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Background The purpose of this study was to analyze the potential of radiomics for disease stratification beyond key molecular, clinical, and standard imaging features in patients with glioblastoma. Methods Quantitative imaging features (n = 1043) were extracted from the multiparametric MRI of 181 patients with newly diagnosed glioblastoma prior to standard-of-care treatment (allocated to a discovery and a validation set, 2:1 ratio). A subset of 386/1043 features were identified as reproducible (in an independent MRI test-retest cohort) and selected for analysis. A penalized Cox model with 10-fold cross-validation (Coxnet) was fitted on the discovery set to construct a radiomic signature for predicting progression-free and overall survival (PFS and OS). The incremental value of a radiomic signature beyond molecular (O6-methylguanine-DNA methyltransferase [MGMT] promoter methylation, DNA methylation subgroups), clinical (patient's age, KPS, extent of resection, adjuvant treatment), and standard imaging parameters (tumor volumes) for stratifying PFS and OS was assessed with multivariate Cox models (performance quantified with prediction error curves). Results The radiomic signature (constructed from 8/386 features identified through Coxnet) increased the prediction accuracy for PFS and OS (in both discovery and validation sets) beyond the assessed molecular, clinical, and standard imaging parameters (P ≤ 0.01). Prediction errors decreased by 36% for PFS and 37% for OS when adding the radiomic signature (compared with 29% and 27%, respectively, with molecular + clinical features alone). The radiomic signature was-along with MGMT status-the only parameter with independent significance on multivariate analysis (P ≤ 0.01). Conclusions Our study stresses the role of integrating radiomics into a multilayer decision framework with key molecular and clinical features to improve disease stratification and to potentially advance personalized treatment of patients with glioblastoma.

Atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system is a highly malignant, pediatric brain tumor typically arising de novo. Inactivation of SMARCB1 is a defining molecular event. We present here a rare case of an adult (35 years) low-grade SMARCB1-deleted brain tumor with transition into prototypical AT/RT over 14 years. Molecular analysis was performed for 3 tumor presentations including copy number analysis, DNA methylation analysis (450k), and whole exome sequencing. We detected the identical somatic SMARCB1 deletion at all 3 time-points. In an unsupervised hierarchical clustering of methylation data together with 127 reference cases comprising 9 brain tumor classes all 3 manifestations clustered with AT/RT. Exome sequencing revealed an increase of mutational burden over time. The acquired mutations and additional copy number changes did not affect known cancer genes. In conclusion, we demonstrate molecular changes associated with histological and clinical transition of a low-grade brain tumor to an adult AT/RT. Our observation of a stable disease course for nearly 10 years in a tumor with SMARCB1 loss and an AT/RT-like DNA methylation profile indicates that caution may be required in the diagnostic interpretation of such findings in adult patients.

Summary Background The WHO classification of brain tumours describes 15 subtypes of meningioma. Nine of these subtypes are allotted to WHO grade I, and three each to grade II and grade III. Grading is based solely on histology, with an absence of molecular markers. Although the existing classification and grading approach is of prognostic value, it harbours shortcomings such as ill-defined parameters for subtypes and grading criteria prone to arbitrary judgment. In this study, we aimed for a comprehensive characterisation of the entire molecular genetic landscape of meningioma to identify biologically and clinically relevant subgroups. Methods In this multicentre, retrospective analysis, we investigated genome-wide DNA methylation patterns of meningiomas from ten European academic neuro-oncology centres to identify distinct methylation classes of meningiomas. The methylation classes were further characterised by DNA copy number analysis, mutational profiling, and RNA sequencing. Methylation classes were analysed for progression-free survival outcomes by the Kaplan-Meier method. The DNA methylation-based and WHO classification schema were compared using the Brier prediction score, analysed in an independent cohort with WHO grading, progression-free survival, and disease-specific survival data available, collected at the Medical University Vienna (Vienna, Austria), assessing methylation patterns with an alternative methylation chip. Findings We retrospectively collected 497 meningiomas along with 309 samples of other extra-axial skull tumours that might histologically mimic meningioma variants. Unsupervised clustering of DNA methylation data clearly segregated all meningiomas from other skull tumours. We generated genome-wide DNA methylation profiles from all 497 meningioma samples. DNA methylation profiling distinguished six distinct clinically relevant methylation classes associated with typical mutational, cytogenetic, and gene expression patterns. Compared with WHO grading, classification by individual and combined methylation classes more accurately identifies patients at high risk of disease progression in tumours with WHO grade I histology, and patients at lower risk of recurrence among WHO grade II tumours (p=0·0096) from the Brier prediction test). We validated this finding in our independent cohort of 140 patients with meningioma. Interpretation DNA methylation-based meningioma classification captures clinically more homogenous groups and has a higher power for predicting tumour recurrence and prognosis than the WHO classification. The approach presented here is potentially very useful for stratifying meningioma patients to observation-only or adjuvant treatment groups. We consider methylation-based tumour classification highly relevant for the future diagnosis and treatment of meningioma. Funding German Cancer Aid, Else Kroner-Fresenius Foundation, and DKFZ/Heidelberg Institute of Personalized Oncology/Precision Oncology Program.

Pediatric glioblastoma (pedGBM) is an extremely aggressive pediatric brain tumor, accounting for ~6% of all central nervous system neoplasms in children. Approximately half of pedGBM harbor recurrent somatic mutations in histone 3 variants or, infrequently, IDH1/2. The remaining subset of pedGBM is highly heterogeneous, and displays a variety of genomic and epigenetic features. In the current study, we aimed to further stratify an H3-/IDH-wild type (wt) pedGBM cohort assessed through genome-wide molecular profiling. As a result, we identified three molecular subtypes of these tumors, differing in their genomic and epigenetic signatures as well as in their clinical behavior. We designated these subtypes 'pedGBM_MYCN' (enriched for MYCN amplification), 'pedGBM_RTK1' (enriched for PDGFRA amplification) and 'pedGBM_RTK2' (enriched for EGFR amplification). These molecular subtypes were associated with significantly different outcomes, i.e. pedGBM_RTK2 tumors show a significantly longer survival time (median OS 44 months), pedGBM_MYCN display extremely poor outcomes (median OS 14 months), and pedGBM_RTK1 tumors harbor an intermediate prognosis. In addition, the various molecular subtypes of H3-/IDH-wt pedGBM were clearly distinguishable from their adult counterparts, underlining their biological distinctiveness. In conclusion, our study demonstrates significant molecular heterogeneity of H3-/IDH-wt pedGBM in terms of DNA methylation and cytogenetic alterations. The recognition of three molecular subtypes of H3-/IDH-wt pedGBM further revealed close correlations with biological parameters and clinical outcomes and may therefore, be predictive of response to standard treatment protocols, but could also be useful for stratification for novel, molecularly based therapies.

Spatial heterogeneity of transcriptional and genetic markers between physically isolated biopsies of a single tumor poses major barriers to the identification of biomarkers and the development of targeted therapies that will be effective against the entire tumor. We analyzed the spatial heterogeneity of multiregional biopsies from 35 patients, using a combination of transcriptomic and genomic profiles. Medulloblastomas (MBs), but not high-grade gliomas (HGGs), demonstrated spatially homogeneous transcriptomes, which allowed for accurate subgrouping of tumors from a single biopsy. Conversely, somatic mutations that affect genes suitable for targeted therapeutics demonstrated high levels of spatial heterogeneity in MB, malignant glioma, and renal cell carcinoma (RCC). Actionable targets found in a single MB biopsy were seldom clonal across the entire tumor, which brings the efficacy of monotherapies against a single target into question. Clinical trials of targeted therapies for MB should first ensure the spatially ubiquitous nature of the target mutation.

Recent developments in sequencing technologies led to the discovery of a novel form of genomic instability, termed chromothripsis. This catastrophic genomic event, involved in tumorigenesis, is characterized by tens to hundreds of simultaneously acquired locally clustered rearrangements on one chromosome. We hypothesized that leukemias developing in individuals with Ataxia Telangiectasia, who are born with two mutated copies of the ATM gene, an essential guardian of genome stability, would show a higher prevalence of chromothripsis due to the associated defect in DNA double-strand break repair. Using whole-genome sequencing, fluorescence in situ hybridization and RNA sequencing, we characterized the genomic landscape of Acute Lymphoblastic Leukemia (ALL) arising in patients with Ataxia Telangiectasia. We detected a high frequency of chromothriptic events in these tumors, specifically on acrocentric chromosomes, as compared with tumors from individuals with other types of DNA repair syndromes (27 cases total, 10 with Ataxia Telangiectasia). Our data suggest that the genomic landscape of Ataxia Telangiectasia ALL is clearly distinct from that of sporadic ALL. Mechanistically, short telomeres and compromised DNA damage response in cells of Ataxia Telangiectasia patients may be linked with frequent chromothripsis. Furthermore, we show that ATM loss is associated with increased chromothripsis prevalence in additional tumor entities.

