A clinically applicable connectivity signature for glioblastoma includes the tumor network driver CHI3L1.

Tumor microtubes (TMs) connect glioma cells to a network with considerable relevance for tumor progression and therapy resistance. However, the determination of TM-interconnectivity in individual tumors is challenging and the impact on patient survival unresolved. Here, we establish a connectivity signature from single-cell RNA-sequenced (scRNA-Seq) xenografted primary glioblastoma (GB) cells using a dye uptake methodology, and validate it with recording of cellular calcium epochs and clinical correlations. Astrocyte-like and mesenchymal-like GB cells have the highest connectivity signature scores in scRNA-sequenced patient-derived xenografts and patient samples. In large GB cohorts, TM-network connectivity correlates with the mesenchymal subtype and dismal patient survival. CHI3L1 gene expression serves as a robust molecular marker of connectivity and functionally influences TM networks. The connectivity signature allows insights into brain tumor biology, provides a proof-of-principle that tumor cell TM-connectivity is relevant for patients' prognosis, and serves as a robust prognostic biomarker.

Cerebrospinal fluid cfDNA sequencing for classification of central nervous system glioma.

PURPOSE: Primary central nervous system (CNS) gliomas can be classified by characteristic genetic alterations. In addition to solid tissue obtained via surgery or biopsy, cell-free DNA (cfDNA) from cerebrospinal fluid (CSF) is an alternative source of material for genomic analyses. EXPERIMENTAL DESIGN: We performed targeted next-generation sequencing (NGS) of CSF cfDNA in a representative cohort of 85 patients presenting at two neurooncological centers with suspicion of primary or recurrent glioma. Copy-number variation (CNV) profiles, single nucleotide variants (SNVs), and small insertions/ deletions (indels) were combined into a molecular-guided tumor classification. Comparison with the solid tumor was performed for 38 cases with matching solid tissue available. RESULTS: Cases were stratified into four groups: glioblastoma (n = 32), other glioma (n = 19), non-malignant (n = 17) and non-diagnostic (n = 17). We introduced a molecular-guided tumor classification, which enabled identification of tumor entities and/ or cancer specific alterations in 75.0 % (n = 24) of glioblastoma and 52.6 % (n = 10) of other glioma cases. The overlap between CSF and matching solid tissue was highest for CNVs (26-48 %) and SNVs at pre-defined gene loci (44 %), followed by SNVs/ indels identified via uninformed variant calling (8-14 %). A molecular-guided tumor classification was possible for 23.5 % (n = 4) of non-diagnostic cases. CONCLUSIONS: We developed a targeted sequencing workflow for CSF cfDNA as well as a strategy for interpretation and reporting of sequencing results based on a molecular-guided tumor classification in glioma.

Prognostic Markers of DNA Methylation and Next-Generation Sequencing in Progressive Glioblastoma from the EORTC-26101 Trial.

PURPOSE: The EORTC-26101 study was a randomized phase II and III clinical trial of bevacizumab in combination with lomustine versus lomustine alone in progressive glioblastoma. Other than for progression-free survival (PFS), there was no benefit from addition of bevacizumab for overall survival (OS). However, molecular data allow for the rare opportunity to assess prognostic biomarkers from primary surgery for their impact in progressive glioblastoma. EXPERIMENTAL DESIGN: We analyzed DNA methylation array data and panel sequencing from 170 genes of 380 tumor samples of the EORTC-26101 study. These patients were comparable with the overall study cohort in regard to baseline characteristics, study treatment, and survival. RESULTS: Of patients' samples, 295/380 (78%) were classified into one of the main glioblastoma groups, receptor tyrosine kinase (RTK)1, RTK2 and mesenchymal. There were 10 patients (2.6%) with isocitrate dehydrogenase mutant tumors in the biomarker cohort. Patients with RTK1 and RTK2 classified tumors had lower median OS compared with mesenchymal (7.6 vs. 9.2 vs. 10.5 months). O6-methylguanine DNA-methyltransferase (MGMT) promoter methylation was prognostic for PFS and OS. Neurofibromin (NF)1 mutations were predictive of response to bevacizumab treatment. CONCLUSIONS: Thorough molecular classification is important for brain tumor clinical trial inclusion and evaluation. MGMT promoter methylation and RTK1 classifier assignment were prognostic in progressive glioblastoma. NF1 mutation may be a predictive biomarker for bevacizumab treatment.

Integrated genetic analyses of immunodeficiency-associated Epstein-Barr virus- (EBV) positive primary CNS lymphomas.

