Meningioma: not always a benign tumor. A review of advances in the treatment of meningiomas

Diarylpentanoid, a curcumin analog, inhibits malignant meningioma growth in both in vitro and in vivo models

BACKGROUND

Malignant meningioma metastasizes systemically, primarily due to its role in epithelial-mesenchymal transition. Although the prognosis is extremely poor, drug development efforts have been limited, because this tumor is categorized as a rare form.

AIM

To examine growth suppressive effect of GO-Y030, a diarylpentanoid curcumin analog, (1E,4E)-1,5-bis [3,5-bis (methoxymethoxy) phenyl] penta-1,4-dien-3-one against the malignant meningioma.

METHODS

The growth suppression of malignant meningioma cells by GO-Y022 and GO-Y030 were examined, using IOMM-Lee and HKBMM cell lines. Male nude mice aged eight weeks, specifically BALB/cSlc-nu/nu mice received a subcutaneous inoculation of IOMM-Lee (10⁷ cells/site) on their back and 30 μg/kg of recombinant hepatocellular growth factor (HGF) was injected into the tumor every three days. After confirmed the growth tumor mass, 500 μL of GO-Y030 diluted with PBS were administrated intraperitoneally daily at doses of 1 mg/kg and 2 mg/kg, respectively.

RESULTS

GO-Y030 exhibits a growth inhibitory effect on malignant meningioma cell lines, IOMM-Lee and HKBMM ranging from 0.8-2.0 μM in vitro. Notably, GO-Y030’s inhibitory effect is about 10 to 16^th times more potent than that of curcumin, which has previously demonstrated potential in combating malignant meningioma. In mouse models, the intraperitoneal administration of GO-Y030 effectively suppresses the growth of malignant meningioma tumors that have been inoculated in the back (P = 0.002). High-performance liquid chromatography analysis has confirmed the distribution of GO-Y030 in the bloodstream and brain tissue. Moreover, GO-Y030 demonstrates the ability to significantly suppress HGF (P < 0.01), nuclear factor kappa B (P < 0.001), and N-cadherin (P < 0.001), all of which contribute to the epithelial-mesenchymal transition.

CONCLUSION

GO-Y030 holds promise as a potent compound for the systemic inhibition of malignant meningioma. GO-Y030 has higher tumor growth inhibitory effect against meningiomas than curcumin, which is known to have antitumor activity through multi-molecular target control resulting in apoptosis induction. GO-Y030 controls at least three molecules of HGF, nuclear factor kappa B, and N-cadherin.

Prognostic value of MIB-1 index in meningioma: a retrospective cohort study to establish an optimal cutoff for recurrence and survival

PURPOSE

Predicting long-term outcomes after meningioma resection remains challenging. Ki-67/MIB-1 correlates with recurrence, yet its optimal cutoff is undefined. This study aims to establish a threshold that enhances risk stratification, improves recurrence prediction, and informs postoperative surveillance and adjuvant treatment strategies.

METHODS

This is retrospective study of patients who underwent meningioma resection. Receiver operating characteristic (ROC) analysis determined the optimal MIB-1 cutoff for predicting recurrence and survival, providing area under the curve (AUC). This cutoff was then applied in Kaplan-Meier survival analyses and multivariable Cox regressions, controlling for age, sex, tumor diameter, tumor location, extent of resection, and adjuvant radiotherapy.

RESULTS

A total of 404 patients were included. Median age was 55.0 years (range: 16-85) and 72.3% were female. The cohort primarily consisted of WHO Grade 1 (69.6%) and Grade 2 (30.0%) meningiomas. An optimal MIB-1 index cutoff of 4.1% was identified using ROC analysis with the Youden index for predicting recurrence (AUC = 0.661, p < 0.001) and survival (AUC = 0.717, p < 0.001). 241 patients (59.7%) had a MIB-1 < 4.1%, and 163 (40.3%) had a MIB-1 ≥ 4.1%. Patients with MIB-1 ≥ 4.1% had a higher risk of recurrence (HR = 2.9, p = 0.009) and mortality (HR = 2.8, p = 0.036). Patients with MIB-1 ≥ 4.1% demonstrated shorter recurrence-free survival (RFS) (119.0 vs. 129.0 months, p < 0.001) and overall survival (OS) (163.0 vs. 229.0 months, p < 0.001).

CONCLUSION

We identified an optimal and actionable MIB-1 index cutoff of 4.1% which independently predicted recurrence, mortality, and shorter RFS and OS for patients undergoing meningioma resection. As the first study to establish and validate this threshold, our findings highlight its potential as an adjunct prognostic tool to refine risk stratification and guide postoperative management.

Real-Time Detection of Meningiomas by Image Segmentation: A Very Deep Transfer Learning Convolutional Neural Network Approach

BACKGROUND/OBJECTIVES

Developing a treatment strategy that effectively prolongs the lives of people with brain tumors requires an accurate diagnosis of the condition. Therefore, improving the preoperative classification of meningiomas is a priority. Machine learning (ML) has made great strides thanks to the development of convolutional neural networks (CNNs) and computer-aided tumor detection systems. The deep convolutional layers automatically extract important and dependable information from the input space, in contrast to more traditional neural network layers. One recent and promising advancement in this field is ML. Still, there is a dearth of studies being carried out in this area.

METHODS

Therefore, starting with the analysis of magnetic resonance images, we have suggested in this research work a tried-and-tested and methodical strategy for real-time meningioma diagnosis by image segmentation using a very deep transfer learning CNN model or DNN model (VGG-16) with CUDA. Since the VGGNet CNN model has a greater level of accuracy than other deep CNN models like AlexNet, GoogleNet, etc., we have chosen to employ it. The VGG network that we have constructed with very small convolutional filters consists of 13 convolutional layers and 3 fully connected layers. Our VGGNet model takes in an sMRI FLAIR image input. The VGG's convolutional layers leverage a minimal receptive field, i.e., 3 × 3, the smallest possible size that still captures up/down and left/right. Moreover, there are also 1 × 1 convolution filters acting as a linear transformation of the input. This is followed by a ReLU unit. The convolution stride is fixed at 1 pixel to keep the spatial resolution preserved after convolution. All the hidden layers in our VGG network also use ReLU. A dataset consisting of 264 3D FLAIR sMRI image segments from three different classes (meningioma, tuberculoma, and normal) was employed. The number of epochs in the Sequential Model was set to 10. The Keras layers that we used were Dense, Dropout, Flatten, Batch Normalization, and ReLU.

RESULTS

According to the simulation findings, our suggested model successfully classified all of the data in the dataset used, with a 99.0% overall accuracy. The performance metrics of the implemented model and confusion matrix for tumor classification indicate the model's high accuracy in brain tumor classification.

CONCLUSIONS

The good outcomes demonstrate the possibility of our suggested method as a useful diagnostic tool, promoting better understanding, a prognostic tool for clinical outcomes, and an efficient brain tumor treatment planning tool. It was demonstrated that several performance metrics we computed using the confusion matrix of the previously used model were very good. Consequently, we think that the approach we have suggested is an important way to identify brain tumors.

A Case Report Depicting a Rare Neurosurgical Disease: Aggressive Meningiomatosis

Background: Although meningiomas are typically solitary lesions, occasionally, two or more separate tumors can occur simultaneously or sequentially, in which case the terms "multiple meningiomas" (MM) or "meningiomatosis" are used. Aggressive meningiomatosis is a rare entity that can significantly influence survival rates and quality of life. Methods: The current article aims to report an interesting case of a 54-year-old Caucasian woman with aggressive meningiomatosis and no relevant familial history. The patient had a history of a left convexity frontal meningioma, resected in October 2023 and identified as a meningothelial meningioma, followed by a left convexity frontopolar meningioma, resected in May 2024 and identified as an anaplastic meningioma. Furthermore, while the first lesion rapidly recurred, an important change in the histopathological grade was observed, and a diagnosis of aggressive meningiomatosis was established. Results: The particularity of this case is given not only by the aggressive growth pattern but also by the different histopathological gradings of the meningiomas and the anaplastic transformation of the recurrence. Conclusions: Aggressive meningiomatosis is a challenging medical condition for which rigorous follow-up is mandatory throughout the lifespan. New tumors with different gradings and localizations can arise, and each must be treated as a new entity. The lack of therapeutic protocols in MM makes such case reports valuable, as they highlight the necessity of specific therapeutic recommendations.

Cancer stem cells in meningiomas: novel insights and therapeutic implications

Meningiomas (MGs), which arise from meningothelial cells of the dura mater, represent a significant proportion of primary tumours of the central nervous system (CNS). Despite advances in treatment, the management of malignant meningioma (MMG) remains challenging due to diagnostic, surgical, and resection limitations. Cancer stem cells (CSCs), a subpopulation within tumours capable of self-renewal and differentiation, are highlighted as key markers of tumour growth, metastasis, and treatment resistance. Identifying additional CSC-related markers enhances the precision of malignancy evaluations, enabling advancements in personalised medicine. The review discusses key CSC biomarkers that are associated with high levels of expression, aggressive tumour behaviour, and poor outcomes. Recent molecular research has identified CSC-related biomarkers, including Oct-4, Sox2, NANOG, and CD133, which help maintain cellular renewal, proliferation, and drug resistance in MGs. This study highlights new therapeutic strategies that could improve patient prognosis with more durable tumour regression. The use of combination therapies, such as hydroxyurea alongside diltiazem, suggests more efficient and effective MG management compared to monotherapy. Signalling pathways such as NOTCH and hedgehog also offer additional avenues for therapeutic development. CRISPR/Cas9 technology has also been employed to create meningioma models, uncovering pathways related to cell growth and proliferation. Since the efficacy of traditional therapies is limited in most cases due to resistance mechanisms in CSCs, further studies on the biology of CSCs are warranted to develop therapeutic interventions that are likely to be effective in MG. Consequently, improved diagnostic approaches may lead to personalised treatment plans tailored to the specific needs of each patient.

