Patients WHO Grade Research Articles

NCOG-37. SINGLE CENTER EXPERIENCE OF IDH INHIBITORS IN THE TREATMENT OF RECURRENT HIGH GRADE GLIOMAS

Abstract BACKGROUND The antitumor effect of IDH inhibitors in high grade gliomas (HGG) is not well known, with conflicting views regarding the role of IDH status and the potential for resistance to DNA damage treatments. We present the outcomes of patients with HGG that were treated with IDH inhibitors at our institution. METHODS We performed a retrospective review of patients with IDH mutant gliomas treated with FDA approved IDH inhibitors (ivosidenib and enasidenib) in the past 5 years at our institution. One cycle of IDH inhibitor was defined as treatment for 28 days. RESULTS We identified 10 HGG patients (both oligodendrogliomas and astrocytomas). Median age at diagnosis was 31 years and 7 were male. Seven patients were diagnosed as WHO grade 3. Six patients were WHO grade 3 oligodendrogliomas, three WHO grade 4 astrocytomas, and one patient WHO grade 3 astrocytoma. Only one patient received enasidenib and the rest were treated with ivosidenib. Eight patients were started on IDH inhibitors after 3 recurrences. Median number of cycles was 5. One patient received 23 cycles, and one patient received 11 cycles. All patients underwent resection, 4 received chemotherapy (including temozolomide, bevacizumab, and CCNU), and 4 radiation prior to starting IDH inhibitors. One patient was treated with Tumor Treating Fields. Five patients progressed during the study follow up, and 3 patients died. Four patients are still on treatment. No serious adverse events. Median PFS after starting an IDH inhibitor was 6 months. DISCUSSION IDH inhibitors were well tolerated in IDH mutant HGG patients previously treated with DNA-damaging agents. It may have a role in the treatment of HGG with multiple recurrences with 3 patients showing stable disease for more than 18 months. More studies are needed to clarify the role of IDH inhibitors in patients with IDH mutant HGG.

BIOM-48. HOXD12 IS AN INDEPENDENTLY PROGNOSTIC AGE-ASSOCIATED INDICATOR FOR POOR SURVIVAL IN OLIGODENDROGLIOMA

Abstract BACKGROUND Oligodendroglioma, IDH-mutant and 1p/19q-codeleted has variable outcomes that are strongly influenced by patient age. This study aimed to discover novel molecular biomarkers that may characterize an aggressive subgroup of oligodendroglioma that is associated with, but independently prognostic of patient age. METHODS Differential gene expression analysis, gene ontology analysis, and gene set enrichment analysis were conducted on TCGA RNA-seq data (N=169) to identify genes and pathways that differ significantly between older and younger patients. Genes whose expression was associated with age and survival in multivariate analyses were further studied using DNA methylation (N=171). The prognostic value of their expression and methylation profiles was then compared to known genomic biomarkers, radiographic features, and histopathologic features. RNA-seq and DNA methylation validation data were obtained from the CGGA (N=44) and a cohort published by Capper et al. (N=144), respectively. RESULTS Highly activated pathways in older oligodendrogliomas were linked to developmental transcription factors. Overexpression of HOXD12 was associated with patient age and survival in the TCGA (FDR< 0.01, FDR=1e-5) and the CGGA (p=0.03, p< 1e-3). Hypermethylation of HOXD12 was associated with age, tumor grade, and survival in the TCGA (p< 1e-5, p< 0.001, p< 1e-3) and with age and tumor grade in Capper et al. (p< 0.02, p=0.001). In the TCGA, HOXD12 hypermethylation and overexpression were independently prognostic of NOTCH1 and PIK3CA mutations, loss of 15q, and MYC activation as well as mitotic figures, Ki-67 index, microvascular proliferation, and necrosis. HOXD12 overexpression was also independently prognostic of T1-post contrast enhancement, whole tumor volume, and peritumoral edema volume. We developed a risk-stratification nomogram predicting 5- and 10-year overall survival using patient age, HOXD12 methylation, and WHO grade. CONCLUSIONS HOXD12 overexpression and hypermethylation are associated with an aggressive subtype of oligodendroglioma and may serve as superior prognostic biomarkers than previously reported genomic, radiographic, and histopathologic features.