Immunodeficiency-associated primary CNS lymphoma (PCNSL) represents a distinct clinicopathological entity, which is typically Epstein-Barr virus-positive (EBV+) and carries an inferior prognosis. Genetic alterations that characterize EBV-related CNS lymphomagenesis remain unclear precluding molecular classification and targeted therapies. In this study, a comprehensive genetic analysis of 22 EBV+ PCNSL, therefore, integrated clinical and pathological information with exome and RNA sequencing (RNASeq) data. EBV+ PCNSL with germline controls carried a median of 55 protein-coding single nucleotide variants (SNVs; range 24-217) and 2 insertions/deletions (range 0-22). Genetic landscape was largely shaped by aberrant somatic hypermutation with a median of 41.01% (range 31.79-53.49%) of SNVs mapping to its target motifs. Tumors lacked established SNVs (MYD88, CD79B, PIM1) and copy number variants (CDKN2A, HLA loss) driving EBV- PCNSL. Instead, EBV+ PCNSL were characterized by SOCS1 mutations (26%), predicted to disinhibit JAK/STAT signaling, and mutually exclusive gain-of-function NOTCH pathway SNVs (26%). Copy number gains were enriched on 11q23.3, a locus directly targeted for chromosomal aberrations by EBV, that includes SIK3 known to protect from cytotoxic T-cell responses. Losses covered 5q31.2 (STING), critical for sensing viral DNA, and 17q11 (NF1). Unsupervised clustering of RNASeq data revealed two distinct transcriptional groups, that shared strong expression of CD70 and IL1R2, previously linked to tolerogenic tumor microenvironments. Correspondingly, deconvolution of bulk RNASeq data revealed elevated M2-macrophage, T-regulatory cell, mast cell and monocyte fractions in EBV+ PCNSL. In addition to novel insights into the pathobiology of EBV+ PCNSL, the data provide the rationale for the exploration of targeted therapies including JAK-, NOTCH- and CD70-directed approaches.

Pleiotropic role of TRAF7 in skull-base meningiomas and congenital heart disease.

While somatic variants of TRAF7 (Tumor necrosis factor receptor-associated factor 7) underlie anterior skull-base meningiomas, here we report the inherited mutations of TRAF7 that cause congenital heart defects. We show that TRAF7 mutants operate in a dominant manner, inhibiting protein function via heterodimerization with wild-type protein. Further, the shared genetics of the two disparate pathologies can be traced to the common origin of forebrain meninges and cardiac outflow tract from the TRAF7-expressing neural crest. Somatic and inherited mutations disrupt TRAF7-IFT57 interactions leading to cilia degradation. TRAF7-mutant meningioma primary cultures lack cilia, and TRAF7 knockdown causes cardiac, craniofacial, and ciliary defects in Xenopus and zebrafish, suggesting a mechanistic convergence for TRAF7-driven meningiomas and developmental heart defects.

Neurological autoimmune diseases following vaccinations against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): A follow-up study.

BACKGROUND AND PURPOSE: Population-based studies suggest severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines may trigger neurological autoimmunity including immune-mediated thrombotic thrombocytopenia. Long-term characterization of cases is warranted to facilitate patient care and inform vaccine-hesitant individuals. METHODS: In this single-center prospective case study with a median follow-up of 387 days long-term clinical, laboratory and imaging characteristics of patients with neurological autoimmunity diagnosed in temporal association (≤6 weeks) with SARS-CoV-2 vaccinations are reported. RESULTS: Follow-up data were available for 20 cases (central nervous system demyelinating diseases n = 8, inflammatory peripheral neuropathies n = 4, vaccine-induced immune thrombotic thrombocytopenia n = 3, myositis n = 2, myasthenia n = 1, limbic encephalitis n = 1, giant cell arteritis n = 1). Following therapy, the overall disability level improved (median modified Rankin Scale at diagnosis 3 vs. 1 at follow-up). The condition of two patients worsened despite immunosuppressants possibly related to their autoimmune diagnoses (limbic encephalitis n = 1, giant cell arteritis n = 1). At 12 months' follow-up, 12 patients achieved complete clinical remissions with partial responses in five and stable disease in one case. Correspondingly, autoimmune antibodies were non-detectable or titers had significantly lowered in all, and repeat imaging revealed radiological responses in most cases. Under vigilant monitoring 15 patients from our cohort underwent additional SARS-CoV-2 vaccinations (BNT162b2 n = 12, mRNA-1273 n = 3). Most patients (n = 11) received different vaccines than prior to diagnosis of neurological autoimmunity. Except for one short-lasting relapse, which responded well to steroids, re-vaccinations were well tolerated. CONCLUSIONS: In this study long-term characteristics of neurological autoimmunity encountered after SARS-CoV-2 vaccinations are defined. Outcome was favorable in most cases. Re-vaccinations were well tolerated and should be considered on an individual risk/benefit analysis.

