The age of adult pilocytic astrocytoma cells.
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ABSTRACT:
SUBMITTER: Voronina N
PROVIDER: S-EPMC8062266 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:INTRODUCTION:Pilocytic astrocytoma (PA) is the most common primary brain neoplasm in children and treated in curative intent with gross total resection (GTR). However, PA is rare in adults, resulting in limited knowledge on the natural clinical course. This study aimed to describe the clinical course and identify prognostic factors of adult patients with PA. METHODS:46 patients???18 years at diagnosis of PA and neurosurgical resection or biopsy between 2000 and 2018 were identified from the Neuro-Biobank of the Medical University of Vienna. In two cases with differing histopathological diagnosis at recurrence, DNA methylation analysis was performed using Illumina Infinium HumanMethylation850 BeadChip (850 k) arrays and the Molecular Neuropathology classifier. Clinico-pathological features were correlated with patient outcomes. RESULTS:Median age at diagnosis was 32.5 years (range: 19-75) and median Ki67 proliferation index was 2.8% (0.5-13.4%). Tumor location significantly correlated with resectability (p?<?0.001). Tumor progression or recurrence was observed in 9/46 (19.6%) patients after a median follow up time of 53.0 months (range 0.5-300). 5-year overall and progression-free survival rates were 85.3% and 70.0%, respectively. 2/9 (22.2%) patients presented with histological changes in the recurrent tumor specimen. In detail, methylation classification redefined the histological diagnosis to anaplastic astrocytoma with piloid features and glioma in one patient, each. Age?>?40 and higher body mass index (BMI) were associated with impaired progression-free and overall survival (p?<?0.05). CONCLUSIONS:Tumor recurrence or progression in adult PA patients was higher than the one reported in pediatric patients. Higher age and BMI were associated with impaired prognosis.
| S-EPMC7280326 | biostudies-literature
Project description:Pilocytic astrocytomas (PAs) are the most common glioma in children. While many PAs are slow growing or clinically indolent, others exhibit more aggressive features with tumor recurrence and death. In order to identify genetic signatures that might predict PA clinical behavior, we performed gene expression profiling on 41 primary PAs arising sporadically and in patients with neurofibromatosis type 1 (NF1). While no expression signature was found that could discriminate clinically-aggressive or recurrent tumors from more indolent cases, PAs arising in patients with NF1 did exhibit a unique gene expression pattern. In addition, we identified a gene expression signature that stratified PAs by location (supratentorial versus infratentorial). Keywords: Human, WHO grade I, Brain tumor, Pilocytic astrocytoma, NF1
2007-03-14 | GSE5675 | GEO
Project description:Genome wide DNA methylation profiling of 79 histologically diagnosed pilocytic astrocytoma (PA) in adults, of which we were able to upload 71 samples. The methylation profiling indicates that many of the histologically diagnosed PA do not show a concordant methylation classification.
2024-01-01 | GSE244566 | GEO
Project description:Pilocytic astrocytoma (PA), the most common childhood brain tumor, is a low-grade glioma with a single driver BRAF rearrangement. Here, we perform scRNAseq in six PAs using methods that enabled detection of the rearrangement. When compared to higher-grade gliomas, a strikingly higher proportion of the PA cancer cells exhibit a differentiated, astrocyte-like phenotype. A smaller proportion of cells exhibit a progenitor-like phenotype with evidence of proliferation. These express a mitogen-activated protein kinase (MAPK) programme that was absent from higher-grade gliomas. Immune cells, especially microglia, comprise 40% of all cells in the PAs and account for differences in bulk expression profiles between tumor locations and subtypes. These data indicate that MAPK signaling is restricted to relatively undifferentiated cancer cells in PA, with implications for investigational therapies directed at this pathway.
| S-EPMC6700116 | biostudies-literature
Project description:Introductionand Importance: Adult Pilocytic Astrocytomas (APA) are infrequent low grade tumors. While supratentorial APA is considered rare, insular APA is extremely rare.Case presentationWe present a case of pure insular APA along with surgical outcomes. Tractography and functional MRI were obtained pre-operatively. The patient underwent neuro-navigation guided microsurgical resection with sub-cortical white matter mapping, utilizing Intra-operative MRI guidance. The Sylvain fissure was opened to secure the M3 branches, and near total resection was achieved.Clinical discussionAPA in the insula is a very rare presentation and is considered challenging. Its proximity to the middle cerebral and lenticulostriate arteries, motor areas, and language areas makes accessing and resecting the tumor challenging. A multidisciplinary approach by an experienced team is needed to plan the management of young adult patients and reach the best outcomes.ConclusionImplementing microsurgical techniques, modern imaging modalities and intraoperative mapping helps to achieve maximal safe resection without risking functions.
