DMD genomic deletions characterize a subset of progressive/higher-grade meningiomas with poor outcome

Domestic Animal Models of Central Nervous System Tumors: Focus on Meningiomas

Intracranial primary tumors (IPTs) are aggressive forms of malignancies that cause high mortality in both humans and domestic animals. Meningiomas are frequent adult IPTs in humans, dogs, and cats, and both benign and malignant forms cause a decrease in life quality and survival. Surgery is the primary therapeutic approach to treat meningiomas, but, in many cases, it is not resolutive. The chemotherapy and targeted therapy used to treat meningiomas also display low efficacy and many side effects. Therefore, it is essential to find novel pharmacological approaches to increase the spectrum of therapeutic options for meningiomas. This review analyzes the similarities between human and domestic animal (dogs and cats) meningiomas by evaluating the molecular and histological characteristics, diagnosis criteria, and treatment options and highlighting possible research areas to identify novel targets and pharmacological approaches, which are useful for the diagnosis and therapy of this neoplasia to be used in human and veterinary medicine.

Subclonal Somatic Copy-Number Alterations Emerge and Dominate in Recurrent Osteosarcoma

Multiple large-scale genomic profiling efforts have been undertaken in osteosarcoma to define the genomic drivers of tumorigenesis, therapeutic response, and disease recurrence. The spatial and temporal intratumor heterogeneity could also play a role in promoting tumor growth and treatment resistance. We conducted longitudinal whole-genome sequencing of 37 tumor samples from 8 patients with relapsed or refractory osteosarcoma. Each patient had at least one sample from a primary site and a metastatic or relapse site. Subclonal copy-number alterations were identified in all patients except one. In 5 patients, subclones from the primary tumor emerged and dominated at subsequent relapses. MYC gain/amplification was enriched in the treatment-resistant clones in 6 of 7 patients with multiple clones. Amplifications in other potential driver genes, such as CCNE1, RAD21, VEGFA, and IGF1R, were also observed in the resistant copy-number clones. A chromosomal duplication timing analysis revealed that complex genomic rearrangements typically occurred prior to diagnosis, supporting a macroevolutionary model of evolution, where a large number of genomic aberrations are acquired over a short period of time followed by clonal selection, as opposed to ongoing evolution. A mutational signature analysis of recurrent tumors revealed that homologous repair deficiency (HRD)-related SBS3 increases at each time point in patients with recurrent disease, suggesting that HRD continues to be an active mutagenic process after diagnosis. Overall, by examining the clonal relationships between temporally and spatially separated samples from patients with relapsed/refractory osteosarcoma, this study sheds light on the intratumor heterogeneity and potential drivers of treatment resistance in this disease.

SIGNIFICANCE

The chemoresistant population in recurrent osteosarcoma is subclonal at diagnosis, emerges at the time of primary resection due to selective pressure from neoadjuvant chemotherapy, and is characterized by unique oncogenic amplifications.

DNA methylation meningioma biomarkers: attributes and limitations

Meningioma, one of the most common primary central nervous system tumors, are classified into three grades by the World Health Organization (WHO) based on histopathology. The gold-standard treatment, surgical resection, is hampered by issues such as incomplete resection in some cases and a high recurrence rate. Alongside genetic alterations, DNA methylation, plays a crucial role in progression of meningiomas in the occurrence and development of meningiomas. The epigenetic landscape of meningioma is instrumental in refining tumor classification, identifying robust molecular markers, determining prognosis, guiding treatment selection, and innovating new therapeutic strategies. Existing classifications lack comprehensive accuracy, and effective therapies are limited. Methylated DNA markers, exhibiting differential characteristics across varying meningioma grades, serve as invaluable diagnostic tools. Particularly, combinatorial methylated markers offer insights into meningioma pathogenesis, tissue origin, subtype classification, and clinical outcomes. This review integrates current research to highlight some of the most promising DNA and promoter methylation markers employed in meningioma diagnostics. Despite their promise, the development and application of DNA methylation biomarkers for meningioma diagnosis and treatment are still in their infancy, with only a handful of DNA methylation inhibitors currently clinically employed for meningioma treatment. Future studies are essential to validate these markers and ascertain their clinical utility. Combinatorial methylated DNA markers for meningiomas have broad implications for understanding tumor development and progression, signaling a paradigm shift in therapeutic strategies for meningiomas.

Meningiomas with CNS invasion

CNS invasion has been included as an independent criterion for the diagnosis of a high-grade (WHO and CNS grade 2 and 3) meningioma in the 2016 and more recently in the 2021 WHO classification. However, the prognostic role of brain invasion has recently been questioned. Also, surgical treatment for brain invasive meningiomas may pose specific challenges. We conducted a systematic review of the 2016-2022 literature on brain invasive meningiomas in Pubmed, Scopus, Web of Science and the Cochrane Library. The prognostic relevance of brain invasion as a stand-alone criterion is still unclear. Additional and larger studies using robust definitions of histological brain invasion and addressing the issue of sampling errors are clearly warranted. Although the necessity of molecular profiling in meningioma grading, prognostication and decision making in the future is obvious, specific markers for brain invasion are lacking for the time being. Advanced neuroimaging may predict CNS invasion preoperatively. The extent of resection (e.g., the Simpson grading) is an important predictor of tumor recurrence especially in higher grade meningiomas, but also - although likely to a lesser degree - in benign tumors, and therefore also in brain invasive meningiomas with and without other histological features of atypia or malignancy. Hence, surgery for brain invasive meningiomas should follow the principles of maximal but safe resections. There are some data to suggest that safety and functional outcomes in such cases may benefit from the armamentarium of surgical adjuncts commonly used for surgery of eloquent gliomas such as intraoperative monitoring, awake craniotomy, DTI tractography and further advanced intraoperative brain tumor visualization.

Review of meningioma diagnosis and management

Meningiomas are the most common intracranial tumors in adult patients. Although the majority of meningiomas are diagnosed as benign, approximately 20% of cases are high-grade tumors that require significant clinical treatment. The gold standard for grading central nervous system tumors comes from the World Health Organization Classification of Tumors of the central nervous system. Treatment options also depend on the location, imaging, and histopathological features of the tumor. This review will cover diagnostic strategies for meningiomas, including 2021 updates to the World Health Organization's grading of meningiomas. Meningioma treatment plans are variable and highly dependent on tumor grading. This review will also update the reader on developments in the treatment of meningiomas, including surgery, radiation therapy and monoclonal antibody treatment.

Downregulation of Dystrophin Expression Occurs across Diverse Tumors, Correlates with the Age of Onset, Staging and Reduced Survival of Patients

Altered dystrophin expression was found in some tumors and recent studies identified a developmental onset of Duchenne muscular dystrophy (DMD). Given that embryogenesis and carcinogenesis share many mechanisms, we analyzed a broad spectrum of tumors to establish whether dystrophin alteration evokes related outcomes. Transcriptomic, proteomic, and mutation datasets from fifty tumor tissues and matching controls (10,894 samples) and 140 corresponding tumor cell lines were analyzed. Interestingly, dystrophin transcripts and protein expression were found widespread across healthy tissues and at housekeeping gene levels. In 80% of tumors, DMD expression was reduced due to transcriptional downregulation and not somatic mutations. The full-length transcript encoding Dp427 was decreased in 68% of tumors, while Dp71 variants showed variability of expression. Notably, low expression of dystrophins was associated with a more advanced stage, older age of onset, and reduced survival across different tumors. Hierarchical clustering analysis of DMD transcripts distinguished malignant from control tissues. Transcriptomes of primary tumors and tumor cell lines with low DMD expression showed enrichment of specific pathways in the differentially expressed genes. Pathways consistently identified: ECM-receptor interaction, calcium signaling, and PI3K-Akt are also altered in DMD muscle. Therefore, the importance of this largest known gene extends beyond its roles identified in DMD, and certainly into oncology.