Summary Two patients who shared similar presenting clinical features of anterograde and retrograde autobiographical amnesia typical of transient epileptic amnesia (TEA) underwent prolonged video electroencephalogram (VEEG) monitoring and were found to have sleep-activated epileptiform activity and frequent subclinical bitemporal seizures predominantly during sleep. Case one is a 59 year old woman whose presenting complaint was memory impairment. Over 18 months, she had three distinct eight hour long episodes of confusion and disorientation with persistent anterograde and retrograde autobiographical amnesia. VEEG recorded frequent interictal bitemporal sharp waves confined to sleep, and 14 subclinical seizures, also mostly during sleep. Case two is a 50 year old woman with known focal epilepsy also presented with memory complaints. Over the course of one year, she had two discrete two hour long episodes of amnesia, with ongoing anterograde and retrograde autobiographical amnesia. VEEG recorded independent bitemporal sharp waves, and 14 subclinical seizures during sleep and drowsiness. Memory impairment improved in both patients with successful treatment of their seizures. While the etiology of accelerated long term forgetting (ALF) and remote memory impairment (RMI) in transient epileptic amnesia (TEA) is unknown, these cases suggest frequent sleep-related seizures may contribute, and highlight the importance of video-EEG monitoring. This article is protected by copyright. All rights reserved.

Pediatric brain tumor entities harbor a variety of gene fusions. Whilst other molecular parameters like somatic mutations and copy number alterations have become pivotal for brain tumor diagnostics, gene fusions are only less well covered by routinely applied methylation arrays or targeted next-generation sequencing of DNA. In a routine diagnostic setting we established and optimized a workflow for investigation of gene fusions in formalin-fixed paraffin-embedded (FFPE) tumor tissues by using RNA sequencing. Assessing different tools for calling fusions from raw data, we found relevant fusions in 66 out of 101 (65%) analyzed cases in a prospective cohort collected over 26 months. In 43 (43%) cases the fusions were of decisive diagnostic relevance and in 40 (40%) cases the fusion genes rendered a druggable target. Besides the relevance of pathognomonic fusions for diagnostics, especially the detection of druggable gene fusions yields direct benefit to the patients. This approach allows for an unbiased search for fusion events in the tested samples. Besides rare variants of established fusions which were not detected by prior targeted analyses, we identified previously unreported fusion events. Exemplified on KIAA1549:BRAF fusion, we in addition provide an overview of the detection accuracy of different methods, including breakpoint detection in DNA methylation array data and fusion gene detection in DNA panel sequencing data. Our data show that RNA sequencing has great diagnostic as well as therapeutic value by clinically detecting relevant alterations.

Isomorphic diffuse glioma (IDG) was first described in 2004 as an epilepsy-associated supratentorial diffuse glioma with low cellularity, low proliferation and very monomorphic tumour cells. Most patients had seizures since childhood but were operated on as adults. To study the position of these lesions among brain tumours we histologically, molecularly and clinically analysed 26 histologically typical IDGs. Tumour cells were GFAP-positive, MAP2-, OLIG2- and CD34-negative and the nuclear ATRX-expression was retained. Proliferation was very low. Sequencing of 24 cases revealed an IDH-wildtype status. Cluster analyses of DNA methylation data showed that IDG has a DNA methylation profile distinct from those of different glial/glio-neuronal brain tumours and normal hemispheric tissue. About half of IDGs had copy number alterations of MYBL1 or MYB (13/25) and half of the cases analysed by RNA-sequencing had gene fusions of MYBL1 or MYB with various gene partners (11/22), often associated with an increased RNA-expression of the respective MYB-family gene. Integrating all data available, 77% of IDGs had either MYBL1 (54%) or MYB (23%) alterations. All patients had a good outcome and most were seizure-free after surgery. In summary, we show that isomorphic diffuse glioma is a distinct benign tumour in the family of MYB/MYBL1-altered gliomas. DNA methylation analysis is very helpful for their identification. More recent analyses of a large cohort of MYB/MYBL1-altered brain tumours suggest the presence of a third methylation group that primarily contains paediatric cases and seems to be distinct from IDG and angiocentric gliomas. Further histological, molecular and clinical analyses are ongoing.

Pineoblastoma (PB) is an aggressive embryonal brain tumor comprising 1% of pediatric CNS tumors. The clinico-molecular heterogeneity and developmental origins underlying PB are poorly understood; therefore, we have assembled a molecular cohort of histologically defined PBs (n=43) with corresponding outcome data. Methylation profiling revealed four molecularly and clinically distinct PB subgroups, including two novel entities. Mutational and transcriptional analysis identified characteristic molecular features of each subgroup, such as mutations in the miRNA processing pathway or FOXR2 proto-oncogene overexpression. Furthermore, subgroups exhibited differences in propensity for metastasis, cytogenetics, and clinical outcomes. To dissect PB developmental origins and resolve PB subgroup biology, we have employed a combination of single-cell genomics and genetically engineered mouse modeling. We created a single-cell transcriptional atlas of the developing murine pineal gland across 11 timepoints and are currently integrating these data with single nuclei RNA-seq data of human PB (n=25). Single-cell analysis of the developing pineal gland revealed three distinct populations of pinealocytes, referred to as early, mid and late pinealocytes, which segregate by developmental stage yet lie along a single developmental trajectory. Preliminary results implicate significant associations between PBs and the early pinealocyte population as well as subgroup-specific differences in intratumoral heterogeneity. Furthermore, this knowledge has informed the downstream generation of biologically faithful disease models, including a transgenic mouse model of the PB-RB subgroup. Remarkably, this model shows up-regulation of key markers of PB such as Crx, Asmt and Otx2 and substantiates early pinealocytes as the probable cell-of-origin for this PB subgroup.

BACKGROUND Our previous analysis of established cancer predisposition genes in medulloblastoma (MB) identified pathogenic germline variants in ~5% of all patients. Here, we extended our analysis to include all protein-coding genes. METHODS Case-control analysis performed on 795 MB patients against >118,000 cancer-free children and adults was performed to identify an association between rare germline variants and MB. RESULTS Germline loss-of-function variants of Elongator Complex Protein 1 (ELP1; 9q31.3) were strongly associated with SHH subgroup (MBSHH). ELP1-associated-MBs accounted for ~15% (29/202) of pediatric MBSHH cases and were restricted to the SHHα subtype. ELP1-associated-MBs demonstrated biallelic inactivation of ELP1 due to somatic chromosome 9q loss and most tumors exhibited co-occurring somatic PTCH1 (9q22.32) alterations. Inheritance was verified by parent-offspring sequencing (n=3) and pedigree analysis identified two families with a history of pediatric MB. ELP1-associated-MBSHH were characterized by desmoplastic/nodular histology (76%; 13/17) and demonstrated a favorable clinical outcome when compared to TP53-associated-MBSHH (5-yr OS 92% vs 20%; p-value=1.3e-6) despite both belonging to the SHHα subtype. ELP1 is a subunit of the Elongator complex, that promotes efficient translational elongation through tRNA modifications at the wobble (U34) position. Biochemical, transcriptional, and proteomic analyses revealed ELP1-associated-MBs exhibit destabilization of the core Elongator complex, loss of tRNA wobble modifications, codon-dependent translational reprogramming, and induction of the unfolded protein response. CONCLUSIONS We identified ELP1 as the most common MB predisposition gene, increasing the total genetic predisposition for pediatric MBSHH to 40%. These results mark MBSHH as an overwhelmingly genetically-predisposed disease and implicate disruption of protein homeostasis in MBSHH development.

Author(s): Heuer, Hilary W; Wang, P; Rascovsky, K; Wolf, A; Appleby, B; Bove, J; Bordelon, Y; Brannelly, P; Brushaber, DE; Caso, C; Coppola, G; Dickerson, B; Dickinson, S; Domoto-Reilly, K; Faber, K; Ferrall, J; Fields, J; Fishman, A; Fong, J; Foroud, T; Forsberg, LK; Gearhart, D; Ghazanfari, B; Ghoshal, N; Goldman, J; Graff-Radford, J; Graff-Radford, N; Grant, I; Grossman, M; Haley, D; Hsiung, G-Y; Huey, E; Irwin, D; Jones, D; Kantarci, K; Karydas, A; Kaufer, D; Kerwin, D; Knopman, D; Kornak, J; Kramer, JH; Kraft, R; Kremers, WK; Kukull, W; Litvan, I; Ljubenkov, P; Mackenzie, IR; Maldonado, M; Manoochehri, M; McGinnis, S; McKinley, E; Mendez, MF; Miller, BL; Onyike, C; Pantelyat, A; Pearlman, R; Petrucelli, L; Potter, M; Rademakers, R; Ramos, EM; Rankin, KP; Roberson, ED; Rogalski, E; Sengdy, P; Shaw, L; Syrjanen, J; Tartaglia, MC; Tatton, N; Taylor, J; Toga, A; Trojanowski, J; Weintraub, S; Wong, B; Wszolek, Z; Boeve, BF; Rosen, HJ; Boxer, AL; ARTFL and LEFFTDS consortia | Abstract: IntroductionBehavioral variant frontotemporal dementia (bvFTD) may present sporadically or due to an autosomal dominant mutation. Characterization of both forms will improve understanding of the generalizability of assessments and treatments.MethodsA total of 135 sporadic (s-bvFTD; mean age 63.3 years; 34% female) and 99 familial (f-bvFTD; mean age 59.9; 48% female) bvFTD participants were identified. f-bvFTD cases included 43 with known or presumed chromosome 9 open reading frame 72 (C9orf72) gene expansions, 28 with known or presumed microtubule-associated protein tau (MAPT) mutations, 14 with known progranulin (GRN) mutations, and 14 with a strong family history of FTD but no identified mutation.ResultsParticipants with f-bvFTD were younger and had earlier age at onset. s-bvFTD had higher total Neuropsychiatric Inventory Questionnaire (NPI-Q) scores due to more frequent endorsement of depression and irritability.Discussionf-bvFTD and s-bvFTD cases are clinically similar, suggesting the generalizability of novel biomarkers, therapies, and clinical tools developed in either form to the other.