MRI-derived radiomics models for prediction of Ki-67 index status in meningioma: a systematic review and meta-analysis

PURPOSE

The Ki-67 marker reflects tumor proliferation and correlates with meningioma prognosis. Here we aim to evaluate the performance of MRI-derived radiomics for Ki-67 index prediction in meningiomas.

METHODS

After a comprehensive search in Web of Science, PubMed, Embase, and Scopus, data extraction and risk of bias assessment was performed. Pooled sensitivity, specificity, positive likelihood ratios (PLR), negative likelihood ratios (NLR), and diagnostic odds ratio (DOR) were computed. The summary receiver operating characteristic (sROC) curve was generated and area under the curve (AUC) was calculated. Separate meta-analyses were conducted for radiomics models and combined models. Heterogeneity was evaluated using the I2 statistic, and subgroup analysis was performed to identify potential sources of heterogeneity. Sensitivity analysis was carried out to detect possible outliers.

RESULTS

Seven studies were included, with six studies analyzed for radiomics model and four for combined model. For radiomics model, the pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 67 %, 82 %, 8.61, 3.54, 0.43, and 0.79, respectively. For combined model, pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 78 %, 78 %, 12.19, 3.47, 0.30, and 0.79, respectively. Sensitivity analysis identified no outliers. In radiomics model, potential sources of heterogeneity included mean age and the application of N4ITK bias correction. For combined model, heterogeneity was influenced by mean age, application of N4ITK bias correction, and the use of external validation.

CONCLUSION

Radiomics shows promising ability to predict the Ki-67 index status in meningioma patients, potentially enhancing clinical decision-making and management strategies.

Serum Metabolomics Profiling Coupled with Machine Learning Identifies Potential Diagnostic and Prognostic Candidate Markers in Meningioma Using Raman Spectroscopy, ATR-FTIR, and LC-MS/MS

Meningioma, the most prevalent brain tumor, poses significant challenges due to its unclear transition from low-grade to aggressive forms, with limited knowledge about grade-specific markers. We have utilized vibrational spectroscopic techniques such as ATR-FTIR and Raman spectroscopy, alongside LC-MS/MS-based mass spectrometry to understand the systemic cues and evaluate them for clinical practice. The acquired Raman and ATR-FTIR spectra of 46 meningioma patients (27 low-grade and 19 high-grade) and 8 healthy individuals revealed 98.15% and 83.33% accuracy based on PC-LDA. The grade classification revealed an accuracy of around 70%, implying the presence of subtypes and transition phases. The observed alterations corresponded to lipids, nucleic acids, and proteins. Further, the LC-MS/MS-based study identified different derivatives of cholines, indoles, lipids, sphingosine, tryptophan, and their respective metabolic pathways as contributors in tumorigenesis and progression. Further, PRM-based targeted validation and feature selection was carried out on 43 meningioma patients and 17 healthy controls. Glycochenodeoxycholic acid, indole-3-acetic acid, trans-3-indoleacrylic acid, glycodeoxycholic acid, 5α-dihydrotestosteroneglucornide, and glycocholic acid segregated meningioma samples with an accuracy of around 90% while features like indole-3-acetic acid, stercobilin, sphingosine-1-phosphate, deoxycholic acid, and citric acid could classify grades with around 70% accuracy. These findings suggest that further validation across larger cohorts could enhance its usage in clinical settings.

Peptide receptor radionuclide therapy with somatostatin analogs beyond gastroenteropancreatic neuroendocrine tumors

First isolated by Brazeau et al. in 1972, somatostatin (SST) is a neuropeptide known for regulating various signaling pathways through its specific cell surface receptors. Somatostatin receptors (SSTRs) comprise a family of five G protein-coupled receptors that are widely distributed across the human body and are expressed by various tumor types. The growing understanding of their clinical potential led to the introduction of both cold and radiolabeled somatostatin analogs (SSAs), which have revolutionized the management of several cancers, especially neuroendocrine tumors. As a direct consequence, advances in peptide receptor radionuclide therapy (PRRT) over the last 30 years led to the approval of 177Lu-DOTATATE for the treatment of gastroenteropancreatic neuroendocrine tumors (GEPNETs). Theoretically, any cancer patients whose tumors express SSTR, as demonstrated in vivo through SSTR-based molecular imaging, could be candidates for PRRT, especially those with limited treatment options. However, evidence on the efficacy of PRRT in non-GEPNET SSTR-expressing tumors is limited, and mainly derived from small retrospective studies. Given the limited therapeutic options for advanced/metastatic patients, there is a clear need for randomized trials to formally approve PRRT with SSAs for patients who may benefit from this treatment, particularly in certain types of neuroendocrine neoplasms such as lung carcinoids, paragangliomas, and meningiomas, where high rates of disease control (up to 80%) can be achieved. In addition, emerging evidence supports the potential of combination therapies, alpha emitters, and non-SSTR-based radionuclide therapy in tumors beyond GEPNET. This review aims to provide a comprehensive overview of PRRT's role in cancers beyond GEPNET, exploring new possibilities and future directions for most SSTR highly expressing tumors.

Malignant Meningiomas: From Diagnostics to Treatment

Meningiomas account for approximately 40% of all primary brain tumors, of which 1.5% are classified as grade 3. Whilst meningiomas are discovered on imaging with high-grade meningiomas being associated with certain imaging features, the final diagnosis is based on histopathology in combination with molecular markers. According to the latest World Health Organization (WHO) Classification of Tumors of the Central Nervous System (CNS), grade 3 should be assigned based on criteria for anaplastic meningiomas, which comprise malignant cytomorphology (anaplasia) that resembles carcinoma, high-grade sarcoma or melanoma; elevated mitotic activity; a TERT promoter mutation and/or a homozygous CDKN2A and/or CDKN2B deletion. Surgery remains the mainstay treatment modality for grade 3 meningiomas, followed by radiotherapy. Limited data are available on the effect of stereotactic radiosurgery and systemic therapy for grade 3 meningiomas; however, studies are underway. Despite optimal treatment, the estimated recurrence rate ranges between 50% and 95% with a 5-year survival rate of 66% and a 10-year estimated survival rate of 14% to 24%.

Meningioma: Molecular Updates from the 2021 World Health Organization Classification of CNS Tumors and Imaging Correlates

Meningiomas, the most common primary intracranial neoplasms, account for more than one-third of primary CNS tumors. While traditionally viewed as benign, meningiomas can be associated with considerable morbidity, and specific meningioma subgroups display more aggressive behavior with higher recurrence rates. The risk stratification for recurrence has been primarily associated with the World Health Organization (WHO) histopathologic grade and extent of resection. However, a growing body of literature has highlighted the value of molecular characteristics in assessing recurrence risk. While maintaining the previous classification system, the 5th edition of the 2021 WHO Classification of Central Nervous System tumors (CNS5) book expands upon the molecular information in meningiomas to help guide management. The WHO CNS5 stratifies meningioma into 3 grades (1-3) based on histopathology criteria and molecular profile. The telomerase reverse transcriptase promoter mutations and cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) deletions now signify a grade 3 meningioma with increased recurrence risk. Tumor location also correlates with underlying mutations. Cerebral convexity and most spinal meningiomas carry a 22q deletion and/or NF2 mutations, while skull base meningiomas have AKT1, TRAF7, SMO, and/or PIK3CA mutations. MRI is the primary imaging technique for diagnosing and treatment-planning of meningiomas, while DOTATATE PET imaging offers supplementary information beyond anatomic imaging. Herein, we review the evolving molecular landscape of meningiomas, emphasizing imaging/genetic biomarkers and treatment strategies relevant to neuroradiologists.

Primary Extracranial Meningiomas of the Sinonasal Tract: A Systematic Review

Background  Primary extracranial meningiomas (PEMs) of the sinonasal tract with no intracranial extension are rare. Our study presents the largest systematic review to date, providing a comprehensive overview and comparison of the characteristics, treatment, and prognosis of PEMs, with comparison to primary intracranial meningiomas (PIMs). Methods  A systematic review was conducted according to the PRISMA guidelines on PubMed, Embase, and Google Scholar up to November 1, 2022. A total of 70 documented cases from 64 articles were included. Data analysis was performed to compare low-grade (World Health Organization [WHO] Grade I) and high-grade (Grade II, III) PEMs. Results  Majority of patients were symptomatic with nasal symptoms (72.1%), followed by eye symptoms (41.2%) and facial swellings (41.2%). The nasal cavity was the most commonly affected site (70.0%). Most tumors were WHO Grade 1 (87.5%) with meningothelial histological subtype. PEMs have a predilection for involvement of surrounding structures, with more than half reporting erosion of sinonasal walls or orbital involvement (64.3%). Despite so, PEMs have a favorable prognosis, with high survival rates (95.3%) and low rate of recurrence (8.5%). Mainstay of treatment is surgical resection (98.6%). A total of 69/70 cases (98.6%) underwent surgical resection. Conclusions  There are no clear defining clinical features of PEMs; hence, it is imperative for clinicians to prioritize histological diagnosis to guide further management. A conclusive diagnosis of PEMs, i.e., exclusion of PIMs, requires imaging and potential intraoperative assessment. Its prognosis is likely dependent on both WHO grading and the ability to achieve complete surgical extirpation. Endoscopic resection is recommended even in high-grade PEMs for localized and resectable disease. Radiotherapy may be reserved for unresectable or recurrent tumors as salvage therapy.