Alliance A071401: Phase II Trial of Focal Adhesion Kinase Inhibition in Meningiomas With Somatic NF2 Mutations

PURPOSE

Patients with progressive or recurrent meningiomas have limited systemic therapy options. Focal adhesion kinase (FAK) inhibition has a synthetic lethal relationship with NF2 loss. Given the predominance of NF2 mutations in meningiomas, we evaluated the efficacy of GSK2256098, a FAK inhibitor, as part of the first genomically driven phase II study in recurrent or progressive grade 1-3 meningiomas.

PATIENTS AND METHODS

Eligible patients whose tumors screened positively for NF2 mutations were treated with GSK2256098, 750 mg orally twice daily, until progressive disease. Efficacy was evaluated using two coprimary end points: progression-free survival at 6 months (PFS6) and response rate by Macdonald criteria, where PFS6 was evaluated separately within grade-based subgroups: grade 1 versus 2/3 meningiomas. Per study design, the FAK inhibitor would be considered promising in this patient population if either end point met the corresponding decision criteria for efficacy.

RESULTS

Of 322 patients screened for all mutation cohorts of the study, 36 eligible and evaluable patients with NF2 mutations were enrolled and treated: 12 grade 1 and 24 grade 2/3 patients. Across all grades, one patient had a partial response and 24 had stable disease as their best response to treatment. In grade 1 patients, the observed PFS6 rate was 83% (10/12 patients; 95% CI, 52 to 98). In grade 2/3 patients, the observed PFS6 rate was 33% (8/24 patients; 95% CI, 16 to 55). The study met the PFS6 efficacy end point both for the grade 1 and the grade 2/3 cohorts. Treatment was well tolerated; seven patients had a maximum grade 3 adverse event that was at least possibly related to treatment with no grade 4 or 5 events.

CONCLUSION

GSK2256098 was well tolerated and resulted in an improved PFS6 rate in patients with recurrent or progressive NF2-mutated meningiomas, compared with historical controls. The criteria for promising activity were met, and FAK inhibition warrants further evaluation for this patient population.

Signaling pathways in brain tumors and therapeutic interventions

Brain tumors, although rare, contribute to distinct mortality and morbidity at all ages. Although there are few therapeutic options for brain tumors, enhanced biological understanding and unexampled innovations in targeted therapies and immunotherapies have considerably improved patients' prognoses. Nonetheless, the reduced response rates and unavoidable drug resistance of currently available treatment approaches have become a barrier to further improvement in brain tumor (glioma, meningioma, CNS germ cell tumors, and CNS lymphoma) treatment. Previous literature data revealed that several different signaling pathways are dysregulated in brain tumor. Importantly, a better understanding of targeting signaling pathways that influences malignant behavior of brain tumor cells might open the way for the development of novel targeted therapies. Thus, there is an urgent need for a more comprehensive understanding of the pathogenesis of these brain tumors, which might result in greater progress in therapeutic approaches. This paper began with a brief description of the epidemiology, incidence, risk factors, as well as survival of brain tumors. Next, the major signaling pathways underlying these brain tumors' pathogenesis and current progress in therapies, including clinical trials, targeted therapies, immunotherapies, and system therapies, have been systemically reviewed and discussed. Finally, future perspective and challenges of development of novel therapeutic strategies in brain tumor were emphasized.

Brain Invasion and Trends in Molecular Research on Meningioma

Meningiomas are the most common primary brain tumors in adults. The treatment of non-benign meningiomas remains a challenging task, and after the publication of the 2021 World Health Organization classification, the importance of molecular biological classification is emerging. In this article, we introduce the mechanisms of brain invasion in atypical meningioma and review the genetic factors involved along with epigenetic regulation. First, it is important to understand the three major steps for brain invasion of meningeal cells: 1) degradation of extracellular matrix by proteases, 2) promotion of tumor cell migration to resident cells by adhesion molecules, and 3) neovascularization and supporting cells by growth factors. Second, the genomic landscape of meningiomas should be analyzed by major categories, such as germline mutations in NF2 and somatic mutations in non-NF2 genes (TRAF7, KLF4, AKT1, SMO, and POLR2A). Finally, epigenetic alterations in meningiomas are being studied, with a focus on DNA methylation, histone modification, and RNA interference. Increasing knowledge of the molecular landscape of meningiomas has allowed the identification of prognostic and predictive markers that can guide therapeutic decision-making processes and the timing of follow-up.

Radiotherapy for meningiomas

Meningiomas are the most common primary central nervous system neoplasm. Despite promising recent progress in elucidating the genomic landscape and underlying biology of these histologically, molecularly, and clinically diverse tumors, the mainstays of meningioma treatment remain maximal safe resection and radiation therapy. The aim of this review of meningioma radiotherapy is to provide a concise summary of the history, current evidence, and future for application of radiotherapy in meningioma treatment.

Proteins implicated in muscular dystrophy and cancer are functional constituents of the centrosome

This study demonstrates that the muscular dystrophy-associated proteins dystrophin, utrophin, dysferlin, and calpain-3 localize to the centrosome and that their absence leads to excess centrosomes, compromised nuclear morphology, impaired centrosome orientation, and defective microtubule nucleation.

Aberrant expression of dystrophin, utrophin, dysferlin, or calpain-3 was originally identified in muscular dystrophies (MDs). Increasing evidence now indicates that these proteins might act as tumor suppressors in myogenic and non-myogenic cancers. As DNA damage and somatic aneuploidy, hallmarks of cancer, are early pathological signs in MDs, we hypothesized that a common pathway might involve the centrosome. Here, we show that dystrophin, utrophin, dysferlin, and calpain-3 are functional constituents of the centrosome. In myoblasts, lack of any of these proteins caused excess centrosomes, centrosome misorientation, nuclear abnormalities, and impaired microtubule nucleation. In dystrophin double-mutants, these defects were significantly aggravated. Moreover, we demonstrate that also in non-myogenic cells, all four MD-related proteins localize to the centrosome, including the muscle-specific full-length dystrophin isoform. Therefore, MD-related proteins might share a convergent function at the centrosome in addition to their diverse, well-established muscle-specific functions. Thus, our findings support the notion that cancer-like centrosome-related defects underlie MDs and establish a novel concept linking MDs to cancer.