DNA methylation data-based precision cancer diagnostics is emerging as the state of the art for molecular tumor classification. Standards for choosing statistical methods with regard to well-calibrated probability estimates for these typically highly multiclass classification tasks are still lacking. To support this choice, we evaluated well-established machine learning (ML) classifiers including random forests (RFs), elastic net (ELNET), support vector machines (SVMs) and boosted trees in combination with post-processing algorithms and developed ML workflows that allow for unbiased class probability (CP) estimation. Calibrators included ridge-penalized multinomial logistic regression (MR) and Platt scaling by fitting logistic regression (LR) and Firth’s penalized LR. We compared these workflows on a recently published brain tumor 450k DNA methylation cohort of 2,801 samples with 91 diagnostic categories using a 5 × 5-fold nested cross-validation scheme and demonstrated their generalizability on external data from The Cancer Genome Atlas. ELNET was the top stand-alone classifier with the best calibration profiles. The best overall two-stage workflow was MR-calibrated SVM with linear kernels closely followed by ridge-calibrated tuned RF. For calibration, MR was the most effective regardless of the primary classifier. The protocols developed as a result of these comparisons provide valuable guidance on choosing ML workflows and their tuning to generate well-calibrated CP estimates for precision diagnostics using DNA methylation data. Computation times vary depending on the ML algorithm from

Author(s): Miyagawa, Toji; Brushaber, Danielle; Syrjanen, Jeremy; Kremers, Walter; Fields, Julie; Forsberg, Leah K; Heuer, Hilary W; Knopman, David; Kornak, John; Boxer, Adam; Rosen, Howard J; Boeve, Bradley F; Appleby, Brian; Bordelon, Yvette; Bove, Jessica; Brannelly, Patrick; Caso, Christina; Coppola, Giovanni; Dever, Reilly; Dheel, Christina; Dickerson, Bradford; Dickinson, Susan; Dominguez, Sophia; Domoto-Reilly, Kimiko; Faber, Kelley; Ferrell, Jessica; Fishman, Ann; Fong, Jamie; Foroud, Tatiana; Gavrilova, Ralitza; Gearhart, Debra; Ghazanfari, Behnaz; Ghoshal, Nupur; Goldman, Jill S; Graff-Radford, Jonathan; Graff-Radford, Neill; Grant, Ian; Grossman, Murray; Haley, Dana; Hsiung, Robin; Huey, Edward; Irwin, David; Jones, David; Jones, Lynne; Kantarci, Kejal; Karydas, Anna; Kaufer, Daniel; Kerwin, Diana; Kraft, Ruth; Kramer, Joel; Kukull, Walter; Litvan, Irene; Lucente, Diane; Lungu, Codrin; Mackenzie, Ian; Maldonado, Miranda; Manoochehri, Masood; McGinnis, Scott; McKinley, Emily; Mendez, Mario F; Miller, Bruce; Multani, Namita; Onyike, Chiadi; Padmanabhan, Jaya; Pantelyat, Alexander; Pearlman, Rodney; Petrucelli, Leonard; Potter, Madeline; Rademakers, Rosa; Ramos, Eliana M; Rankin, Kate; Rascovsky, Katya; Roberson, Erik D; Rogalski, Emily; Sengdy, Pheth; Shaw, Leslie; Tartaglia, Maria C; Tatton, Nadine; Taylor, Joanne; Toga, Arthur; Trojanowski, John Q; Wang, Ping; Weintraub, Sandra; Wong, Bonnie; Wszolek, Zbigniew | Abstract: IntroductionWe created global rating scoring rules for the CDR® plus NACC FTLD to detect and track early frontotemporal lobar degeneration (FTLD) and to conduct clinical trials in FTLD.MethodsThe CDR plus NACC FTLD rating was applied to 970 sporadic and familial participants from the baseline visit of Advancing Research and Treatment in Frontotemporal Lobar Degeneration (ARTFL)/Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects (LEFFTDS). Each of the eight domains of the CDR plus NACC FTLD was equally weighed in determining the global score. An interrater reliability study was completed for 40 participants.ResultsThe CDR plus NACC FTLD showed very good interrater reliability. It was especially useful in detecting clinical features of mild non-fluent/agrammatic variant primary progressive aphasia participants.DiscussionThe global CDR plus NACC FTLD score could be an attractive outcome measure for clinical trials in symptomatic FTLD, and may be useful in natural history studies and clinical trials in FTLD spectrum disorders.

We report a group of patients presenting with a progressive dementia syndrome characterized by predominant dysfunction in core executive functions, relatively young age of onset and positive biomarkers for Alzheimer’s pathophysiology. Atypical frontal, dysexecutive/behavioural variants and early-onset variants of Alzheimer’s disease have been previously reported, but no diagnostic criteria exist for a progressive dysexecutive syndrome. In this retrospective review, we report on 55 participants diagnosed with a clinically defined progressive dysexecutive syndrome with 18F-fluorodeoxyglucose-positron emission tomography and Alzheimer’s disease biomarkers available. Sixty-two per cent of participants were female with a mean of 15.2 years of education. The mean age of reported symptom onset was 53.8 years while the mean age at diagnosis was 57.2 years. Participants and informants commonly referred to initial cognitive symptoms as ‘memory problems’ but upon further inquiry described problems with core executive functions of working memory, cognitive flexibility and cognitive inhibitory control. Multi-domain cognitive impairment was evident in neuropsychological testing with executive dysfunction most consistently affected. The frontal and parietal regions which overlap with working memory networks consistently demonstrated hypometabolism on positron emission tomography. Genetic testing for autosomal dominant genes was negative in all eight participants tested and at least one APOE ε4 allele was present in 14/26 participants tested. EEG was abnormal in 14/17 cases with 13 described as diffuse slowing. Furthermore, CSF or neuroimaging biomarkers were consistent with Alzheimer’s disease pathophysiology, although CSF p-tau was normal in 24% of cases. Fifteen of the executive predominate participants enrolled in research neuroimaging protocols and were compared to amnestic (n = 110), visual (n = 18) and language (n = 7) predominate clinical phenotypes of Alzheimer’s disease. This revealed a consistent pattern of hypometabolism in parieto-frontal brain regions supporting executive functions with relative sparing of the medial temporal lobe (versus amnestic phenotype), occipital (versus visual phenotype) and left temporal (versus language phenotype). We propose that this progressive dysexecutive syndrome should be recognized as a distinct clinical phenotype disambiguated from behavioural presentations and not linked specifically to the frontal lobe or a particular anatomic substrate without further study. This clinical presentation can be due to Alzheimer’s disease but is likely not specific for any single aetiology. Diagnostic criteria are proposed to facilitate additional research into this understudied clinical presentation., We present a retrospective case series of 55 individuals presenting with a progressive dysexecutive syndrome with biomarker evidence of Alzheimer’s disease. This clinical syndrome should be recognized as a distinct clinical phenotype that is disambiguated form behavioural presentations and not linked to a particular anatomic substrate without further study., Graphical Abstract Graphical Abstract

Among individuals with dementia with Lewy bodies, pathologic correlates of clinical course include the presence and extent of coexisting Alzheimer’s pathology and the presence of transitional or diffuse Lewy body disease. The objectives of this study are to determine (i) whether 18F-fluorodeoxyglucose PET signature patterns of dementia with Lewy bodies are associated with the extent of coexisting Alzheimer’s pathology and the presence of transitional or diffuse Lewy body disease and (ii) whether these 18F-fluorodeoxyglucose pattern(s) are associated with clinical course in dementia with Lewy bodies. Two groups of participants were included: a pathology-confirmed subset with Lewy body disease (n = 34) and a clinically diagnosed group of dementia with Lewy bodies (n = 87). A subset of the clinically diagnosed group was followed longitudinally (n = 51). We evaluated whether 18F-fluorodeoxyglucose PET features of dementia with Lewy bodies (higher cingulate island sign ratio and greater occipital hypometabolism) varied by Lewy body disease subtype (transitional versus diffuse) and Braak neurofibrillary tangle stage. We investigated whether the PET features were associated with the clinical trajectories by performing regression models predicting Clinical Dementia Rating Scale Sum of Boxes. Among autopsied participants, there was no difference in cingulate island sign or occipital hypometabolism by Lewy body disease type, but those with a lower Braak tangle stage had a higher cingulate island sign ratio compared to those with a higher Braak tangle stage. Among the clinically diagnosed dementia with Lewy bodies participants, a higher cingulate island ratio was associated with better cognitive scores at baseline and longitudinally. A higher 18F-fluorodeoxyglucose PET cingulate island sign ratio was associated with lower Braak tangle stage at autopsy, predicted a better clinical trajectory in dementia with Lewy body patients and may allow for improved prognostication of the clinical course in this disease., In dementia with Lewy bodies, a higher cingulate island sign ratio on 18F-fluorodeoxyglucose PET was associated with a lower Braak neurofibrillary tangle stage. We investigated whether the cingulate island sign was associated with clinical trajectory. A higher cingulate island sign ratio was associated with better cognition at baseline and longitudinally., Graphical Abstract Graphical Abstract

Introduction It is important to establish the natural history of familial frontotemporal lobar degeneration (f-FTLD) and provide clinical and biomarker data for planning these studies, particularly in the asymptomatic phase. Methods The Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects protocol was designed to enroll and follow at least 300 subjects for more than at least three annual visits who are members of kindreds with a mutation in one of the three most common f-FTLD genes—microtubule-associated protein tau, progranulin, or chromosome 9 open reading frame 72. Results We present the theoretical considerations of f-FTLD and the aims/objectives of this protocol. We also describe the design and methodology for evaluating and rating subjects, in which detailed clinical and neuropsychological assessments are performed, biofluid samples are collected, and magnetic resonance imaging scans are performed using a standard protocol. Discussion These data and samples, which are available to interested investigators worldwide, will facilitate planning for upcoming disease-modifying therapeutic trials in f-FTLD.

