285 research outputs found

    Intraventricular Meningiomas: Clinical-Pathological and Genetic Features of a Monocentric Series

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    Intraventricular meningiomas (IVMs) are rare (0.5-5%) and usually low-grade (90% grade I) brain neoplasms. Their recurrence rate is lower than that of extra-axial meningiomas, but their surgical resection can be burdened with life-threatening complications, which represent the major cause of the reported 4% mortality. The aim of this study is to characterize the molecular portrait of IVMs to identify potential therapeutic targets. For this, we explored mutations and copy number variations (CNV) of 409 cancer-related genes and tumor mutational burden (TMB) of six cases, using next-generation sequencing. Five IVMs were grade I and one was grade II; none recurred, in spite of partial surgical resection in one case. NF2 mutation was the only recurring alteration and was present in three of the six IVMs, in association with SMARCB1 mutation in one case. None of the cases was hypermutated (TMB > 10 mutations/Mb). NF2-mutant progressing or recurring IVMs could potentially be treated with targeted therapies applied to other NF2-mutant tumors, as an alternative to surgery or radiosurgery, while in view of their low TMB they are unlikely candidates to immune check-point inhibition

    Ultra-Mutation in IDH Wild-Type Glioblastomas of Patients Younger than 55 Years is Associated with Defective Mismatch Repair, Microsatellite Instability, and Giant Cell Enrichment

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    Glioblastomas (GBMs) are classified into isocitrate dehydrogenase (IDH) mutants and IDH wild-types (IDH-wt). This study aimed at identifying the mutational assets of IDH-wt GBMs in patients aged 18-54 years for which limited data are available

    Exceptional Response in BRAF p.V600E-Mutant Enteric-Type Adenocarcinoma of the Lung With Cutaneous Spread: A Case Report

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    Background: Enteric-type adenocarcinoma of the lung (lung-ETAC) is a rare form of lung cancer with histologic similarities to colorectal cancer, with aggressive behavior and unfavorable prognosis. Case presentation: An 81-year-old man presented with discolored skin lesions on the chest and abdomen. After comprehensive evaluation, including skin biopsy and molecular profiling, the patient was diagnosed with having lung-ETAC with a BRAF p.V600E mutation. Treatment with dabrafenib and trametinib initially resulted in positive results, with improvement in skin lesions and overall clinical condition. Nevertheless, approximately 6 months after, the disease had progression with new skin lesions reappearing. Conclusions: We reported a unique case of a patient with BRAF p.V600E-mutant lung-ETAC with metastatic skin lesions achieving complete cutaneous response after targeted treatment with dabrafenib and trametinib, highlighting the potential for targeted therapy in patients with lung-ETAC harboring a BRAF p.V600E mutation

    Comprehensive molecular portrait using next generation sequencing of resected intestinal-type gastric cancer patients dichotomized according to prognosis

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    In this study, we evaluated whether the presence of genetic alterations detected by next generation sequencing may define outcome in a prognostically-selected and histology-restricted population of resected gastric cancer (RGC). Intestinal type RGC samples from 34 patients, including 21 best and 13 worst prognostic performers, were studied. Mutations in 50 cancer-associated genes were evaluated. A significant difference between good and poor prognosis was found according to clinico-pathologic factors. The most commonly mutated genes in the whole population were PIK3CA (29.4%), KRAS (26.5%), TP53 (26.5%) MET (8.8%), SMAD4 (8.8%) and STK11 (8.8%). Multiple gene mutations were found in 14/21 (67%) patients with good prognosis, and 3/13 (23%) in the poor prognosis group. A single gene alteration was found in 5/21 (24%) good and 6/13 (46%) poor prognosis patients. No mutation was found in 2/21 (9.5%) and 4/13 (31%) of these groups, respectively. In the overall series, ß-catenin expression was the highest (82.4%), followed by E-Cadherin (76.5%) and FHIT (52.9%). The good prognosis group was characterized by a high mutation rate and microsatellite instability. Our proof-of-principle study demonstrates the feasibility of a molecular profiling approach with the aim to identify potentially druggable pathways and drive the development of customized therapies for RGC

    IDH-wild type glioblastomas featuring at least 30% giant cells are characterized by frequent RB1 and NF1 alterations and hypermutation