Treatment Options for Recurrent Primary CNS Lymphoma.

OPINION STATEMENT: Primary CNS lymphoma (PCNSL) constitutes a rare extranodal variant of non-Hodgkin lymphoma (NHL) with an annual incidence of 0.45/100,000. Given the paucity of large prospective clinical trials, there is no consensus treatment for refractory or relapsed (r/r) PCNSL, and available strategies are largely based on retrospective analyses. Patient age, performance status, previously administered treatment, duration of response, and molecular characteristics guide selection of salvage therapy. Patients with a good performance status (KPS >70), particularly ≤65 years, and adequate organ function should be considered for salvage polychemotherapy. Based on its high overall response rate even in the relapsed setting, we choose high-dose (≥ 3.5g/m2) methotrexate (HD-MTX) based regimens, e.g., R-MPV (rituximab, HD-MTX, procarbazine, and vincristine), for remission re-induction as long as patients were sensitive to first line HD-MTX-based regimens, especially when duration of previous response was ≥ 1 year. Following successful remission induction, we choose myeloablative chemotherapy (e.g., thiotepa, busulfan, cyclophosphamide) and subsequent autologous stem cell transplant in curative intent whenever feasible. Alternatively, conventional chemotherapy regimens (for example, monthly HD-MTX) or low-dose whole-brain radiation therapy (WBRT) are selected for consolidation in non-transplant candidates in complete remission. In cases of HD-MTX refractory disease or contraindications, we use pemetrexed; temozolomide/rituximab; high-dose cytarabine; or whole brain radiation for remission induction. Clinical trial participation is considered as well. Emerging therapies for upfront or salvage therapy under ongoing investigation include bruton tyrosine kinase inhibition (e.g., ibrutinib), immunomodulatory drugs (e.g., lenalidomide), immune checkpoint inhibitors (ICI, e.g., nivolumab), and chimeric antigen receptor T (CAR-T) cell therapy.

Metabolic Heterogeneity of Brain Tumor Cells of Proneural and Mesenchymal Origin.

Brain-tumor-initiating cells (BTICs) of proneural and mesenchymal origin contribute to the highly malignant phenotype of glioblastoma (GB) and resistance to current therapies. BTICs of different subtypes were challenged with oxidative phosphorylation (OXPHOS) inhibition with metformin to assess the differential effects of metabolic intervention on key resistance features. Whereas mesenchymal BTICs varied according to their invasiveness, they were in general more glycolytic and less responsive to metformin. Proneural BTICs were less invasive, catabolized glucose more via the pentose phosphate pathway, and responded better to metformin. Targeting glycolysis may be a promising approach to inhibit tumor cells of mesenchymal origin, whereas proneural cells are more responsive to OXPHOS inhibition. Future clinical trials exploring metabolic interventions should account for metabolic heterogeneity of brain tumors.

Neurological autoimmune diseases following vaccinations against SARS-CoV-2: a case series.

BACKGROUND AND PURPOSE: Population-based studies suggest that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines may trigger immune-mediated thrombotic thrombocytopenia (VITT) raising concerns for other autoimmune responses. The aim was to characterize neurological autoimmunity after SARS-CoV-2 vaccinations. METHODS: In this single-centre prospective case study patients with neurological autoimmunity in temporal association (≤6 weeks) with SARS-CoV-2 vaccinations and without other triggers are reported. Clinical, laboratory and imaging data were collected with a median follow-up of 49 days. RESULTS: In the study period 232,603 inhabitants from the main catchment area of our hospital (Rhein-Neckar-Kreis, county) received SARS-CoV-2 vaccinations. Twenty-one cases (new onset n = 17, flares n = 4) diagnosed a median of 11 days (range 3-23) following SARS-CoV-2 vaccinations (BNT162b2 n = 12, ChAdOx1 n = 8, mRNA-1273 n = 1) were identified. Cases included VITT with cerebral venous sinus thrombosis (n = 3), central nervous system demyelinating diseases (n = 8), inflammatory peripheral neuropathies (n = 4), myositis (n = 3), myasthenia (n = 1), limbic encephalitis (n = 1) and giant cell arteritis (n = 1). Patients were predominantly female (ratio 3.2:1) and the median age at diagnosis was 50 years (range 22-86). Therapy included administration of steroids (n = 15), intravenous immunoglobulins in patients with Guillain-Barré syndrome or VITT (n = 4), plasma exchange in cases unresponsive to steroids (n = 3) and anticoagulation in VITT. Outcomes were favourable with partial and complete remissions achieved in 71% and 24%, respectively. Two patients received their second vaccination without further aggravation of autoimmune symptoms under low-dose immunosuppressants. CONCLUSIONS: In this study various neurological autoimmune disorders encountered following SARS-CoV-2 vaccinations are characterized. Given the assumed low incidence and mostly favourable outcome of autoimmune responses, the benefits of vaccinations outweigh the comparatively small risks.

