-
Brain Pathology (Zurich, Switzerland) Jan 2021Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytoma predominantly affecting children and young adults. We performed comprehensive genomic characterization on a...
Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytoma predominantly affecting children and young adults. We performed comprehensive genomic characterization on a cohort of 67 patients with histologically defined PXA (n = 53, 79%) or anaplastic PXA (A-PXA, n = 14, 21%), including copy number analysis (ThermoFisher Oncoscan, n = 67), methylation profiling (Illumina EPIC array, n = 43) and targeted next generation sequencing (n = 32). The most frequent alterations were CDKN2A/B deletion (n = 63; 94%) and BRAF p.V600E (n = 51, 76.1%). In 7 BRAF p.V600 wild-type cases, alternative driver alterations were identified involving BRAF, RAF1 and NF1. Downstream phosphorylation of ERK kinase was uniformly present. Additional pathogenic alterations were rare, with TERT, ATRX and TP53 mutations identified in a small number of tumors, predominantly A-PXA. Methylation-based classification of 46 cases utilizing a comprehensive reference tumor allowed assignment to the PXA methylation class in 40 cases. A minority grouped with the methylation classes of ganglioglioma or pilocytic astrocytoma (n = 2), anaplastic pilocytic astrocytoma (n = 2) or control tissues (n = 2). In 9 cases, tissue was available from matched primary and recurrent tumors, including 8 with anaplastic transformation. At recurrence, two tumors acquired TERT promoter mutations and the majority demonstrated additional non-recurrent copy number alterations. Methylation class was preserved at recurrence. For 62 patients (92.5%), clinical follow-up data were available (median follow-up, 5.4 years). Overall survival was significantly different between PXA and A-PXA (5-year OS 80.8% vs. 47.6%; P = 0.0009) but not progression-free survival (5-year PFS 59.9% vs. 39.8%; P = 0.05). WHO grade remained a strong predictor of overall survival when limited to 38 cases defined as PXA by methylation-based classification. Our data confirm the importance of WHO grading in histologically and epigenetically defined PXA. Methylation-based classification may be helpful in cases with ambiguous morphology, but is largely confirmatory in PXA with well-defined morphology.
Topics: Adolescent; Adult; Aged; Astrocytoma; Brain Neoplasms; Child; Child, Preschool; Cohort Studies; DNA Methylation; Female; Humans; Male; Middle Aged; Neoplasm Grading; Young Adult
PubMed: 32619305
DOI: 10.1111/bpa.12874 -
Neurobiology of Disease Jan 2016Glioblastoma (GBM, Grade IV astrocytoma) is the most common and most aggressive of the primary malignant brain tumors in adults. Hypoxia is a distinct feature in GBM and... (Review)
Review
Glioblastoma (GBM, Grade IV astrocytoma) is the most common and most aggressive of the primary malignant brain tumors in adults. Hypoxia is a distinct feature in GBM and plays a significant role in tumor progression, resistance to treatment and poor outcomes. This review considers the effects of hypoxia on astrocytic tumors and the mechanisms that contribute to tumor progression and therapeutic resistance, with a focus on the vascular changes, chemotaxic signaling pathways and metabolic alterations involved.
Topics: Animals; Astrocytoma; Brain Neoplasms; Humans; Hypoxia
PubMed: 26094595
DOI: 10.1016/j.nbd.2015.06.007 -
Neurosurgical Review Oct 2022The development of minimally invasive neuroendoscopy has advanced in recent years. The introduction of the neuroendoscopic ultrasonic aspirator (NUA) increased the... (Review)
Review
The development of minimally invasive neuroendoscopy has advanced in recent years. The introduction of the neuroendoscopic ultrasonic aspirator (NUA) increased the treatment spectrum of neuroendoscopy. This review aimed to present a systematic overview of the extent of resection, lesion characteristics, technical aspects, complications, and clinical outcomes related to using the NUA. Articles were identified by searching the PubMed/Medline, Embase, and Web of Science database through June 2022 with restriction to the last 20 years. We included case series, case reports, clinical trials, controlled clinical trials, meta-analyses, randomized controlled trials, reviews, and systematic reviews written in English. Studies reporting on endonasal approach or hematoma evacuation using the NUA were excluded. The references of the identified studies were reviewed as well. Nine full-text articles were included in the analysis, with a total of 40 patients who underwent surgery for a brain tumor using NUA. The most common underlying pathology treated by NUA was colloid cyst (17.5%), pilocytic astrocytoma (12.5%), subependymal giant cell astrocytoma (7.5%), subependymoma (7.5%), and craniopharyngioma (7.5%). Complete or near-total resection was achieved in 62.5%. The most frequently reported postoperative complication was secondary hydrocephalus (10%), meningitis/-encephalitis (7.5%), cognitive impairment (7.5%), and subdural hygroma (7.5%). In one case (2.5%), surgery-related death occurred due to a severe course of meningoencephalitis. According to the preliminary data, NUA seems to be a safe and efficient minimally invasive alternative to conventional microscopic resection of brain tumors. Further studies to investigate advantages and disadvantages of using the NUA are needed.
