Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Neuro Oncol ; 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32242226

RESUMO

BACKGROUND: Both genetic and methylation analysis have been shown to provide insight into the diagnosis and prognosis of many brain tumors. However, the implication of methylation profiling and its interaction with genetic alterations in pediatric low-grade gliomas (PLGGs) are unclear. METHODS: We performed a comprehensive analysis of PLGG with long term clinical follow up. In total 152 PLGGs were analyzed from a range of pathological subtypes including 40 gangliogliomas. Complete molecular analysis was compared to genome-wide methylation data and outcome in all patients. For further analysis of specific PLGG groups, including BRAF p.V600E mutant gliomas, we compiled an additional cohort of clinically and genetically defined tumors from 3 large centers. RESULTS: Unsupervised hierarchical clustering revealed 5 novel subgroups of PLGG. These were dominated by non-neoplastic factors such as tumor location and lymphocytic infiltration. Midline PLGG clustered while deep hemispheric lesions differed from lesions in the periphery. Mutations were distributed throughout these location-driven clusters of PLGG. A novel methylation cluster suggesting high lymphocyte infiltration was confirmed pathologically and exhibited worse progression-free survival compared to PLGG harboring similar molecular alterations (p = 0.008, multivariate analysis: p = 0.035). Although the current methylation classifier revealed low confidence in 44% of cases and failed to add information in most PLGG it was helpful in reclassifying rare cases. The addition of histopathological and molecular information to specific methylation subgroups such as pleomorphic xanthoastrocytoma (PXA)-like tumors could stratify these tumors into low and high risk (p = 0.0014). CONCLUSION: The PLGG methylome is affected by multiple non-neoplastic factors. Combined molecular and pathological analysis is key to provide additional information when methylation classification is used for PLGG in the clinical setting.

2.
Cancer Cell ; 37(4): 569-583.e5, 2020 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-32289278

RESUMO

Pediatric low-grade gliomas (pLGG) are frequently driven by genetic alterations in the RAS-mitogen-activated protein kinase (RAS/MAPK) pathway yet show unexplained variability in their clinical outcome. To address this, we characterized a cohort of >1,000 clinically annotated pLGG. Eighty-four percent of cases harbored a driver alteration, while those without an identified alteration also often exhibited upregulation of the RAS/MAPK pathway. pLGG could be broadly classified based on their alteration type. Rearrangement-driven tumors were diagnosed at a younger age, enriched for WHO grade I histology, infrequently progressed, and rarely resulted in death as compared with SNV-driven tumors. Further sub-classification of clinical-molecular correlates stratified pLGG into risk categories. These data highlight the biological and clinical differences between pLGG subtypes and opens avenues for future treatment refinement.

3.
J Neuropathol Exp Neurol ; 79(4): 437-447, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32053195

RESUMO

The diagnosis of medulloblastoma incorporates the histologic and molecular subclassification of clinical medulloblastoma samples into wingless (WNT)-activated, sonic hedgehog (SHH)-activated, group 3 and group 4 subgroups. Accurate medulloblastoma subclassification has important prognostic and treatment implications. Immunohistochemistry (IHC)-based and nanoString-based subgrouping methodologies have been independently described as options for medulloblastoma subgrouping, however have not previously been directly compared. We describe our experience with nanoString-based subgrouping in a clinical setting and compare this with our IHC-based results. Study materials included FFPE tissue from 160 medulloblastomas. Clinical data and tumor histology were reviewed. Immunohistochemical-based subgrouping using ß-catenin, filamin A and p53 antibodies and nanoString-based gene expression profiling were performed. The sensitivity and specificity of IHC-based subgrouping of WNT and SHH-activated medulloblastomas was 91.5% and 99.54%, respectively. Filamin A immunopositivity highly correlated with SHH/WNT-activated subgroups (sensitivity 100%, specificity 92.7%, p < 0.001). Nuclear ß-catenin immunopositivity had a sensitivity of 76.2% and specificity of 99.23% for detection of WNT-activated tumors. Approximately 23.8% of WNT cases would have been missed using an IHC-based subgrouping method alone. nanoString could confidently predict medulloblastoma subgroup in 93% of cases and could distinguish group 3/4 subgroups in 96.3% of cases. nanoString-based subgrouping allows for a more prognostically useful classification of clinical medulloblastoma samples.