Exome sequencing identifies SLIT2 variants in primary CNS lymphoma.

SLIT2 constitutes a known tumour suppressor gene, which has not yet been implicated in the pathogenesis of primary central nervous system lymphoma (PCNSL). Performing exome sequencing on paired blood and tumour DNA samples from six treatment-naïve PCNSL patients, we identified novel SLIT2 variants (p.N63S, p.T590M, p.T732S) that were associated with shorter progression-free survival in our cohort and shorter overall survival in a large validation cohort of lymphoid malignancies from the cBio Cancer Genomics Portal. WNT- and NF-κB-reporter luciferase assays suggest detected alterations are loss-of-function variants. Given the possible prognostic implications, the role of SLIT2 in PCNSL pathogenesis and progression warrants further investigation.

Autoimmune disease-related primary CNS lymphoma: systematic review and meta-analysis.

BACKGROUND: Recent studies suggest a relatively high prevalence of autoimmune disorders (AD) among primary CNS lymphoma (PCNSL) patients, however, the literature is limited to case reports. To gain a better understanding of AD-PCNSL we reviewed and analyzed all cases described in the literature. METHODS: We searched the MEDLINE database using the search terms 'central nervous system lymphoma' or 'CNS lymphoma' along with AD-related terms. We selected 39 records for qualitative synthesis of data and identified 50 AD-PCNSL. Clinical, imaging and outcome data were collected. Overall survival (OS) was analyzed with the Kaplan-Meier method. Univariate and multivariate analyses were performed using log rank test and Cox proportional hazard model. RESULTS: Most common AD were systemic lupus erythematosus (24%), multiple sclerosis (16%), and myasthenia gravis (14%). All patients had received immunosuppressants for their AD. Median interval from AD until PCNSL diagnosis was 108 months (range: 11-420). Male-to-female ratio was 0.42 and AD-PCNSL was diagnosed at a median age of 57 years (range: 2-88). On imaging lesions typically localized to the hemispheres (65%) and displayed peripheral enhancement (74%). Pathological evaluation revealed diffuse large-B-cell lymphoma (DLBCL) subtype (80%) and Epstein-Barr virus positivity (75%) in most AD-PCNSL. Median OS was 31 months. Age > 60 years (p = 0.014) was identified as a significant prognostic factor. CONCLUSIONS: AD requiring immunosuppression appear over-represented in the population of PCNSL patients. Aggressive polychemotherapy can accomplish long term OS in AD-PCNSL comparable to immunocompetent patients. Age > 60 may serve as a prognostic factor.

Leptomeningeal dissemination of low-grade neuroepithelial CNS tumors in adults: a 15-year experience.

BACKGROUND: Leptomeningeal dissemination (LD) in adults is an exceedingly rare complication of low-grade neuroepithelial CNS tumors (LGNs). We aimed to determine relative incidence, clinical presentation, and predictors of outcome. METHODS: We searched the quality control database of the Section of Neuro-Oncology, Yale Cancer Center, for patients with LGN (WHO grade I/II) seen between 2002 and 2017. For cases complicated by LD, we recorded demographics, clinical signs, histopathological diagnosis, and imaging findings. A comprehensive literature review was performed. RESULTS: Eleven consecutive patients with LD were identified, representing 2.3% of individuals with LGN seen at our institution between 2002 and 2017 (n = 475). Ependymoma was the predominant histological entity. Mean time interval from diagnosis of LGN to LD was 38.6 ± 10 months. Symptoms were mostly attributed to communicating hydrocephalus. Tumor deposits of LD were either nodular or linear with variable enhancement (nonenhancing lesions in 4 of 11 patients). Localized (surgery, radiosurgery, involved-field, or craniospinal radiation therapy) or systemic treatments (chemotherapy) were provided. All patients progressed radiographically. Median overall survival after LD was 102 months. Survival was prolonged when a combination of localized and systemic therapies was administered (188.5 vs 25.5 months; P = .03). Demographics and tumor spectrum reported in the literature were similar to our cohort. CONCLUSIONS: LD is a rare complication of LGNs. A high level of suspicion is required for timely diagnosis as early symptoms are nonspecific and commonly do not occur until years after initial tumor diagnosis. Repeated aggressive treatment appears to be beneficial in improving survival.