Objective The Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects evaluates familial frontotemporal lobar degeneration (FTLD) kindreds with MAPT, GRN, or C9orf72 mutations. Objectives were to examine whether health‐related quality of life (HRQoL) correlates with clinical symptoms and caregiver burden, and whether self‐rated and informant‐rated HRQoL would correlate with each other. Methods Individuals were classified using the Clinical Dementia Rating (CDR®) Scale plus National Alzheimer's Coordinating Center (NACC) FTLD. HRQoL was measured with DEMQOL and DEMQOL‐proxy; caregiver burden with the Zarit Burden Interview (ZBI). For analysis, Pearson correlations and weighted kappa statistics were calculated. Results The cohort of 312 individuals included symptomatic and asymptomatic individuals. CDR® plus NACC FTLD was negatively correlated with DEMQOL (r = −0.20, P = .001), as were ZBI and DEMQOL (r = −0.22, P = .0009). There was fair agreement between subject and informant DEMQOL (κ = 0.36, P

Introduction The Advancing Research and Treatment in Frontotemporal Lobar Degeneration and Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects longitudinal studies were designed to describe the natural history of familial-frontotemporal lobar degeneration due to autosomal dominant mutations. Methods We examined cognitive performance, behavioral ratings, and brain volumes from the first time point in 320 MAPT, GRN, and C9orf72 family members, including 102 non–mutation carriers, 103 asymptomatic carriers, 43 mildly/questionably symptomatic carriers, and 72 carriers with dementia. Results Asymptomatic carriers showed similar scores on all clinical measures compared with noncarriers but reduced frontal and temporal volumes. Those with mild/questionable impairment showed decreased verbal recall, fluency, and Trail Making Test performance and impaired mood and self-monitoring. Dementia was associated with impairment in all measures. All MAPT carriers with dementia showed temporal atrophy, but otherwise, there was no single cognitive test or brain region that was abnormal in all subjects. Discussion Imaging changes appear to precede clinical changes in familial-frontotemporal lobar degeneration, but specific early clinical and imaging changes vary across individuals.

Aims: DNA methylation-based central nervous system (CNS) tumour classification has identified numerous molecularly distinct tumour types, and clinically relevant subgroups among known CNS tumour entities that were previously thought to represent homogeneous diseases. Our study aimed at characterizing a novel, molecularly defined variant of glioneuronal CNS tumour. Patients and methods: DNA methylation profiling was performed using the Infinium MethylationEPIC or 450 k BeadChip arrays (Illumina) and analysed using the ‘conumee’ package in R computing environment. Additional gene panel sequencing was also performed. Tumour samples were collected at the German Cancer Research Centre (DKFZ) and provided by multinational collaborators. Histological sections were also collected and independently reviewed. Results: Genome-wide DNA methylation data from >25 000 CNS tumours were screened for clusters separated from established DNA methylation classes, revealing a novel group comprising 31 tumours, mainly found in paediatric patients. This DNA methylation-defined variant of low-grade CNS tumours with glioneuronal differentiation displays recurrent monosomy 14, nuclear clusters within a morphology that is otherwise reminiscent of oligodendroglioma and other established entities with clear cell histology, and a lack of genetic alterations commonly observed in other (paediatric) glioneuronal entities. Conclusions: DNA methylation-based tumour classification is an objective method of assessing tumour origins, which may aid in diagnosis, especially for atypical cases. With increasing sample size, methylation analysis allows for the identification of rare, putative new tumour entities, which are currently not recognized by the WHO classification. Our study revealed the existence of a DNA methylation-defined class of low-grade glioneuronal tumours with recurrent monosomy 14, oligodendroglioma-like features and nuclear clusters.

Embryonal tumours with multilayered rosettes (ETMRs) are aggressive paediatric embryonal brain tumours with a universally poor prognosis1. Here we collected 193 primary ETMRs and 23 matched relapse samples to investigate the genomic landscape of this distinct tumour type. We found that patients with tumours in which the proposed driver C19MC2–4 was not amplified frequently had germline mutations in DICER1 or other microRNA-related aberrations such as somatic amplification of miR-17-92 (also known as MIR17HG). Whole-genome sequencing revealed that tumours had an overall low recurrence of single-nucleotide variants (SNVs), but showed prevalent genomic instability caused by widespread occurrence of R-loop structures. We show that R-loop-associated chromosomal instability can be induced by the loss of DICER1 function. Comparison of primary tumours and matched relapse samples showed a strong conservation of structural variants, but low conservation of SNVs. Moreover, many newly acquired SNVs are associated with a mutational signature related to cisplatin treatment. Finally, we show that targeting R-loops with topoisomerase and PARP inhibitors might be an effective treatment strategy for this deadly disease.

Normal pressure hydrocephalus (NPH) is a syndrome that was characterized several decades ago; however, its optimal diagnosis and management remain unclear. Our objective was to evaluate citation and bibliometric characteristics of the 100 most cited articles about NPH to better understand the state of research efforts in the field and where improvements may arise.Elsevier's Scopus database was searched for the 100 most cited articles that focused on NPH. Articles were characterized and various bibliometric parameters were compared. Categorical data were analyzed using Pearson χThe 100 most cited articles were published between 1965 and 2014, from 16 unique countries in 38 unique journals. The most common outcome types of these articles were clinical (n = 77). Median number of citations and rate of citations were 114 citations and 5.9 citations/year since publication, respectively, with a significant inverse linear relationship between the 2 parameters (P0.01). The most common year of publication was 2002 (n = 10), and the most common country of origin was the United States (n = 40). Higher citation rates were associated with more recent articles (P0.01) and more authors (P0.01).In the 100 most cited articles about NPH, there has been a distinct shift toward a more globalized effort in recent decades. The lack of more impactful articles in recent decades highlights that particular classic studies still penetrate practice and the possible need to reconsider our contemporary views on NPH to further advance the field.

INTRODUCTION Recurrent medulloblastoma (MB) confers an abysmal prognosis with ~10% 5-year overall survival. Optimal treatment paradigms for relapsed disease are largely unknown. Conservation of molecular subgroup at relapse has been described and divergent clonal evolution implicated, yet multi-dimensional molecular characterization of larger cohorts are warranted to substantiate these findings and to disclose potential mechanisms underlying treatment failure and disease recurrence. METHODS A multi-institutional series of 85 patient-matched, primary MBs and their relapses was profiled by DNA methylation array (Illumina 450K/850K). Entity and molecular subgroup classifications were assigned using random forest tumor classifiers (Molecular Neuropathology v.11b4). Genome-wide copy-number aberrations were also inferred from these data while parallel next-generation (whole-exome or targeted panel) sequencing on the majority of the cohort facilitated inference of somatic driver mutations. RESULTS Comprised of WNT (1%), SHH (41%), Group 3 (22%), Group 4 (35%), primary tumors largely retained subgroup affiliation at relapse with the notable exception of 14% of cases. The majority (8/12) of discrepant classifications were determined to be secondary glioblastomas, while three Group 4 primary tumors relapsed as Group 3. Amongst conserved pairs, copy-number analyses suggest somatic clonal divergence between primary MBs and their respective relapses with an average of 0.8 (range 0–5) primary-specific and 2.0 (range 0–11) relapse-specific cytogenetic alterations. Despite high global methylation correlations between primary/relapse pairs (median 0.95), epigenetic evolution at relapse is suggested by the lower degree of conservation amongst promoter-associated probes (median 0.83, p < 2.2e-16). CONCLUSION Secondary malignancy, particularly glioblastoma, may masquerade as relapsed MB, highlighting the utility of molecular characterization for relapsed disease and necessity for vigilant clinical surveillance. By deciphering the evolution of MB from diagnosis to relapse, a fundamental understanding of disease pathogenesis may be garnered, motivating rational and targeted clinical interventions in early therapy and at the time of relapse.

