Astrocytomas In Children Research Articles

Concise review of radiosurgery for contemporary management of pilocytic astrocytomas in children and adults.

Pilocytic astrocytoma (PA) may be seen in both adults and children as a distinct histologic and biologic subset of low-grade glioma. Surgery is the principal treatment for the management of PAs; however, selected patients may benefit from irradiation particularly in the setting of inoperability, incomplete resection, or recurrent disease. While conventionally fractionated radiation therapy has been traditionally utilized for radiotherapeutic management, stereotactic irradiation strategies have been introduced more recently to improve the toxicity profile of radiation delivery without compromising tumor control. PAs may be suitable for radiosurgical management due to their typical appearance as well circumscribed lesions. Focused and precise targeting of these well-defined lesions under stereotactic immobilization and image guidance may offer great potential for achieving an improved therapeutic ratio by virtue of radiosurgical techniques. Given the high conformality along with steep dose gradients around the target volume allowing for reduced normal tissue exposure, radiosurgery may be considered a viable modality of radiotherapeutic management. Another advantage of radiosurgery may be the completion of therapy in a usually shorter overall treatment time, which may be particularly well suited for children with requirement of anesthesia during irradiation. Several studies have addressed the utility of radiosurgery particularly as an adjuvant or salvage treatment modality for PA. Nevertheless, despite the growing body of evidence supporting the use of radiosurgery, there is need for a high level of evidence to dictate treatment decisions and establish its optimal role in the management of PA. Herein, we provide a concise review of radiosurgery for PA in light of the literature.

A comparative study betwee Medulloblastoma And Cerebellar astrocytoma In children

study was conducted between 2000 & 2002, 50 children with histopathologyically verified medulloblastoma and cerebellar astrocytoma in neurosurgical department of Surgical Specialties Hospital. Ages ranged from 2-19 years, peak incidence between 5-10 years. No significant gender differences found. CT scan confirmed features of medulloblastoma: midline location, well defined margin & hyperdensity of lesion with homogenous enhancement after I.V. contrast infusion. In cerebellar astrocytoma, 60% were midline tumor, most of which were solid & 40% were hemispheric lesion, most of which were cystic. Calcification on CT scans seen more in medulloblastoma.Shunt operation was the main procedure conducted for treatment of hydrocephalus associated with these tumors, but other CSF diversion procedures, especially safety burrhole at time of tumor resection was carried on in cystic lesion located off the midline. Total removal was achieved in 46.7% of children with medulloblastomas & 50% of children with cerebellar astrocytomas. Brain stem violation was evident more in medulloblastoma & was the main factor behind the incomplete tumor removal in significant number of cases that adversely affected the outcome. postoperative complications (pseudomeningocele, cerebellar mutism, meningitis, CSF leak, cranial nerve palsy…etc.) encountered more in children with medulloblastoma. Mortality rate was 6.7% in medulloblastomas & 10% in cerebellar astrocytoma. The cause of death in patients with medulloblastoma was meningitis & patients with cerebellar astrocytomas was brain stem injury. early diagnosis & total removal of tumor with proper postoperative care would essentially decrease the postoperative morbidity & mortality

Three-Dimensional Pseudo-Continuous Arterial Spin Labeling Parameters Distinguish Pediatric Medulloblastoma and Pilocytic Astrocytoma.