Circadian Period 2 (Per2) downregulate inhibitor of differentiation 3 (Id3) expression via PTEN/AKT/Smad5 axis to inhibits glioma cell proliferation

ABSTRACT In this study, we employed multiple laboratory techniques to acknowledge the biological activities and processes of Per2 and Id3 in glioma. We analyzed TCGA and CGGA databases for seeking association among Per2, Id3, and clinical features in glioma. Immunohistochemistry and Western blot were used to detect protein expression levels. CCK-8 assay, colony formation assay, Transwell assay, the wound healing assay, flow cytometric, and Xenograft nude mice were used to acknowledge the impact of Per2 and Id3 on biological behavior of glioma. The results showed that the Per2 mRNA expression was negatively correlated with the WHO grade, while the Id3 mRNA expression was positively correlated with the WHO grade in patients with glioma in TCGA and CGGA databases. Per2 and Id3 maintained separate prognostic abilities and had a negative connection in human glioma. In the clinical sample study, Per2 and Id3 were validated at the protein level with the same results compared to the mRNA expression level in TCGA and CGGA. By using a wide range of functional examples, overexpression of Per2 restrains malignant biological behaviors in glioma cells by many ways, while Id3 promotes malignant biological behaviors in glioma cells. Furthermore, overexpression of Per2 can inhibit Id3 expression via regulating PTEN/AKT/Smad5 signaling pathway and thereby abolish malignant biological behaviors that are caused by Id3 overexpression. These results suggested that Per2 inhibits glioma cell proliferation through regulating PTEN/AKT/Smad5/Id3 signaling pathway, which may be a viable therapeutic target for glioma.

PTBP1 is a Novel Poor Prognostic Factor for Glioma.

Objective Polypyrimidine tract-binding protein 1 (PTBP1) is an RNA-binding protein, which plays a role in pre-mRNA splicing and in the regulation of alternative splicing events. However, little was known about the correlation between PTBP1 and glioma and its prognostic significance in glioma patients. Our aim was to investigate the expression, functional role, and prognostic value of PTBP1 in glioma. Methods We explored the expression of PTBP1 protein using immunohistochemistry in 150 adult malignant glioma tissues and 20 normal brain tissues and evaluated its association with clinicopathological parameters by chi-square test. Kaplan-Meier method was used to evaluate the prognostic effect of PTBP1 in glioma. Univariate/multivariate Cox analyses were used to identify independent prognostic factors. Transcriptional regulation network was constructed based on differentially expressed genes (DEGs) of PTBP1 from TCGA/CGGA database. GO and KEGG enrichment analyses were used to explore the function and pathways of DEGs. Results Out of the 150 malignant glioma tissues (60 LGG and 90 GBMs) and 20 normal brain tissues in our cohort, PTBP1 protein was high expressed in glioma tissues (79/150, 52.7%), but no expression was detected in normal brain tissues (0/20, 0%). The expression of PTBP1 was significantly higher in GBMs (P < 0.001). More than half of GBMs (62/90, 68.9%) were PTBP1 high expression. Chi-square test showed that the expression of PTBP1 was correlated with patient age, WHO grade, Ki-67 index, and IDH status. High expression of PTBP1 was significantly associated with poor prognosis in glioma, and it was an independent risk factor in glioma patients. Furthermore, we shed light on the underlying mechanism of PTBP1 by constructing a miR-218-TCF3-PTBP1 transcriptional network in glioma. Conclusion PTBP1 was high expressed in glioma, and it significantly correlated with poor prognosis, suggesting a potential therapeutic target for glioma, particularly for GBM.

Nomograms for predicting the overall survival of patients with cerebellar glioma: an analysis of the surveillance epidemiology and end results (SEER) database

At present, our understanding of cerebellar glioma is still insufficient. This study collected information on patients in the SEER database to identify the predictive factors for patients with cerebellar glioma. Data from patients with cerebellar glioma diagnosed from 1975 to 2018 were retrieved from the Surveillance Epidemiology and End Results Database. We randomly divided the patients into a training group and a validation group, established a nomogram based on the training group, and used the validation group data to verify the clinical value of the model. A total of 508 patients were included in this study. Multivariate analysis was performed based on the data before randomization, and the results showed that the patient's age, WHO grade, histological type, and extent were significantly correlated with the survival rate. The C-index of the OS nomograms of the training cohort was 0.909 (95% CI, (0.880–0.938)) and 0.932 (95% CI, (0.889–0.975)) in the validation group. The calibration curve of OS for 3 and 5 years showed that there was good consistency between the actual survival probability and the predicted survival probability. For patients with cerebellar glioma, the age at diagnosis, WHO grade of the glioma, histological type, and extension are the four factors that most strongly affect the overall survival outcomes. Furthermore, our model may be a useful tool for predicting OS in these patients.

P09.04 T2 hyperintense regions on MRI in gliomas: a comparison between routine clinical MRI and 7T MRI

Abstract BACKGROUND Gliomas can be highly heterogeneous on brain MRI, especially at higher grades. These tumors often include a low-grade component and/or surrounding edema. Both these components appear as hyperintense regions on clinical T2-weighted MR images and cannot be accurately distinguished. Ultrahigh field 7T MR systems have the potential for a higher sensitivity due to its increase signal-to-noise ratio (SNR). This could allow for enhanced detailed visualization of gliomas. Therefore our goal was to assess the difference in extent of T2 hyperintense regions in glioma patients between clinical (1.5T/3T) and 7T MR images. MATERIAL AND METHODS We prospectively scanned 6 glioma patients (3 glioblastomas (GBM) WHO grade IV post-operative, 1 anaplastic diffuse glioma (ADG) WHO grade III, 1 biopsied oligodendroglioma (OD) WHO grade II and 1 suspected low-grade glioma (LGG); 4 Females, mean age: 56.8 years and 2 Males, mean age: 45.5 years) on a routine clinical MRI scanner (3T or 1.5T) and on a 7T MRI scanner (Philips Achieva). Resolution of the T2-weighted image at 7T, 3T and 1.5T: 0.75mm3, 3mm3 and 5mm3, respectively. T2-weighted scans were visually assessed by an independent researcher and experienced neuro-radiologist. The T2 hyperintense regions were measured in 3 directions and compared brain structures as reference points between the clinical and 7T scans (e.g. brain stem, gyri), also considering differences in slice thickness and spatial resolution. RESULTS T2 hyperintensity lesion measurements in the AP direction were as follows: GBM: 114.7mm (clinical field strength) vs 115.56mm (7T); ADG: 45mm vs 58.87mm and 24.7mm vs 25.55mm; OD: 45.1mm vs 48.5mm; GBM: 45.3mm vs 44.75mm; suspected LGG: 47.4mm vs 51.57mm; GBM: 105.8mm vs 114.5mm. We observed the largest difference between 3T and 7T T2 hyperintense region measurement to be 13.87mm (30%), belonging to a GBM WHO grade IV patient. For all patients the T2 hyperintense region was measured on average 8.3% larger at 7T MRI compared to the routine clinical MRI scan. Overall the T2 hyperintense regions at 7T appeared sharper and tumor boundaries were better defined. Likewise, the contrast between the tumor and healthy tissue was enhanced, most likely because of the increase in spatial resolution. CONCLUSION In gliomas the T2 hyperintense regions were more extensive at 7T MRI compared to the routine clinical MRI. These preliminary results might indicate that at clinical field strength the extent of the lesion is underestimated and that 7T MRI can potentially aid in detecting this more extensive disease process. Therefore, 7T MRI scan in gliomas might have a future role in treatment decisions regarding the extent of tumor resection and radiotherapy planning.

The Ki-67 Proliferation Index as a Marker of Time to Recurrence in Intracranial Meningioma.

There are examples of incongruence between the WHO grade and clinical course in meningioma patients. This incongruence between WHO grade and recurrence has led to search for other prognostic histological markers. To study the correlation between the Ki-67 proliferative index (PI), risk of recurrence, and recurrence rates in meningioma patients. We prospectively collected pathological diagnosis of de novo consecutive meningiomas. In total, we followed 159 patients with clinical controls until recurrence, death, or emigration. We estimated the correlation between risk of recurrence and Ki-67 PI when adjusted for age at diagnosis, sex, WHO grade, extent of surgical resection, and tumor location. We estimated the cumulative incidence of recurrence when considering death without recurrence a competing risk. We report recurrence rates per 100 person-years. A 1%-point increase of Ki-67 PI yielded a hazard ratio of 1.12 (95% CI: 1.01-1.24) in a multivariate analysis. The cumulative incidence of recurrence was 3% for Ki-67 0% to 4% vs 19% for Ki-67 >4% meningiomas after 1 yr, but 24%vs 35%, respectively, after 10 yr. There was no significant difference in mean Ki-67 PI between nonrecurrent and recurrent meningioma in a 2-sample t-test (P=.08). The strongest relationship was detected between Ki-67 PI and time to recurrence: Ki-67 <4% meningiomas recurred after median 4.8 yr, compared to 0.60 to 0.75 yr for patients with higher Ki-67 PI. Ki-67 PI was a marker for time to recurrence rather than a predictor of recurrence. Ki-67 PI may be utilized for patient tailored follow-up.

Intraventricular choroid plexus tumors: clinical characteristics and impact of current management on survival