Fractionated Radiotherapy With Stereotactic Radiosurgery Boost Controls Gross Disease in Grade 2 Meningioma

OBJECTIVE

Opportunity exists for improved local control rates of grade 2 meningiomas that recur despite maximal surgical resection and adjuvant fractionated radiotherapy (RT). We describe a dose escalation strategy of increasing the total tumor radiation dose by adding a stereotactic radiosurgery (SRS) boost targeting gross disease to fractionated RT.

METHODS

A single-institution retrospective cohort of patients from 2009-2023 with grade 2 meningioma treated with surgical resection, fractionated RT, and SRS boost were evaluated for baseline characteristics, local disease control, and adverse events (AE).

RESULTS

Fourteen meningioma patients were included. Ten patients (71.4%) underwent radiosurgery at initial diagnosis, while 4 patients (28.6%) were treated for recurrent disease. The median fractionated dose was 54 Gy, while the median dose for SRS was 7.5 Gy. Among the 13 patients with follow-up available, median follow-up was 34 months. Three patients (23%) had treatment failures; however, none occurred within the SRS volume and 2 thirds occurred in patients treated for recurrent disease. Eighteen-month progression-free survival was 92.3%, while 18-month overall survival was 100%. Most patients experienced no or mild AEs; however, 3 patients (23%) experienced a high-grade (Common Terminology Criteria for Adverse Events v5.0 grade ≥3) AE including radiation necrosis, seizures, and cognitive decline.

CONCLUSIONS

We found 100% in-field local control at 3 years from an SRS boost to fractionated RT targeting gross disease with an acceptable toxicity profile, suggesting this may be an effective and improved adjuvant treatment strategy in patients with grade 2 meningioma.

Knowledge discovery from database: MRI radiomic features to assess recurrence risk in high-grade meningiomas

PURPOSE

We used knowledge discovery from radiomics of T2-weighted imaging (T2WI) and contrast-enhanced T1-weighted imaging (T1C) for assessing relapse risk in patients with high-grade meningiomas (HGMs).

METHODS

279 features were extracted from each ROI including 9 histogram features, 220 Gy-level co-occurrence matrix features, 20 Gy-level run-length matrix features, 5 auto-regressive model features, 20 wavelets transform features and 5 absolute gradient statistics features. The datasets were randomly divided into two groups, the training set (~ 70%) and the test set (~ 30%). Combinations of data preprocessing methods, including normalization (Min-Max, Z-score, Mean), dimensionality reduction (Pearson Correlation Coefficients (PCC)), feature selector (max-Number, cluster) and ten-fold cross-validation were analyzed for their prediction performance. Kaplan-Meier curve, Cox proportional hazards regression model were used and concordance index (C-index), integrated Brier score (IBS) were selected. Model performance was assessed using the C-index.

RESULTS

WHO grade, age, gender, histogram (Mean, Perc.90%, Perc.99%), Gray-level co-occurrence matrix (S(3, -3)DifVarnc, S(5, 5)Correlat, S(1, 0)SumEntrp, S(2, -2)InvDfMom), Teta1, WavEnLL_s-2 and GrVariance were identified as the significant recurrence factors. The pipeline using Mean_PCC_Cluster_10 of T1C yielded the highest efficiency with an IBS of 0.170, 0.188, 0.208 and C-index of 0.709, 0.705, 0.602 in the train, test and validation sets, respectively. The pipeline using MinMax_PCC_Cluster_19 of T2WI yielded the highest efficiency with an IBS of 0.189, 0.175, 0.185 and C-index of 0.783, 0.66, 0.649 in the train, test and validation sets. The pipeline using MinMax_PCC_Cluster_13 of T2WI + T1C yielded the highest efficiency with an IBS of 0.152, 0.164, 0.191 and C-index of 0.701, 0.656, 0.593 in the train, test and validation sets, respectively.

CONCLUSION

Knowledge discovery from MRI radiomic features can slightly help predict recurrence risk in HGMs. T2WI or T1C yielded better efficiency than T2WI + T1C. The parameters with the best power were Mean, Perc.99%, WavEnLL_s-2, Teta1 and GrVariance.

Identification of key elements in MRI reporting of intracranial meningiomas based on a nationwide survey of clinical experts in Germany

While MRI has become the imaging modality of choice for intracranial meningiomas, no radiologic reporting guidance exists to date that relies on a systematic collection of information relevant to the core medical disciplines involved in the management of these patients. To address this issue, a nationwide expert survey was conducted in Germany. A literature-based catalog of potential reporting elements for MRI examinations of meningioma patients was developed interdisciplinarily. Subsequently, all board-certified members of the German Societies of Neuroradiology, Neurosurgery and Radiation Oncology with expertise in managing meningioma patients were invited to vote on the relevance of the suggested items via online survey. A total of 150 experts participated in the study (104 neurosurgeons/radiation oncologists, 46 neuroradiologists). The reporting elements of tumor location, extent, growth pattern, contrast uptake, associated cysts, and impact on adjacent anatomic structures received widespread approval (> 75.0% of all participants). In addition, a vast majority (> 75.0%) supported reference to perifocal edema, signs of mass effect, and hydrocephalus. Postoperative imaging is particularly requested to describe the extent of resection (94.0%) and treatment-related changes (89.3%). Advanced methods (diffusion, perfusion, proton spectroscopy) and meningioma-specific classifications (Nauta, Zee, Sindou) were judged to be less relevant (< 50.0% agreement) to MRI reporting. To serve as a vital clinical communication tool and enable an optimal contribution to the care of meningioma patients, the radiological report should focus on the fundamental information requirements of the neuro-oncology treatment team encompassing primarily tumor location, extent, tissue imaging characteristics, and potential impairment of neighboring anatomical structures.

Efficacy, safety and dose patterns of tranexamic acid in meningioma surgery: a systematic review and updated meta-analysis of randomized controlled trials

We reviewed the efficacy and safety of intravenous administration of tranexamic acid (TXA) in randomized trials involving patients undergoing intracranial meningioma resection surgery, with special emphasis on the effects of different dosages. A comprehensive search was conducted in the following databases: Cochrane, PubMed, Embase, Scopus, Lilacs, and Web of Science. Two reviewers independently screened titles and abstracts, reviewed the full texts and collected data. Efficacy outcomes analyzed included intraoperative blood loss, blood transfusion rate, duration of surgery, and length of hospital stay. The safety outcomes evaluated included postoperative complications such as seizures, thromboembolic events, and hematoma. A subgroup analysis was performed based on the dosage and timing of administration. Six randomized controlled trials (RCTs) were included, covering 881 patients. Meta-analysis of the data demonstrated that the use of TXA resulted in a significant reduction in intraoperative blood loss (Mean Difference [MD] = -270.26 ml, 95% CI [-422.84, -117.67], p < 0.01, I² = 99%), blood transfusion rate (Relative Risk [RR] = 0.60, 95% CI: [0.46, 0.78], p < 0.01, I² = 3%), duration of surgery (MD = -19.76 min, 95% CI: [-41.74, 2.23], p < 0.01, I² = 75%), and length of hospital stay (MD: -0.48 days, 95% CI: [-0.93, -0.04], p < 0.01, I² = 32%). No significant differences were found in the postoperative complications assessed. In the dosage analysis, the preoperative 20 mg/kg regimen, along with the intraoperative maintenance dose of 1 mg/kg/h, was more effective in reducing intraoperative blood loss in the TXA group, although not statistically significant (323.64 ml vs. 145.54 ml, p = 0.29). The administration of TXA in patients undergoing intracranial meningioma resection surgery showed beneficial results in all efficacy outcomes evaluated, without increasing postoperative complications. However, further studies, especially multicenter ones, are needed to confirm our results.

[En plaque convexity hyperostotic meningioma: 69 cases from a singlecenter]

BACKGROUND

To date, 16 cases of en plaque hyperostotic meningioma of the convexity have been described. There are no clinical guidelines for the treatment of such patients.

OBJECTIVE

To study the factors influencing the results of surgical treatment of en plaque convexity hyperostotic meningioma, to formulate the appropriate decision-making algorithm.

MATERIAL AND METHODS

A retrospective total group of 69 patients with en plaque convexity hyperostotic meningioma who underwent surgery at Burdenko Neurosurgical Center between 2014 and 2023. We analyzed clinical manifestations, tactics and results of surgery and radiotherapy using statistical methods.

RESULTS AND DISCUSSION

Total resection of small local non-infiltrative hyperostotic meningioma not involving the superior sagittal sinus did not cause neurological deterioration. In case of spread infiltrative hyperostotic meningiomas, the best results (including regression of intracranial hypertension in all cases) were obtained after non-radical surgeries (resection of hyperostosis without wide excision of the dura or even without dura opening). Extent of resection of involved dura and intracranial tumor did not affect relapse-free survival. Additional morbidity at discharge from the clinic was 35%, after ≥6 months - 16%. The most common (27.5%) complication was pseudomeningocele. Redo surgery rate for pseudomeningocele - 7%, hematomas - 7%, wound infection - 6%. There were no mortality in the series. Radiotherapy increased relapse-free survival without statistical confirmation.

CONCLUSION

Total resection provides optimal results in patients with small convexity hyperostotic meningioma and no brain invasion. Resection of hyperostosis and expansive cranioplasty are preferable for large and giant convexity hyperostotic meningioma involving venous sinuses and / or the brain.

MicroRNA Analysis in Meningiomas with Different Degrees of Tissue Stiffness: A Potential Tool for Effective Preoperative Planning

BACKGROUND AND OBJECTIVES

Meningioma, the most common primary intracranial tumor, presents challenges in surgical treatment because of varying tissue stiffness. This study explores the molecular background of meningioma stiffness, a critical factor in surgical planning and prognosis, focusing on the utility of microRNAs (miRNAs) as diagnostic biomarkers of tissue stiffness.