Molecular landscapes of longitudinal NF2/22q and non-NF2/22q meningiomas show different life histories

Recurrence is a major complication of some meningiomas. Although there were many studies on biomarkers associated with higher grades or increased aggressiveness, few studies specifically examined longitudinal samples of primary meningiomas and recurrences from the same patients for molecular life history. We studied 99 primary and recurrent meningiomas from 42 patients by FISH for 22q, 1q, 1p, 3p, 5q, 6q, 10p, 10q, 14q, 18q, CDKN2A/B homozygous deletion, ALT (Alternative Lengthening of Telomere), TERT re-arrangement, targeted sequencing and TERTp sequencing. Although NF2 mutation and 22q were well known to be aetiological events in meningiomas, we found that in these paired meningiomas, combining the two events resulted in an NF2/22q group (57 tumors from 25 patients) which were almost mutually exclusive with those cases without these two changes (42 tumors from 17 patients) for NF2/22q. No other molecular changes were totally unique to NF2/22q or non-NF2/22q tumors. For molecular evolution, NF2/22q meningiomas had higher cytogenetic abnormalities than non-NF2/22q meningiomas (p = 0.003). Most of the cytogenetic changes in NF2/22q meningiomas were present from the outset whereas for non-NF2/22q meningiomas, cytogenetic events were uncommon in the primary tumors and most were acquired in recurrences. For non-NF2/22q tumors, CDKN2A/B homozygous deletion, 1q gain, 18p loss, 3p loss, and ALT were preferentially found in recurrences. Mutations were largely conserved between primary and recurrent tumors. Phylogenetic trees showed 11/11 patients with multiple recurrent tumors had a conserved evolutionary pattern. We conclude that for molecular life history, NF2 and 22q should be regarded as a group. NF2/22q recurring meningiomas showed more cytogenetic abnormalities in the primary tumors, whereas non-NF2/22q meningiomas showed CDKN2A/B deletion and other cytogenetic abnormalities and ALT at recurrences. Although chromosome 1p loss is a known poor prognostic marker in meningiomas, it was also associated with a shorter TBR (time between resection) in this cohort (p = 0.002).

Molecular diagnosis and treatment of meningiomas: an expert consensus (2022)

ABSTRACT

Meningiomas are the most common primary intracranial neoplasm with diverse pathological types and complicated clinical manifestations. The fifth edition of the WHO Classification of Tumors of the Central Nervous System (WHO CNS5), published in 2021, introduces major changes that advance the role of molecular diagnostics in meningiomas. To follow the revision of WHO CNS5, this expert consensus statement was formed jointly by the Group of Neuro-Oncology, Society of Neurosurgery, Chinese Medical Association together with neuropathologists and evidence-based experts. The consensus provides reference points to integrate key biomarkers into stratification and clinical decision making for meningioma patients.

REGISTRATION

Practice guideline REgistration for transPAREncy (PREPARE), IPGRP-2022CN234.

Advances in Molecular Biological and Translational Studies in World Health Organization Grades 2 and 3 Meningiomas: A Literature Review

The treatment of World Health Organization (WHO) grades 2 and 3 meningiomas remains difficult and controversial. The pathogenesis of high-grade meningiomas was expected to be elucidated to improve treatment strategies. The molecular biology of meningiomas has been clarified in recent years. High-grade meningiomas have been linked to NF2 mutations and 22q deletion. CDKN2A/B homozygous deletion and TERT promoter mutations are independent prognostic factors for WHO grade 3 meningiomas. In addition to 22q loss, 1p, 14p, and 9q loss have been linked to high-grade meningiomas. Meningiomas enriched in copy number alterations may be biologically invasive. Furthermore, several new comprehensive classifications of meningiomas have been proposed based on these molecular biological features, including DNA methylation status. The new classifications may have implications for treatment strategies for refractory aggressive meningiomas because they provide a more accurate prognosis compared to the conventional WHO classification. Although several systemic therapies, including molecular targeted therapies, may be effective in treating refractory aggressive meningiomas, these drugs are being tested. Systemic drug therapy for meningioma is expected to be developed in the future. Thus, this review aims to discuss the distinct genomic alterations observed in WHO grade 2 and 3 meningiomas, as well as their diagnostic and therapeutic implications and systemic drug therapies for high-grade meningiomas.

Potential Molecular Mechanisms of Recurrent and Progressive Meningiomas: A Review of the Latest Literature

Meningiomas, the most frequent primary intracranial tumors of the central nervous system in adults, originate from the meninges and meningeal spaces. Surgical resection and adjuvant radiation are considered the preferred treatment options. Although most meningiomas are benign and slow-growing, some patients suffer from tumor recurrence and disease progression, eventually resulting in poorer clinical outcomes, including malignant transformation and death. It is thus crucial to identify these “high-risk” tumors early; this requires an in-depth understanding of the molecular and genetic alterations, thereby providing a theoretical foundation for establishing personalized and precise treatment in the future. Here, we review the most up-to-date knowledge of the cellular biological alterations involved in the progression of meningiomas, including cell proliferation, neo-angiogenesis, inhibition of apoptosis, and immunogenicity. Focused genetic alterations, including chromosomal abnormalities and DNA methylation patterns, are summarized and discussed in detail. We also present latest therapeutic targets and clinical trials for meningiomas' treatment. A further understanding of cellular biological and genetic alterations will provide new prospects for the accurate screening and treatment of recurrent and progressive meningiomas.

Clinical Significance of Molecular Alterations and Systemic Therapy for Meningiomas: Where Do We Stand?

Simple Summary

Meningiomas are the most frequent intracranial tumors and comprise a heterogeneous spectrum of diseases, ranging from small, asymptomatic tumors that do not need treatment to large, symptomatic ones causing seizures or neurological deficits that require surgery and/or radiotherapy. Systemic therapy is reserved for progressive or recurrent meningiomas when surgery and/or radiotherapy options have been exhausted, with only modest activity in terms of disease control and survival. Novel molecular alterations are correlated with grading, location, and prognosis of meningiomas. Moreover, some of these driver alterations regulate meningioma growth and progression and may be targeted by specific drugs that are under investigation in clinical trials. Lastly, the microenvironment surrounding meningiomas may also contribute to regulating tumor growth: in particular, PD-L1 and/or M2 macrophage expression may represent a target for immunotherapy.

Abstract

Meningiomas are common intracranial tumors that can be treated successfully in most cases with surgical resection and/or adjuvant radiotherapy. However, approximately 20% of patients show an aggressive clinical course with tumor recurrence or progressive disease, resulting in significant morbidity and increased mortality. Despite several studies that have investigated different cytotoxic agents in aggressive meningiomas in the past several years, limited evidence of efficacy and clinical benefit has been reported thus far. Novel molecular alterations have been linked to a particular clinicopathological phenotype and have been correlated with grading, location, and prognosis of meningiomas. In this regard, SMO, AKT, and PIK3CA mutations are typical of anterior skull base meningiomas, whereas KLF4 mutations are specific for secretory histology, and BAP1 alterations are common in progressive rhabdoid meningiomas. Alterations in TERT, DMD, and BAP1 correlate with poor outcomes. Moreover, some actionable mutations, including SMO, AKT1, and PIK3CA, regulate meningioma growth and are under investigation in clinical trials. PD-L1 and/or M2 macrophage expression in the microenvironment provides evidence for the investigation of immunotherapy in progressive meningiomas.

miR‑31‑5p‑DMD axis as a novel biomarker for predicting the development and prognosis of sporadic early‑onset colorectal cancer