| S-EPMC8080460 | biostudies-literature
Project description:Pilocytic astrocytoma (PA) is the most common tumor of the pediatric central nervous system (CNS). A body of research over recent years has demonstrated a key role for mitogen-activated protein kinase (MAPK) pathway signaling in the development and behavior of PAs. Several mechanisms lead to activation of this pathway in PA, mostly in a mutually exclusive manner, with constitutive BRAF kinase activation subsequent to gene fusion being the most frequent. The high specificity of this fusion to PA when compared with other CNS tumors has diagnostic utility. In addition, the frequency of alteration of this key pathway provides an opportunity for molecularly targeted therapy in this tumor. Here, we review the current knowledge on mechanisms of MAPK activation in PA and some of the downstream consequences of this activation, which are now starting to be elucidated both in vitro and in vivo, as well as clinical considerations and possible future directions.
| S-EPMC3350769 | biostudies-literature
Project description:Pilocytic astrocytoma (PA) is the most common brain tumor in children but is rare in adults, and hence poorly studied in this age group. We investigated 222 PA and report increased aneuploidy in older patients. Aneuploid genomes were identified in 45% of adult compared with 17% of pediatric PA. Gains were non-random, favoring chromosomes 5, 7, 6 and 11 in order of frequency, and preferentially affecting non-cerebellar PA and tumors with BRAF V600E mutations and not with KIAA1549-BRAF fusions or FGFR1 mutations. Aneuploid PA differentially expressed genes involved in CNS development, the unfolded protein response, and regulators of genomic stability and the cell cycle (MDM2, PLK2),whose correlated programs were overexpressed specifically in aneuploid PA compared to other glial tumors. Thus, convergence of pathways affecting the cell cycle and genomic stability may favor aneuploidy in PA, possibly representing an additional molecular driver in older patients with this brain tumor.
| S-EPMC4741644 | biostudies-literature
Project description:Microglia in the microenvironment of low-grade tumors have been shown to allow and support tumor growth, but the expression profile of these microglia are unknown. To examine the role of microglia in junior pilocytic astrocytomas, macrophages were flow sorted from cyroprotected surgical excisions of tumors and normal brain tissues. Upregulated markers of tumor-associated microglia were verified and compared to mouse tumor-associated microglia.
2020-07-03 | GSE65867 | GEO
Project description:Pilocytic astrocytoma (PA) is the most common pediatric glioma, arising from a single driver MAPK pathway alteration. Classified as a grade I tumor according to the 2016 WHO classification, prognosis is excellent with a 10-year survival rate > 95% after surgery. However, rare cases present with anaplastic features, including an unexpected high mitotic/proliferative index, thus posing a diagnostic and therapeutic challenge. Based on small histomolecular series and case reports, such tumors arising at the time of diagnosis or recurrence have been designated by many names including pilocytic astrocytoma with anaplastic features (PAAF). Recent DNA methylation-profiling studies performed mainly on adult cases have revealed that PAAF exhibit a specific methylation signature, thus constituting a distinct methylation class from typical PA [methylation class anaplastic astrocytoma with piloid features-(MC-AAP)]. However, the diagnostic and prognostic significance of MC-AAP remains to be determined in children. We performed an integrative work on the largest pediatric cohort of PAAF, defined according to strict criteria: morphology compatible with the diagnosis of PA, with or without necrosis, ≥ 4 mitoses for 2.3 mm2, and MAPK pathway alteration. We subjected 31 tumors to clinical, imaging, morphological and molecular analyses, including DNA methylation profiling. We identified only one tumor belonging to the MC-AAP (3%), the others exhibiting a methylation profile typical for PA (77%), IDH-wild-type glioblastoma (7%), and diffuse leptomeningeal glioneuronal tumor (3%), while three cases (10%) did not match to a known DNA methylation class. No significant outcome differences were observed between PAAF with necrosis versus no necrosis (p = 0.07), or with 4-6 mitoses versus 7 or more mitoses (p = 0.857). Our findings argue that the diagnostic histomolecular criteria established for anaplasia in adult PA are not of diagnostic or prognostic value in a pediatric setting. Further extensive and comprehensive integrative studies are necessary to accurately define this exceptional entity in children.
| S-EPMC6989446 | biostudies-literature
Project description:Pilocytic astrocytoma is the most common type of brain tumor in pediatric population, generally connected with favorable prognosis, although recurrences or dissemination sometimes are also observed. For tumors originating in supra- or infratentorial location different molecular background was suggested but plausible correlations between transcriptional profile and radiological features and/or clinical course are still undefined. The purpose of this study was to identify gene expression profiles related to the most frequent locations of this tumor, subtypes based on various radiological features and clinical pattern of the disease. According to the radiological features presented on MRI, all cases were divided into four subtypes: solid or mainly solid, cystic with an enhancing cyst wall, cystic with a non-enhancing cyst wall and solid with central necrosis. Bioinformatic analyses showed that gene expression profile of pilocytic astrocytoma highly depends on the tumor location. Most prominent differences were noted for IRX2, PAX3, CXCL14, LHX2, SIX6, CNTN1 and SIX1 genes expression which could distinguish pilocytic astrocytomas of different location even within supratentorial region. Analysis of the genes potentially associated between radiological features showed much weaker transcriptome differences. Single genes showed association with the tendency to progression. Here we showed that pilocytic astrocytomas of three different locations could be precisely differentiated on the basis of gene expression level but their transcriptional profiles did not strongly reflect the radiological appearance of the tumor or the course of the disease.
2015-10-30 | GSE73066 | GEO