METHODS

Patients with meningiomas treated surgically at the University Hospital Brno were included in this study. Total RNA, isolated from tumor tissue samples, underwent quality control and small RNA sequencing to analyze miRNA expression. Differentially expressed miRNAs were identified, and their association with tumor stiffness was assessed.

RESULTS

This study identified specific miRNAs differentially expressed in meningiomas with different stiffness levels. Key miRNAs, such as miR-31-5p and miR-34b-5p, showed significant upregulation in stiffer meningiomas. These findings were validated using reverse transcription-quantitative polymerase chain reaction, revealing a potential link between miRNA expression and tumor consistency. The expression of miR-31-5p was most notably associated with the stiffness of the tumor tissue (sensitivity = 71% and specificity = 83%).

CONCLUSION

This research highlights the potential of miRNAs as biomarkers for determining meningioma tissue stiffness. Identifying specific miRNAs associated with tumor consistency could improve preoperative planning and patient prognosis. These findings pave the way for further exploration of miRNAs in the clinical assessment of meningiomas.

Differential Expression of Proteins and Genes at the Tumor-Brain Interface in Invasive Meningioma

Most meningiomas are dural-based extra-axial tumors in close contact with the brain. Expression of genes and proteins at the tumor-brain interface in brain-invasive meningioma is basically unknown. Using the NanoString pan-cancer panel, differential expression of genes in the invasive edge versus main tumor body was determined in 12 invasive meningiomas (comprising the discovery cohort), and 6 candidate genes: DTX1, RASGRF1, GRIN1, TNR, IL6, and NR4A1, were identified. By immunohistochemistry, DTX1 and RASGRF1 expression correlated with gene expression, and were studied in an expanded cohort of 21 invasive and 15 noninvasive meningiomas, together with Ki-67. Significantly higher expression of DTX1, RASGFR1, and Ki-67 was found in the invasive edge compared with the main tumor body. Increased expression of RASGRF1 and Ki-67 was more clearly associated with brain invasion. The situation with DTX1 was less definitive since increased expression was observed in meningiomas both at the invasive edge and when in close contact with brain but without invasion. Pathway analyses identified significant links between DTX1 and RASGRF1 and key biological processes, including cell-cell adhesion, and signaling pathways including Notch, RAS, MAPK, and Rho. Higher expression of DTX1, RASGRF1, and Ki-67 in the brain-invasive area of meningiomas suggests that these proteins play a role in the process of brain invasion.

Multimodal brain tumor segmentation and classification from MRI scans based on optimized DeepLabV3+ and interpreted networks information fusion empowered with explainable AI

Explainable artificial intelligence (XAI) aims to offer machine learning (ML) methods that enable people to comprehend, properly trust, and create more explainable models. In medical imaging, XAI has been adopted to interpret deep learning black box models to demonstrate the trustworthiness of machine decisions and predictions. In this work, we proposed a deep learning and explainable AI-based framework for segmenting and classifying brain tumors. The proposed framework consists of two parts. The first part, encoder-decoder-based DeepLabv3+ architecture, is implemented with Bayesian Optimization (BO) based hyperparameter initialization. The different scales are performed, and features are extracted through the Atrous Spatial Pyramid Pooling (ASPP) technique. The extracted features are passed to the output layer for tumor segmentation. In the second part of the proposed framework, two customized models have been proposed named Inverted Residual Bottleneck 96 layers (IRB-96) and Inverted Residual Bottleneck Self-Attention (IRB-Self). Both models are trained on the selected brain tumor datasets and extracted features from the global average pooling and self-attention layers. Features are fused using a serial approach, and classification is performed. The BO-based hyperparameters optimization of the neural network classifiers is performed and the classification results have been optimized. An XAI method named LIME is implemented to check the interpretability of the proposed models. The experimental process of the proposed framework was performed on the Figshare dataset, and an average segmentation accuracy of 92.68 % and classification accuracy of 95.42 % were obtained, respectively. Compared with state-of-the-art techniques, the proposed framework shows improved accuracy.

Radiographic predictors of peritumoral brain edema in intracranial meningiomas: a review of current controversies and illustrative cases

Meningiomas are among the most common primary tumors of the central nervous system. In the past several decades, many researchers have emphasized the importance of radiographic findings and their possible role in predicting the various aspects of the meningioma biology. One of the factors most commonly analyzed with respect to the lesions' clinical behavior is peritumoral brain edema (PTBE), not only one of the most common signs associated with meningiomas, but also a significant clinical problem. Radiographic predictors of PTBE are usually noted as being the size of the tumor, its location, irregular margins, heterogeneity, and the peritumoral arachnoid plane with its pial vascular recruitment. Here, we review the available literature on the topic of these radiographic predictors of PTBE formation, we analyze the methodology of the research conducted, and we highlight the many controversies still present. Indeed, the evidence about PTBE pathogenesis, predictive factors, and clinical significance still seems to be mostly inconclusive, despite intense research in the area. We believe that by highlighting the many inconsistencies in the methodology used, we can showcase how little is actually known about the pathogenesis of PTBE, which in turn has important clinical implications. Additionally, we provide several MR images of intracranial meningiomas from our own practice which, we believe, showcase the unpredictable nature of PTBE, and demonstrate vividly the topics we discuss.

H3K27me3 Loss in Central Nervous System Tumors: Diagnostic, Prognostic, and Therapeutic Implications

Central nervous system (CNS) tumors represent a formidable clinical challenge due to their molecular complexity and varied prognostic outcomes. This review delves into the pivotal role of the epigenetic marker H3K27me3 in the development and treatment of CNS tumors. H3K27me3, specifically the trimethylation of lysine 27 on the histone H3 protein, plays a crucial role in regulating gene expression and maintaining chromatin architecture (e.g., in X-chromosome inactivation). Notably, a reduction in H3K27me3 levels, frequently tied to mutations in the H3 gene family such as H3F3A and HIST1H3B, is evident in diverse brain tumor variants, including the diffuse midline glioma characterized by the H3K27M mutation and certain pediatric high-grade gliomas. The loss of H3K27me3 has been linked to more aggressive behavior in meningiomas, with the trimethylation loss associated with significantly shorter recurrence-free survival (RFS) among grade 2 meningiomas, albeit not within grade 1 tumors. Pediatric posterior fossa ependymomas characterized by a lowered H3K27me3 and DNA hypomethylation exhibit poor prognosis, underscoring the prognostic significance of these epigenetic alterations in CNS tumors. Comprehending the role of H3K27me3 in CNS tumors is vital for advancing diagnostic tools and therapeutic interventions, with the goal of enhancing patient outcomes and quality of life. This review underscores the importance of ongoing investigations into H3K27me to refine and optimize management strategies for CNS tumors, paving the way for improved personalized medicine practices in oncology.

Benign extracranial meningioma with pulmonary metastasis: a case report and review of literature

BACKGROUND

Meningiomas are common central nervous system tumors, predominantly intracranial, they rarely develop extracranially. Moreover, benign meningiomas seldom metastasize.

CASE PRESENTATION

This article presents a case report of a 55-year-old Chinese male patient with a primary World Health Organization grade 1 meningioma originating from the petrous apex of the temporal bone, accompanied by pulmonary metastasis. Following two incomplete resections of the primary tumor, the patient underwent radiotherapy and has since maintained a stable condition.

CONCLUSION

The case report highlights the rare occurrence of pulmonary metastasis in a benign World Health Organization grade 1 meningioma originating from an extracranial site. It also illustrates the important role of radiotherapy in treating patients with meningioma. Additionally, a review of related literature is provided to gain insights for the diagnosis and treatment of the disease.

Meningioma: International Consortium on Meningiomas consensus review on scientific advances and treatment paradigms for clinicians, researchers, and patients

Meningiomas are the most common primary intracranial tumors in adults and are increasing in incidence due to the aging population and increased access to neuroimaging. While most exhibit nonmalignant behavior, a subset of meningiomas are biologically aggressive and are associated with treatment resistance, resulting in significant neurologic morbidity and even mortality. In recent years, meaningful advances in our understanding of the biology of these tumors have led to the incorporation of molecular biomarkers into their grading and prognostication. However, unlike other central nervous system (CNS) tumors, a unified molecular taxonomy for meningiomas has not yet been established and remains an overarching goal of the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy-Not Official World Health Organization (cIMPACT-NOW) working group. Additionally, clinical equipoise still remains on how specific meningioma cases and patient populations should be optimally managed. To address these existing gaps, members of the International Consortium on Meningiomas including field-leading experts, have prepared this comprehensive consensus narrative review directed toward clinicians, researchers, and patients. Included in this manuscript are detailed overviews of proposed molecular classifications, novel biomarkers, contemporary treatment strategies, trials on systemic therapies, health-related quality-of-life studies, and management strategies for unique meningioma patient populations. In each section, we discuss the current state of knowledge as well as ongoing clinical and research challenges to road map future directions for further investigation.

Computed tomography and magnetic resonance imaging findings of intracranial and extracranial meningioma with perineural spread through the foramen rotundum: A case report

We report a case of a 73-year-old woman presenting with intracranial and extracranial meningioma with perineural spread crossing the foramen rotundum and pterygopalatine fossa, primarily along the maxillary nerve. She visited our hospital with the chief complaint of the left cheek swelling. Subsequent magnetic resonance imaging revealed a well-demarcated mass containing intracranial (cavernous sinus, Meckel's cave, and middle cranial fossa) and extracranial components (pterygopalatine fossa, orbit, nasal cavity, ethmoid and sphenoid sinuses, infratemporal fossa, and buccal space) through the foramen rotundum. A biopsy specimen was obtained from the cheek mass, and the histopathological diagnosis was meningothelial meningioma.