The incidence of colorectal cancer (CRC) is increasing in young adults, but knowledge regarding the molecular features of sporadic early-onset colorectal cancer (SEOCRC) is limited. The objective of the present study was to investigate potential key tumorigenesis-associated genes and their regulatory microRNAs (miRNAs) in SEOCRC. Using miRNA and mRNA expression screening of SEOCRC and sporadic late-onset colorectal cancer (SLOCRC) by next generation sequencing (NGS) and bioinformatics, the SEOCRC-associated miRNAome and transcriptome were analyzed. In SEOCRC miRNA and mRNA expression profiles, the tumorigenesis-associated genes and their regulatory miRNAs were analyzed according to the miRTarBase database, and specific miRNA-mRNA pairs were selected as the candidate biomarkers in SEOCRC, which were further verified in another cohort of SEOCRC and SLOCRC patients' colon cancer and paracancerous tissues using reverse transcription-quantitative PCR and immunohistochemistry. Moreover, the clinical relevance of these paired signatures to clinicopathological features was determined in 80 patients with SEOCRC. The expression of dystrophin (DMD) was downregulated and that of miR-31-5p was upregulated in SEOCRC tissue compared with adjacent peritumoral tissue. While DMD and miR-31-5p were not differentially expressed in SLOCRC tissues compared with that in adjacent peritumoral tissues. The miR-31-5p-DMD axis was identified as the key regulatory axis specific to SEOCRC, and DMD expression was closely associated with TNM stage and lymph node metastasis. Importantly, Kaplan-Meier analysis revealed that patients with low DMD expression had significantly poorer overall survival, cancer specific survival and recurrence free survival compared with those with high expression of DMD. In conclusion, the miR-31-5p-DMD axis may serve as a novel biomarker in predicting the development of SEOCRC, and DMD can be used as a promising biomarker for the prognosis of SEOCRC.

Skull Base Tumors: Neuropathology and Clinical Implications

Tumors that arise in and around the skull base comprise a wide range of common and rare entities. Recent studies have advanced our understanding of their pathogenesis, which in some cases, have significantly influenced clinical practice. The genotype of meningiomas is strongly associated with their phenotype, including histologic subtype and tumor location, and clinical outcome. A single molecular alteration, NAB2-STAT6 fusion, has redefined the category of solitary fibrous tumors to include the previous entity hemangiopericytomas. Schwannomas, both sporadic and familial, are characterized by near ubiquitous alterations in NF2 , with additional mutations in SMARCB1 or LZTR1 in schwannomatosis. In pituitary adenohypophyseal tumors, cell lineage transcription factors such as SF-1, T-PIT, and PIT-1 are now essential for classification, providing a more rigorous taxonomy for tumors that were previously considered null cell adenomas. The pituicyte lineage transcription factor TTF-1 defines neurohypophyseal tumors, which may represent a single nosological entity with a spectrum of morphologic manifestations (ie, granular cell tumor, pituicytoma, and spindle cell oncocytoma). Likewise, the notochord cell lineage transcription factor brachyury defines chordoma, discriminating them from chondrosarcomas. The identification of nonoverlapping genetic drivers of adamantinomatous craniopharyngiomas and papillary craniopharyngiomas indicates that these are distinct tumor entities and has led to successful targeted treatment of papillary craniopharyngiomas using BRAF and/or mitogen-activated protein kinase inhibitors. Similarly, dramatic therapeutic responses have been achieved in patients with Langerhans cell histiocytosis, both with BRAF -mutant and BRAF -wildtype tumors. Familiarity with the pathology of skull base tumors, their natural history, and molecular features is essential for optimizing patient care.

Integrated Molecular-Morphologic Meningioma Classification: A Multicenter Retrospective Analysis, Retrospectively and Prospectively Validated

PURPOSE

Meningiomas are the most frequent primary intracranial tumors. Patient outcome varies widely from benign to highly aggressive, ultimately fatal courses. Reliable identification of risk of progression for individual patients is of pivotal importance. However, only biomarkers for highly aggressive tumors are established (CDKN2A/B and TERT), whereas no molecularly based stratification exists for the broad spectrum of patients with low- and intermediate-risk meningioma.

METHODS

DNA methylation data and copy-number information were generated for 3,031 meningiomas (2,868 patients), and mutation data for 858 samples. DNA methylation subgroups, copy-number variations (CNVs), mutations, and WHO grading were analyzed. Prediction power for outcome was assessed in a retrospective cohort of 514 patients, validated on a retrospective cohort of 184, and on a prospective cohort of 287 multicenter cases.

RESULTS

Both CNV- and methylation family-based subgrouping independently resulted in increased prediction accuracy of risk of recurrence compared with the WHO classification (c-indexes WHO 2016, CNV, and methylation family 0.699, 0.706, and 0.721, respectively). Merging all risk stratification approaches into an integrated molecular-morphologic score resulted in further substantial increase in accuracy (c-index 0.744). This integrated score consistently provided superior accuracy in all three cohorts, significantly outperforming WHO grading (c-index difference P = .005). Besides the overall stratification advantage, the integrated score separates more precisely for risk of progression at the diagnostically challenging interface of WHO grade 1 and grade 2 tumors (hazard ratio 4.34 [2.48-7.57] and 3.34 [1.28-8.72] retrospective and prospective validation cohorts, respectively).

CONCLUSION

Merging these layers of histologic and molecular data into an integrated, three-tiered score significantly improves the precision in meningioma stratification. Implementation into diagnostic routine informs clinical decision making for patients with meningioma on the basis of robust outcome prediction.

The integrated multiomic diagnosis of sporadic meningiomas: a review of its clinical implications

Introduction

Meningiomas are generally considered “benign,” however, these tumors can demonstrate variability in behavior and a surprising aggressiveness with elevated rates of recurrence. The advancement of next-generation molecular technologies have led to the understanding of the genomic and epigenomic landscape of meningiomas and more recent correlations with clinical characteristics and behavior.

Methods

Based on a thorough review of recent peer-reviewed publications (PubMed) and edited texts, we provide a molecular overview of meningiomas with a focus on relevant clinical implications.

Results

The identification of specific somatic driver mutations has led to the classification of several major genomic subgroups, which account for more than 80% of sporadic meningiomas, and can be distinguished using noninvasive clinical variables to help guide management decisions. Other somatic genomic modifications, including non-coding alterations and copy number variations, have also been correlated with tumor characteristics. Furthermore, epigenomic modifications in meningiomas have recently been described, with DNA methylation being the most widely studied and potentially most clinically relevant. Based on these molecular insights, several clinical trials are currently underway in an effort to establish effective medical therapeutic options for meningioma.

Conclusion

As we enhance our multiomic understanding of meningiomas, our ability to care for patients with these tumors will continue to improve. Further biological insights will lead to additional progress in precision medicine for meningiomas.

Implementation of TERT promoter mutations improve prognostication of the WHO classification in meningioma

TERT promoter mutations have been associated with increased risk of recurrence in meningioma cohorts, thus a potential biomarker for aggressive phenotypes. A main purpose of refining tumour classification is better predictions on the patient level. We compiled data from previous published cohorts to investigate patient-level predictions of recurrence based on TERTp-mut status. Implementation of TERTp-mut into the WHO grading led to better patient prognostication by improved prediction of recurrence. Our results support implementation of TERTp-mut into diagnostics and classification of meningiomas.

TERT Alterations Predict Tumor Progression in De Novo High-Grade Meningiomas Following Adjuvant Radiotherapy

Background

Adjuvant radiotherapy (RT) is one of the most commonly used treatments for de novo high-grade meningiomas (HGMs) after surgery, but genetic determinants of clinical benefit are poorly characterized.

Objective

We describe efforts to integrate clinical genomics to discover predictive biomarkers that would inform adjuvant treatment decisions in de novo HGMs.

Methods

We undertook a retrospective analysis of 37 patients with de novo HGMs following RT. Clinical hybrid capture-based sequencing assay covering 184 genes was performed in all cases. Associations between tumor clinical/genomic characteristics and RT response were assessed. Overall survival (OS) and progression-free survival (PFS) curves were plotted using the Kaplan–Meier method.