Introduction Behavior/Comportment/Personality (BEHAV) and Language (LANG) domains were added to the Clinical Dementia Rating (CDR®) for improving evaluation of patients with frontotemporal lobar degeneration (FTLD) (CDR® plus NACC FTLD). Methods We analyzed the CDR® plus NACC FTLD among participants from the baseline visit of the Advancing Research and Treatment for Frontotemporal Lobar Degeneration/Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects Consortium. Results The CDR® plus NACC FTLD was able to detect early symptoms in the mildly impaired participants who were rated as CDR® sum of boxes (CDR®-SB) = 0. The CDR®-SB was not sensitive, particularly in participants with mild nonfluent/agrammatic primary progressive aphasia. Participants with familial and sporadic behavioral variant FTD exhibited similar CDR® plus NACC FTLD profiles except that language impairment was more frequent in participants with mild sporadic behavioral variant FTD. Adding the BEHAV and/or LANG domains to the CDR®-SB significantly enhanced discriminatory power in differentiating among the FTLD spectrum disorders. Discussion The BEHAV and LANG domains enable the CDR® plus NACC FTLD to capture early symptomatology of FTLD.

Author(s): Chen, Qin; Boeve, Bradley F; Tosakulwong, Nirubol; Lesnick, Timothy; Brushaber, Danielle; Dheel, Christina; Fields, Julie; Forsberg, Leah; Gavrilova, Ralitza; Gearhart, Debra; Haley, Dana; Gunter, Jeffrey L; Graff-Radford, Jonathan; Jones, David; Knopman, David; Graff-Radford, Neill; Kraft, Ruth; Lapid, Maria; Rademakers, Rosa; Wszolek, Zbigniew K; Rosen, Howie; Boxer, Adam L; Kantarci, Kejal | Abstract: Background and purposeThe objective of this study was to longitudinally investigate the trajectory of change in 1 H MRS measurements in asymptomatic MAPT mutation carriers who became symptomatic during follow-up, and to determine the time at which the neurochemical alterations accelerated during disease progression.MethodsWe identified eight MAPT mutations carriers who transitioned from asymptomatic to symptomatic disease during follow-up. All participants were longitudinally followed with an average of 7.75 years (range 4-11 years) and underwent two or more single voxel 1 H MRS examinations from the posterior cingulate voxel, with a total of 60 examinations. The rate of longitudinal change for each metabolite was estimated using linear mixed models. A flex point model was used to estimate the flex time point of the change in slope.ResultsThe decrease in the NAA/mI ratio accelerated 2.09 years prior to symptom onset, and continued to decline. A similar trajectory was observed in the presumed glial marker mI/Cr ratio accelerating 1.86 years prior to symptom onset.ConclusionsOur findings support the potential use of longitudinal 1 H MRS for monitoring the neurodegenerative progression in MAPT mutation carriers starting from the asymptomatic stage.

Pathology, research and practice 216(1), 152728 (2020). doi:10.1016/j.prp.2019.152728, Published by Elsevier, München

Objective: To characterize the clinical, EEG, and neuroimaging profiles of transient epileptic amnesia (TEA). Methods: We performed a retrospective analysis of patients diagnosed with TEA at the Mayo Clinic Minnesota from January 1, 1998 to September 21, 2017. Diagnostic criteria included the presence of recurrent episodes of transient amnesia with preservation of other cognitive functions and evidence for epilepsy [epileptiform abnormalities on EEG, clinical features of seizures, or symptomatic response to anti-seizure medications (ASMs)]. Results: Nineteen patients were identified (14 men, 5 women) with median onset age 66 years and median time to diagnosis 2 years. Thirteen patients (68%) reported persistent cognitive/behavioral symptoms, including 4 (21%) for whom these were the chief presenting complaints. EEG revealed epileptiform abnormalities involving the frontal and/or temporal regions in 12/19 individuals (63%), including activation during sleep in all of these cases. In numerous cases, sleep and prolonged EEG evaluations identified abnormalities not previously seen on shorter or awake-state studies. Brain MRI revealed focal abnormalities in only 4/19 cases (21%). FDG-PET identified focal hypometabolism in 2/8 cases where it was performed, both involving the frontal and/or temporal regions. Anti-seizure therapy, most often with a single agent, resulted in improvement (reduction in spell frequency and/or subjective improvement in interictal cognitive/behavioral complaints) in all 17 cases with available follow-up. Conclusions: TEA is a treatable cause of amnestic spells in older adults. This syndrome is frequently associated with persistent interictal cognitive/behavioral symptoms and thus can be mistaken for common mimics. In the appropriate clinical context, our findings support the use of early prolonged EEG with emphasis on sleep monitoring as a key diagnostic tool. FDG-PET may also complement MRI in distinguishing TEA from neurodegenerative disease when suspected.

ObjectiveTo evaluate FDG-PET as an antemortem diagnostic tool for Alzheimer-related TAR DNA-binding protein of 43 kDa (TDP-43) proteinopathy.MethodsWe conducted a cross-sectional neuroimaging–histologic analysis of patients with antemortem FDG-PET and postmortem brain tissue from the Mayo Clinic Alzheimer's Disease Research Center and Study of Aging with Alzheimer spectrum pathology. TDP-43-positive status was assigned when TDP-43-immunoreactive inclusions were identified in the amygdala. Statistical parametric mapping (SPM) analyses compared TDP-43-positive (TDP-43[+]) with TDP-43-negative cases (TDP-43[−]), correcting for field strength, sex, Braak neurofibrillary tangle, and neuritic plaque stages. Cross-validated logistic regression analyses were used to determine whether regional FDG-PET values predict TDP-43 status. We also assessed the ratio of inferior temporal to medial temporal (IMT) metabolism as this was proposed as a biomarker of hippocampal sclerosis.ResultsOf 73 cases, 27 (37%) were TDP-43(+), of which 6 (8%) had hippocampal sclerosis. SPM analysis showed TDP-43(+) cases having greater hypometabolism of medial temporal, frontal superior medial, and frontal supraorbital (FSO) regions (punc < 0.001). Logistic regression analysis showed only FSO and IMT to be associated with TDP-43(+) status, identifying up to 81% of TDP-43(+) cases (p < 0.001). An IMT/FSO ratio was superior to the IMT in discriminating TDP-43(+) cases: 78% vs 48%, respectively.ConclusionsAlzheimer-related TDP-43 proteinopathy is associated with hypometabolism in the medial temporal and frontal regions. Combining FDG-PET measures from these regions may be useful for antemortem prediction of Alzheimer-related TDP-43 proteinopathy.Classification of evidenceThis study provides Class II evidence that hypometabolism in the medial temporal and frontal regions on FDG-PET is associated with Alzheimer-related TDP-43 proteinopathy.

Introduction Some models of therapy for neurodegenerative diseases envision starting treatment before symptoms develop. Demonstrating that such treatments are effective requires accurate knowledge of when symptoms would have started without treatment. Familial frontotemporal lobar degeneration offers a unique opportunity to develop predictors of symptom onset. Methods We created dementia risk scores in 268 familial frontotemporal lobar degeneration family members by entering covariate-adjusted standardized estimates of brain atrophy into a logistic regression to classify asymptomatic versus demented participants. The score's predictive value was tested in a separate group who were followed up longitudinally (stable vs. converted to dementia) using Cox proportional regressions with dementia risk score as the predictor. Results Cross-validated logistic regression achieved good separation of asymptomatic versus demented (accuracy = 90%, SE = 0.06). Atrophy scores predicted conversion from asymptomatic or mildly/questionably symptomatic to dementia (HR = 1.51, 95% CI: [1.16,1.98]). Discussion Individualized quantification of baseline brain atrophy is a promising predictor of progression in asymptomatic familial frontotemporal lobar degeneration mutation carriers.

Author(s): Forsberg, Leah K; Boeve, Bradley F; Boxer, Adam L; Rosen, Howard J; Kornak, John; Heuer, Hilary W; Fields, Julie A; Brushaber, Danielle; Machulda, Mary M; Sturm, Virginia; Staffaroni, Adam M; Ljubenkov, Peter A; Denver, Reilly; Ong, Elise; Appleby, Brian; Bordelon, Yvette M; Brannelly, Patrick; Coppola, Giovanni; Dickerson, Brad C; Dickinson, Susan; Kimiko, Domoto-Reilly; Faber, Kelley; Fong, Jamie; Foroud, Tatiana M; Gavrilova, Ralitza H; Gearhart, Debra; Ghoshal, Nupur; Goldman, Jill; Graff-Radford, Jonathan; Graff-Radford, Neil R; Grossman, Murray; Robin Hsiung, Ging-Yuek; Huey, Edward D; Irwin, David; Jones, David T; Kantarci, Kejal; Karydas, Anna M; Kaufer, Daniel; Kerwin, Diana R; Knopman, David S; Kraft, Ruth A; Kramer, Joel H; Kremers, Walter K; Kukull, Walter A; Litvan, Irene; Lucente, Diane E; Lungu, Codrin; Mackenzie, Ian R; McGinnis, Scott M; Mendez, Mario F; Miller, Bruce L; Onyike, Chiadi U; Pantelyat, Alex; Pearlman, Rodney; Petrucelli, Leonard; Potter, Madeline; Rademakers, Rosa; Ramos, Eliana Marisa; Rankin, Katherine; Rascovsky, Katya; Roberson, Erik D; Rogalski, Emily J; Shaw, Leslie M; Sutherland, Marg; Syrjanen, Jeremy; Tartaglia, Carmela; Tatton, Nadine; Taylor, Joanne; Toga, Arthur W; Trojanowski, John Q; Weintraub, Sandra; Wong, Bonnie; Wszolek, Zbigniew