Topics: Astrocytoma; Brain; Brain Neoplasms; Colloid Cysts; Humans; Neuroendoscopy; Pituitary Neoplasms; Ultrasonics
PubMed: 35896917
DOI: 10.1007/s10143-022-01837-w -
BMC Cancer Dec 2022Juvenile Pilocytic Astrocytomas (JPAs) are one of the most common pediatric brain tumors, and they are driven by aberrant activation of the mitogen-activated protein...
BACKGROUND
Juvenile Pilocytic Astrocytomas (JPAs) are one of the most common pediatric brain tumors, and they are driven by aberrant activation of the mitogen-activated protein kinase (MAPK) signaling pathway. RAF-fusions are the most common genetic alterations identified in JPAs, with the prototypical KIAA1549-BRAF fusion leading to loss of BRAF's auto-inhibitory domain and subsequent constitutive kinase activation. JPAs are highly vascular and show pervasive immune infiltration, which can lead to low tumor cell purity in clinical samples. This can result in gene fusions that are difficult to detect with conventional omics approaches including RNA-Seq.
METHODS
To this effect, we applied RNA-Seq as well as linked-read whole-genome sequencing and in situ Hi-C as new approaches to detect and characterize low-frequency gene fusions at the genomic, transcriptomic and spatial level.
RESULTS
Integration of these datasets allowed the identification and detailed characterization of two novel BRAF fusion partners, PTPRZ1 and TOP2B, in addition to the canonical fusion with partner KIAA1549. Additionally, our Hi-C datasets enabled investigations of 3D genome architecture in JPAs which showed a high level of correlation in 3D compartment annotations between JPAs compared to other pediatric tumors, and high similarity to normal adult astrocytes. We detected interactions between BRAF and its fusion partners exclusively in tumor samples containing BRAF fusions.
CONCLUSIONS
We demonstrate the power of integrating multi-omic datasets to identify low frequency fusions and characterize the JPA genome at high resolution. We suggest that linked-reads and Hi-C could be used in clinic for the detection and characterization of JPAs.
Topics: Child; Adult; Humans; Multiomics; Proto-Oncogene Proteins B-raf; Oncogene Proteins, Fusion; Astrocytoma; Brain Neoplasms; Receptor-Like Protein Tyrosine Phosphatases, Class 5
PubMed: 36503484
DOI: 10.1186/s12885-022-10359-z -
BMC Medical Imaging Jan 2019The purpose of this retrospective review is to determine the MR imaging features of pilocytic astrocytoma (PA) in the spinal cord to help neuroradiologists...
BACKGROUND
The purpose of this retrospective review is to determine the MR imaging features of pilocytic astrocytoma (PA) in the spinal cord to help neuroradiologists preoperatively differentiate PA from other intramedullary tumors.
METHODS
Neuro-oncology database review revealed 13 consecutive patients with a pathological spinal PA diagnosis and availability of preoperative MR imaging. Three patients had preoperative diffusion-weighted MR imaging. Demographics and conventional and diffusion MR imaging records were retrospectively evaluated.
RESULTS
Among 13 cases of spinal PA, six PAs were located in the cervical region, 4 in the cervical-thoracic region, and 3 in the thoracic region. The average length of vertebral segments involved for the tumors were 4.7 ± 4.6 segments. Six tumors had associated syringomyelia. Eight PAs were located eccentrically in the spinal cord, and eleven had well-defined margins. Eight tumors (61.5%) were intermixed cystic and solid. All were contrast-enhanced, and 53.8% of all PAs showed focal nodule enhancement of the solid components. Two PAs showed intratumoral hemorrhages, and only one demonstrated cap sign. The ADC values (n = 3) of the tumors were 1.40 ± 0.28 × 10 mm/s (min-max: 1.17-1.71 × 10 mm/s).
CONCLUSIONS
PA should be considered in the differential diagnosis of intramedullary tumors that occur in the cervical and thoracic regions. Eccentric growth pattern, well-defined margin, intermixed cystic and solid appearance, focal nodular enhancement of solid components and syringomyelia are relatively frequent features. Relatively high ADC values compared with normal-appearing spinal cord parenchyma are common in spinal PA.