Results

Among the 172 HGMs from a single institution, 42 cases (37 WHO grade 2 meningiomas and five WHO grade 3 meningiomas) were identified as de novo HGMs following RT. Only TERT mutations [62.5% C228T; 25% C250T; 12.5% copy number amplification (CN amp.)] were significantly associated with tumor progression after postoperative RT (adjusted p = 0.003). Potential different somatic interactions between TERT and other tested genes were not identified. Furthermore, TERT alterations (TERT-alt) were the predictor of tumor progression (Fisher’s exact tests, p = 0.003) and were associated with decreased PFS (log-rank test, p = 0.0114) in de novo HGMs after RT.

Conclusion

Our findings suggest that TERT-alt is associated with tumor progression and poor outcome of newly diagnosed HGM patients after postoperative RT.

Receptor Tyrosine Kinases as Candidate Prognostic Biomarkers and Therapeutic Targets in Meningioma

Meningioma (MGM) is the most common type of intracranial tumor in adults. The validation of novel prognostic biomarkers to better inform tumor stratification and clinical prognosis is urgently needed. Many molecular and cellular alterations have been described in MGM tumors over the past few years, providing a rational basis for the identification of biomarkers and therapeutic targets. The role of receptor tyrosine kinases (RTKs) as oncogenes, including those of the ErbB family of receptors, has been well established in several cancer types. Here, we review histological, molecular, and clinical evidence suggesting that RTKs, including the epidermal growth factor receptor (EGFR, ErbB1), as well as other members of the ErbB family, may be useful as biomarkers and therapeutic targets in MGM.

Discovering the Molecular Landscape of Meningioma: The Struggle to Find New Therapeutic Targets

Meningiomas are the most common primary CNS tumors. They are usually benign but can present aggressive behavior in about 20% of cases. The genetic landscape of meningioma is characterized by the presence (in about 60% of cases) or absence of NF2 mutation. Low-grade meningiomas can also present other genetic alterations, particularly affecting SMO, TRAF7, KLF4 AKT1 and PI3KCA. In higher grade meningiomas, mutations of TERT promoter and deletion of CDKN2A/B seem to have a prognostic value. Furthermore, other genetic alterations have been identified, such as BAP1, DMD and PBRM1. Different subgroups of DNA methylation appear to be correlated with prognosis. In this review, we explored the genetic landscape of meningiomas and the possible therapeutic implications.

RBM10: Structure, functions, and associated diseases

RBM10 is a nuclear RNA-binding protein (RBP) that regulates the alternative splicing of primary transcripts. Recently, research on RBM10 has become increasingly active owing to its clinical importance, as indicated by studies on RBM0 mutations that cause TARP syndrome, an X-linked congenital pleiotropic developmental anomaly, and various cancers such as lung adenocarcinoma in adults. Herein, the molecular biology of RBM10 and its significance in medicine are reviewed, focusing on the gene and protein structures of RBM10, its cell biology, molecular functions and regulation, relationship with the paralogous protein RBM5, and the mutations of RBM10 and their associated diseases. Finally, the challenges in future studies of RBM10 are discussed in the concluding remarks.

Associations of meningioma molecular subgroup and tumor recurrence

BACKGROUND

We and others have identified mutually exclusive molecular subgroups of meningiomas; however, the implications of this classification for clinical prognostication remain unclear. Integrated genomic and epigenomic analyses implicate unique oncogenic processes associated with each subgroup, suggesting the potential for divergent clinical courses. The aim of this study was to understand the associated clinical outcomes of each subgroup, as this could optimize treatment for patients.

METHODS

We analyzed outcome data for 469 meningiomas of known molecular subgroup, including extent of resection, postoperative radiation, surveillance imaging, and time to recurrence, when applicable. Statistical relationships between outcome variables and subgroup were assessed. Features previously associated with recurrence were further investigated after stratification by subgroup. We used Kaplan-Meier analyses to compare progression-free survival, and identified factors significantly associated with recurrence using Cox proportional hazards modeling.

RESULTS

Meningioma molecular subgroups exhibited divergent clinical courses at 2 years of follow-up, with several aggressive subgroups (NF2, PI3K, HH, tumor necrosis factor receptor-associated factor 7 [TRAF7]) recurring at an average rate of 22 times higher than others (KLF4, POLR2A, SMARCB1). PI3K-activated tumors recurred earlier than other subgroups but had intermediate long-term outcome. Among low-grade tumors, HH and TRAF7 meningiomas exhibited elevated recurrence compared with other subgroups. Recurrence of NF2 tumors was associated with male sex, high grade, and elevated Ki-67. Multivariate analysis identified molecular subgroup as an independent predictor of recurrence, along with grade and previous recurrence.

CONCLUSION

We describe distinct clinical outcomes and recurrence rates associated with meningioma molecular subgroups. Our findings emphasize the importance of genomic characterization to guide postoperative management decisions for meningiomas.

Associations of pathological diagnosis and genetic abnormalities in meningiomas with the embryological origins of the meninges

Certain driver mutations and pathological diagnoses are associated with the anatomical site of meningioma, based on which the meninges have different embryological origins. We hypothesized that mutations and pathological diagnoses of meningiomas are associated with different embryological origins. We comprehensively evaluated associations among tumor location, pathological diagnosis (histological type), and genetic alterations including AKT1, KLF4, SMO, POLR2A, and NF2 mutations and 22q deletion in 269 meningioma cases. Based on the embryological origin of meninges, the tumor locations were as follows: neural crest, paraxial mesodermal, and dorsal mesodermal origins. Tumors originating from the dura of certain embryologic origin displayed a significantly different pathological diagnoses and genetic abnormality ratio. For instance, driver genetic mutations with AKT1, KLF4, SMO, and POLR2A, were significantly associated with the paraxial mesodermal origin (p = 1.7 × 10⁻¹⁰). However, meningiomas with NF2-associated mutations were significantly associated with neural crest origin (p = 3.9 × 10^–12). On analysis of recurrence, no difference was observed in embryological origin. However, POLR2A mutation was a risk factor for the tumor recurrence (p = 1.7 × 10⁻², Hazard Ratio 4.08, 95% Confidence Interval 1.28–13.0). Assessment of the embryological origin of the meninges may provide novel insights into the pathomechanism of meningiomas.

Molecular alterations in meningioma: prognostic and therapeutic perspectives

PURPOSE OF REVIEW

To discuss recent advances in the meningioma biology and their clinical implications.

RECENT FINDINGS

Meningioma is the most common primary intracranial tumor. Mostly benign, 20% of cases display an aggressive behavior despite best standard of care. The genetic landscape of meningiomas is divided according to NF2 mutational status. Although about 60% of meningiomas display NF2 mutations, the other share is more heterogenous. Mutations in TRAF7, SMO, v-akt murine thymoma viral oncogene homolog 1 (AKT1), PI3KCA and KLF4 are seen mostly in WHO grade 1 meningiomas. In higher grade meningiomas, mutations of the TERT promoter and deletions of CDKN2A/B emerge and have prognostic value. Moreover, mutations in DMD, BAP1 and PBRM1 have recently been discovered and are being further explored. DNA methylation subgroups offer valuable insight into meningioma prognosis and its implementation in clinical setting is under evaluation. Moreover, the study of distinct meningioma populations such as radiation-induced meningioma and progestin-associated meningioma may provide further insight into meningioma oncogenesis and potential therapeutic targets.