IMPORTANCE: A National Institute on Aging and Alzheimer’s Association workgroup proposed a research framework for Alzheimer disease in which biomarker classification of research participants is labeled AT(N) for amyloid, tau, and neurodegeneration biomarkers. OBJECTIVE: To determine the associations between AT(N) biomarker profiles and memory decline in a population-based cohort of individuals without dementia age 60 years or older, and to determine whether biomarkers provide incremental prognostic value beyond more readily available clinical and genetic information. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort study of cognitive aging in Olmsted County, Minnesota, that included 480 nondemented Mayo Clinic Study of Aging participants who had a clinical evaluation and amyloid positron emission tomography (PET) (A), tau PET (T), and magnetic resonance imaging (MRI) cortical thickness (N) measures between April 16, 2015, and November 1, 2017, and at least 1 clinical evaluation follow-up by November 12, 2018. EXPOSURES: Age, sex, education, cardiovascular and metabolic conditions score, APOE genotype, and AT(N) biomarker profiles. Each of A, T, or (N) can be abnormal (+) or normal (−), resulting in 8 AT(N) profiles. MAIN OUTCOMES AND MEASURES: Primary outcome was a composite memory score measured longitudinally at 15-month intervals. Analyses measured the associations between predictor variables and the memory score, and whether AT(N) biomarker profiles significantly improved prediction of memory z score rates of change beyond a model with clinical and genetic variables only. RESULTS: Participants were followed up for a median of 4.8 years (interquartile range [IQR], 3.8-5.1) and 44% were women (211/480). Median (IQR) ages ranged from 67 years (65-73) in the A−T−(N)− group to 83 years (76-87) in the A+T+(N)+ group. Of the participants, 92% (441/480) were cognitively unimpaired but the A+T+(N)+ group had the largest proportion of mild cognitive impairment (30%). AT(N) biomarkers improved the prediction of memory performance over a clinical model from an R(2) of 0.26 to 0.31 (P

The spectrum of tumours arising in childhood is fundamentally different from that seen in adults, and they are known to be divergent from adult malignancies in terms of cellular origins, epidemiology, genetic complexity, driver mutations and underlying mutational processes. Despite the immense knowledge generated through sequencing efforts and functional characterization of identified (epi-)genetic alterations over the past decade, the clinical implications of this knowledge have so far been limited. Novel preclinical platforms such as the European Innovative Therapies for Children with Cancer–Paediatric Preclinical Proof-of-Concept Platform and the US-based Pediatric Preclinical Testing Consortium are being developed to try to change this by aiming to recapitulate the extensive heterogeneity of paediatric tumours and thereby, hopefully, improve the ability to predict clinical benefit. Numerous studies have also been established worldwide to provide patients with access to real-time molecular profiling and the possibility of more precise mechanism-of-action-based treatments. In addition to tumour-intrinsic findings and mechanisms, ongoing studies are investigating features such as the immune microenvironment of paediatric tumours in comparison with adult cancers — currently of very timely clinical relevance. However, there is an ongoing need for rigorous preclinical biomarker and target validation to feed into the next generation of molecularly stratified clinical trials. This Review aims to provide a comprehensive state-of-the-art overview of the molecular landscape of paediatric solid tumours, including their underlying genomic alterations and interactions with the microenvironment, complemented with our current understanding of potential therapeutic vulnerabilities and how these can be preclinically tested using more accurate predictive methods. Finally, we provide an outlook on the challenges and opportunities associated with translating this overwhelming scientific progress into real clinical benefit. Paediatric solid tumours are known to be divergent from adult malignancies. This Review describes the molecular landscape of paediatric solid tumours, the therapeutic vulnerabilities that can be targeted and the preclinical models available to test the efficacy of investigational drugs with a view to accelerating translational progress.

Despite decades of research, brain tumours remain among the deadliest of all forms of cancer. The ability of these tumours to resist almost all conventional and novel treatments relates, in part, to the unique cell-intrinsic and microenvironmental properties of neural tissues. In an attempt to encourage progress in our understanding and ability to successfully treat patients with brain tumours, Cancer Research UK convened an international panel of clinicians and laboratory-based scientists to identify challenges that must be overcome if we are to cure all patients with a brain tumour. The seven key challenges summarized in this Position Paper are intended to serve as foci for future research and investment.

[Purpose] Recent studies revealed divergent gene expression patterns in Ewing sarcoma (EwS) with canonical EWSR1–ETS gene fusions and undifferentiated round cell sarcomas (URCS) with EWSR1 rearrangements fused to the non-ETS gene NFATc2. Thus, the question arises whether the latter tumors really belong to EwS., [Methods] We collected five cases matching the group of URCS with EWSR1–NFATc2 fusion and performed DNA methylation and copy number profiling. Results were compared to methylation data of 30 EwS with various EWSR1–ETS fusions and one EwS with FUS–ERG fusion, 16 URCS with CIC rearrangement and 10 URCS with BCOR alteration and a total of 81 EWSR1-associated soft tissue sarcomas including 7 angiomatoid fibrous histiocytomas, 7 clear cell sarcomas of the soft tissue, 28 desmoplastic small round cell tumors, 10 extraskeletal myxoid chondrosarcomas and 29 myxoid liposarcomas., [Results] Unsupervised hierarchical clustering and t-distributed stochastic neighbor embedding analysis of DNA methylation data revealed a homogeneous methylation cluster for URCS with EWSR1–NFATc2 fusion, which clearly segregated from EwS and the other subtypes. Copy number profiles of EWSR1–NFATc2 cases showed recurrent losses on chromosome 9q and segmental gains on 20q13 and 22q12 involving the EWSR1 and NFATc2 loci, respectively., [Conclusion] In summary, URCS with EWSR1–NFATc2 fusion share a distinct DNA methylation signature and carry characteristic copy number alterations, which emphasizes that these sarcomas should be considered separately from EwS., The work was supported by the German Cancer Aid (Grant 70112499). The laboratory of T.G.P.G. was supported for this project by grants from the Dr. Leopold und Carmen Ellinger Stiftung and the German Cancer Aid (Grant 70112257).

BACKGROUND: Disproportionately enlarged subarachnoid-space hydrocephalus (DESH), a feature of normal pressure hydrocephalus (NPH), is not well known or recognized. It can be misinterpreted as cortical atrophy, suggestive of neurodegenerative disease. METHODS: We report two cases with DESH, the first highlighting autopsy findings and the second the effect of shunting on neuroimaging. RESULTS: We report a 67-year-old man who presented with clinical features of NPH, but the diagnosis was not considered because radiographic findings were interpreted as cortical atrophy. At autopsy the patient had findings consistent with NPH and no significant neurodegenerative brain disease. The second patient with DESH and NPH underwent shunt surgery. The entrapped fluid greatly diminished after the surgery, confirming that the cortically entrapped fluid is not atrophy, but due to a CSF dynamic process. CONCLUSIONS: Neurologists should recognize DESH and not misinterpret this as cortical atrophy. Patients with DESH have tight sulci adjacent to the entrapped fluid pockets, distinguishing it from cortical atrophy. 18F-Fluorodeoxyglucose PET can also be used to differentiate DESH from cortical atrophy.

Mesenchymal stromal cells are multipotent cells that are being used to treat a variety of medical conditions. Over the past decade, there has been considerable excitement about using MSCs to treat neurodegenerative diseases, which are diseases that are typically fatal and without other robust therapies. In this review, we discuss the proposed MSC mechanisms of action in neurodegenerative diseases, which include growth factor secretion, exosome secretion, and attenuation of neuroinflammation. We then provide a summary of preclinical and early clinical work on MSC therapies in amyotrophic lateral sclerosis, multiple system atrophy, Parkinson’s disease, and Alzheimer’s disease. Continued rigorous and controlled studies of MSC therapies will be critical in order to establish efficacy and protect patients from possible untoward side effects.

BACKGROUND: Pediatric low-grade glioma (pLGG) is the most common CNS tumor of childhood. Progression-free survival (PFS) is much lower than overall survival emphasizing the need for alternative treatments. In addition, many children suffer functional morbidities such as visual and motor disturbances. Recently, there has been an appropriate prioritization of functional outcomes in children with pLGG. METHODS: We present the results of a PBTC phase II trial evaluating selumetinib, (AZD6244, ARRY-142886) a MEK-1/2 inhibitor, in children with recurrent/progressive pLGG on 2 strata, including visual outcomes. RESULTS: Stratum 3 enrolled Neurofibromatosis type 1 (NF1)-associated pLGG. Ten of 25 (40%) eligible patients had partial response (PR), 14/25 (56%) had stable disease (SD) and 1/25 (4%) had progressive disease (PD); 2-year PFS was 96+4%. Ten patients with optic pathway glioma (OPG) were evaluable for visual acuity (VA) at baseline and 1 year. VA improved in 2/10 patients (20%) and was stable in 8/10 (80%). One patient (10%) had improvement in visual fields (VF) and 9 patients (90%) had stable VF. Stratum 4 included patients with non-NF1-associated recurrent/progressive hypothalamic and OPG. Five of 25 (20%) eligible patients had PR, 16/25 (64%) had SD and 4 (16%) had PD; 2-year PFS was 78+8.5%. Nineteen of 25 patients were evaluable for VA. VA improved in 4/19 patients (21%), was stable in 13/19 (68%) and worsened in 2/19 (11%). Five patients (26%) had improved VF and 14 (74%) had stable VF. The most common toxicities included grade 1/2 CPK elevation, diarrhea, hypoalbuminemia and rash. Rare grade 3 toxicities included elevated CPK, rash and paronychia. CONCLUSIONS: Selumetinib was tolerable and effective in treating children with NF1-associated and sporadic recurrent/progressive hypothalamic and OPG based upon radiographic response and PFS. Twenty-seven of 29 (93%) evaluable patients had stable or improved vision based on VA and VF testing.