Primary dural lymphomas: Clinical presentation, management, and outcome.

BACKGROUND: Clinical experience is limited for primary central nervous system (CNS) lymphoma that arises from the dura mater, which is denoted with the term primary dural lymphoma (PDL). This study was aimed at determining the relative incidence, presentation, and outcomes of PDL. METHODS: The institutional databases of the Divisions of Neuro-Oncology at the Massachusetts General Hospital and the Yale School of Medicine were retrospectively searched for patients with primary CNS lymphoma. Patients with pathologically confirmed dural lymphoma and no evidence of primary cerebral or systemic involvement were identified. Clinical data, diagnostic findings, treatments, and outcomes were recorded. RESULTS: A total of 20 patients with PDL were identified, and they represented 6.3% of the individuals with primary CNS lymphomas (20 of 316). Histopathological examination of PDL revealed the following underlying subtypes: diffuse large B-cell lymphoma (10 of 20 patients), marginal zone lymphoma (6 of 20), follicular lymphoma (2 of 20), undefined B-cell non-Hodgkin lymphoma (1 of 20), and T-cell non-Hodgkin lymphoma (1 of 20). On imaging, all tumors appeared as extra-axial masses with avid contrast enhancement and mostly mimicked meningioma. The median apparent diffusion coefficient value was 667 ± 26 mm2 /s. Cerebrospinal fluid analyses and symptoms were nonspecific, and the diagnosis rested on tissue analysis. Therapeutic approaches included surgery, radiotherapy, and chemotherapy. The median overall survival was not reached after 5 years. Three patients were deceased at database closure because of tumor progression. The extent of tumor resection correlated positively with overall survival (P = .044). CONCLUSIONS: PDL is a rare variant of primary CNS lymphoma that can be radiographically mistaken for meningioma. The outcome is excellent with multimodality treatment, and aggressive surgery may convey a survival advantage in select cases.

Prognostic markers for immunodeficiency-associated primary central nervous system lymphoma.

BACKGROUND: Immunodeficiency is a major risk factor for primary central nervous system lymphoma (PCNSL), but data on the disease in immunocompromised hosts are scarce. We aimed to define clinical and imaging features and determine prognostic factors for immunodeficiency-associated PCNSL. METHODS: All PCNSL cases seen at Yale-New Haven Hospital between 2002 and 2017 were retrospectively screened for immunodeficiency. For patients with immunosuppression, biopsies were evaluated and clinical data were collected. Predictors of survival were identified using Kaplan-Meier survival analysis and log-rank test. p values < 0.05 were considered significant. RESULTS: 23 patients with immunodeficiencies were identified: eleven on immunosuppressants after solid organ transplantation, seven with human immunodeficiency virus infection, and five on immunosuppressive treatment due to various autoimmune disorders. PCNSL cases were largely Epstein-Barr-Virus positive (78%), histologically classified as diffuse large B cell lymphomas (87%), and showed peripheral contrast enhancement (81%) and corresponding heterogeneous diffusion-weighted imaging patterns (DWI) on magnetic resonance imaging (MRI) (71%). Median overall survival was 31 months. Age > 60 years at diagnosis (p < 0.01), peripheral enhancement of the mass on MRI (p = 0.04), heterogeneous DWI patterns (p = 0.04), and clonal immunoglobulin heavy chain gene rearrangement (IgHR) (p = 0.03) were found to be negative prognostic markers. CONCLUSIONS: Immunodeficiency-associated PCNSL presents with similar clinical, pathological and imaging features. Age > 60 years, clonal IgHR, heterogeneous DWI pattern and peripheral enhancement on MRI may serve as predictors of less favorable outcome.

Integrated genomic analyses of de novo pathways underlying atypical meningiomas.

This corrects the article DOI: 10.1038/ncomms14433.