SUMMARY

The mutational landscape of meningioma has expanded following the use of the new genetic sequencing approaches. Novel mutations have been characterized and reveal their prognostic and therapeutic applications. This improved understanding of meningioma biology has promising implications for novel treatment strategies.

DDX3X: structure, physiologic functions and cancer

The DEAD-box helicase family member DDX3X (DBX, DDX3) functions in nearly all stages of RNA metabolism and participates in the progression of many diseases, including virus infection, inflammation, intellectual disabilities and cancer. Over two decades, many studies have gradually unveiled the role of DDX3X in tumorigenesis and tumour progression. In fact, DDX3X possesses numerous functions in cancer biology and is closely related to many well-known molecules. In this review, we describe the function of DDX3X in RNA metabolism, cellular stress response, innate immune response, metabolic stress response in pancreatic β cells and embryo development. Then, we focused on the role of DDX3X in cancer biology and systematically demonstrated its functions in various aspects of tumorigenesis and development. To provide a more intuitive understanding of the role of DDX3X in cancer, we summarized its functions and specific mechanisms in various types of cancer and presented its involvement in cancer-related signalling pathways.

The Duchenne muscular dystrophy gene and cancer

BACKGROUND

Mutation of the Duchenne muscular dystrophy (DMD) gene causes Duchenne and Becker muscular dystrophy, degenerative neuromuscular disorders that primarily affect voluntary muscles. However, increasing evidence implicates DMD in the development of all major cancer types. DMD is a large gene with 79 exons that codes for the essential muscle protein dystrophin. Alternative promotor usage drives the production of several additional dystrophin protein products with roles that extend beyond skeletal muscle. The importance and function(s) of these gene products outside of muscle are not well understood.

CONCLUSIONS

We highlight a clear role for DMD in the pathogenesis of several cancers, including sarcomas, leukaemia's, lymphomas, nervous system tumours, melanomas and various carcinomas. We note that the normal balance of DMD gene products is often disrupted in cancer. The short dystrophin protein Dp71 is, for example, typically maintained in cancer whilst the full-length Dp427 gene product, a likely tumour suppressor, is frequently inactivated in cancer due to a recurrent loss of 5' exons. Therefore, the ratio of short and long gene products may be important in tumorigenesis. In this review, we summarise the tumours in which DMD is implicated and provide a hypothesis for possible mechanisms of tumorigenesis, although the question of cause or effect may remain. We hope to stimulate further study into the potential role of DMD gene products in cancer and the development of novel therapeutics that target DMD.

Distinct genomic subclasses of high-grade/progressive meningiomas: NF2-associated, NF2-exclusive, and NF2-agnostic

BACKGROUND

Genomic studies of high-grade/progressive meningiomas have reported a heterogeneous mutation spectrum, identifying few recurrently mutated genes. Most studies have been underpowered to detect genomic subclasses of aggressive meningiomas due to relatively small number of available samples. Here, we present a genomic survey of one of the largest multi-institutional cohorts of high-grade/progressive meningiomas to date.

METHODS

850 high-grade/progressive meningiomas, including 441 WHO grade 2 and 176 WHO grade 3 meningiomas and 220 progressive WHO grade 1 meningiomas, were tested as part of a clinical testing program by hybridization capture of 406 cancer-related genes to detect base substitutions, indels, amplifications, deletions, and rearrangements. Information from pathology reports, histopathology review, and patient clinical data was assessed.

RESULTS

Genomic analyses converged to identify at least three distinct patterns of biologically-aggressive meningiomas. The first and most common contained NF2-mutant tumors (n = 426, 50%), was associated with male sex (64.4% %, p = 0.0001) and often harbored additional mutations in CDKN2A/B (24%), and the chromatin regulators ARID1A (9%), and KDM6A (6%). A second group (NF2-agnostic) featured TERT promoter (TERTp; n = 56) or TP53 mutations (n = 25) and were either NF2-mutant or wild-type, and displayed no association with either sex (p = 0.39). The remaining group generally lacked NF2 mutations, and accounted for 40% of the cases-with three subgroups. One consistent primarily of grade 3 lesions harboring alterations in chromatin regulators BAP1 (n = 22) or PBRM1 (n = 16). A second subgroup contained AKT1 (n = 26), PIK3CA (n = 14) and SMO (n = 7) mutant skull-based meningiomas, and a third mixed subgroup included 237 meningiomas with a heterogeneous spectrum of low frequency and non-recurrent alterations.

CONCLUSIONS

Our findings indicate that the patterns of genomic alterations in high-grade/progressive meningiomas commonly group into three different categories. The most common NF2-associated canonical group frequently harbored CDKN2A/B alterations, which is potentially amenable to targeted therapies. An NF2-agnostic group harbored frequent TERTp and TP53 mutations. The final subclass, distinct from the canonical NF2 mutant associated pathway, was partly characterized by BAP1/PBRM1 alterations (rhabdoid/papillary histology) or skull-base disease. Overall, these data increase our understanding of the pathobiology of high-grade/progressive meningiomas and can guide the design of clinical trials.

IRB APPROVAL STATUS

Reviewed and approved by Western IRB; Protocol No. 20152817.

High Tumor Mitochondrial DNA Content Correlates With an Improved Patient's Outcome in WHO Grade III Meningioma

Background: Studies have shown mitochondrial genome content (mtDNA content) varies in many malignancies. However, its distribution and prognostic values in high-grade meningioma remain largely unknown. In this retrospective study, we sought to assess a putative correlation between the mtDNA content and clinical characteristics. Methods: Mitochondrial DNA was extracted from 87 World Health Organization grade III meningioma samples using a qPCR method. The distribution of mtDNA content in WHO grade III meningioma and its correlations with clinical variables were assessed. Furthermore, we prognostic values were also determined. Results: Mean mtDNA content was 617.7 (range, 0.8-3000). There was no mtDNA distribution difference based on the histological subtypes (P = 0.07). Tumors with preoperative radiation were associated with lower mtDNA content (P = 0.041), whereas no correlations with other clinical variables were observed. A high mtDNA content was associated with significantly better PFS (P = 0.044) and OS (P = 0.019). However, in patients who received postoperative radiotherapy, low mtDNA content was associated with better PFS (P = 0.028), while no difference in OS was observed (P = 0.272). Low mtDNA content was also associated with better OS and PFS in subgroups of patients with ER negative status (PFS, P = 0.002; OS, P = 0.002). Conclusions: Consistent with other tumors, high mtDNA content was associated with better outcome in WHO grade III meningioma in our cohort. However, for patients who received post-operative radiation therapy, low mtDNA content was associated with better PFS. These findings suggest that mtDNA content may further be explored as a potential biomarker for high-grade meningioma patients and for those who received postoperative radiation therapy.

Molecular Mechanism and Approach in Progression of Meningioma

Meningioma is the most common tumor of the central nervous system, most of which is benign. Even after complete resection, a high rate of recurrence of meningioma is observed. From in-depth study of its pathogenesis, it has been found that a number of chromosomal variations and abnormal molecular signals are closely related to the occurrence and development of malignancy in meningioma, which may provide the theoretical basis and potential direction for accurate and targeted treatment. We have reviewed advances in chromosomal variations and molecular mechanisms involved in the progression of meningioma, and have highlighted the association with malignant biological behavior including cell proliferation, angiogenesis, increased invasiveness, and inhibition of apoptosis. In addition, the chemotherapy of meningioma is summarized and discussed.

