentorial). Differential methylation of 5404 sites identified enrichment of genes involved in 'embryonic nervous system development'. Specific hypermethylation of NEUROG1 and NR2E1 was identified as a feature of cortical tumours. A highly accurate method to classify tumours according to behaviour, which combined three clinical features (age, location and extent of resection) and methylation level at a single site, was identified. Our findings show location-specific epigenetic profiles for PAs, potentially reflecting their cell type of origin. This may account for differences in clinical behaviour according to location independent of histopathology. We also defined an accurate method to predict tumour behaviour at diagnosis. This warrants further testing in similar patient cohorts.

Implantable systems for drug delivery to the brain

Most diseases and disorders of the brain require long-term therapy and a constant supply of drugs. Implantable drug-delivery systems provide long-term, sustained drug delivery in the brain. The present review discusses different type of implantable systems such as solid implants, in situ forming implants, in situ forming microparticles, depot formulations, polymeric-lipid implants, sucrose acetate isobutyrate and N-stearoyl L-alanine methyl ester systems for continuous drug delivery into brain for various brain diseases including glioblastomas, medulloblastoma, epilepsy, stroke, schizophrenia and Alzheimer's diseases. Implantable neural probes and microelectrode array systems for brain are also discussed in brief.

Piplartine Analogues and Cytotoxic Evaluation against Glioblastoma

Piplartine (1) is an alkamide extracted from plants of the genus Piper which shows several pharmacological properties, including antitumor activity. To improve this activity, a series of analogues based on 1 have been synthesized by esterification and amidation using the 3,4,5-trimethoxycinnamic acid-like starting material. During the study, the moieties 3-(3,4,5-trimethoxyphenyl)acrylate and 3-(3,4,5-trimethoxyphenyl)acrylamide were maintained on esters and amides respectively. Meanwhile, functional changes were exploited, and it was revealed that the presence of two aromatic rings in the side-chain was important to improve the cytotoxic activity against the U87MG cell line, such as the compound (E)-benzhydryl 3-(3,4,5-trimethoxyphenyl)acrylate (10), an ester that exhibited strong cytotoxicity and a similar level of potency to that of paclitaxel, a positive control. Compound 10 had a marked concentration-dependent inhibitory effect on the viability of the U87MG cell line with apoptotic and oxidative processes, showing good potential for altering main molecular pathways to prevent tumor development. Moreover, it has strong bioavailability with non-genotoxic and non-cytotoxic properties on human blood cells. In conclusion, the findings of the present study demonstrated that compound 10 is a promising agent that may find applications combatting diseases associated with oxidative stress and as a prototype for the development of novel drugs used in the treatment of glioblastoma.

A case report of targeted therapy with apatinib in a patient with recurrent high grade glioma

RATIONALE

Despite the approval of antiangiogenic therapy for high grade glioma (HGG) patients, survival benefits are still limited. New treatment plans have always been developed to improve the survival.

PATIENT CONCERNS

A 26-year-old woman was admitted to our hospital for distending pain of head and eye.

DIAGNOSES

Resonance imaging (MRI) revealed a large spherical heterogeneously enhancing, mixed cystic and solid mass in the right frontal region, and the midline shifted.

INTERVENTION

The patient received apatinib therapy for positive vascular endothelial growth factor.

OUTCOMES

A partial response was observed after 4 weeks and remains sustained until now.

LESSONS

It suggests that apatinib might be a feasible option for the treatment in advanced HGG patients or patients with poor physical condition.

CREB3L1 and PTN expressions correlate with prognosis of brain glioma patients

The present study was conducted to investigate the clinical significance of cAMP responsive element binding protein 3 like 1 (CREB3L1) and pleiotrophin (PTN) expression in prognosis of patients with brain gliomas. Human brain tissue samples were collected from normal glial tissues (control), low- and high-grade glioma tissues. CREB3L1 and PTN expression levels in cells were assessed by immunohistochemistry (IHC), and population distribution of the CREB3L1- and PTN-presenting patients was examined. The CREB3L1 and PTN mRNA expression levels in three types of the brain cells was determined by RT-PCR. Survival rates for population of the CREB3L1- and PTN-presenting patients were examined. CREB3L1⁺ cell counts were decreased with increased PTN⁺ cells in the low-grade and high-grade glioma tissues as compared with the control. Population proportion of the CREB3L1⁺-presenting patients decreased from the control to the high-grade glioma and the population of the PTN⁺-presenting patients increased in low- and high-grade gliomas as compared with the control (both P<0.05). The decrease in the CREB3L1 mRNA expression was associated with the increase in the PTN mRNA expression in the low- and high-grade gliomas (P<0.05). Survival time for patients with CREB3L1^- and PTN⁺ gliomas was shorter than patients with CREB3L1⁺ and PTN^- gliomas in the investigated cohorts (both P<0.05). There was a relationship between the expression levels of both proteins and survival time. CREB3L1 and PTN expression levels serve as biomarkers with utility in grading gliomas. Absence of CREB3L1 and presence of PTN in brain glioma cells correlate with survival time of the glioma patients.