Choroid plexus tumors (CPTs) represent one of the most common intraventricular tumors. Although most are benign, they often reach considerable sizes before clinical manifestation, challenging their surgical management. We aim to describe the clinical characteristics and the impact of current management on the survival of patients harboring intraventricular CPT. The National Cancer Database (NCDB) was queried to identify biopsy-proven intraventricular CPT patients (2004-2015). Demographic and patterns of care were described, the log-rank method was used to independently analyze survival according to age, WHO grade and extent of resection (EOR). Multivariate analysis was performed to investigate the impact of prognostic factors on overall survival (OS). A total of 439 CPT patients with known WHO grade were included. WHO grade I tumors were more frequent in adults, while WHO grade III tumors were more common in pediatric population. Most CPTs were benign, with a median tumor size of 3-4cm. Mean tumor size in pediatric population was greater than in adult population (4.39cm vs. 2.7cm; p < 0.01). Frequency was similar between males and females (51.7% vs. 48.3%; p > 0.0.5). Five- and ten-year OS among all patients was 87% and 84%, respectively. EOR was not associated with survival for any WHO grade. On multivariable analysis, only patient age (p = 0.022), WHO grade (p = 0.003) and medical comorbidity scores (p = 0.002) were independently associated with OS after diagnosis. Patients with CPTs present at different stages of life, with sizable tumor burden and distinct WHO grade prevalence. Considering their favorable survival, efforts to improve tumor control should be meticulously weighed against the long-term risk associated with surgery, radiation, and chemotherapy.

Quantitative analysis of 2-hydroxyglutarate as a controversial oncometabolite in malignant gliomas.

There is a great effort to connect the accumulation of 2-hydroxyglutarate (2-HG) oncometabolite with cellular onco-epigenetic status and subsequently predict the prognoses of glioma patients. In this observational study, the concentrations of D- and L- 2-HG were determined in 57 tumor tissue samples of glioma patients (n=57) WHO grade I through IV (astrocytoma, oligodendroglioma, secondary glioblastoma, and glioblastoma multiforme) in vitro. Also, genetic mutation status on isocitrate dehydrogenase 1 and 2 (IDH 1/2) was determined from these samples. The objective of this study was to confirm or to reject the hypothesis of the direct correlation of 2-HG concentration in tumor tissue and the results from IDH 1/IDH 2 point mutation analyses. The concentrations of 2-HG were quantified using high sensitive HPLC and Q-TOF HRMS spectrometer setup. Concurrently, the genetic mutation analyses of both IDH 1 (cytosolic) and IDH 2 (mitochondrial) were performed by the isolation of tumor tissue DNA, PCR amplification, and subsequent Sanger forward sequencing. Our results indicate that there is no definite correlation between the two as we identified cases of glioma tumors with significantly increased concentration of one or both L- and D- 2-HG but no IDH 1/2 mutations (44% 2-HG positive cases).

Correlation of preoperative seizures with a wide range of tumor molecular markers in gliomas: An analysis of 442 glioma patients from China

PurposeEpileptic seizures often develop in 40–70 % of glioma patients and have a significant impact on patients’ quality of life. Many biomarkers have been suggested to be associated with glioma-related preoperative seizures (GPS). The purpose of the present study was to investigate the possible correlation between GPS and clinicopathological factors and a wide range of glioma-associated molecular markers (GMMs). MethodsFirst, a retrospective cohort study of 442 patients with glioma was evaluated at the PLA General Hospital. Univariate and multivariate logistic analyses were used to identify basic factors associated with GPS. Second, 40 pairs of cases who underwent deep sequencing of 68 GMMs were selected from both groups for in-depth analysis. ResultsOf the 442 patients examined in this study, 137 (31 %) had GPS. By analyzing the characteristics of these patients, the results showed that patient age (OR: 0.981, p = 0.037, 95 % CI: 0.964−0.999), WHO grade (OR: 0.678, p = 0.008, 95 % CI: 0.509−0.903) and IDH mutations (OR: 1.886, p = 0.013, 95 % CI: 1.143–3.11) in patients were associated with the occurrence of GPS. In our cohort, GPS did not differ by sex, tumor location, histopathological subtype, p53 expression, ARTX loss, MGMT gene promotor methylation, TERT promoter mutation, or 1p/19q co-deletion status.The results of the matching study showed that the paired groups had similar genetic expression profiles, and the mutation of these 68 GMMs was not correlated with the occurrence of GPS. ConclusionThe current study updates existing information on GPS and genetic markers in gliomas and explores the correlation of a wide range of GMMs and GPS. These factors may provide insights for developing effective treatment strategies aimed at seizure control.

High expression of GPNMB indicates an unfavorable prognosis in glioma: Combination of data from the GEO and CGGA databases and validation in tissue microarray.