4.
Neuro Oncol ; 22(2): 290-297, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31504816

RESUMO

BACKGROUND: Cerebellar mutism syndrome (CMS) is a common complication following resection of posterior fossa tumors, most commonly after surgery for medulloblastoma. Medulloblastoma subgroups have historically been treated as a single entity when assessing CMS risk; however, recent studies highlighting their clinical heterogeneity suggest the need for subgroup-specific analysis. Here, we examine a large international multicenter cohort of molecularly characterized medulloblastoma patients to assess predictors of CMS. METHODS: We assembled a cohort of 370 molecularly characterized medulloblastoma subjects with available neuroimaging from 5 sites globally, including Great Ormond Street Hospital, Christian Medical College and Hospital, the Hospital for Sick Children, King Hussein Cancer Center, and Lucile Packard Children's Hospital. Age at diagnosis, sex, tumor volume, and CMS development were assessed in addition to molecular subgroup. RESULTS: Overall, 23.8% of patients developed CMS. CMS patients were younger (mean difference -2.05 years ± 0.50, P = 0.0218) and had larger tumors (mean difference 10.25 cm3 ± 4.60, P = 0.0010) that were more often midline (odds ratio [OR] = 5.72, P < 0.0001). In a multivariable analysis adjusting for age, sex, midline location, and tumor volume, Wingless (adjusted OR = 4.91, P = 0.0063), Group 3 (adjusted OR = 5.56, P = 0.0022), and Group 4 (adjusted OR = 8.57 P = 9.1 × 10-5) tumors were found to be independently associated with higher risk of CMS compared with sonic hedgehog tumors. CONCLUSIONS: Medulloblastoma subgroup is a very strong predictor of CMS development, independent of tumor volume and midline location. These findings have significant implications for management of both the tumor and CMS.

5.
Pediatr Blood Cancer ; 67(3): e28102, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31793190

RESUMO

Diffuse intrinsic pontine glioma (DIPG) is characterized by a short history of brainstem symptoms and well-known magnetic resonance imaging features with a fatal outcome. However, we report three unusual cases of brainstem tumors with an initial indolent and protracted course, which subsequently developed the classical imaging and clinical features of DIPG. Our findings support this notion that K27M is an early event in development and suggest that the emergence of additional events resulted in rapid progression after a long period of latency. Identification of such markers of aggressive behavior in the context of an indolent course is needed for better characterization and treatment management.

6.
Nat Commun ; 10(1): 4343, 2019 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-31554817

RESUMO

Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.


Assuntos
Neoplasias Encefálicas/genética , Metilação de DNA , Epigenômica/métodos , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Receptores Proteína Tirosina Quinases/genética , Quinase do Linfoma Anaplásico/genética , Quinase do Linfoma Anaplásico/metabolismo , Neoplasias Encefálicas/classificação , Neoplasias Encefálicas/metabolismo , Feminino , Glioma/classificação , Glioma/metabolismo , Humanos , Lactente , Recém-Nascido , Masculino , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Receptor trkA/genética , Receptor trkA/metabolismo , Análise de Sobrevida , Sequenciamento Completo do Exoma/métodos
7.
J Neurooncol ; 145(1): 107-114, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31468270

RESUMO

PURPOSE: Children with recurrent medulloblastoma have a poor prognosis. Re-irradiation is an option for some patients, but has not been well-studied in the era of molecular characterization for pediatric medulloblastoma. METHODS: This was a retrospective cohort study of 14 children age 18 years and younger at initial diagnosis with recurrent medulloblastoma, who received two or more courses of radiation therapy (RT). Molecular subgrouping was performed using nanoString and was available for nine patients. The primary study endpoint was overall survival. RESULTS: Re-irradiation (RT2) was directed at the supratentorial brain in six patients, infratentorial brain in one patient, and spine in seven patients. In addition, six patients received stem cell transplant as part of salvage therapy. Median OS for all patients was 12.4 months. One patient with recurrent Wnt-activated medulloblastoma remains alive with 154 months' survival; median survival was not reached for four patients with Group 4 disease, while three with Shh-activated disease had median survival of 2.2 months. A single patient with Group 3 disease died 4.3 months after RT2. Patients treated with RT2 to the spine for diffuse disease had poorer OS (p = 0.02), as compared to focal RT2 for intracranial recurrence. Distant failure, outside RT2 volumes, was the predominant pattern of recurrence after RT2. CONCLUSIONS: Re-irradiation for recurrent pediatric medulloblastoma can offer some patients disease control, particularly those with focally recurrent disease in the brain. Prospective studies are needed to confirm subgroups of patients who may benefit most from RT2.