Topics: Adolescent; Adult; Astrocytoma; Cervical Cord; Child; Diagnosis, Differential; Diffusion Magnetic Resonance Imaging; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Retrospective Studies; Spinal Cord Neoplasms; Young Adult
PubMed: 30642288
DOI: 10.1186/s12880-018-0296-y -
International Journal of Molecular... Mar 2022The present investigation aimed to explore the intact proteome of tissues of pediatric brain tumors of different WHO grades and localizations, including medulloblastoma,...
The present investigation aimed to explore the intact proteome of tissues of pediatric brain tumors of different WHO grades and localizations, including medulloblastoma, pilocytic astrocytoma, and glioblastoma, in comparison with the available data on ependymoma, to contribute to the understanding of the molecular mechanisms underlying the onset and progression of these pathologies. Tissues have been homogenized in acidic water−acetonitrile solutions containing proteases inhibitors and analyzed by LC−high resolution MS for proteomic characterization and label-free relative quantitation. Tandem MS spectra have been analyzed by either manual inspection or software elaboration, followed by experimental/theoretical MS fragmentation data comparison by bioinformatic tools. Statistically significant differences in protein/peptide levels between the different tumor histotypes have been evaluated by ANOVA test and Tukey’s post-hoc test, considering a p-value > 0.05 as significant. Together with intact protein and peptide chains, in the range of molecular mass of 1.3−22.8 kDa, several naturally occurring fragments from major proteins, peptides, and proteoforms have been also identified, some exhibiting proper biological activities. Protein and peptide sequencing allowed for the identification of different post-translational modifications, with acetylations, oxidations, citrullinations, deamidations, and C-terminal truncations being the most frequently characterized. C-terminal truncations, lacking from two to four amino acid residues, particularly characterizing the β-thymosin peptides and ubiquitin, showed a different modulation in the diverse tumors studied. With respect to the other tumors, medulloblastoma, the most frequent malignant brain tumor of the pediatric age, was characterized by higher levels of thymosin β4 and β10 peptides, the latter and its des-IS form particularly marking this histotype. The distribution pattern of the C-terminal truncated forms was also different in glioblastoma, particularly underlying gender differences, according to the definition of male and female glioblastoma as biologically distinct diseases. Glioblastoma was also distinguished for the peculiar identification of the truncated form of the α-hemoglobin chain, lacking the C-terminal arginine, and exhibiting oxygen-binding and vasoconstrictive properties different from the intact form. The proteomic characterization of the undigested proteome, following the top-down approach, was challenging to originally investigate the post-translational events that differently characterize pediatric brain tumors. This study provides a contribution to elucidate the molecular profiles of the solid tumors most frequently affecting the pediatric age, and which are characterized by different grades of aggressiveness and localization.
Topics: Brain Neoplasms; Cerebellar Neoplasms; Child; Female; Glioblastoma; Humans; Male; Medulloblastoma; Peptides; Proteome; Proteomics
PubMed: 35328618
DOI: 10.3390/ijms23063196 -
Nature Communications Aug 2019Pilocytic 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...
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.
Topics: Animals; Astrocytoma; Brain Neoplasms; Humans; MAP Kinase Signaling System; Mice; Microglia; Mitogen-Activated Protein Kinases; Neural Stem Cells; Oligodendroglia; Oncogene Proteins, Fusion; Proto-Oncogene Proteins B-raf; Tumor Cells, Cultured
PubMed: 31427603
DOI: 10.1038/s41467-019-11493-2 -
Journal of Neuro-oncology May 2023Astrocytomas and oligodendrogliomas are mainly diffuse primary brain tumors harboring a diagnostic and prognostically favorable isocitrate dehydrogenase mutation. They... (Review)
Review
PURPOSE
Astrocytomas and oligodendrogliomas are mainly diffuse primary brain tumors harboring a diagnostic and prognostically favorable isocitrate dehydrogenase mutation. They are still incurable besides growing molecular knowledge and therapy options. Circumscribed astrocytomas are also discussed here, although they represent a separate entity despite similarities in the nomenclature.
METHODS
We reviewed clinical trials, preclinical approaches as well as guideline recommendations form the major scientific Neuro-Oncology organizations for astrocytomas and oligodendrogliomas according to PRISMA guidelines.
RESULTS
After histopathological diagnosis and eventually a maximal safe resection, patients with good prognostic factors may be followed by magnetic resonance imaging (MRI). If further treatment is necessary, either after diagnosis or at progression, diffuse astrocytomas and oligodendrogliomas are mainly treated with combined radiochemotherapy or maximal safe resection followed by combined radiochemotherapy according to current guidelines based on randomized trials. Circumscribed gliomas like pilocytic astrocytomas, CNS WHO grade 1, or pleomorphic xanthoastrocytomas, CNS WHO grade 2, are often treated with surgery alone. Current approaches for therapy optimization include decision of the best chemotherapy regimen. The IDH mutation presents a rational target for small molecule inhibition and immune therapy in diffuse astrocytomas and oligodendrogliomas, while the BRAF pathway is frequently mutated and treatable in circumscribed gliomas.