Tumors arising in the pineal region comprise a spectrum of different entities with distinct clinical and histopathological characteristics. Pineocytoma (PC), pineal parenchymal tumors of intermediate differentiation (PPTID) and papillary tumors of the pineal region (PTPR) mainly occur in adult patients and are low to moderately aggressive neoplasms (WHO °I-III). In contrast, pineoblastoma (PB) are high-grade (WHO °IV) malignancies primarily affecting children and adolescents. Especially for patients with unresectable or metastatic disease or at very young age survival outcomes remain poor despite aggressive multimodal treatment regimen. To date, no therapeutically actionable molecular targets have been identified. A subset of PB occur in patients with cancer predisposition syndromes including DICER1 and RB1 germline mutations, the latter in the context of trilateral retinoblastoma (TLRB). We analyzed a cohort of ~230 pineal tumors of different histologies using genome-wide DNA methylation profiling and copy-number analysis, as well as gene panel sequencing, miRNA sequencing and gene expression profiling. Unsupervised clustering based on DNA methylation profiles revealed clear separation of known histopathological entities (PC, PTPR, PPTID) and, furthermore, distinction of subclasses within these groups. Interestingly, several biologically discrete subgroups emerged within the group of histologically diagnosed PBs or pineal primitive embryonal tumors/PNETs, which displayed distinct clinical associations (e.g. age distribution). RB1 alterations were recurrent in a small subgroup (PB_RB) including TLRBs as well as sporadic PB cases (~60%) showing similarities with retinoblastoma. About 45% of cases in the largest PB subgroup (PB_B) harbored alterations within the miRNA processing pathway (affecting DROSHA, DGCR8 or DICER1) suggesting a central role of altered miRNA biogenesis in the development of this group which showed evidence for global reduction of mature miRNA by miRNA-Seq. With this study, we provide a foundation for further clinical, molecular and functional characterization of PB subgroups.

Papillary glioneuronal tumor (PGNT) predominantly arises in children, adolescents and young adults. Its diagnosis poses a major diagnostic challenge. Recently, SLC44A1-PRKCA fusions have been described in PGNT. We subjected 28 brain tumors from different institutions histologically diagnosed as PGNT to molecular analysis and morphological analysis. Array-based methylation analysis revealed that 17/28 tumors exhibited methylation profiles typical for other tumor entities, mostly dysembryoplastic neuroepithelial tumor and hemispheric pilocytic astrocytoma. Conversely, 11/28 tumors exhibited a unique profile thus constituting a distinct methylation class PGNT. By screening the extended Heidelberg cohort containing over 25000 CNS tumors, we identified three additional tumors belonging to this methylation cluster, but originally histologically diagnosed otherwise. RNA sequencing for the detection of SLC44A1-PRKCA fusions could be performed on 19 of the tumors, 10 of them belonging to the methylation class PGNT. In two additional cases, SLC44A1-PRKCA fusions were confirmed by FISH. We detected fusions involving PRKCA in all of the cases of this methylation class with material available for analyses: the canonical SLC44A1-PRKCA fusion was observed in 11/12 tumors, while the remaining case exhibited a NOTCH1-PRKCA fusion. Neither of the fusions was found in the tumors belonging to other methylation classes. Our results point towards a high misclassification rate of the morphological diagnosis PGNT and clearly demonstrate the necessity of molecular analyses. PRKCA fusions are highly diagnostic for PGNT and detection by RNA sequencing allows identification of rare fusion partners. Methylation analysis recognizes a unique methylation class PGNT irrespective of the nature of the PRKCA Fusion.

Objectiveβ-Amyloid (Aβ) pathology is common in patients with probable dementia with Lewy bodies (DLB). However, the pathologic basis and the differential diagnostic performance of Aβ PET are not established in DLB. Our objective was to investigate the pathologic correlates of 11C-Pittsburgh compound B(PiB) uptake on PET in cases with antemortem diagnosis of probable DLB or Lewy body disease (LBD) at autopsy.MethodsAutopsied cases who underwent antemortem PiB-PET and were assigned a clinical diagnosis of probable DLB or LBD at autopsy were included (n = 39). The primary endpoint was pathologic diagnosis of LBD, Alzheimer disease (AD), or mixed (LBD and AD) pathology; the secondary endpoints included Thal Aβ phase and diffuse and neuritic Aβ plaques.ResultsLower global cortical PiB standardized uptake value ratio (SUVr) distinguished cases with LBD from cases with AD or mixed pathology with an accuracy of 93%. Greater global cortical PiB SUVr correlated with higher Thal Aβ phase (r = 0.75, p ≤ 0.001). Voxel–based analysis demonstrated that Aβ pathology relatively spared the occipital lobes in cases with mixed pathology and LBD compared to cases with AD without LBD, in whom the entire cerebral cortex was involved. Global cortical PiB SUVr was associated primarily with the abundance of diffuse Aβ plaques in cases with LBD in a multivariable regression model.ConclusionLower PiB uptake accurately distinguishes cases with LBD from cases with AD or mixed pathology, correlating with the Thal Aβ phase. The severity of diffuse Aβ pathology is the primary contributor to elevated PiB uptake in LBD.Classification of evidenceThis study provides Class III evidence that lower PiB uptake accurately distinguishes patients with LBD from those with AD or mixed pathology.

Purpose: Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive paediatric brain tumour with fatal outcome. The Individualised Therapy For Relapsed Malignancies In Childhood (INFORM) registry study offers comprehensive molecular profiling of high-risk tumours to identify target alterations for potential precision therapy. We analysed molecular characteristics and clinical data after brainstem biopsy of all enrolled newly diagnosed DIPGs. Patients and methods: From -February 2015 to February 2018, 21 subsequent primary DIPG cases were enrolled in the nation-wide multicentre INFORM registry study after brainstem biopsy. Whole-genome, whole-exome sequencing and DNA methylation analysis were performed, and RNA-sequencing was added in case of sufficient material. Clinical data were obtained from standardised questionnaires and the INFORM clinical data bank. Results: Tumour material obtained from brainstem biopsy was sufficient for DNA analysis in all cases and RNA analysis in 16 of 21 cases. In 16 of 21 cases (76%), potential targetable alterations were identified including highly relevant MET and NTRK1 fusions as well as an EZH2 alteration not previously described in DIPG. In 5 of 21 cases, molecular information was used for initiation of targeted treatment. The majority of patients (19/21) presented with neurological deficits at diagnosis. Newly arising or worsening of neurological deficits post-biopsy occurred in nine patients. Symptoms were reversible or improved notably in eight cases. Conclusion: In this multicentre study setting, brainstem biopsy of DIPG was feasible and yielded sufficient material for comprehensive molecular profiling. Relevant molecular targets were identified impacting clinical management in a substantial subset. Death or severe bleeding occurred in none of the cases. One of 20 patients experienced unilateral paraesthesia possibly related to biopsy.

The introduction of the classification of brain tumours based on their DNA methylation profile has significantly changed the diagnostic approach for cases with ambiguous histology, non-informative or contradictory molecular profiles or for entities where methylation profiling provides useful information for patient risk stratification, for example in medulloblastoma and ependymoma. We present our experience that combines a conventional molecular diagnostic approach with the complementary use of a DNA methylation-based classification tool, for adult brain tumours originating from local as well as national referrals. We report the frequency of IDH mutations in a large cohort of nearly 1550 patients, EGFR amplifications in almost 1900 IDH-wildtype glioblastomas, and histone mutations in 70 adult gliomas. We demonstrate how additional methylation-based classification has changed and improved our diagnostic approach. Of the 325 cases referred for methylome testing, 179 (56%) had a calibrated score of 0.84 and higher and were included in the evaluation. In these 179 samples, the diagnosis was changed in 45 (25%), refined in 86 (48%) and confirmed in 44 cases (25%). In addition, the methylation arrays contain copy number information that usefully complements the methylation profile. For example, EGFR amplification which is 95% concordant with our Real-Time PCR-based copy number assays. We propose here a diagnostic algorithm that integrates histology, conventional molecular tests and methylation arrays.