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    : Giant cell glioblastoma (GC-GBM) is a rare variant of IDH-wt GBM histologically characterized by the presence of numerous multinucleated giant cells and molecularly considered a hybrid between IDH-wt and IDH-mutant GBM. The lack of an objective definition, specifying the percentage of giant cells required for this diagnosis, may account for the absence of a definite molecular profile of this variant. This study aimed to clarify the molecular landscape of GC-GBM, exploring the mutations and copy number variations of 458 cancer-related genes, tumor mutational burden (TMB), and microsatellite instability (MSI) in 39 GBMs dichotomized into having 30-49% (15 cases) or\u2009 65\u200950% (24 cases) GCs. The type and prevalence of the genetic alterations in this series was not associated with the GCs content (<\u200950% or 65\u200950%). Most cases (82% and 51.2%) had impairment in TP53/MDM2 and PTEN/PI3K pathways, but a high proportion also featured TERT promoter mutations (61.5%) and RB1 (25.6%) or NF1 (25.6%) alterations. EGFR amplification was detected in 18% cases in association with a shorter overall survival (P\u2009=\u20090.004). Sixteen (41%) cases had a TMB\u2009>\u200910 mut/Mb, including two (5%) that harbored MSI and one with a POLE mutation. The frequency of RB1 and NF1 alterations and TMB counts were significantly higher compared to 567 IDH wild type (P\u2009<\u20090.0001; P\u2009=\u20090.0003; P\u2009<\u20090.0001) and 26 IDH-mutant (P\u2009<\u20090.0001; P\u2009=\u20090.0227; P\u2009<\u20090.0001) GBMs in the TCGA PanCancer Atlas cohort. These findings demonstrate that the molecular landscape of GBMs with at least 30% giant cells is dominated by the impairment of TP53/MDM2 and PTEN/PI3K pathways, and additionally characterized by frequent RB1 alterations and hypermutation and by EGFR amplification in more aggressive cases. The high frequency of hypermutated cases suggests that GC-GBMs might be candidates for immune check-point inhibitors clinical trials

    Mutational and copy number asset of primary sporadic neuroendocrine tumors of the small intestine

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    Small intestine neuroendocrine tumors (SI-NETs) represent the most common histotype among small intestine neoplasms, and metastatic disease is usually present at diagnosis. A retrospective series of 52 sporadic primary surgically resected SI-NETs, which were metastatic at diagnosis, was analyzed by high-coverage target sequencing (HCTS) for the mutational status of 57 genes and copy number status of 40 genes selected from recently published genome sequencing data. Seven genes were found to be recurrently mutated: CDKN1B (9.6%), APC and CDKN2C (each 7.7%), BRAF, KRAS, PIK3CA, and TP53 (each 3.8%). Copy number analysis showed frequent allelic loss of 4 genes located on chromosome 18 (BCL2, CDH19, DCC, and SMAD4) in 23/52 (44.2%) and losses on chromosomes 11 (38%) and 16 (15%). Other recurrent copy number variations were gains for genes located on chromosomes 4 (31%), 5 (27%), 14 (36%), and 20 (20%). Univariate survival analysis showed that SRC gene copy number gains were associated with a poorer prognosis (p = 0.047). Recurrent copy number variations are important events in SI-NET and SRC may represent a novel prognostic biomarker for this tumor type

    Gene Expression Profiling of Pancreas Neuroendocrine Tumors with Different Ki67-Based Grades.

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    Pancreatic neuroendocrine tumors (PanNETs) display variable aggressive behavior. A major predictor of survival is tumor grade based on the Ki67 proliferation index. As information on transcriptomic profiles of PanNETs with different tumor grades is limited, we investigated 29 PanNETs (17 G1, 7 G2, 5 G3) for their expression profiles, mutations in 16 PanNET relevant genes and LINE-1 DNA methylation profiles. A total of 3050 genes were differentially expressed between tumors with different grades (p < 0.05): 1279 in G3 vs. G2; 2757 in G3 vs. G1; and 203 in G2 vs. G1. Mutational analysis showed 57 alterations in 11 genes, the most frequent being MEN1 (18/29), DAXX (7/29), ATRX (6/29) and MUTYH (5/29). The presence and type of mutations did not correlate with the specific expression profiles associated with different grades. LINE-1 showed significantly lower methylation in G2/G3 versus G1 tumors (p = 0.007). The expression profiles of matched primaries and metastasis (nodal, hepatic and colorectal wall) of three cases confirmed the role of Ki67 in defining specific expression profiles, which clustered according to tumor grades, independently from anatomic location or patient of origin. Such data call for future exploration of the role of Ki67 in tumor progression, given its involvement in chromosomal stability
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