Peptide Receptor Radionuclide Therapy in Advanced Refractory Meningiomas: Efficacy and Toxicity in a Long Follow-up

Recurrence of meningiomas after surgery and radiotherapy deserves specific attention because of the lack of active third-line therapies. Somatostatin receptors are usually overexpressed on the cell membrane of meningiomas, and this has led the way to a radionuclide theranostic approach. Diagnoses with 68Ga-DOTA-octreotide and peptide receptor radionuclide therapy (PRRT) with 90Y/177Lu-DOTA-octreotide are currently possible options within experimental protocols or as compassionate use in small patient groups. Methods: From October 2009 to October 2021, 42 meningioma patients with radiologic recurrence after standard therapies were treated with 90Y-DOTATOC (dosage of 1.1 or 5.5 GBq) or with 177Lu-DOTATATE (dosage of 3.7 or 5.5 GBq) in a mean of 4 cycles. All patients showed intense uptake at diagnostic 68Ga-DOTATOC PET/CT or in an 111In-octreotide scan. Results: Of 42 patients treated, 5 patients received 90Y-DOTATOC with a cumulative activity of 11.1 GBq and 37 patients received 177Lu-DOTATATE with a cumulative activity of 22 GBq. The disease control rate was 57%. With a median follow-up of 63 mo, median progression-free survival was 16 mo, and median overall survival was 36 mo. Retreatment 177Lu-PRRT was performed in 6 patients with an administered median activity of 13 GBq in a mean of 5 cycles. With a 75.8-mo follow-up, median progression-free survival and overall survival were 6.5 and 17 mo, respectively. Only 1 patient discontinued the treatment because of grade 3 platelet toxicity. A rapidly transient grade 2 neutropenia was recorded in 1 retreated patient. Conclusion: PRRT in patients with advanced meningiomas overexpressing somatostatin receptor 2 was active and well tolerated, showing a 57% disease control rate. Furthermore, PRRT could represent a potential retreatment option. Further studies, also in combination with other treatments, are warranted.

MicroRNAs in meningiomas: Potential biomarkers and therapeutic targets

Meningiomas, characterized primarily as benign intracranial or spinal tumors, present distinctive challenges due to their variable clinical behavior, with certain cases exhibiting aggressive features linked to elevated morbidity and mortality. Despite their prevalence, the underlying molecular mechanisms governing the initiation and progression of meningiomas remain insufficiently understood. MicroRNAs (miRNAs), small endogenous non-coding RNAs orchestrating post-transcriptional gene expression, have garnered substantial attention in this context. They emerge as pivotal biomarkers and potential therapeutic targets, offering innovative avenues for managing meningiomas. Recent research delves into the intricate mechanisms by which miRNAs contribute to meningioma pathogenesis, unraveling the molecular complexities of this enigmatic tumor. Meningiomas, originating from arachnoid meningothelial cells and known for their gradual growth, constitute a significant portion of intracranial tumors. The clinical challenge lies in comprehending their progression, particularly factors associated with brain invasion and heightened recurrence rates, which remain elusive. This comprehensive review underscores the pivotal role of miRNAs, accentuating their potential to advance our comprehension of meningioma biology. Furthermore, it suggests promising directions for developing diagnostic biomarkers and therapeutic interventions, holding the promise of markedly improved patient outcomes in the face of this intricate and variable disease.

Epidemiological features of spinal intradural tumors, a single-center clinical study in Beijing, China

BACKGROUND

Spinal intradural tumors are rare and heterogeneous in histological type, aggressiveness, and symptomatology, and there is a lack of data about them. This study investigated the epidemiological features of spinal intradural tumors.

METHODS

This retrospective analysis included patients with spinal intradural tumors who underwent surgical treatment at the Myelopathy and Spondylosis Ward Beijing Jishuitan Hospital between January 2012 and December 2022.

RESULTS

This study included 1321 patients [aged 47.19 ± 14.90 years, 603 (45.65%) males] with spinal intradural tumors. The most common histological subtype was schwannoma [n = 511 (38.68%)], followed by spinal meningioma [n = 184 (13.93%)] and ependymoma [n = 101 (7.65%)]. Fifteen (1.14%) patients were diagnosed with metastatic spinal intradural tumors as a presentation of another primary cancer type. The spinal intradural tumors were mostly found in the lumbar region [n = 436 (33.01%)], followed by the thoracic vertebrae [n = 390 (29.52%)], cervical vertebrae [n = 154 (11.66%)], and thoracolumbar region [n = 111 (8.40%)]. Schwannomas mostly affected the lumbar region [n = 256 (52.64%)], spinal meningiomas in the thoracic region [n = 153 (83.15)], and ependymomas in the lumbar region [56 (55.45%)]. The de novo metastases were mostly found in the lumbar region [n = 8 (53.33%)].

CONCLUSION

According to the results of our single-center study, the most common spinal intradural tumor in Northern China is schwannoma, followed by spinal meningioma and ependymoma.

Comprehensive assessment of atypical and anaplastic pediatric meningiomas utilizing national cancer database: a retrospective cohort study

PURPOSE

To examine demographic and clinical characteristics and their association with survival in grade 2 and 3 pediatric meningiomas in a large cohort using the National Cancer Database (NCDB).

METHODS

We conducted a comprehensive analysis using data from NCDB between 2004 to 2018. Tumor-specific data included tumor grade and size. Treatment details, including surgical resection, extent of resection, and radiotherapy, were gathered. Our analytic approach incorporated logistic and Poisson regression, Kaplan-Meier survival estimates, and Cox proportional hazards models.

RESULTS

Among the included 239 patients aged 0-21 years, age category distribution was significantly different between grade 2 and grade 3 tumors (p = 0.018). For grade 2 meningiomas, 51.5% of patients were female, and 76.7% were white. 85.3% of patients with grade 2 meningiomas underwent surgical resection, of which 67% underwent gross total resection. Overall survival (OS) was significantly different between resected and non-resected patients (p = 0.048). Uninsured patients were over seven times as likely to have prolonged length of stay (LOS) versus those with private insurance (OR = 7.663, p = 0.014). For grade 3 meningiomas, 51.4% of patients were male, and 82.9% were white. 91.4% of patients with grade 3 meningiomas underwent surgical resection, of which 53.3% underwent subtotal resection. OS was not significantly different between resected and non-resected patients (p = 0.659).

CONCLUSION

In summary, there were significant differences in age, maximum tumor dimension, unplanned readmission, radiotherapy, and treatment combinations between grade 2 and 3 meningiomas. These findings highlight the intricacies of managing pediatric meningiomas and emphasize the necessity for tailored therapeutic approaches to enhance outcomes in the future.

ADAM12 Silencing Mediated by FOXC2 Represses Meningioma Progression Through Inactivating the JAK1/STAT3/VEGFA Pathway

Meningioma is a prevalently intracranial tumor, and the malignant type is aggressive with high recurrence. A Disintegrin and Metalloprotease 12 (ADAM12) is a common oncogene and differentially expressed in meningioma. However, its roles and mechanisms in meningioma development remain obscure. The differentially expressed genes in meningioma were analyzed by GEO (GSE77259 and GSE43290) datasets and weighted gene co-expression network analysis (WGCNA) based on GSE16581. ADAM12 expression was measured via qRT-PCR and western blot. The correlation between ADAM12 and FOXC2 was predicted through JASPER tool and identified via luciferase reporter analysis. Cell proliferation, migration and invasion were investigated using CCK-8, EdU, transwell assays. The JAK1/STAT3/VEGFA signaling was activated by IL-6, and analyzed via western blot. The differentially expressed ADAM12 in meningioma was screened by WGCNA and GEO analyses. ADAM12 silencing repressed meningioma cell proliferation, and decreased migration and invasion. The transcription factor FOXC2 expression was enhanced in meningioma based on GSE77259 and GSE43290 datasets, and positively induced ADAM12 transcription. The JAK1/STAT3/VEGFA signaling was inactivated due to ADAM12 silencing and activated via IL-6. Upregulation of FOXC2 promoted cell proliferation, migration and invasion, and these effects were reversed by silencing ADAM12. ADAM12 knockdown mediated via FOXC2 silencing restrained proliferation, migration and invasion of meningioma cells through inactivating the JAK1/STAT3/VEGFA pathway.

Targeting histone deacetylase 6 (HDAC6) to enhance radiation therapy in meningiomas in a 2D and 3D in vitro study

BACKGROUND

External radiation therapy (RT) is often a primary treatment for inoperable meningiomas in the absence of established chemotherapy. Histone deacetylase 6 (HDAC6) overexpression, commonly found in cancer, is acknowledged as a driver of cellular growth, and inhibiting HDACs holds promise in improving radiotherapeutic efficacy. Downregulation of HDAC6 facilitates the degradation of β-catenin. This protein is a key element in the Wnt/β-catenin signalling pathway, contributing to the progression of meningiomas.

METHODS

In order to elucidate the associations and therapeutic potential of HDAC6 inhibitors (HDAC6i) in conjunction with RT, we administered Cay10603, HDAC6i, to both immortalised and patient-derived meningioma cells prior to RT in this study.

FINDINGS

Our findings reveal an increase in HDAC6 expression following exposure to RT, which is effectively mitigated with pre-treated Cay10603. The combination of Cay10603 with RT resulted in a synergistic augmentation of cytotoxic effects, as demonstrated through a range of functional assays conducted in both 2D as well as 3D settings; the latter containing syngeneic tumour microenvironment (TME). Radiation-induced DNA damage was augmented by pre-treatment with Cay10603, concomitant with the inhibition of β-catenin and minichromosome maintenance complex component 2 (MCM2) accumulation within the nucleus. This subsequently inhibited c-myc oncogene expression.