The medical necessity of advanced molecular testing in the diagnosis and treatment of brain tumor patients

Accurate pathologic diagnoses and molecularly informed treatment decisions for a wide variety of cancers depend on robust clinical molecular testing that uses genomic, epigenomic, and transcriptomic-based tools. Nowhere is this more essential than in the workup of brain tumors, as emphasized by the incorporation of molecular criteria into the 2016 World Health Organization classification of central nervous system tumors and the updated official guidelines of the National Comprehensive Cancer Network. Despite the medical necessity of molecular testing in brain tumors, access to and utilization of molecular diagnostics is still highly variable across institutions, and a lack of reimbursement for such testing remains a significant obstacle. The objectives of this review are (i) to identify barriers to adoption of molecular testing in brain tumors, (ii) to describe the current molecular tools recommended for the clinical evaluation of brain tumors, and (iii) to summarize how molecular data are interpreted to guide clinical care, so as to improve understanding and justification for their coverage in the routine workup of adult and pediatric brain tumor cases.

High Copy-Number Variation Burdens in Cranial Meningiomas From Patients With Diverse Clinical Phenotypes Characterized by Hot Genomic Structure Changes

Meningiomas, as the most common primary tumor of the central nervous system, are known to harbor genomic aberrations that associate with clinical phenotypes. Here we performed genome-wide genotyping for cranial meningiomas in 383 Chinese patients and identified 9,821 copy-number variations (CNVs). Particularly, patients with diverse clinical features had distinct tumor CNV profiles. CNV burdens were greater in high-grade (WHO grade II and III) samples, recurrent lesions, large tumors (diameter >4.3 cm), and those collected from male patients. Nevertheless, the level of CNV burden did not relate to tumor locations, peritumoral brain edema, bone invasion, or multiple lesions. Overall, the most common tumor CNVs were the copy-number gain (CNG) at 22q11.1 and the copy-number losses (CNLs) at 22q13.2, 14q11.2, 1p34.3, and 1p31.3. Recurrent lesions were featured by the CNLs at 1p31.3, 6q22.31, 9p21.3, and 11p12, and high-grade samples had more CNVs at 4q13.3 and 6q22.31. Meanwhile, large tumors were more likely to have the CNVs at 1p31.3 and 1p34.3. Additionally, recurrence prediction indicated the CNLs at 4p16.3 (p = 0.009, hazard ratio = 5.69) and 10p11.22 (p = 0.037, hazard ratio = 4.53) were candidate independent risk factors.

Advances in Molecular Classification and Therapeutic Opportunities in Meningiomas

PURPOSE OF REVIEW

Our understanding of the genetic and epigenetic alterations in meningioma and the underlying tumor biology of meningioma has significantly changed over the past decade and resulted in revision of prognostically relevant meningioma subclasses within and beyond the WHO classification of CNS tumors.

RECENT FINDINGS

The 2016 WHO classification of CNS tumors recognizes WHO grade I, II, and III based on histopathological features. Recent work has identified genetic alterations with prognostic implications, including mutations of the TERT promoter, loss of function of the DMD gene, and inactivation of the tumor suppressor BAP-1. Studies of DNA methylation patterns in meningiomas have resulted in a novel and prognostically relevant meningioma subclassification schema. There have been major advances in our understanding of prognostically relevant genetic and epigenetic changes in meningioma which will hopefully allow for improvement in clinical trial design and the development of more effective therapies for meningioma.

The Essentials of Molecular Testing in CNS Tumors: What to Order and How to Integrate Results

PURPOSE OF REVIEW

Molecular testing has become essential for the optimal workup of central nervous system (CNS) tumors. There is a vast array of testing from which to choose, and it can sometimes be challenging to appropriately incorporate findings into an integrated report. This article reviews various molecular tests and provides a concise overview of the most important molecular findings in the most commonly encountered CNS tumors.

RECENT FINDINGS

Many molecular alterations in CNS tumors have been identified over recent years, some of which are incorporated into the 2016 World Health Organization (WHO) classification and the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy-Not Official WHO (cIMPACT-NOW) updates. Array-based methylation profiling has emerged over the past couple of years and will likely replace much of currently used ancillary testing for diagnostic purposes. A combination of next-generation sequencing (NGS) panel and copy number array is ideal for diffuse gliomas and embryonal tumors, with a low threshold to employ in other tumor types. With the recent advances in molecular diagnostics, it will be ever more important for the pathologist to recognize the molecular testing available, which tests to perform, and to appropriately integrate results in light of clinical, radiologic, and histologic findings.

Pediatric clear cell meningioma involving the middle cranial fossa in the context of NF2 and SMARCE1 mutations

Meningiomas are an uncommon entity in children and adolescents. <30 cases of pediatric clear cell meningioma (CCM), a World Health Organization (WHO) Grade II tumor, have been reported in the literature. These tumors are more likely to recur than the more common WHO Grade I meningiomas, especially with incomplete surgical resection. CCMs are most commonly found in the spine and posterior cranial fossa. Recently, SMARCE1 mutations have been linked to the development of CCM. To evaluate the progression of pediatric CCM in the context of emerging genetic knowledge, we reviewed all 45 cases of CCM at our institution for a 23 year period (1997-2019) to identify pediatric cases. Forty-four of the tumors arose in adults from age 34-81 years. The one pediatric case originally presented at age 4 years; the patient was found to have a CCM in the left cavernous sinus projecting into the posterior fossa, associated with a novel germline SMARCE1 mutation and somatic NF1 and DMD mutations. After two years, the patient had a recurrence of the tumor and underwent a second resection. This is the 5th reported case of CCM in the middle cranial fossa, and the only recurrent case, as well as the only reported case of recurrent pediatric CCM associated with a germline SMARCE1 mutation. Further study of the natural history of tumors associated with germline SMARCE1 loss could potentially inform prognosis.

Poor prognosis associated with TERT gene alterations in meningioma is independent of the WHO classification: an individual patient data meta-analysis

BACKGROUND

TERT gene alterations (TERT-alt) have been linked to increased risk of recurrence in meningiomas, whereas the association to mortality largely remain incompletely investigated. As incongruence between clinical course and WHO grade exists, reliable biomarkers have been sought.

METHODS

We applied the Preferred Reporting Items for Systematic Review and Meta-Analyses of individual participant data Statement. We compiled data from eight studies and allocated patients to TERT-alt (n=59) or TERT promoter wild-type (TERTp-wt; n=618). We compared the two groups stratified for WHO grades as: incidence rates, survival probabilities and cumulative recurrences. We estimated the effects of WHO grade, age at diagnosis and sex as HRs.

RESULTS

TERT-alt occurred in 4.7%, 7.9% and 15.4% of WHO-I/WHO-II/WHO-III meningiomas, respectively. The median recurrence-free survival was 14 months for all TERT-alt patients versus 101 months for all TERTp-wt patients. The HR for TERT-alt was 3.74 in reference to TERTp-wt. For all TERT-alt patients versus all TERTp-wt patients, the median overall survival was 58 months and 160 months, respectively. The HR for TERT-alt was 2.77 compared with TERTp-wt. TERT-alt affected prognosis independent of WHO grades. Particularly, the recurrence rate was 4.8 times higher in WHO-I/-II TERT-alt patients compared with WHO-III TERTp-wt patients. The mortality rate was 2.7 times higher in the WHO-I and WHO-II TERT-alt patients compared with WHO-III TERTp-wt patients.