Glycoprotein non-metastatic melanoma protein B (GPNMB), a transmembrane glycoprotein, has been reported to be involved in tumor progression, but its prognostic value for glioma and the mechanistic effects on glioma progression have not been clearly explored. The present study aimed to investigate the prognostic role of GPNMB in glioma and the potential mechanisms of how GPNMB mediates glioma progression. Differentially expressed genes between the four highest and four lowest GPNMB expression samples in the GSE53733 dataset were first determined. Gene ontology, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis and Gene set enrichment analysis results demonstrated that the significantly enriched pathways in samples with high GPNMB expression compared with those with low GPNMB expression were associated with hypoxia, angiogenesis, migration and invasion. Pearson correlation analysis was conducted to investigate the correlations between GPNMB expression and the markers of hypoxia, angiogenesis, migration and invasion in GSE53733, which were further validated using another mRNA microarray dataset from the Chinese Glioma Genome Atlas (CGGA). In addition, using the CGGA dataset, high GPNMB expression was demonstrated to be significantly associated with advanced WHO grade and short survival time in patients with glioma. Of note, based on the immunohistochemical staining of the tissue microarrays, Kaplan-Meier analysis with the Renyi test and a Cox proportional hazards model were used to validate the unfavorable prognostic role of high GPNMB expression in glioma. In conclusion, high GPNMB expression may be associated with high tumor grade and unfavorable prognosis in glioma. GPNMB expression was demonstrated to correlate with the markers of hypoxia, angiogenesis, migration and invasion, which may be potential mechanisms through which GPNMB mediates glioma progression.

LGALS3 Is a Poor Prognostic Factor in Diffusely Infiltrating Gliomas and Is Closely Correlated With CD163+ Tumor-Associated Macrophages.

Background: Glioma, the most common brain tumor, is a heterogeneous group of glia-derived tumors, the majority of which have characteristics of diffuse infiltration and immunosuppression. The LGALS protein family is a large class of sugar-binding proteins. Among them, LGALS3 has been reported to promote tumor development and progression in some cancers. However, the clinical significance and biological functions of LGALS3 in glioma remain virtually unknown. The purpose of our research is to detect LGALS3 expression and its prognostic value in glioma and reveal the relationship between its expression and the clinico/molecular-pathological features of patients and immune cell infiltration.Methods: LGALS3 protein expression was examined by immunohistochemistry. The mRNA expression data of LGALS3 was downloaded and analyzed from TCGA and Rembrandt datasets. The association between LGALS3 and glioma clinically relevant diagnostic/molecular markers (IDH, 1p19q, ATRX, MGMT, and TERT) was examined using the Chi-Squared (χ2) test. The correlation between LGALS3 expression and the infiltration of multiple intra-tumoral immune cell types, including B cells (CD20), T cells (CD4 and CD8), macrophages (CD68), and M2 tumor-associated macrophages (CD163), was evaluated by Spearman correlation analysis. Kaplan-Meier analysis and the Cox regression analysis were applied to evaluate the prognostic value of LGALS3 in glioma. The log-rank test was used to evaluate Kaplan-Meier results for significance.Results: Out of all 304 glioma cases, LGALS3 protein was expressed in 125 glioma cases (41.1%, 125/304), with 69.2% (9/13) in WHO I, 9.8% (8/82) in WHO II, 34.2% (26/76) in WHO III, and 61.7% (82/133) in WHO IV. The expression of LGALS3 was correlated with patient age, WHO grade, PHH3 (mitosis), Ki67 index, IDH, 1p/19q codeletion, and TERT promoter status. LGALS3 was an independent poor prognostic marker in diffusely infiltrating gliomas and was positively correlated with immune cell infiltration, particularly CD163+ tumor-associated macrophages in the TCGA dataset, Rembrandt dataset, and our SYSUCC cohort (R = 0.419, 0.627, and 0.724).Conclusion: LGALS3 was highly expressed in pilocytic astrocytoma, GBM, and IDH wild-type LGG. It served as a poor prognostic marker in diffusely infiltrating gliomas. Based on its prognostic significance and strong correlation with CD163+ TAMs, it may act as an important therapeutic target for human glioma.

Correlation of Expression Transforming Growth Factor-β1, E-cadherin, and Ki-67 in Meningiomas

BACKGROUND: Meningioma is the most common primary intracranial tumors in adults, accounts for 36% of total intracranial tumors. Obtaining the clinicopathological characteristics of patients with meningioma and investigating, the association between signaling pathways with disease progression could provide a basis for therapeutic development.AIM: This study aims to investigate the expression of transforming growth factor-β1 (TGF-β1), E-cadherin, and Ki-67 in meningiomas.MATERIALS AND METHODS: This study examined the expression levels of E-cadherin, Ki-67, and TGF-β1 with respect to the WHO grade in patients with meningioma. A total of 62 meningioma samples were analyzed. By the WHO criteria, 54 specimens were diagnosed as the WHO Grade 1, 6 as Grade 2, and 2 as Grade 3. Grade 1 was classified as low-grade meningioma, while Grade 2 and Grade 3 were classified as high-grade meningioma (HGM).RESULTS: In this study, the mean age diagnosis was 41.97 ± 9.79 years old, with female: male ratio of 8:1. There was no association between age, sex, and tumor location with the progression of meningioma. Immune-characterization revealed that HGM was associated with the higher number of Ki-67+ cells (p &lt; 0.0001) and lower expression of TGF-β1 and E-cadherin (p &lt; 0.001). The number of Ki-67+ cells was inversely correlated with TGF-β1 and E-cadherin (p &lt; 0.05). TGF-β1 expression was positively correlated with E-cadherin expression (p &lt; 0.0001).CONCLUSION: This study concluded that HGM was highly proliferative (high Ki-67+) and invasive (low E-cadherin), with dysregulated TGF-β1 signaling. In addition, younger age at diagnosis and high female: male ratio in our series suggests that Indonesian females might possess specific risk factors for having meningioma.

Is H3K27me3 status really a strong prognostic indicator for pediatric posterior fossa ependymomas? A single surgeon, single center experience.

Posterior fossa ependymomas (PFE) are among the most frequently occurring solid tumors in children. Their definitive treatment is surgical excision and adjuvant radio-chemotherapy. This study aimed to investigate prognostic effects of age, H3K27me3 status, extent of resection, radiation treatment (RT), Ki67 index, WHO grade, and ATRX and H3K27M mutations in PFE patients. This retrospective study included 42 pediatric patients with PFE who had undergone operation at our institution between 1996 and 2018. Patient demographics and treatment information were obtained from patient notes. Information on radiological location of tumors (median vs paramedian), extent of tumor resection, and recurrence was obtained from preoperative and postoperative magnetic resonance imaging. Formalin-fixed paraffin-embedded tumor samples were evaluated for H3K27me3 immunostaining, Ki67 index, WHO grades, and ATRX and H3K27M mutations. Tumor samples with global reduction in H3K27me3 were grouped as posterior fossa ependymoma group A (PFA) and those with H3K27me3 nuclear immunopositivity as posterior fossa ependymoma group B (PFB). We evaluated the cohort's 5-year progression-free survival (PFS) and overall survival (OS). There were 20 (47.6%) female and 22 (52.4%) male patients in the cohort. The mean age of patients was 4.4 (range, 0.71-14.51) years. Overall, tumors in 31 (73.8%) and 11 (26.2%) patients were found to be PFA and PFB, respectively. There was no statistically significant age or sex difference between PFA and PFB. All patients received chemotherapy, whereas only 28 (66.6%) received RT. The WHO grades of PFA were statistically higher than those of PFB. There was no significant difference between PFA and PFB in terms of extent of resection, disease recurrence, and survival parameters. Nine of 42 tumor samples had ATRX mutations. One patient with PFA showed H3K27M mutation. Age, WHO grade, H3K27me3 status, and RT had no effect on patients' PFS and OS. Patients with total surgical excisions had significantly better PFS and OS rates. Those with Ki67 < 50% also had better OS rates. Determining H3K27me3 status by immunohistochemistry is a widely accepted method for molecular subgrouping of PFEs. Most of the reports in the literature state that molecular subgroups of PFEs have significantly different clinical outcomes. However, in our present series, we have shown that the extent of surgical excision is still the most important prognostic indicator in PFEs. We also conclude that the prognostic effect of H3K27me3 status-based molecular subgrouping may be minimized with a more aggressive surgical strategy followed in PFAs.

Circular RNA circ_0074026 indicates unfavorable prognosis for patients with glioma and facilitates oncogenesis of tumor cells by targeting miR-1304 to modulate ERBB4 expression.

Glioma (GM) is a common malignancy all over the world. A novel circular RNA (circRNA), circ_0074026, has been documented to be upregulated in GM tissues than that of normal counterparts, as confirmedby circRNA microarray. However, the biological mechanism of circ_0074026 is still unreported in GM. The expression of circ_0074026 in GM specimens or cells was detected by quantitative real-time polymerase chain reaction. Fisher's exact test was utilized to evaluate the clinical relevance of circ_0074026 in patients with GM. Kaplan-Meier and Cox regression analysis were used to estimate the prognostic value of circ_0074026. Cell counting kit-8 (CCK-8), acridine orange/ethidium bromide double fluorescence staining, flow cytometry, wound healing, and Transwell assays were used to detect the malignant behaviors of GM cells including cell growth, apoptosis, migration, and invasion. CCK-8 and flow cytometric experiments were utilized to evaluate whether circ_0074026 had a side effect on normal human astrocyte cells. The interaction between miR-1304 and circ_0074026 or ERBB4 3'-untranslated region (3'-UTR) was predicted withcircular RNA Interactome and TargetScan, respectively, and then confirmed by the dual-luciferase reporter test. The levels of circ_0074026 were both apparently increased in GM samples and cells. The elevated expression of circ_0074026 was linked to patients' tumor size, WHO grade, disease-free survival, and overall survival. The depletion of circ_0074026 can block cell growth, migration, invasion, and impel cell apoptosis in the LN229 cell line. However, ectopically expressed circ_0074026 caused the opposite effect in the U251 cell line. The following dual-luciferase reporter assay demonstrated that miR-1304 interacted with circ_0074026 and ERBB4 3'-UTR. Furthermore, the rescue assay indicated that circ_0074026 modulated ERBB4 to promote tumor progression by regulating miR-1304. Thus, anovel regulatory pathway may provide a new therapeutic target for patients with GM.

MA20.06 Neutrophil to Lymphocyte Ratio Is an Independent Prognostic Predictor in Thymoma

Thymoma is the most common primary neoplasm of the anterior mediastinum in adults and conventional prognostic factors include Masaoka Stage, WHO histology and completeness of resection. Little is known of preoperative peripheral neutrophil-to-lymphocyte ratio (NLR) as an independent additional discriminator of prognosis. We performed an international multicentre retrospective cohort study (UK Health Research Reference 19/HRA/0440 and EU internal approval reference xxxxxx). We included patients who underwent complete resection for thymoma and data was acquired through patient medical records with follow up data obtained through national database and hospital records. NLR calculated on pre-operation bloods results. From July 1987 to December 2017, 433 patients underwent surgery for thymoma. The majority were male 228(53%) with a mean age (SD) of 55(15) years. The surgical approach was sternotomy in 335 patients (77%), thoracotomy in 23(5%) and VATS in 75(17%). The WHO classification was type A 63(15%), AB 126(29%), B1 98(23%), B2 55(13%) and B3 86(20%) patients. The Masaoka-Koga stage was I in 135(33%) II in 194(47%), III in 54 (13%) and IV in 31(7%) patients. Median (IQR) follow-up time was 86 (30 to 152) months with a 5 and 10-year survival of 88% and 79% respectively. The median NLR was 2.1 (1.5 to 3.1), when split into three groups (NLR < 1.4, NLR between 1.4 and 2.3 and NLR > 2.3), higher NLR was associated with poorer survival (log rank P<0.001) that persisted on Cox regression after adjustment for WHO grade and Masaoka stage with a HR of 1.69 (95% CI 1.20 to 2.39; P=0.002). Pre-operative NLR is a simple, low cost biomarker that can stratify risk of death independent to WHO grade and Masaoka stage in patients undergoing surgery for thymoma.

New insights into the genomic landscape of meningiomas identified FGFR3 in a subset of patients with favorable prognoses.

Background: With a prevalence of 170 000 adults in the US alone, meningiomas are the most common primary intracranial tumors. The management of skull base meningiomas is challenging due to their complexity and proximity to crucial nearby structures. The identification of oncogenic mutations has provided further insights into the tumorigenesis of meningioma and the possibility of targeted therapy. This study aimed to further investigate the association of mutational profiles with anatomical distribution, histological subtype, WHO grade, and recurrence in patients with meningioma. Methods: Tissue samples were collected from 71 patients diagnosed with meningioma from 2008 to 2016. A total of 51 cases were skull based. Samples were subjected to targeted sequencing using a next generation customized cancer gene panel (n = 66 genes analyzed). Results: We detected genomic alterations (GAs) in 68 tumors, averaging 1.56 ± 1.07 genomic alterations (GAs) per sample. NF2 was the most frequently altered gene (36/71 cases). Interestingly, we identified a number of mutations in non-NF2 genes, including a hotspot TERTp c.−124: G > A mutation that may be related to poor prognosis and FGFR3 mutations that may represent biomarkers of a favorable prognosis as reported in other cancers. Conclusions: We demonstrate that comprehensive genomic profiling in our population can reveal a potential new prognostic biomarkers of skull base meningioma. These mutations can enhance diagnostic accuracy and clinical decision-making. Among our findings were the identification of a TERTp mutation and the first report of FGFR3 mutations that may represent biomarkers for the identification of skull base meningioma patients with a favorable prognosis.

Rap2B promotes cell adhesion, proliferation, migration and invasion of human glioma.

Rap2B, a member of the GTP-binding proteins, is generally up-regulated in numerous types of tumors. Nevertheless, the influence and regulatory mechanisms of Rap2B in gliomas are still not corroborated. Therefore, we analyzed the expression of Rap2B in glioma tissues and cells, and researched its significance in adhesion, proliferation, migration and invasion of the glioma cell line. We analyzed the expression of Rap2B in different pathologic grades of glioma tissues by tissue microarray and immunohistochemistry. We assessed the expression of Rap2B in glioma tissue and non-tumor tissue by Western blot. And the expression of Rap2b protein in glioma cells and normal human astrocytes (NHA) was detected by Western blot. In addition, we disclosed the effect of Rap2B knockdown on cell adhesion, proliferation, migration and invasion by using cell attachment assay, CCK-8 assay, cell migration assay and Wound Healing assay, cell invasion assay, respectively. Western blot was used to detect the changes of expression level of NF-kB, MMP-2 and MMP-9 protein when downregulated the expression of Rap2B. The tissue microarray immunohistochemical results of glioma showed that the expression of Rap2B had no significant correlations between Rap2B expression and the clinicopathologic variables, including patient age (P=0.352), gender (P=0.858), WHO Grade (P=0.693) and histology type (P=0.877). Western blot analysis showed that the glioma tissue had a dramatically increase of Rap2B expression compared with the non-tumor tissues (P<0.01). And the expression of Rap2B was markedly up-regulated in all 5 glioma cell lines compared with that in normal human astrocytes (NHA) (P<0.01). We found that the ability of adhesion, proliferation, migration and invasion of glioma cells were significantly decreased after downregulated Rap2B expression compared with the control group (P<0.05). In addition, Western blot results showed that the expression levels of NF-kB, MMP-2 and MMP-9 in the interference group were significantly lower than those in the negative control group (P<0.05). Rap2B expression is up-regulated in glioma tissues and glioma cell lines. Knockdown of Rap2B inhibits glioma cells' adhesion and proliferation in vitro. Knockdown of Rap2B inhibits glioma cells' migration in vitro. Knockdown of Rap2B inhibits glioma cells' invasion and MMPs activity through NF-kB pathway.

Long non-coding RNA LINC01503 predicts worse prognosis in glioma and promotes tumorigenesis and progression through activation of Wnt/β-catenin signaling.

Long-noncoding RNAs (lncRNAs) have been recently shown to be involved in the regulation of numerous biological processes including tumor progression. In this study, we aimed to explore the role of lncRNA LINC01503 (LINC01503) in the development and progression of glioma. Relative levels of LINC01503 were evaluated in tumor tissues from 133 patients with glioma as well as from cultured glioma cell lines. The correlation among LINC01503 levels, pathological types, and survivals of glioma patients were also determined using the Kaplan-Meier method and multivariate analysis. Next, we investigated the effect of LINC01503 on the proliferation, colony formation, apoptosis, migration and invasion in the U251 and LN299 cells. Relative protein expression was analyzed by Western blot assays. We found that LINC01503 expression level was significantly up-regulated in glioma tissue and cells, and that its overexpression was significantly correlated with KPS, tumor size and WHO grade in glioma patients. Kaplan-Meier analysis showed that patients with higher levels of LINC01503 had significantly poorer overall survival and disease-free survival than those with lower expression of this lncRNA in glioma patients. Multivariate analysis further confirmed that LINC01503 is an independent prognostic factor in patients with glioma. Functional assays with in vitro showed that knockdown of LINC01503 in the U251 and LN299 cell lines suppressed cells growth, colony formation, invasion and migration, and promoted apoptosis. Mechanistic investigation showed that LINC01503 can modulate Wnt/β-catenin signaling, as determined by that knockdown of LINC01503 decreased the TOP-FLASH activity and β-catenin, cyclin D1 and c-myc. Our findings suggested that LINC01503 conferred oncogenic function in glioma and may be a new prognostic biomarker and novel therapeutic strategy for this malignancy.

Long non-coding RNA MEG3 regulates proliferation, apoptosis, and autophagy and is associated with prognosis in glioma.

Accumulating evidence indicates that dysregulated long noncoding RNAs (lncRNAs) play critical roles in tumorigenesis and cancer progression. LncRNA-maternally expressed gene 3 (MEG3) has been shown to be involved in the initiation and development of several cancers, including glioma. However, the clinical prognostic value of MEG3 in glioma has not yet been fully elucidated. The expression levels of MEG3 were detected in 79 glioma tissues and adjacent normal brain tissues, as well as, glioma cells and normal human astrocytes by qRT-PCR. Kaplan-Meier and Cox regression methods were utilized for the survival analysis. MTT assay, flow cytometry, and immunofluorescence assay were carried out to detect the impact of MEG3 on glioma cell proliferation, apoptosis, and autophagy. The current results showed that MEG3 expression was significantly downregulated in glioma tissues and cell line and negatively correlated with WHO grade in glioma patients. Low MEG3 expression was significantly associated with the advanced WHO grade, low Karnofsky performance score (KPS), IDH wild-type, and tumor recurrence. Patients displaying a low expression of MEG3 contributed to poor overall survival. The downregulated level of MEG3, advanced WHO grade, low KPS, IDH wild-type, and tumor recurrence were independent poor prognostic indicators in glioma patients. The in vitro experiments demonstrated that the MEG3 overexpression remarkably suppressed the proliferation while facilitating apoptosis and autophagy in glioma cells. These findings indicated a critical role of MEG3 in glioma cell proliferation, apoptosis, and autophagy. Also, the gene was found to be significantly associated with the prognosis in glioma patients. Thus, it might provide a new target for predicting prognosis and therapeutic intervention in glioma.