INTERPRETATION

Our findings demonstrate the therapeutic potential of Cay10603 to improve the radiosensitisation and provide rationale for combining HDAC6i with RT for the treatment of meningioma.

FUNDING

This work was funded by Brain Tumour Research Centre of Excellence award to C Oliver Hanemann.

Hsa_circ_0004872 mitigates proliferation, metastasis and immune escape of meningioma cells by suppressing PD-L1

Meningioma is a prevalent intracranial malignancy known for its aggressive growth. Circular RNAs (circRNAs) play a crucial role in the development of various cancers. However, their involvement in meningioma remains understudied. This study aimed to investigate the function and underlying mechanism of hsa_circ_0004872 in meningioma. The molecular expression of hsa_circ_0004872, PD-L1 and EIF4A3 was identified by RT-qPCR and/or western blot assays. Cell viability, migration, and invasion were assessed through CCK-8 and Transwell assays, respectively. Cytotoxicity was determined using an LDH assay, and cell apoptosis was monitored by flow cytometry. The RNA and protein interactions were assessed through RNA-protein immunoprecipitation (RIP) and RNA pull down analyses. Our findings revealed that hsa_circ_0004872 expression was significantly downregulated in both meningioma tissue samples and cells. Overexpression of hsa_circ_0004872 inhibited the proliferation, metastasis, and immune escape of meningioma cells, as well as enhanced the cytotoxicity of CD8+ T cells by suppressing PD-L1. Furthermore, hsa_circ_0004872 directly interacted with EIF4A3, leading to the degradation of PD-L1 mRNA. Finally, inhibiting EIF4A3 improved the proliferation, metastasis, and immune escape of meningioma cells, as well as the cytotoxicity of CD8+ T cells. Our study demonstrated that hsa_circ_0004872 mitigated the proliferation, metastasis,and immune escape of meningioma cells by targeting the EIF4A3/PD-L1 axis. These findings suggested that hsa_circ_0004872 and EIF4A3 might serve as promising biological markers and therapeutic targets for meningioma treatment.

Sulforaphane suppresses cell proliferation and induces apoptosis in glioma via the ACTL6A/PGK1 axis

This study aimed to examine the expression and biological functions of ACTL6A in glioma cells (U251), the effects of sulforaphane on the growth of U251 cells and the involvement of the ACTL6A/PGK1 pathway in those effects. The U251 cell line was transfected with ACTL6A over-expression plasmids to upregulate the protein, or with ACTL6A inhibitor to underexpress it, then treated with different concentrations of sulforaphane. Cell viability, proliferation, and apoptosis were assessed using standard assays, and levels of mRNAs encoding ACTL6A, PGK1, cyclin D1, Myc, Bax or Bcl-2 were measured using quantitative real-time polymerase chain reaction (qRT-PCR). ACTL6A and PGK1 were expressed at higher levels in glioma cell lines than in normal HEB cells. ACTL6A overexpression upregulated PGK1, whereas ACTL6A inhibition had the opposite effect. ACTL6A overexpression induced proliferation, whereas its inhibition repressed proliferation, enhanced apoptosis, and halted the cell cycle. Moreover, sulforaphane suppressed the growth of U251 cells by inactivating the ACTL6A/PGK1 axis. ACTL6A acts via PGK1 to play a critical role in glioma cell survival and proliferation, and sulforaphane targets it to inhibit glioma.

Clinical value of semi-quantitative parameters in 68Ga-DOTANOC PET/CT in treatment and diagnostics of cranial meningioma in a single-center retrospective analysis

BACKGROUND

The value of somatostatin-analogon PET tracers in theranostics in cranial meningioma has been demonstrated in several studies however, the value of semi-quantitative parameters for therapy and patient outcome is still unclear.

METHODS

A retrospective study was performed comparing measured semi-quantitative 68Ga-DOTANOC PET/CT parameters (maximum standardized uptake value = SUVmax, mean standardized uptake value = SUVmean, and metabolic tumor volume = MTV) and calculated ratios (SUVmax tumor/to pituitary gland, SUVmax tumor to superior sinus sagittalis), versus WHO grades and overall outcome. Patients with histological confirmed meningioma or high probability for meningioma in previous cranial MRI were eligible.

RESULTS

Thirty-two patients from January 2018 to February 2023 were retrospectively included. WHO grade I meningioma was confirmed in 17 patients, WHO grade II in five patients, WHO grade III in two patients, while in eight patients diagnosis was solely based on MRI and 68Ga-DOTANOC PET/CT findings. In 12 cases stable disease was present, in 15 cases radiation therapy was chosen, in three cases neurosurgery was preferred while in two cases palliative care was chosen. Median SUVmax values increased with WHO grade (15.84, 17.22, and 28.4, p = 0.134, Kruskal-Wallis-test) and no statistically significant difference was present for MTV, SUVmax, and calculated ratios, although the ratio for SUVmax tumor to superior sinus sagittalis had the lowest value of p = 0.067.

CONCLUSION

Increased SUVmax values in the tumor in 68Ga-DOTANOC PET/CT are associated with higher WHO grade, although further studies including larger patient collectives are needed to solidify this hypothesis.

LymphoDose: a lymphocyte dose estimation framework-application to brain radiotherapy

Objective. Severe radiation-induced lymphopenia occurs in 40% of patients treated for primary brain tumors and is an independent risk factor of poor survival outcomes. We developed anin-silicoframework that estimates the radiation doses received by lymphocytes during volumetric modulated arc therapy brain irradiation.Approach. We implemented a simulation consisting of two interconnected compartmental models describing the slow recirculation of lymphocytes between lymphoid organs (M1) and the bloodstream (M2). We used dosimetry data from 33 patients treated with chemo-radiation for glioblastoma to compare three cases of the model, corresponding to different physical and biological scenarios: (H1) lymphocytes circulation only in the bloodstream i.e. circulation inM2only; (H2) lymphocytes recirculation between lymphoid organs i.e. circulation inM1andM2interconnected; (H3) lymphocytes recirculation between lymphoid organs and deep-learning computed out-of-field (OOF) dose to head and neck (H&N) lymphoid structures. A sensitivity analysis of the model's parameters was also performed.Main results. For H1, H2 and H3 cases respectively, the irradiated fraction of lymphocytes was 99.8 ± 0.7%, 40.4 ± 10.2% et 97.6 ± 2.5%, and the average dose to irradiated pool was 309.9 ± 74.7 mGy, 52.6 ± 21.1 mGy and 265.6 ± 48.5 mGy. The recirculation process considered in the H2 case implied that irradiated lymphocytes were irradiated in the field only 1.58 ± 0.91 times on average after treatment. The OOF irradiation of H&N lymphoid structures considered in H3 was an important contribution to lymphocytes dose. In all cases, the estimated doses are low compared with lymphocytes radiosensitivity, and other mechanisms could explain high prevalence of RIL in patients with brain tumors.Significance. Our framework is the first to take into account OOF doses and recirculation in lymphocyte dose assessment during brain irradiation. Our results demonstrate the need to clarify the indirect effects of irradiation on lymphopenia, in order to potentiate the combination of radio-immunotherapy or the abscopal effect.

Clinical value of semi-quantitative parameters in 68Ga-DOTANOC PET/CT in treatment and diagnostics of cranial meningioma in a single-center retrospective analysis

BACKGROUND

The value of somatostatin-analogon PET tracers in theranostics in cranial meningioma has been demonstrated in several studies; however, the value of semi-quantitative parameters for therapy and patient outcome is still unclear.

METHODS

A retrospective study was performed comparing measured semi-quantitative 68Ga-DOTANOC PET/CT parameters (maximum standardized uptake value = SUVmax, mean standardized uptake value = SUVmean, and metabolic tumor volume = MTV) and calculated ratios (SUVmax tumor to pituitary gland and SUVmax tumor to superior sinus sagittalis), versus the WHO grades and overall outcome. Patients with histological confirmed meningioma or high probability for meningioma in the previous cranial MRI were eligible.

RESULTS

Thirty-two patients from January 2018 to February 2023 were retrospectively included. The WHO grade I meningioma was confirmed in 17 patients, the WHO grade II in five patients, and the WHO grade III in two patients, while in eight patients, diagnosis was solely based on MRI and 68Ga-DOTANOC PET/CT findings. In 12 cases, stable disease was present, in 15 cases, radiation therapy was chosen, in three cases, neurosurgery was preferred, while in two cases, palliative care was chosen. Median SUVmax values increased with the WHO grade (15.84, 17.22, and 28.4, p = 0.134, Kruskal-Wallis test), and no statistically significant difference was present for MTV, SUVmax, and calculated ratios.

CONCLUSION

Increased SUVmax values in the tumor in 68Ga-DOTANOC PET/CT are associated with higher WHO grade, although further studies including larger patient collectives are needed to solidify this hypothesis.

Chronic hyperglycemia and intracranial meningiomas

Meningiomas are among the most common primary tumors of the central nervous system. Previous research into the meningioma histological appearance, genetic markers, transcriptome and epigenetic landscape has revealed that benign meningiomas significantly differ in their glucose metabolism compared to aggressive lesions. However, a correlation between the systemic glucose metabolism and the metabolism of the tumor hasn't yet been found. We hypothesized that chronic levels of glycaemia (approximated with glycated hemoglobin (HbA1c)) are different in patients with aggressive and benign meningiomas. The study encompassed 71 patients with de novo intracranial meningiomas, operated on in three European hospitals, two in Croatia and one in Spain. Our results show that patients with WHO grade 2 meningiomas had significantly higher HbA1c values compared to patients with grade 1 lesions (P = 0.0290). We also found a significant number of patients (19/71; 26.7%) being hyperglycemic, harboring all the risks that such a condition entails. Finally, we found a significant correlation between our patients' age and their preoperative HbA1c levels (P = 0.0008, ρ(rho) = 0.388), suggesting that older meningioma patients are at a higher risk of having their glycaemia severely dysregulated. These findings are especially important considering the current routine and wide-spread use of corticosteroids as anti-edematous treatment. Further research in this area could lead to better understanding of meningiomas and have immediate clinical impact.

Analysis of risk factors affecting wound healing and wound infection after meningioma resection

To analyse the risk factors affecting wound healing and infection after spinal meningioma resection surgery. The surgical incision healing of 137 patients who underwent spinal meningioma resection at our hospital from January 2021 to January 2024 was analysed. The data collected included physical examination findings, haematological and biochemical measurements, and various scales assessed upon admission and after surgery. These data were then analysed. The surgical wound healing, infection and postoperative complications were statistically analysed. Multiple logistic regression analysis method was used to conduct risk factor analysis on corresponding indicators; the odds ratio and p value of 95% confidence interval were calculated. Factors such as age and smoking history were significantly negatively correlated with wound healing after meningioma resection (odds ratio < 1.000, p < 0.05), while preoperative albumin and platelet count were significantly positively correlated with wound healing (odds ratio > 1.000, p < 0.05). Age, WHO Meningioma Grading, preoperative albumin and preoperative platelet were significantly negatively correlated with wound infection after meningioma resection (odds ratio < 1.000, p < 0.05). The history of virus infection and history of neurological disorders were significantly positively correlated with wound infection (odds ratio > 1.000, p < 0.05). The influence of each factor is different. Age, smoking history, WHO Meningioma Grading, preoperative albumin, preoperative platelets, history of virus infection and history of neurological disorders had the greatest influence on wound healing and infection after meningioma resection.

The role of preoperative hematological inflammatory markers as a predictor of meningioma grade: A systematic review and meta-analysis

Background

Inflammatory processes play an important role in the aggressiveness of a tumor. However, the relationship between inflammatory markers in meningioma grade is not well known. Knowledge of preoperative meningioma grade plays an important role in the prognosis and treatment of this tumor. This study aims to assess preoperative hematological inflammatory markers as a predictor of the pathological grade of meningioma.

Methods

To ensure comprehensive retrieval of relevant studies, we searched the following key databases, PubMed, Science Direct, and Biomed Central, with evidence related to preoperative hematological inflammatory markers among meningioma up to September 2023. The studies involved were selected based on established eligibility criteria. The analysis in this study uses Review Manager 5.4.

Results

Six studies were obtained from the search results. The total number of patients 2789 (469 high-grade meningioma and 2320 low-grade meningioma) analysis shows elevated neutrophil-to-lymphocyte ratio (NLR) (mean difference [MD]: 0.29; 95% confidence interval [CI] 0.13-0.45; P = 0.0004), monocyte-to-lymphocyte ratio (MLR) (MD: 0.02; 95% CI 0.00-0.04; P = 0.003), and low lymphocyte-to-monocyte ratio (LMR) (MD: -0.82; 95% CI -1.46--0.18; P = 0.005) significantly associated with high-grade meningioma compared to low-grade meningioma. No significant correlation between high-grade and low-grade meningioma based on platelet-lymphocyte ratio value is observed.

Conclusion

The parameters of NLR, MLR, and LMR have been found to be cost-effective preoperative methods that demonstrate potential value in the prediction of meningioma grade. To enhance the reliability of the findings, it is imperative to do further prospective study.

Management of cavernous sinus meningiomas: Clinical features, treatment strategies, and long-term outcomes

OBJECTIVES

The purpose of this research was to summarize the clinical and prognostic features of cavernous sinus meningiomas (CSM), evaluate the treatment strategies and long-term prognosis of CSM, and improve the management of CSM and the treatment effect for patients.

METHODS

We retrospectively studied the data of 54 patients who received initial surgical resection and 45 patients who received initial gamma knife radiosurgery (GKRS) for CSM at West China Hospital of Sichuan University from 2009 to 2021. Progression-free survival (PFS), Karnofsky Performance Scale (KPS) scores and neurological function recovery were adopted to assess a comprehensive management strategy for CSM.

RESULTS

Gross total resection (GTR) was performed in 51.9 % of cases with 3.7 % surgical mortality. The average follow-up time was 48.7 months, with a progression rate of 29.3 %. The overall improvement rate for cranial nerve function deficits was 50.0 %. By survival analysis, the extent of resection and the histological grade were significantly related to the prognosis. The role of postoperative GKRS is uncertain. For patients who received initial GKRS, the progression rate was 17.8 %, and the overall improvement rate for cranial nerve function deficits was 61.1 %. Primary treatment with GKRS showed better long-term tumor control in patients with CSM (P = 0.046).

CONCLUSIONS

Maximum safe resection of CSM can improve the neurological function and quality of life of patients, but aggressive resection will cause high perioperative mortality and complication rates. For CSM patients who are suitable for initial gamma knife treatment, choosing GKRS can achieve better long-term tumor control and neurological outcomes.

Headache Disorders: Differentiating Primary and Secondary Etiologies

In the initial assessment of a headache patient, several dangerous secondary etiologies must be considered. A thorough history and physical examination, along with a comprehensive differential diagnosis may alert a physician to the diagnosis of a secondary headache particularly when it is accompanied by certain clinical features. Evaluation and workup include a complete neurological examination, consideration of neuroimaging, and serum/spinal fluid analysis if indicated. Careful attention to the patients' history and physical examination will guide the diagnostic work-up and management. In this review, we summarize the diagnostic workup of various primary and secondary headache etiologies. Although most headaches are primary in nature, it is essential to screen for headache "red flags", as they can suggest life threatening secondary etiologies. When secondary causes are suspected, appropriate neuroimaging can further differentiate the underlying cause. The appropriate imaging is dependent on the most likely secondary etiology, which is deduced from history and physical examination. When no red flags are present, primary headaches are more likely. These can be differentiated by frequency, location, duration, triggers, and presence of aura. The different clinical presentations for secondary headaches, as well as the distinguishing features for primary headaches are outlined in this review.

Theranostics in Neurooncology: Heading Toward New Horizons

Therapeutic approaches to brain tumors remain a challenge, with considerable limitations regarding delivery of drugs. There has been renewed and increasing interest in translating the popular theranostic approach well known from prostate and neuroendocrine cancer to neurooncology. Although far from perfect, some of these approaches show encouraging preliminary results, such as for meningioma and leptomeningeal spread of certain pediatric brain tumors. In brain metastases and gliomas, clinical results have failed to impress. Perspectives on these theranostic approaches regarding meningiomas, brain metastases, gliomas, and common pediatric brain tumors will be discussed. For each tumor entity, the general context, an overview of the literature, and future perspectives will be provided. Ongoing studies will be discussed in the supplemental materials. As most theranostic agents are unlikely to cross the blood-brain barrier, the delivery of these agents will be dependent on the successful development and clinical implementation of techniques enhancing permeability and retention. Moreover, the international community should strive toward sufficiently large and randomized studies to generate high-level evidence on theranostic approaches with radioligand therapies for central nervous system tumors.

Next-Generation DNA Sequencing of Grade 1 Meningioma Tumours: A Case Report of Angiomatous and Psammomatous Meningiomas

We performed the next-generation sequencing (NGS) analysis of a rare grade 1 brain meningioma (angiomatous type) and a common grade 1 spinal meningioma (psammomatous type) and compared their mutation profiling. The data were analysed using the Ion Reporter 5.16 programme (Thermo Fisher Scientific, Waltham, MA). Sequencing analysis identified 10 novel variants and two previously reported variants that were common between these two tumours. Nine variants were missense, which included an insertion in EGFR c.1819_1820insCA, causing frameshifting, and a single nucleotide deletion in HRAS and HNF1A genes, causing frameshifting in these genes. These were common variants identified for both tumours. Also, 10 synonymous variants and 10 intronic variants were common between these two tumours. In intronic variants, two were splice site_5' variants (acceptor site variants). Typical of the angiomatous type tumour, there were 11 novel and six previously reported variants that were not found in the psammomatous tumour; three variants were synonymous, 11 were missense mutations, and three were deletions causing frameshifting. The deletion variants were in the SMARCB1, CDH1, and KDR genes. In contrast, eight novel and five previously reported variants were found in the psammomatous meningioma tumour. In this tumour, two variants were synonymous: a deletion causing a frameshifting in [(c.3920delT; p. (Ile1307fs)], and a two-base pair insertion and deletion (INDEL) [(c.3986_3987delACinsGT; p. (His1329Arg)] both in the APC gene were also found. Among our findings, we have identified that ALK, VHL, CTNNB1, EGFR, ERBB4, PDGFRA, KDR, SMO, ABL1, HRAS, ATM, HNF1A, FLT3, and RB1 mutations are common for psammomatous meningioma and angiomatous tumours. Variants typical for angiomatous (brain) meningioma are PIK3CA, KIT, PTPN11, CDH1, SMAD4, and SMARCB1; the variants typical for psammomatous meningioma are APC, FGFR2, HNF1A, STK11, and JAK3. The RET splice variant (c.1880-2A>C) found in both meningioma tumours is reported (rs193922699) as likely pathogenic in the Single Nucleotide Polymorphism Database (dbSNP). All missense variants detected in these two meningiomas are found in the cancer-driver genes. The eight variants we found in genes such as EGFR, PDGFRA, SMO, FLT3, PIK3CA, PTPN11, CDH1, and RB1 are glioma-driver genes. We did not find any mutations in genes such as BRAF, IDH1, CDKN2A, PTEN, and TP53, which are also listed as cancer-driver genes in gliomas. Mutation profiling utilising NGS technology in meningiomas could help in the accurate diagnosis and classification of these tumours and also in developing more effective treatments.

Personalized Prognosis with Machine Learning Models for Predicting In-Hospital Outcomes Following Intracranial Meningioma Resections

BACKGROUND

Meningiomas display diverse biological traits and clinical behaviors, complicating patient outcome prediction. This heterogeneity, along with varying prognoses, underscores the need for a precise, personalized evaluation of postoperative outcomes.

METHODS

Data from the American College of Surgeons National Surgical Quality Improvement Program database identified patients who underwent intracranial meningioma resections from 2014 to 2020. We focused on 5 outcomes: prolonged LOS, nonhome discharges, 30-day readmissions, unplanned reoperations, and major complications. Six machine learning algorithms, including TabPFN, TabNet, XGBoost, LightGBM, Random Forest, and Logistic Regression, coupled with the Optuna optimization library for hyperparameter tuning, were tested. Models with the highest area under the receiver operating characteristic (AUROC) values were included in the web application. SHapley Additive exPlanations were used to evaluate the importance of predictor variables.

RESULTS

Our analysis included 7000 patients. Of these patients, 1658 (23.7%) had prolonged LOS, 1266 (18.1%) had nonhome discharges, 573 (8.2%) had 30-day readmission, 253 (3.6%) had unplanned reoperation, and 888 (12.7%) had major complications. Performance evaluation indicated that the top-performing models for each outcome were the models built with LightGBM and Random Forest algorithms. The LightGBM models yielded AUROCs of 0.842 and 0.846 in predicting prolonged LOS and nonhome discharges, respectively. The Random Forest models yielded AUROCs of 0.717, 0.76, and 0.805 in predicting 30-day readmissions, unplanned reoperations, and major complications, respectively.

CONCLUSIONS

The study successfully demonstrated the potential of machine learning models in predicting short-term adverse postoperative outcomes after meningioma resections. This approach represents a significant step forward in personalizing the information provided to meningioma patients.

Preoperative CT histogram analysis to predict the expression of Ki-67 in solid pseudopapillary tumours of the pancreas

AIM

To explore the value of preoperative computed tomography (CT) histogram features in predicting the expression status of Ki-67 in patients with solid pseudopapillary pancreatic tumours (SPTP).

MATERIALS AND METHODS

This retrospective study analysed venous phase CT images of 39 patients with SPTP confirmed at surgery and histopathology and measured using the Ki-67 proliferation index from November 2015 to February 2022. According to the Ki-67 proliferation index, they were divided into high expression (Ki-67 ≥ 4%) and low expression (Ki-67 < 4%) groups. The histogram features of quantitative parameters were extracted using MaZda software, and the quantitative parameters of CT histograms were compared between groups. The receiver operating characteristic (ROC) curves of the patients were plotted according to the parameters, with statistically significant differences. The area under the curve (AUC), sensitivity, and specificity were calculated, and the effectiveness of the histogram parameters in predicting Ki-67 expression was analysed and evaluated.

RESULTS

In total, 27 SPTP patients were enrolled, including 11 with high expression of Ki-67 and 16 with low expression. Comparative analysis of the Ki-67 high- and low-expression groups revealed a statistically significant in necrosis and variance (p<0.05). ROC curve analysis showed that the AUC of necrosis and variance predicting Ki-67 expression status were 0.753 and 0.841, the sensitivities were 81.8% and 81.3%, and the specificities were 68.7% and 81.8%, respectively.

CONCLUSION

Preoperative CT histogram features help predict Ki-67 expression status in patients with SPTP.

Establishment of tumor microenvironment-preserving organoid model from patients with intracranial meningioma

BACKGROUND

Although meningioma is the most common primary brain tumor, treatments rely on surgery and radiotherapy, and recurrent meningiomas have no standard therapeutic options due to a lack of clinically relevant research models. Current meningioma cell lines or organoids cannot reflect biological features of patient tumors since they undergo transformation along culture and consist of only tumor cells without microenvironment. We aim to establish patient-derived meningioma organoids (MNOs) preserving diverse cell types representative of the tumor microenvironment.

METHODS

The biological features of MNOs were evaluated using WST, LDH, and collagen-based 3D invasion assays. Cellular identities in MNOs were confirmed by immunohistochemistry (IHC). Genetic alteration profiles of MNOs and their corresponding parental tumors were obtained by whole-exome sequencing.

RESULTS

MNOs were established from four patients with meningioma (two grade 1 and two grade 2) at a 100% succession rate. Exclusion of enzymatic dissociation-reaggregation steps endowed MNOs with original histology and tumor microenvironment. In addition, we used a liquid media culture system instead of embedding samples into Matrigel, resulting in an easy-to-handle, cost-efficient, and time-saving system. MNOs maintained their functionality and morphology after long-term culture (> 9 wk) and repeated cryopreserving-recovery cycles. The similarities between MNOs and their corresponding parental tumors were confirmed by both IHC and whole-exome sequencing. As a representative application, we utilized MNOs in drug screening, and mifepristone, an antagonist of progesterone receptor, showed prominent antitumor efficacy with respect to viability, invasiveness, and protein expression.

CONCLUSION

Taken together, our MNO model overcame limitations of previous meningioma models and showed superior resemblance to parental tumors. Thus, our model could facilitate translational research identifying and selecting drugs for meningioma in the era of precision medicine.

Drug target therapy and emerging clinical relevance of exosomes in meningeal tumors

Meningioma is the most common central nervous system (CNS) tumor. In recent decades, several efforts have been made to eradicate this disease. Surgery and radiotherapy remain the standard treatment options for these tumors. Drug therapy comes to play its role when both surgery and radiotherapy fail to treat the tumor. This mostly happens when the tumors are close to vital brain structures and are nonbenign. Although a wide variety of chemotherapeutic drugs and molecular targeted drugs such as tyrosine kinase inhibitors, alkylating agents, endocrine drugs, interferon, and targeted molecular pathway inhibitors have been studied, the roles of numerous drugs remain unexplored. Recent interest is growing toward studying and engineering exosomes for the treatment of different types of cancer including meningioma. The latest studies have shown the involvement of exosomes in the theragnostic of various cancers such as the lung and pancreas in the form of biomarkers, drug delivery vehicles, and vaccines. Proper attention to this new emerging technology can be a boon in finding the consistent treatment of meningioma.

A novel patient-derived meningioma spheroid model as a tool to study and treat epithelial-to-mesenchymal transition (EMT) in meningiomas

Meningiomas are the most common intracranial brain tumours. These tumours are heterogeneous and encompass a wide spectrum of clinical aggressivity. Treatment options are limited to surgery and radiotherapy and have a risk of post-operative morbidities and radiation neurotoxicity, reflecting the need for new therapies. Three-dimensional (3D) patient-derived cell culture models have been shown to closely recapitulate in vivo tumour biology, including microenvironmental interactions and have emerged as a robust tool for drug development. Here, we established a novel easy-to-use 3D patient-derived meningioma spheroid model using a scaffold-free approach. Patient-derived meningioma spheroids were characterised and compared to patient tissues and traditional monolayer cultures by histology, genomics, and transcriptomics studies. Patient-derived meningioma spheroids closely recapitulated morphological and molecular features of matched patient tissues, including patient histology, genomic alterations, and components of the immune microenvironment, such as a CD68 + and CD163 + positive macrophage cell population. Comprehensive transcriptomic profiling revealed an increase in epithelial-to-mesenchymal transition (EMT) in meningioma spheroids compared to traditional monolayer cultures, confirming this model as a tool to elucidate EMT in meningioma. Therefore, as proof of concept study, we developed a treatment strategy to target EMT in meningioma. We found that combination therapy using the MER tyrosine kinase (MERTK) inhibitor UNC2025 and the histone deacetylase (HDAC) inhibitor Trichostatin A (TSA) effectively decreased meningioma spheroid viability and proliferation. Furthermore, we demonstrated this combination therapy significantly increased the expression of the epithelial marker E-cadherin and had a repressive effect on WHO grade 2-derived spheroid invasion, which is suggestive of a partial reversal of EMT in meningioma spheroids.

A novel BRAF::PTPRN2 fusion in meningioma: a case report

Gene fusion events have been linked to oncogenesis in many cancers. However, gene fusions in meningioma are understudied compared to somatic mutations, chromosomal gains/losses, and epigenetic changes. Fusions involving B-raf proto-oncogene, serine/threonine kinase (BRAF) are subtypes of oncogenic BRAF genetic abnormalities that have been reported in certain cases of brain tumors, such as pilocytic astrocytomas. However, BRAF fusions have not been recognized in meningioma. We present the case of an adult female presenting with episodic partial seizures characterized by déjà vu, confusion, and cognitive changes. Brain imaging revealed a cavernous sinus and sphenoid wing mass and she underwent resection. Histopathology revealed a World Health Organization (WHO) grade 1 meningioma. Genetic profiling with next generation sequencing and microarray analysis revealed an in-frame BRAF::PTPRN2 fusion affecting the BRAF kinase domain as well as chromothripsis of chromosome 7q resulting in multiple segmental gains and losses including amplifications of cyclin dependent kinase 6 (CDK6), tyrosine protein-kinase Met (MET), and smoothened (SMO). Elevated pERK staining in tumor cells provided evidence of activated mitogen-activated protein kinase (MAPK) signaling. This report raises the possibility that gene fusion events may be involved in meningioma pathogenesis and warrant further investigation.