CONCLUSION
Despite establishment of standard treatment approaches for gliomas that include resection, radio- and chemotherapy, there is a lack of effective treatments for progressive disease. Immune- and targeted therapies are currently investigated.
Topics: Humans; Oligodendroglioma; Astrocytoma; Glioma; Magnetic Resonance Imaging; Mutation
PubMed: 36566461
DOI: 10.1007/s11060-022-04216-z -
Neurosurgical Review Apr 2021Glial tumors in the cerebellopontine angle (CPA) are uncommon and comprise less than 1% of CPA tumors. We present four cases of pilocytic astrocytoma of the CPA (PA-CPA)... (Review)
Review
Glial tumors in the cerebellopontine angle (CPA) are uncommon and comprise less than 1% of CPA tumors. We present four cases of pilocytic astrocytoma of the CPA (PA-CPA) that were treated in our department. Patients who received surgical treatment for PA-CPA from January 2004 to December 2019 were identified by a computer search of their files from the Department of Neurosurgery, Tübingen. Patients were evaluated for initial symptoms, pre- and postoperative facial nerve function and cochlear function, complications, and recurrence rate by reviewing surgical reports, patient documents, neuroradiological data, and follow-up data. We identified four patients with PA-CPA out of about 1500 CPA lesions (~ 0.2%), which were surgically treated in our department in the last 16 years. Of the four patients, three were male, and one was a female patient. Two were adults, and two were children (mean age 35 years). A gross total resection was achieved in three cases, and a subtotal resection was attained in one case. Two patients experienced a moderate facial palsy immediately after surgery (House-Brackmann grade III). In all cases, the facial function was intact or good (House-Brackmann grades I-II) at the long-term follow-up (mean follow-up 4.5 years). No mortality occurred during follow-up. Three of the patients had no recurrence at the latest follow-up (mean latest follow-up 4.5 years), while one patient had a slight recurrence. PA-CPA can be safely removed, and most complications immediately after surgery resolve in the long-term follow-up.
Topics: Aged; Astrocytoma; Cerebellopontine Angle; Child; Disease Management; Facial Paralysis; Female; Follow-Up Studies; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Neuroma, Acoustic; Neurosurgical Procedures
PubMed: 32297071
DOI: 10.1007/s10143-020-01293-4 -
Neuropathology and Applied Neurobiology Dec 2022Anaplastic ganglioglioma is a rare tumour, and diagnosis has been based on histological criteria. The 5th edition of the World Health Organization Classification of...
AIMS
Anaplastic ganglioglioma is a rare tumour, and diagnosis has been based on histological criteria. The 5th edition of the World Health Organization Classification of Tumours of the Central Nervous System (CNS WHO) does not list anaplastic ganglioglioma as a distinct diagnosis due to lack of molecular data in previous publications. We retrospectively compiled a cohort of 54 histologically diagnosed anaplastic gangliogliomas to explore whether the molecular profiles of these tumours represent a separate type or resolve into other entities.
METHODS
Samples were subjected to histological review, desoxyribonucleic acid (DNA) methylation profiling and next-generation sequencing. Morphological and molecular data were summarised to an integrated diagnosis.
RESULTS
The majority of tumours designated as anaplastic gangliogliomas resolved into other CNS WHO diagnoses, most commonly pleomorphic xanthoastrocytoma (16/54), glioblastoma, isocitrate dehydrogenase protein (IDH) wild type and diffuse paediatric-type high-grade glioma, H3 wild type and IDH wild type (11 and 2/54), followed by low-grade glial or glioneuronal tumours including pilocytic astrocytoma, dysembryoplastic neuroepithelial tumour and diffuse leptomeningeal glioneuronal tumour (5/54), IDH mutant astrocytoma (4/54) and others (6/54). A subset of tumours (10/54) was not assignable to a CNS WHO diagnosis, and common molecular profiles pointing to a separate entity were not evident.
CONCLUSIONS
In summary, we show that tumours histologically diagnosed as anaplastic ganglioglioma comprise a wide spectrum of CNS WHO tumour types with different prognostic and therapeutic implications. We therefore suggest assigning this designation with caution and recommend comprehensive molecular workup.
Topics: Child; Humans; Ganglioglioma; Retrospective Studies; Glioma; Astrocytoma; Brain Neoplasms; Central Nervous System Neoplasms; Isocitrate Dehydrogenase
PubMed: 35977725
DOI: 10.1111/nan.12847