As more biomarkers for Alzheimer’s disease and age-related brain conditions become available, more sophisticated analytic approaches are needed to take full advantage of the information they convey. Most work has been done using categorical approaches but the joint relationships of tau PET, amyloid PET and cortical thickness in their continuous distributions to cognition have been under-explored. We evaluated non-demented subjects over age 50 years in the Mayo Clinic Study of Aging, 2037 of whom had undergone 3 T MRI scan, 985 amyloid PET scan with 11C-Pittsburgh compound B (PIB) and MRI, and 577 PIB-PET, 18F-AV1451 flortaucipir PET and MRI. Participants received a nine-test cognitive battery. Three test scores (logical memory delayed recall, visual reproduction delayed recall and auditory verbal learning test delayed recall) were used to generate a memory composite z-score. We used Gradient Boosting Machine models to analyse the relationship between regional cortical thickness, flortaucipir PET signal, PIB-PET signal and memory z-scores. Age, education, sex and number of test exposures were included in the model as covariates. In this population-based study of non-demented subjects, most of the associations between biomarkers and memory z-scores accrued after 70 years of age. Entorhinal cortex exhibited the strongest associations between biomarkers and memory z-scores. Other temporal regions showed similar but attenuated associations, and non-temporal regions had negligible associations between memory z-scores and biomarkers. Entorhinal flortaucipir PET signal, PIB-PET signal and entorhinal cortical thickness were independently and additively associated with declining memory z-scores. In contrast to global PIB-PET signal where only very high amyloid-β levels were associated low memory z-scores, entorhinal flortaucipir PET signal just above background levels was associated with low memory z-scores. The lowest memory z-scores occurred with the confluence of elevated entorhinal flortaucipir PET signal and lower entorhinal cortical thickness.

There has been no comparison of excessive daytime sleepiness (EDS) in patients with Alzheimer’s disease dementia (AD), dementia with Lewy bodies (DLB), and behavioral variant frontotemporal dementia (bvFTD). We identified patients with mild dementia who met criteria for these disorders who also had the Epworth Sleepiness Scale (ESS) completed. The sample included 17 bvFTD, 111 AD, and 31 DLB. An ESS score ≥10 was considered abnormal and consistent with EDS. Analyses with age and sex as covariates revealed higher mean ESS scores for DLB compared to the other groups (DLB 13.9 [5], bvFTD 9.6 [8], AD 8.8 [5], P < .05). An ESS score ≥10 was significantly more likely to occur in DLB compared to bvFTD or AD (DLB 81% vs bvFTD 47% vs AD 45%, P < .01). In patients with mild dementia, EDS is greatest in DLB and comparably lower in bvFTD and AD.

BACKGROUND: Pediatric low-grade glioma (pLGG) is the most common central nervous system tumor of childhood. Although overall survival is very good, many children suffer from multiple progressions and functional morbidities. There is no one universally accepted therapy for children with recurrent disease, however, standard cytotoxic chemotherapies are often utilized by most practitioners. The Pediatric Brain Tumor Consortium conducted a multi-institutional phase II study evaluating selumetinib (AZD6244, ARRY-142886), a MAP/ERK Kinase I/II inhibitor, in patients with recurrent, refractory or progressive pLGG assigned to numerous strata. The aim of the study was to evaluate the efficacy of selumetinib in these patients. METHODS: Eligibility required age 3–21 y/o, a Lansky or Karnofsky performance score greater than 60 and the presence of recurrent, refractory or progressive pLGG after at least one standard therapy. Stratum 1 included children with World Health Organization (WHO) grade I pilocytic astrocytoma (PA) harboring either one of the two most common BRAF aberrations (KIAA1549-BRAF fusion or the BRAF(V600E) mutation). Stratum 3 included children with any neurofibromatosis type 1 (NF1)-associated pLGG (WHO grades I and II). Selumetinib was provided as capsules given orally at the recommended phase II dose of 25 mg/m(2) twice daily. The primary endpoint was stratum-specific objective response rate assessd by the local site and sustained for at least 8 weeks. All responses were reviewed centrally and statistical analyses were done as per protocol. Although the trial (NCT01089101) is still ongoing in other strata, enrollment and planned follow-up is compete on both strata 1 and 3. FINDINGS: Between July 25, 2013, and June 12, 2015, 25 eligible and evaluable children were accrued to stratum 1, and between August 28, 2013, and June 25, 2015, 25 eligible and evaluable children were accrued to stratum 3. On stratum 1, 9/25 (36%) patients achieved a partial response (PR). The median follow-up for the 11 patients who have not yet experienced an event is 36.4 months (4.4–50.5; IQR=23.9). On stratum 3, 10/25 (40%) patients achieved a PR with a median follow-up of 48.6 months (8.6–59.1; IQR=12.2) for the 17 subjects without progressions. All patients evaluable for visual acuity had improved or stable vision. The most common attributable toxicities on both strata were grade 1 and 2 CPK elevation, hypoalbuminemia, dyspnea, rash, duodenal ulcer, anemia, dry skin, fatigue and diarrhea. Rare grade 3 toxicities included elevated CPK (n=5), maculopapular rash (n=5), neutropenia (n=3), nausea (n=3), paronychia (n=3), acneiform rash (n=2), diarrhea (n=2), elevated ALT (n=1), decreased ejection fraction (n=1), gastric hemorrhage (n=1), headache (n=1), skin infection (n=1), tooth infection (n=1) and weight gain (n=1). There was only one grade 4 toxicity, lymphopenia. There were no treatment-realted deaths. Patient reported outcomes and quality of life assessments were not part of the current study. INTERPRETATION: Selumetinib is active against recurrent, refractory or progressive PA harboring common BRAF aberrations and NF1-associated pLGG. To our knowledge, this is one of the first prospectively tested and successful molecularly-targeted agents in pLGG. These data not only provide an alternative to standard chemotherapy for these subgroups of patients, but this success has led to an interest in exploring efficacy in patients as a first-line therapy. In fact, these data have directly led to the development of two Children’s Oncology Group phase III studies in newly diagnosed pLGG patients both with and without NF1 comparing standard chemotherapy to selumetinib. The current trial was funded by a National Cancer Institute (NCI) Cancer Therapy Evaluation Program (CTEP) PBTC U01 Grant: 2UM1CA081457 (UM1) and by the American Lebanese Syrian Associated Charities.

Since it was first described in 1965, normal pressure hydrocephalus (NPH) has been a controversial subject. New studies have shed light on its epidemiology and pathogenesis and provided objective ways to measure outcome in patients with NPH. Neuroimaging has improved and allows better recognition of both NPH and the presence of overlapping diseases RECENT FINDINGS: Several recent epidemiologic studies confirm that NPH is a rare disease, but the presence of large ventricles is a common finding with aging. NPH may be multifactorial, including congenital causes, vascular disease, and impaired CSF absorption. MRI features of NPH include enlarged ventricular size and CSF fluid collection outside the ventricles not due to atrophy. The term disproportionately enlarged subarachnoid space hydrocephalus (DESH) has been used to describe prognostic MRI features in NPH, including a "tight high convexity" and enlargement of CSF spaces in the sylvian fissure. DESH has been included in the Japanese guideline for the diagnosis and treatment of NPH. A new NPH scale has been published that provides an objective framework for evaluating patients with NPH before and after shunt placement. Programmable shunts can noninvasively manage overdrainage complications. Surgical outcome has been improving over time. Recent studies have led to improved recognition of overlapping diseases such as Alzheimer pathology, which co-occurs in about 30% of NPH cases. Fludeoxyglucose positron emission tomography (FDG-PET) is a promising imaging modality for diagnosing NPH and detecting concomitant degenerative disease.A systematic approach to patients with possible NPH allows recognition of the subset of patients who will respond to shunt surgery and identification of those with alternative diagnoses.

Tumors of the central nervous system are the most common form of childhood malignancy, and remain the leading cause of cancer-related morbidity and mortality in children. Despite extensive efforts, the efficacy of the traditional treatments is limited and the overall prognosis is poor. In recent years it has become apparent that pediatric gliomas differ from their adult counterparts, explaining in part why the therapies extrapolated from adult gliomas have failed, and further supporting the need to understand the biology of the childhood disease. Deep sequencing studies on brain tumor specimens within various cancer genome consortia (e.g. ICGC PedBrain, TCGA) has yielded a wealth of information about molecular aberrations that had accumulated in tumors. This has unravelled a considerable degree of heterogeneity and thus resulted in the delineation of different molecular subgroups. Furthermore, it has provided comprehensive insights into tumor genomes deduction. Nevertheless, validation of oncogenically relevant genes and therapeutically actionable targets in an in vivo context still remains a major challenge in the process of developing novel treatment approaches. We have generated state-of-the-art in vivo methodologies based on somatic gene transfer for generating animal models faithfully recapitulating the molecular and clinical characteristics of the respective human counterpart. In this study, we focused on NTRK2 fusions and FGFR1 mutations and characterized the tumors obtained by either in utero electroporation or lentiviral injection into postnatal (P0-P1) mice. Tumor derived cell lines grown in stem cell media were tested for conventional therapies (e.g. TMZ) and screening of available small inhibitor compounds. In addition, we have characterized the tumor microenvironment of these lesions, mainly the infiltrating immune cell populations. This study thus represents an important contribution to the understanding of pediatric glioma biology as well as to translational efforts in developing new treatment approaches for these malignant tumors. Citation Format: Or Zohar, Itai Moshe, Ismer Britta, David T. Jones, Dinorah Friedmann-Morvinski. Generation, characterization and functional validation of novel preclinical models for human pediatric glioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3042.