Introduction: Arterial Spin Labeling (ASL), a perfusion assessment without using gadolinium-based contrast agents, is outstandingly advantageous for pediatric patients. The differentiation of medulloblastomas from pilocytic astrocytomas in children plays a significant role in determining treatment strategies and prognosis. This study aimed to assess the use of ASL parameters during the differentiation between pediatric medulloblastoma and pilocytic astrocytoma.Methods: The institutional review board of Children's Hospital 2 approved this prospective study. The brain magnetic resonance imaging (MRI) protocol, including axial three-dimensional (3D) pseudo-continuous ASL, was evaluated in 33 patients, who were divided into a medulloblastoma group (n = 25) and a pilocytic astrocytoma group (n = 8). The quantified region of interest (ROI) values for the tumors and the tumor to parenchyma ratios were collected and compared between the two groups. Receiver operating characteristic (ROC) curve analysis and the Youden index were utilized to identify the best cut-off, sensitivity, specificity, and area under the curve (AUC) values for significant ASL parameters.Results: The cerebral blood flow (CBF) and the ratio between the CBF of the tumor relative to that of the parenchyma (rCBF) values for medulloblastomas were significantly higher than those for pilocytic astrocytomas (p < 0.05). A cut-off value of 0.51 for rCBF was able to discriminate between medulloblastoma and pilocytic astrocytoma, generating a sensitivity of 88%, a specificity of 75%, and an AUC of 83.5%.Conclusion: The rCBF measurement, obtained during MRI with 3D pseudo-continuous ASL, plays a supplemental role in the differentiation of medulloblastoma from pilocytic astrocytoma.

PATH-15. PROTEOMIC SIGNATURES PREDICT GRADE IN PEDIATRIC AND YOUNG ADULT INFILTRATIVE ASTROCYTOMAS

BACKGROUNDInfiltrative astrocytomas in children and young adults pose a treatment challenge due to the difficulty of achieving gross total resection and tumor resistance to irradiation and chemotherapy. Histopathologic grade is an essential part of determining prognosis and treatment, but it is subjective and provides limited understanding of the molecular mechanisms underlying tumor development and progression.METHODSWe performed liquid chromatography/mass spectrometry (LC/MS-MS) on 28 FFPE samples of primary infiltrative astrocytomas (10 grade II, 8 grade III and 10 grade IV – WHO classification) from Nationwide Children’s Hospital (NCH). Initial unsupervised clustering was performed. Lasso regression yielded a protein signature separating low- and high-grade tumors which was validated using a similar cohort of pediatric and young adult infiltrative astrocytomas from the Proteomic Data Commons (PDC) (n=28) of the National Cancer Institute.RESULTSUnsupervised clustering of NCH samples essentially recapitulated grade and lasso regression yielded a 10-protein signature that distinguished grade II from grade III/IV tumors. This 10-protein signature when applied to the PDC validation dataset, accurately predicted grade for 89.3% of the tumors (p=0.00014).CONCLUSIONSWe identified a quantitative protein signature that can reliably distinguish between low- and high-grade infiltrative astrocytomas from FFPE tissue. Further validation will enable the development an objective prognostic proteomic clinical test that complements and may outperform current histopathological strategies. Additionally, proteomic profiling of tumors will clarify the molecular mechanisms contributing to treatment resistance and tumor progression and help identify novel treatment targets. Independent functional validation and characterization of proteins is ongoing.

Surveillance imaging of grade 1 astrocytomas in children: can duration and frequency of follow-up imaging and the use of contrast agents be reduced?

PurposeThe optimum strategy for the surveillance of low-grade gliomas in children has not been established, and there is concern about the use of gadolinium-based contrast agents (GBCAs), particularly in children, due to their deposition in the brain. The number of surveillance scans and the use of GBCAs in surveillance of low-risk tumours should ideally be limited. We aimed to investigate the consistency and utility of our surveillance imaging and also determine to what extent the use of GBCAs contributed to decisions to escalate treatment in children with grade 1 astrocytomas.MethodsThis was a retrospective single-centre study at a tertiary paediatric hospital. All children with a new diagnosis of a non-syndromic World Health Organization (WHO) grade 1 astrocytoma between 2007 and 2013 were included, with surveillance imaging up to December 2018 included in analysis. The intervals of surveillance imaging were recorded, and imaging and electronic health records were examined for decisions related to treatment escalation.ResultsEighty-eight patients had 690 surveillance scans in the study period. Thirty-one patients had recurrence or progression leading to treatment escalation, 30 of whom were identified on surveillance imaging. The use of GBCAs did not appear to contribute to multidisciplinary team (MDT) decisions in the majority of cases.ConclusionSurveillance imaging could be reduced in number and duration for completely resected cerebellar tumours. MDT decisions were rarely made on the basis of post-contrast imaging, and GBCA administration could therefore potentially be restricted in the setting of surveillance of grade 1 astrocytomas in children.

Congenital subpendymal giant cell astrocytoma in children with tuberous sclerosis complex: growth patterns and neurological outcome.

Literature regarding congenital subependymal giant cell astrocytomas (SEGA) is limited, and suggests they are at risk of rapid growth and complications. We sought to characterise the growth patterns of congenital SEGA. The second part of the study was an exploratory analysis of congenital SEGA as a possible biomarker for poor neurological outcome. This single-centre case series describes ten patients with TSC who had SEGA diagnosed before 12 months. SEGA diameter and volumetric growth were analysed using serial MRIs. Neurological outcomes were compared to a genotype-matched group. All children with congenital SEGA had a TSC2 mutation. Patients were followed for 1-8.7 years, during which median SEGA growth rate was 1.1 mm/yr in diameter or 150 mm3/yr volumetrically. SEGA with volume > 500 mm3 had a significantly higher growth rate compared with smaller SEGA (462 mm3/yr vs. 42 mm3/yr, p = 0.0095). Children with congenital SEGA had a high prevalence of severe epilepsy, developmental disability and autism spectrum disorder. Congenital SEGA can follow a relatively benign course with a lower growth rate compared with published literature. Frequent neuroimaging surveillance is recommended for congenital SEGA with volumes exceeding 500 mm3. Congenital SEGA occur in 9.2% of paediatric patients with tuberous sclerosis complex. There are few published cases of congenital SEGA to date. This case series of ten patients adds our experience seen in a tertiary referral hospital over 10 years. Congenital SEGA can follow a relatively benign course with a lower growth rate compared with published literature. Congenital SEGA with volume exceeding 500 mm3 had a significantly higher growth rate compared with smaller SEGA and should have more frequent neuroimaging surveillance.

MICROSURGICAL MANAGEMENT OF LOW-GRADE SPINAL CORD ASTROCYTOMA IN ADULTS: A PERSONAL CASE SERIES REPORT AND BRIEF LITERATURE REVIEW.

SUMMARYAstrocytoma is the second most common intramedullary tumor of predominantly low-grade malignancy in adult patients. Adult astrocytomas have better-quality prognosis compared with astrocytomas in children. Although a standardized surgical management protocol for spinal cord glioma is currently unavailable, surgery of low-grade astrocytoma should be aimed at gross total resection to preserve neurological function and to improve the outcome. Herein, we present a personal case series of four consecutive adult spinal cord astrocytoma patients who were operated on during the last few years. Tumor resection was performed in all patients utilizing microsurgical technique and intraoperative neurophysiologic monitoring. We also provide a literature review of the treatment of intramedullary astrocytoma in adults and discuss contemporary surgical management and prognosis.

Characteristics, survival and incidence rates and trends of pilocytic astrocytoma in children in the United States; SEER-based analysis

IntroductionPilocytic astrocytoma (PA) is a neurological neoplasm and a common neurological tumor among children. No recent reports have studied the recent demographic characteristics of PA cases in the US. MethodologyWe used the Surveillance, Epidemiology, and End Results (SEER) Program to retrieve data on children diagnosed with PA between 2000 and 2015. We calculated the incidence, annual percentage changes (APC), and survival. ResultsOur study included 3084 children with PA, with an incidence of 8.227 per 1,000,000 person-years, being highest among whites (9.062), and children aged 1–4 year (11.175). Overall incidence in children increased significantly over the study period, with an APC of 0.825% (95% CI[0.027–1.630], P = .044). Moreover, incidence among blacks increased significantly over the study period (APC = 3.466%, 95% CI[0.342–6.688], P = .032), but did not change among other races. The relative 5-year survival of included patients was 95.3%, with patients younger than 1 year having the worst survival. ConclusionsOverall PA incidence and incidence among blacks has been increasing last decade. Additionally, PA survival was found to be worse among infants. Further studies are also needed to investigate the effect of the age and race on the incidence and survival of PA.

Use of Apparent Diffusion Coefficient Histogram in Differentiating Between Medulloblastoma and Pilocytic Astrocytoma in Children

BackgroundThis research aimed to investigate the value of apparent diffusion coefficient (ADC) histogram in differentiating between medulloblastoma and pilocytic astrocytoma in children.Material/MethodsThirty-three children with posterior cranial fossa tumor confirmed by operation and pathology participated in this retrospective study, including 18 children with medulloblastoma and 15 children with pilocytic astrocytoma. ADC images of the maximum lay of tumors were selected, and the region of interest was delineated by Mazda software and analyzed by histogram. Histogram characteristic parameters of the 2 tumors were statistically analyzed to determine the significantly different characteristic parameters between the 2 tumor types.ResultsThere were significant differences in the mean value, variance, skewness, kurtosis, and 1th, 10th, 50th, and 90th percentiles of 9 characteristic parameters extracted by histogram (P<0.05). The corresponding receiver operating characteristic (ROC) curves were drawn, in which the mean value and 50th percentile were best identified. When the maximum area under the ROC curve was 1 and the optimal threshold was 137.7 and 125.5, the specificity and sensitivity were both 100%.ConclusionsADC histograms can be used to differentiate between medulloblastoma and pilocytic astrocytoma in children and provide reliable and objective evidence for the differentiation.

Clinicopathological study of cerebellar astrocytoma in children

Clinicopathological study of cerebellar astrocytoma in children

Surgery for subependymal giant cell astrocytomas in children with tuberous sclerosis complex.

Subependymal giant cell astrocytomas (SEGAs) are low-grade intraventricular glial tumors that develop in 10-15% of patients with tuberous sclerosis complex; they often cause hydrocephalus and are potentially accessible to a surgical treatment. Our aim is to evaluate morbidity and results after surgery in symptomatic and asymptomatic patients. We present a retrospective series of 18 pediatric patients operated on for SEGA between 2006 and 2016 at our institution. We reviewed surgical indications, preoperative clinical and radiologic data, surgical management, and clinical and radiological follow-up. Mean age at surgery was 10.7years. The surgical decision was based on clinical signs of raised intracranial pressure due to hydrocephalus in 8 and on radiological findings without any clinical signs in the other 10 patients (increased in SEGA volume with or without ventricular enlargement). Surgical treatment consisted in a frontal trans-ventricular microsurgical approach in 17 patients and an endoscopic approach in 1. External ventricular drainage was placed in all the patients but 1. Ventriculoperitoneal shunting (VPS) became necessary in 6 patients, all of them presenting with a preoperative active hydrocephalus. Morbidity appeared very low with meningitis occurring in 1 patient. Resection was complete in 15 children with no recurrence during a mean follow-up of 5.25years and incomplete in 3 requiring a second surgery. Surgery of SEGA represents a very effective treatment with low morbidity and no mortality in the present series. In patients operated before the onset of clinical signs of hydrocephalus, internal VPS could be avoided whereas in others, an additional shunt surgery became necessary. This gives arguments in favor of a regular MRI surveillance in tuberous sclerosis complex patients with SEGA in order to best propose resective surgery once a growth of tumor and/or ventricular size have been confirmed but before raised intracranial pressure occurs.

Exophytic bulbar pilocytic astrocytoma and post-operative cerebral salt wasting syndrome

Cerebral salt wasting syndrome (CSWS) is a well-described consequence of several neurological disorders. Although the exact etiology of CSWS is still not completely elucidated, it is believed that the hypothalamus plays a pivotal role in the genesis of this disorder. We report for the first time 3 cases of CSWS occurring during the post-operative course following surgical resection of exophytic bulbar pilocytic astrocytomas in children. Since these 3 cases shared in common a medial implication of the medulla, we suggest that specific interconnectivity between the dorso-medial portion of the medulla oblongata and the hypothalamus might thus represent an anatomical pathway of interest in the pathogenesis of CSWS. Our findings suggest that the resection of medially located exophytic bulbar tumors might constitutes a risk factor in the development of CSWS. Particular care should thus be carried towards the prompt detection and treatment of CSWS in the post-operative courses of exophytic bulbar tumors.

The effect of cerebellar tumor resection on pain perception in pediatric patients.

126 Background: Acute cerebellar infarctions have been shown to lead to affective and cognitive deficits in pediatric patients. However, the consequences of cerebellar insult on pain processing are unknown. Recent evidence not only suggests that the cerebellum plays a role in affective processing, but it also demonstrates increased activity in this area when individuals experience experimental or clinical pain, particularly in the posterior cerebellum. The goal of this study is to evaluate the effect of cerebellar resection of low-grade astrocytomas in children on pain perception. Describing the impact of this treatment may be of particular importance in children, as it may alter sensory development into adulthood. Methods: Twelve pediatric patients treated with surgery only for non-malignant astrocytomas (mean age = 13.78 ± 5.64) and ten age-, gender-, race- and handedness-matched healthy controls (mean age = 14.52 ± 5.96) were evaluated using quantitative sensory testing and magnetic resonance imaging, comprising diffusion tensor imaging, resting state and event-related functional MRI scans. Five of these patients had tumors localized to the posterior cerebellar hemispheres. The psychophysical measures assessed included heat and cold detection thresholds (HDT, CDT), heat and cold pain thresholds (HPT, CPT), and cold pain tolerance using a cold pressor task. Results: Patients with lesions in the posterior cerebellum (n = 5) were shown to have a significantly lower tolerance to the cold pressor test than controls (n = 10). No significant differences were detected for the threshold measures. This suggests increased pain sensitivity in these patients to suprathreshold noxious stimuli compared to controls. Patients with lesions that did not include the posterior cerebellar hemispheres (n = 7) did not show significant differences with controls in terms of cold pain tolerance or thresholds. Conclusions: The differences in cold pain tolerance between patients and controls are presumed to result from damage to the posterior cerebellar hemispheres, potentially interfering with the modulation of pain pathways. Analysis of the preliminary imaging data is underway and recruitment is ongoing. Support: NIH/R21CA185870(EM)

Features of surgical treatment of cerebellar astrocytomas in children of the first years of life

Introduction: Astrocytomas make up to 30-50% of all brain tumors in children and remains one of the actual problems of pediatric neurosurgery. Objective: To conduct a retrospective analysis of the treatment of cerebellar astrocytomas in children of early age during 30 years, to identify the factors determining the prognosis of the disease. Materials and methods: Results of treatment of 83 children of early age, operated for astrocytomas of cerebellum in the Pediatric Department in 1980-2009 years were analyzed. Male patients were 48 (57.8%), female — 35 (41.2%). Benign astrocytomas are diagnosed in 67 (80.7%) cases and malignant in 16 (19.3%). Astrocytoma of the cerebellum in 43 (51.8%) children contained a cystic component. Postoperative mortality over a 30-year period was 15.8%. Catamnesis was analyzed in 65 patients in terms in average 6.1 years. The evaluation of quality of life was based on a scale Yu.A. Orlov (2007). Results: The total removing of the tumor was done in 61.9% of patients, subtotal in 26.3%, partial in 11.8%, biopsies of tumours in 1.2%. Shunt surgery complement the removing of tumors in 40.8% cases. Postoperative mortality rate decreased from 18.2% in 1980-1989. to 6.7% in 2000-2009. In 1980-1989 years total removal was in 35.4%, in 2000-2009 in 66.7%. Survival at 1 year after operation was in 93.8%, 2 years – in 86.1%, 5 years – in 67.7% of cases. The good quality of life was noted in 21 (32.3%) of the children, satisfactory in 35 (53.8%), poor in 7 (10.8%) and the vegetative state in 2 (3.1%) children. Conclusions: The amount of removal of the tumor, the degree of malignancy, presence of cystic components affect the quality and duration of life of children of early age with cerebellar astrocytomas.

OP12NEW TOOLS TO STUDY HISTONE H3.3 MUTATIONS IN DIPG AND PHGG

INTRODUCTION: Diffuse intrinsic pontine glioma (DIPG) is an aggressive malignant astrocytoma in children, with poor survival rate and few treatment options. Recently, K27M somatic mutations have been identified in histone H3.1 and H3.3 proteins in 80% of DIPGs and 20% of non-brain stem paediatric gliomas. In addition, 30% of paediatric high grade gliomas (pHGG) exhibit G34R or G34V H3.3 mutations. Several studies have highlighted the epigenetic changes associated with these mutations, however their precise role in tumourigenesis is still unknown. METHOD: We have generated novel polyclonal antibodies that can discriminate H3.3 G34R and G34V mutant proteins from their wild-type counterparts. The antibodies were validated by western blot, immunofluorescence and immunohistochemistry. RESULTS: The antibodies exhibit specific reactivity against recombinant H3.3 proteins, transfected mammalian cells, DIPG and pHGG H3.3 mutant cell lines, and patient samples. CONCLUSION: These antibodies can now be used to study the consequences of single amino acid substitutions in H3.3, for example by providing insights into spatial/anatomical aspects of the mutations in DIPG. They may find prognostic utility in the rapid identification of H3.3 mutant DIPG/pHGG cases and will be used to identify novel downstream targets and pathways of the different mutants in DIPG/pHGG genesis and progression.

In Utero and Early-Life Exposure to Ambient Air Toxics and Childhood Brain Tumors: A Population-Based Case-Control Study in California, USA.

Background:Little is known about the influence of environmental factors on the etiology of childhood brain tumors.Objectives:We examined risks for brain tumors in children after prenatal and infant exposure to monitored ambient air toxics.Methods:We ascertained all cases of medulloblastoma, central nervous system primitive neuroectodermal tumor (PNET), and astrocytoma before 6 years of age diagnosed in 1990–2007 from the California Cancer Registry and selected controls randomly from birth rolls matched by birth year. Exposures to air toxics during pregnancy/infancy for 43 PNET, 34 medulloblastoma, and 106 astrocytoma cases and 30,569 controls living within 5 mi of a monitor were determined. With factor analysis we assessed the correlational structures of 26 probable carcinogenic toxics, and estimated odds ratios by brain tumor type in logistic regression models.Results:PNETs (≤ 38 cases) were positively associated with interquartile range (IQR) increases in prenatal exposure to acetaldehyde [odds ratio (OR) = 2.30; 95% CI: 1.44, 3.67], 1,3-butadiene (OR = 2.23; 95% CI: 1.28, 3.88), benzene, and toluene; and with IQR increases in exposure during the first year of life to ortho-dichlorobenzene (OR = 3.27; 95% CI: 1.17, 9.14), 1,3-butadiene (OR = 3.15; 95% CI: 1.57, 6.32), and benzene. All exposures except ortho-dichlorobenzene loaded on the same factor. Medulloblastoma (≤ 30 cases) was associated with prenatal exposure to polycyclic aromatic hydrocarbons (PAHs combined: OR = 1.44; 95% CI: 1.15, 1.80). Exposures to lead and some PAHs during the first year of life were positively associated with astrocytoma, but the confidence intervals included the null value (e.g., for lead, OR = 1.40; 95% CI: 0.97, 2.03).Conclusions:Our data suggest that in utero and infancy exposures to air toxics generated by industrial and road traffic sources may increase the risk of PNET and medulloblastoma, with limited support for increased risks for astrocytoma in children up to age 6.Citation:von Ehrenstein OS, Heck JE, Park AS, Cockburn M, Escobedo L, Ritz B. 2016. In Utero and early-life exposure to ambient air toxics and childhood brain tumors: a population-based case–control study in California, USA. Environ Health Perspect 124:1093–1099; http://dx.doi.org/10.1289/ehp.1408582

Pathologie tumorale de la moelle et de ses enveloppes chez l’adulte et l’enfant

Intraductal tumors are rare tumors exhibiting slow progression and varied and nonspecific clinical symptoms. Tumors affecting the cord envelopes mainly develop from nerve sheaths and meninges (meningioma and schwannoma respectively). The most frequent intramedullary tumors are gliomas (astrocytoma in children and ependymoma in adults), but there are many other tumors that are not so rare. The diagnosis is made primarily by magnetic resonance imaging (MRI). Imaging is useful to determine the location of the injury. Tumor location to an anatomical space (epidural and intradural intramedullary) provides the best diagnostic approach. Therapeutic monitoring with MRI allows early diagnosis of recurrence or surveillance of residual tumor tissue.

Expression of Methylthioadenosine Phosphorylase (MTAP) in Pilocytic Astrocytomas

Background/Objectives: Pilocytic astrocytomas (PAs) are the most frequent astrocytomas in children and adolescents. Methilthioadenosine phosphorylase(MTAP) is a tumor-suppressor gene, the loss of expression of which is associated with a poor prognosis and better response to specific chemotherapy in leukemia and non-small-cell lung cancer. The expression of MTAP in brain tumors remains largely unknown and its biological role in PA is still unexplored. Our aims were to describe the immunohistochemical MTAP expression in a series of PAs and relate it to the clinicopathological features of the patients. Methods: We assessed MTAP expression on immunohistochemistry in 69 pediatric and adult patients with PA in a tissue microarray platform. Results: Retained expression of MTAP was seen in >85% of the tumors compared to in the nonneoplastic adjacent tissue. Only 3 supratentorial tumors showed a complete loss of MTAP expression. No significant association with clinicopathological features or overall survival of the patients was found. Conclusions: MTAP expression is retained in PAs and is not an outcome predictor for these tumors. Nevertheless, a subset of patients with PAs exhibiting a loss of MTAP could potentially benefit from treatment with specific chemotherapy, especially when lesions are recurrent or surgical resection is not recommended.

Low grade astrocytoma in children under the age of three years: a report from the Canadian pediatric brain tumour consortium

In children under the age of 3years, the most common solid tumors are brain tumors. Low grade astrocytomas represent 30-40% of brain tumours in this age group. This study reviewed the incidence, characteristics, therapy, and outcome of children less than 36months of age diagnosed with a low grade astrocytoma from 1990 to 2005 in Canada. A data bank was established using data collected from Canadian pediatric oncology centers on children less than age 3 diagnosed with brain tumors between 1990 and 2005. Cases of low grade astrocytoma were extracted from this data bank and their characteristics summarized. From the 579 cases in the data bank, 153 cases of low grade astrocytoma (26%) were identified. The mean duration of symptoms prior to presentation was 13weeks, and 53% of patients underwent a greater than 90% resection of their tumor, while 30% underwent 10-90% resection. Seventy-one percent of patients received no further therapy after surgery and of the 45 who received therapy following surgery, 43 received chemotherapy, and 5 received radiation therapy. Sixty-eight patients had recurrence or progression of their tumor. Eighty-seven percent of patients were alive at the time of the survey with a 2year survival rate of 95.3±1.8%, 5year survival rate of 93.1±2.1% and 10year survival rate of 89.1±2.8%. The 5year survival rate for Canadian children less than 36months of age with a low grade astrocytoma was 93.0±2.8% which is similar to that for older children with this tumor.

Commentary on: "A Multi-Institutional Experience in Pediatric High Grade Glioma".

Commentary on: "A Multi-Institutional Experience in Pediatric High Grade Glioma".