CONCLUSIONS

TERT-alt is an important biomarker for significantly higher risk of recurrence and death in meningiomas. TERT-alt should be managed and surveilled aggressively. We propose that TERT-alt analysis should be implemented as a routine diagnostic test in meningioma and integrated into the WHO classification.

TRIAL REGISTRATION NUMBER

PROSPERO: CRD42018110566.

A Risk Score Based on 5 Clinico-Pathological Variables Predicts Recurrence of Atypical Meningiomas

The use of adjuvant radiotherapy is controversial in patients with atypical meningiomas treated with gross total resection (GTR). This study aimed to determine whether clinico-pathological features could be helpful to predict the recurrence risk in this group of patients and to identify high-risk ones who could benefit from adjuvant treatment. We collected 200 patients with primary atypical meningiomas treated with GTR but with no adjuvant radiotherapy from 5 different centers. A risk score, formulated by assigning 1 point for the presence and 0 points for the absence of 5 high-risk parameters (male sex, parasagittal site, Simpson grade 3, mitotic index ≥ 6/10 HPF, and sheeting), was the most significant predictor of recurrence. A score ≥2 was associated with 4.7 risk of shorter disease-free survival (p < 0.0001). Our findings indicate that the presence of at least 2 clinico-pathological high-risk factors predicts recurrence of totally resected primary atypical meningiomas and could be helpful for identifying patients who could benefit from adjuvant radiotherapy.

Molecular characteristics of meningiomas

Meningioma is the most common primary intracranial tumor in adults. The grading of meningioma is based on World Health Organization criteria, which rely on histopathological features alone. This grading system is unable to conclusively predict the clinical behavior of these tumors (i.e., recurrence or prognosis in benign or atypical grades). Advances in molecular techniques over the last decade that include genomic and epigenomic data associated with meningiomas have been used to identify genetic biomarkers that can predict tumor behavior. This review summarizes the molecular characteristics of meningioma using genetic and epigenetic biomarkers. Molecular alterations that can predict meningioma behavior may be integrated into the upcoming World Health Organization grading system.

Genomic Analysis of Posterior Fossa Meningioma Demonstrates Frequent AKT1 E17K Mutations in Foramen Magnum Meningiomas

Objective  Posterior fossa meningiomas are surgically challenging tumors that are associated with high morbidity and mortality. We sought to investigate the anatomical distribution of clinically actionable mutations in posterior fossa meningioma to facilitate identifying patients amenable for systemic targeted therapy trials. Methods  Targeted sequencing of clinically targetable AKT1 , SMO , and PIK3CA mutations was performed in 61 posterior fossa meningioma using Illumina NextSeq 500 to a target depth of >500 × . Samples were further interrogated for 53 cancer-relevant RNA fusions by the Archer FusionPlex panel to detect gene rearrangements. Results   AKT 1 ( E17K ) mutations were detected in five cases (8.2%), four in the foramen magnum and one in the cerebellopontine angle. In contrast, none of the posterior fossa tumors harbored an SMO ( L412F ) or a PIK3CA ( E545K ) mutation. Notably, the majority of foramen magnum meningiomas (4/7, 57%) harbored an AKT1 mutation. In addition, common clinically targetable gene fusions were not detected in any of the cases. Conclusion  A large subset of foramen magnum meningiomas harbor AKT1 E17K mutations and are therefore potentially amenable to targeted medical therapy. Genotyping of foramen magnum meningiomas may enable more therapeutic alternatives and guide their treatment decision process.

Smooth Surface Visual Imaging Method for Eliminating High Reflection Disturbance

At present, visual imaging is widely applied for surface defects such as bumps and scratches in the manufacture of precise parts with a highly reflective surface. However, the high light reflection and halo disturbance as a result of the illumination in visual imaging exert a direct influence on the accuracy of defect detection. In this regard, the present paper develops an adaptive illumination method based on space–time modulation for a visual imaging system. Furthermore, a digital micro-mirror device (DMD) is employed to realize the pixel-level spatiotemporal modulation of illumination. Then, in combination with the illumination intensity feedback of charge coupled device (CCD), the time-space ratio is adjusted automatically to achieve adaptive uniform illumination and effectively suppress the high light reflection and halo disturbance of highly reflective surfaces. The experimental results show that, in terms of restraining high light disturbance, the visibility and accuracy of visual imaging are improved.

Mutational patterns and regulatory networks in epigenetic subgroups of meningioma

DNA methylation patterns delineate clinically relevant subgroups of meningioma. We previously established the six meningioma methylation classes (MC) benign 1-3, intermediate A and B, and malignant. Here, we set out to identify subgroup-specific mutational patterns and gene regulation. Whole genome sequencing was performed on 62 samples across all MCs and WHO grades from 62 patients with matched blood control, including 40 sporadic meningiomas and 22 meningiomas arising after radiation (Mrad). RNA sequencing was added for 18 of these cases and chromatin-immunoprecipitation for histone H3 lysine 27 acetylation (H3K27ac) followed by sequencing (ChIP-seq) for 16 samples. Besides the known mutations in meningioma, structural variants were found as the mechanism of NF2 inactivation in a small subset (5%) of sporadic meningiomas, similar to previous reports for Mrad. Aberrations of DMD were found to be enriched in MCs with NF2 mutations, and DMD was among the most differentially upregulated genes in NF2 mutant compared to NF2 wild-type cases. The mutational signature AC3, which has been associated with defects in homologous recombination repair (HRR), was detected in both sporadic meningioma and Mrad, but widely distributed across the genome in sporadic cases and enriched near genomic breakpoints in Mrad. Compared to the other MCs, the number of single nucleotide variants matching the AC3 pattern was significantly higher in the malignant MC, which also exhibited higher genomic instability, determined by the numbers of both large segments affected by copy number alterations and breakpoints between large segments. ChIP-seq analysis for H3K27ac revealed a specific activation of genes regulated by the transcription factor FOXM1 in the malignant MC. This analysis also revealed a super enhancer near the HOXD gene cluster in this MC, which, together with general upregulation of HOX genes in the malignant MC, indicates a role of HOX genes in meningioma aggressiveness. This data elucidates the biological mechanisms rendering different epigenetic subgroups of meningiomas, and suggests leveraging HRR as a novel therapeutic target.

Canine osteosarcoma genome sequencing identifies recurrent mutations in DMD and the histone methyltransferase gene SETD2

Osteosarcoma (OS) is a rare, metastatic, human adolescent cancer that also occurs in pet dogs. To define the genomic underpinnings of canine OS, we performed multi-platform analysis of OS tumors from 59 dogs, including whole genome sequencing (n = 24) and whole exome sequencing (WES; n = 13) of primary tumors and matched normal tissue, WES (n = 10) of matched primary/metastatic/normal samples and RNA sequencing (n = 54) of primary tumors. We found that canine OS recapitulates features of human OS including low point mutation burden (median 1.98 per Mb) with a trend towards higher burden in metastases, high structural complexity, frequent TP53 (71%), PI3K pathway (37%), and MAPK pathway mutations (17%), and low expression of immune-associated genes. We also identified novel features of canine OS including putatively inactivating somatic SETD2 (42%) and DMD (50%) aberrations. These findings set the stage for understanding OS development in dogs and humans, and establish genomic contexts for future comparative analyses.