Assuntos
Neoplasias Cerebelares/radioterapia , Meduloblastoma/radioterapia , Reirradiação/métodos , Terapia de Salvação , Adolescente , Adulto , Neoplasias Cerebelares/patologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Meduloblastoma/patologia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
8.
Pediatr Blood Cancer ; 66(6): e27694, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30848061

RESUMO

Most medulloblastoma protocols worldwide include vincristine during radiation and chemotherapy. A significant dose-limiting toxicity is peripheral neuropathy; however, there is a paucity of data to support the view that omission of vincristine does not impact survival. Herein we report two adolescent patients with Group 4 and SHH medulloblastoma, where vinblastine successfully replaced vincristine with resolution of their peripheral neuropathy. We furthermore show vinblastine is highly active in vitro and demonstrates equivalent antitumoral activity compared to vincristine. Substitution of vincristine with vinblastine in future studies should be considered for all patients with medulloblastoma, particularly those with hereditary neuropathy, severe vincristine toxicity, and adults.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Neoplasias Cerebelares/tratamento farmacológico , Meduloblastoma/tratamento farmacológico , Vimblastina/uso terapêutico , Adolescente , Neoplasias Cerebelares/patologia , Feminino , Humanos , Meduloblastoma/patologia , Prognóstico
9.
Cancer ; 125(11): 1867-1876, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30768777

RESUMO

BACKGROUND: Posterior fossa ependymoma (PFE) comprises 2 groups, PF group A (PFA) and PF group B (PFB), with stark differences in outcome. However, to the authors' knowledge, the long-term outcomes of PFA ependymoma have not been described fully. The objective of the current study was to identify predictors of survival and neurocognitive outcome in a large consecutive cohort of subgrouped patients with PFE over 30 years. METHODS: Demographic, survival, and neurocognitive data were collected from consecutive patients diagnosed with PFE from 1985 through 2014 at the Hospital for Sick Children in Toronto, Ontario, Canada. Subgroup was assigned using genome-wide methylation array and/or immunoreactivity to histone H3 K27 trimethylation (H3K27me3). RESULTS: A total of 72 PFE cases were identified, 89% of which were PFA. There were no disease recurrences noted among patients with PFB. The 10-year progression-free survival rate for all patients with PFA was poor at 37.1% (95% confidence interval, 25.9%-53.1%). Analysis of consecutive 10-year epochs revealed significant improvements in progression-free survival and/or overall survival over time. This pertains to the increase in the rate of gross (macroscopic) total resection from 35% to 77% and the use of upfront radiotherapy increasing from 65% to 96% over the observed period and confirmed in a multivariable model. Using a mixed linear model, analysis of longitudinal neuropsychological outcomes restricted to patients with PFA who were treated with focal irradiation demonstrated significant continuous declines in the full-scale intelligence quotient over time with upfront conformal radiotherapy, even when correcting for hydrocephalus, number of surgeries, and age at diagnosis (-1.33 ± 0.42 points/year; P = .0042). CONCLUSIONS: Data from a molecularly informed large cohort of patients with PFE clearly indicate improved survival over time, related to more aggressive surgery and upfront radiotherapy. However, to the best of the authors' knowledge, the current study is the first, in a subgrouped cohort, to demonstrate that this approach results in reduced neurocognitive outcomes over time.


Assuntos
Ependimoma/terapia , Neoplasias Infratentoriais/terapia , Transtornos Neurocognitivos/etiologia , Procedimentos Neurocirúrgicos/efeitos adversos , Radioterapia/efeitos adversos , Adolescente , Criança , Pré-Escolar , Ependimoma/mortalidade , Ependimoma/psicologia , Feminino , Humanos , Lactente , Neoplasias Infratentoriais/mortalidade , Neoplasias Infratentoriais/psicologia , Masculino , Terapia Neoadjuvante/efeitos adversos , Ontário , Análise de Sobrevida , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA