High-grade astrocytoma in very young children

High-grade glioma in infants and very young children: characteristics, treatment, and outcomes

PURPOSE

High-grade gliomas in infants and very young children (less than 3 to 5 years old) pose significant challenges due to the limited scientific literature available and high risks associated with treatments. This study aims to investigate their characteristics, treatment, and outcomes.

METHODS

A cohort study was conducted at Children's Cancer Hospital, Egypt. Cases included children aged < 5 years old with confirmed CNS high-grade glioma. Baseline clinical and radiological characteristics, besides potential prognostic factors were assessed.

RESULTS

In total, 76 cases were identified, 7 of them were < 1 year old. Gross- or near-total resection (GTR/NTR) was achieved in 32.9% of all cases. Of the tested cases, H3K27M-alteration was present in 5 subjects only. The 3-year OS and EFS for all cases were 26.9% and 15.4%, respectively. Extent of resection was the most important prognostic factor, as those achieving GTR/NTR experienced more than double the survival compared to those who do not (p = 0.05). Age had a "bimodal" effect on EFS, with those aged 1 to 3 years old faring better than younger and older age groups. Subjects with midline tumors had worse survival compared to non-midline tumors (1-year EFS = 18.5% vs 35%, respectively, p = 0.02).

CONCLUSION

This study in a large cohort of HGG in infants and very young children offers insights into the characteristics and treatment challenges. Extent of resection, age group, and tumor localization are important prognostic factors. Further research with larger sample size is warranted to refine treatment approaches and improve outcomes.

The performance of diffusion tensor imaging parameters for the distinction between medulloblastoma and pilocytic astrocytoma

BACKGROUND

The aim of this study was to evaluate the performance of diffusion tensor imaging (DTI) parameters for the distinction between pediatric medulloblastomas and pilocytic astrocytomas.

METHODS

DTI was performed in 36 patients, who were divided into two groups: group 1 consisted of 26 patients with medulloblastoma, whereas group 2 consisted of 10 patients with pilocytic astrocytoma. The Mann-Whitney U Test was utilized to compare the tumoral fractional anisotropy (tFA) and diffusivity (tMD) values and the tumor to parenchyma ratios for these values (rFA and rMD, respectively) between these two groups. Receiver operating characteristic (ROC) curve analysis and the Youden Index were applied to compute the cut-off point, and then the area under the curve (AUC), sensitivity, and specificity were calculated.

RESULTS

The tFA and rFA values of group 1 were significantly higher than those of group 2 (P<0.05). In contrast, the tMD and rMD values of group 1 were significantly lower than those of group 2 (P<0.05). Among the FA parameters, a cut-off tFA value of 0.37 provided the best ability to discriminate between medulloblastomas and pilocytic astrocytomas, producing a sensitivity value of 84.6%, a specificity of 80%, and an AUC of 81.7%. The cut-off values for MD and rMD were determined to be 1.06 × 10-3 mm2/s and 1.33, respectively, and were determined to be the most efficacious parameters for the differential diagnosis between medulloblastoma and pilocytic astrocytoma, which generated sensitivity, specificity, and AUC values of 100%.

CONCLUSIONS

DTI parameters can play pivotal roles in the discrimination between medulloblastoma and pilocytic astrocytoma.

Bilateral thalamic high-grade astrocytomas in an early-adolescent child: A case report

An early-adolescent girl presented with incoordination, headache, vomiting and dysphonia. MRI brain demonstrated diffuse increased T2 and FLAIR signal in bilateral thalami, consistent with anaplastic astrocytomas. A stereotactic burr-hole biopsy provided frozen tissues sections demonstrating an IDH-1 wildtype astrocytoma (anaplastic grade III according to prior WHO classification 2016-21). Chemoradiotherapy was commenced. Bilateral thalamic high-grade astrocytomas are very rare in the paediatric population and require timely diagnosis and interdisciplinary management. CT and MR imaging help point towards this diagnosis in the correct clinical context.

Transcranial Photosensitizer-Free Laser Treatment of Glioblastoma in Rat Brain

Over sixty years, laser technologies have undergone a technological revolution and become one of the main tools in biomedicine, particularly in neuroscience, neurodegenerative diseases and brain tumors. Glioblastoma is the most lethal form of brain cancer, with very limited treatment options and a poor prognosis. In this study on rats, we demonstrate that glioblastoma (GBM) growth can be suppressed by photosensitizer-free laser treatment (PS-free-LT) using a quantum-dot-based 1267 nm laser diode. This wavelength, highly absorbed by oxygen, is capable of turning triplet oxygen to singlet form. Applying 1267 nm laser irradiation for a 4 week course with a total dose of 12.7 kJ/cm2 firmly suppresses GBM growth and increases survival rate from 34% to 64%, presumably via LT-activated apoptosis, inhibition of the proliferation of tumor cells, a reduction in intracranial pressure and stimulation of the lymphatic drainage and clearing functions. PS-free-LT is a promising breakthrough technology in non- or minimally invasive therapy for superficial GBMs in infants as well as in adult patients with high photosensitivity or an allergic reaction to PSs.

Prognostic factors for pediatric, adolescent, and young adult patients with non-DIPG grade 4 gliomas: a contemporary pooled institutional experience

PURPOSE

WHO grade 4 gliomas are rare in the pediatric and adolescent and young adult (AYA) population. We evaluated prognostic factors and outcomes in the pediatric versus AYA population.

METHODS

This retrospective pooled study included patients less than 30 years old (yo) with grade 4 gliomas treated with modern surgery and radiotherapy. Overall survival (OS) and progression-free survival (PFS) were characterized using Kaplan-Meier and Cox regression analysis.

RESULTS

Ninety-seven patients met criteria with median age 23.9 yo at diagnosis. Seventy-seven patients were ≥ 15 yo (79%) and 20 patients were < 15 yo (21%). Most had biopsy-proven glioblastoma (91%); the remainder had H3 K27M-altered diffuse midline glioma (DMG; 9%). All patients received surgery and radiotherapy. Median PFS and OS were 20.9 months and 79.4 months, respectively. Gross total resection (GTR) was associated with better PFS in multivariate analysis [HR 2.00 (1.01-3.62), p = 0.023]. Age ≥ 15 yo was associated with improved OS [HR 0.36 (0.16-0.81), p = 0.014] while female gender [HR 2.12 (1.08-4.16), p = 0.03] and DMG histology [HR 2.79 (1.11-7.02), p = 0.029] were associated with worse OS. Only 7% of patients experienced grade 2 toxicity. 62% of patients experienced tumor progression (28% local, 34% distant). Analysis of salvage treatment found that second surgery and systemic therapy significantly improved survival.

CONCLUSION

Age is a significant prognostic factor in WHO grade 4 glioma, which may reflect age-related molecular alterations in the tumor. DMG was associated with worse OS than glioblastoma. Reoperation and systemic therapy significantly increased survival after disease progression. Prospective studies in this population are warranted.

Extent of Tumor Resection and Survival in Pediatric Patients With High-Grade Gliomas: A Systematic Review and Meta-analysis

IMPORTANCE

Pediatric patients with high-grade gliomas have a poor prognosis. The association among the extent of resection, tumor location, and survival in these patients remains unclear.

OBJECTIVE

To ascertain whether gross total resection (GTR) in hemispheric, midline, or infratentorial pediatric high-grade gliomas (pHGGs) is independently associated with survival differences compared with subtotal resection (STR) and biopsy at 1 year and 2 years after tumor resection.

DATA SOURCES

PubMed, EBMR, Embase, and MEDLINE were systematically reviewed from inception to June 3, 2022, using the keywords high-grade glioma, pediatric, and surgery. No period or language restrictions were applied.

STUDY SELECTION

Randomized clinical trials and cohort studies of pHGGs that stratified patients by extent of resection and reported postoperative survival were included for study-level and individual patient data meta-analyses.

DATA EXTRACTION AND SYNTHESIS

Study characteristics and mortality rates were extracted from each article. Relative risk ratios (RRs) were pooled using random-effects models. Individual patient data were evaluated using multivariate mixed-effects Cox proportional hazards regression modeling. The PRISMA reporting guideline was followed, and the study was registered a priori.

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) and RRs were extracted to indicate associations among extent of resection, 1-year and 2-year postoperative mortality, and overall survival.

RESULTS

A total of 37 studies with 1387 unique patients with pHGGs were included. In study-level meta-analysis, GTR had a lower mortality risk than STR at 1 year (RR, 0.69; 95% CI, 0.56-0.83; P < .001) and 2 years (RR, 0.74; 95% CI, 0.67-0.83; P < .001) after tumor resection. Subtotal resection was not associated with differential survival compared with biopsy at 1 year (RR, 0.82; 95% CI, 0.66-1.01; P = .07) but had decreased mortality risk at 2 years (RR, 0.89; 95% CI, 0.82-0.97; P = .01). The individual patient data meta-analysis of 27 articles included 427 patients (mean [SD] age at diagnosis, 9.3 [5.9] years), most of whom were boys (169 of 317 [53.3%]), had grade IV tumors (246 of 427 [57.7%]), and/or had tumors that were localized to either the cerebral hemispheres (133 of 349 [38.1%]) or midline structures (132 of 349 [37.8%]). In the multivariate Cox proportional hazards regression model, STR (HR, 1.91; 95% CI, 1.34-2.74; P < .001) and biopsy (HR, 2.10; 95% CI, 1.43-3.07; P < .001) had shortened overall survival compared with GTR but no survival differences between them (HR, 0.91; 95% CI, 0.67-1.24; P = .56). Gross total resection was associated with prolonged survival compared with STR for hemispheric (HR, 0.29; 95% CI, 0.15-0.54; P < .001) and infratentorial (HR, 0.44; 95% CI, 0.24-0.83; P = .01) tumors but not midline tumors (HR, 0.63; 95% CI, 0.34-1.19; P = .16).

CONCLUSIONS AND RELEVANCE

Results of this study show that, among patients with pHGG, GTR is independently associated with better overall survival compared with STR and biopsy, especially among patients with hemispheric and infratentorial tumors, and support the pursuit of maximal safe resection in the treatment of pHGGs.

Novel Pharmacological Treatment Options in Pediatric Glioblastoma-A Systematic Review

Simple Summary

Childhood glioblastoma is an aggressive brain tumor in children that has a very poor prognosis. Standard therapy includes surgery, irradiation and chemotherapy with temozolomide. So far, there is no effective drug treatment for pediatric glioblastoma patients. This systematic review aims to outline currently available data on novel pharmacological treatment options. None of the included phase II studies showed any benefit regarding overall survival or a prolongation of stable disease. New genomic technologies discovered the biologic heterogeneity of these tumors, demanding more individualized immunotherapeutic and targeted approaches. Autoimmune modulated therapies and further targeting of tumor-specific receptors provide promising preclinical results. Clinical trials aligned to the tumor characteristics are needed to establish effective new therapeutic approaches.

Abstract

Background: Pediatric glioblastoma (GBM) is an aggressive central nervous system tumor in children that has dismal prognosis. Standard of care is surgery with subsequent irradiation and temozolomide. We aimed to outline currently available data on novel pharmacological treatments for pediatric GBM. Methods: We conducted a systematic literature search in PubMed and Embase, including reports published in English from 2010 to 2021. We included randomized trials, cohort studies and case series. Phase I trials were not analyzed. We followed PRISMA guidelines, assessed the quality of the eligible reports using the Newcastle-Ottawa scale (NOS) and the RoB-2 tool and registered the protocol on PROSPERO. Results: We included 6 out of 1122 screened reports. All six selected reports were prospective, multicenter phase II trials (five single-arm and one randomized controlled trial). None of the investigated novel treatment modalities showed any benefit regarding overall or progression free survival. Conclusions: To date, the role of pharmacological approaches regarding pediatric GBM remains unclear, since no novel treatment approach could provide a significant impact on overall or progression free survival. Further research should aim to combine different treatment strategies in large international multicenter trials with central comprehensive diagnostics regarding subgrouping. These novel treatment approaches should include targeted and immunotherapeutic treatments, potentially leading to a more successful outcome.

Molecular Landscape in Infant High-Grade Gliomas: A Single Center Experience

High-grade gliomas (HGG) represent about 15% of all pediatric brain tumors, with a dismal prognosis and survival rates ranging from 15 to 35%. Approximately 10–12% of pediatric HGGs (pHGG) occur in children younger than five years of age at diagnosis, specifically infants (iHGG), with an unexpected overall survival rate (OS) in 60–70% of cases. In the literature, iHGGs include a large variety of heterogeneous lesions with different molecular profiles that likely explain their different outcomes. We report our single-institution experience of iHGG including 11 children under five years of age with newly diagnosed HGG between 2011 and 2021. All patients received surgery and adjuvant chemotherapy; only two patients received radiotherapy because their age at diagnosis was more than four years-old. Molecular investigations, including next generation sequencing (NGS) and DNA methylation, detected three NTRK-fusions, one ROS1-fusions, one MN1-rearrangement, and two PATZ1-fusions. According to the molecular results, when chemotherapy failed to control the disease, two patients benefited from target therapy with a NTRK-Inhibitor larotrectinib, achieving a complete remission and a very good partial response, respectively, and no severe side-effects. In conclusion, molecular investigations play a fundamental role in the diagnostic work-up and also in the therapeutic decision. Their routine use in clinical practice could help to replace highly toxic chemotherapy regimens with a target therapy that has moderate adverse effects, even in long-term follow-up.

Advanced Magnetic Resonance Imaging in Pediatric Glioblastomas

The shortly upcoming 5th edition of the World Health Organization Classification of Tumors of the Central Nervous System is bringing extensive changes in the terminology of diffuse high-grade gliomas (DHGGs). Previously "glioblastoma," as a descriptive entity, could have been applied to classify some tumors from the family of pediatric or adult DHGGs. However, now the term "glioblastoma" has been divested and is no longer applied to tumors in the family of pediatric types of DHGGs. As an entity, glioblastoma remains, however, in the family of adult types of diffuse gliomas under the insignia of "glioblastoma, IDH-wildtype." Of note, glioblastomas still can be detected in children when glioblastoma, IDH-wildtype is found in this population, despite being much more common in adults. Despite the separation from the family of pediatric types of DHGGs, what was previously labeled as "pediatric glioblastomas" still remains with novel labels and as new entities. As a result of advances in molecular biology, most of the previously called "pediatric glioblastomas" are now classified in one of the four family members of pediatric types of DHGGs. In this review, the term glioblastoma is still apocryphally employed mainly due to its historical relevance and the paucity of recent literature dealing with the recently described new entities. Therefore, "glioblastoma" is used here as an umbrella term in the attempt to encompass multiple entities such as astrocytoma, IDH-mutant (grade 4); glioblastoma, IDH-wildtype; diffuse hemispheric glioma, H3 G34-mutant; diffuse pediatric-type high-grade glioma, H3-wildtype and IDH-wildtype; and high grade infant-type hemispheric glioma. Glioblastomas are highly aggressive neoplasms. They may arise anywhere in the developing central nervous system, including the spinal cord. Signs and symptoms are non-specific, typically of short duration, and usually derived from increased intracranial pressure or seizure. Localized symptoms may also occur. The standard of care of "pediatric glioblastomas" is not well-established, typically composed of surgery with maximal safe tumor resection. Subsequent chemoradiation is recommended if the patient is older than 3 years. If younger than 3 years, surgery is followed by chemotherapy. In general, "pediatric glioblastomas" also have a poor prognosis despite surgery and adjuvant therapy. Magnetic resonance imaging (MRI) is the imaging modality of choice for the evaluation of glioblastomas. In addition to the typical conventional MRI features, i.e., highly heterogeneous invasive masses with indistinct borders, mass effect on surrounding structures, and a variable degree of enhancement, the lesions may show restricted diffusion in the solid components, hemorrhage, and increased perfusion, reflecting increased vascularity and angiogenesis. In addition, magnetic resonance spectroscopy has proven helpful in pre- and postsurgical evaluation. Lastly, we will refer to new MRI techniques, which have already been applied in evaluating adult glioblastomas, with promising results, yet not widely utilized in children.

Pediatric Neuro-Oncology

Central nervous system (CNS) tumors are the most common solid tumor in pediatrics and represent the largest cause of childhood cancer-related mortality. With advances in molecular characterization of tumors, considerable developments have occurred impacting diagnosis and management, and refined prognostication. Advances in management have led to better survival, but mortality remains high and significant morbidity persists. Novel therapeutic approaches targeting the biology of these tumors are being investigated to improve overall survival and decrease treatment-related morbidity. Further molecular understanding of pediatric CNS tumors will lead to continued refinement of tumor classification, management, and prognostication.

The role of diffusion tensor imaging metrics in the discrimination between cerebellar medulloblastoma and brainstem glioma

BACKGROUND

Differentiation between cerebellar medulloblastoma and brainstem glioma is necessary for certain clinical circumstances. We aimed to evaluate the function of diffusion tensor imaging (DTI) metrics in the differentiation between cerebellar medulloblastomas and brainstem gliomas in children.

PROCEDURE

The institutional review board approved this prospective study. Brain magnetic resonance imaging (MRI), including DTI, was assessed in 40 patients, who were divided into two groups: a medulloblastoma group (group 1, n = 25) and a brainstem glioma group (group 2, n = 15). The Mann-Whitney U test was utilized to compare tumoral fractional anisotropy (FA) and diffusivity (MD) values and tumor-to-parenchyma ratios for these values (rFA and rMD, respectively) between the two groups. Receiver-operating characteristic (ROC) curve analysis and the Youden index were exploited to calculate the cutoff value, along with the area under the curve (AUC), sensitivity, and specificity.

RESULTS

The FA value for medulloblastomas was significantly higher than that for brainstem gliomas (P < 0.05). In contrast, the MD and rMD values for medulloblastoma were significantly lower than those for brainstem gliomas (P < 0.05). A cutoff MD value of 0.97 was identified as the most effective factor for the differential diagnosis between medulloblastomas and brainstem gliomas, which reached a sensitivity of 96%, a specificity of 100%, and an AUC of 99.5%.

CONCLUSION

DTI metrics play a significant role in the differentiation between medulloblastoma and brainstem glioma in pediatric patients.

Genetics of Common Pediatric Brain Tumors

Central nervous system tumors are the most common solid tumors in pediatrics and represent the largest cause of childhood cancer-related mortality. Improvements have occurred in the management of these patients leading to better survival, but significant morbidity persists. With the era of next generation sequencing, considerable advances have occurred in the understanding of these tumors both biologically and clinically. This information has impacted diagnosis and management. Subgroups have been identified, improving risk stratification. Novel therapeutic approaches, specifically targeting the biology of these tumors, are being investigated to improve overall survival and decrease treatment-related morbidity. The intent of this review is to discuss the genetics of common pediatric brain tumors and the clinical implications. This review will include known genetic disorders associated with central nervous system tumors, neurofibromatosis, tuberous sclerosis, Li-Fraumeni syndrome, Gorlin syndrome, and Turcot syndrome, as well as somatic mutations of glioma, medulloblastoma, and ependymoma.

Use of High-Dose Chemotherapy in Front-Line Therapy of Infants Aged Less Than 12 Months Treated for Aggressive Brain Tumors

Introduction: Malignant brain tumors in infants less than 12 months of age are extremely rare, and they have poor prognosis. We evaluated genetic characteristics and response rates of infants with congenital brain tumors subjected to high-dose chemotherapy and autologous stem cell transplant after gross total tumor resection. Materials and Methods: In total, 10 infants, aged less than 12 months, were enrolled in this study. The median age was 56 days (range: 1-279 days). Pathological examination demonstrated the following: four anaplastic astrocytomas, two glioblastomas, two central nervous system (CNS) embryonal tumors, not otherwise specified (NOS), and two atypical teratoid/rhabdoid tumors. Results: All patients were exposed to induction chemotherapy regimen, two high-dose chemotherapy courses, and autologous stem cell transplant after maximal surgery. At 1-3-5 years, the global overall survival (OS) was 90, 70, and 70% and the progression-free survival (PFS) was 80-60 and 60%. In all the patients, the copy number variants (CNVs) profile was analyzed using the SNP/CGH array approach. To investigate the clinical relevance of germline SMARCB1 mutation in AT/RT patients, we performed sequence analysis of the coding regions. The two patients with AT/RT were found to have germline SMARCB1 mutations. No BRAF mutations were found, and only NTRK gene fusion was present in one patient. We also have examined the association with OS and PFS and different histological subtypes of infant CNS proving that high-grade astrocytoma has better overall survival than other tumor types (p: 0.007 and p: 0.0590). Conclusion: High-dose chemotherapy regimen represents a valid therapeutic approach for congenital brain tumors with a high rate of response. The molecular analysis has to be analyzed in all infants' brain tumor types. High-grade gliomas are characterized by a better prognosis than other histologies of infant CNS.

Ganglioglioma in a Survivor of Infantile Glioblastoma

Congenital tumors account for 2% to 4% of all pediatric central nervous system tumors. Glioblastoma multiforme (GBM) represents a small subset of these tumors. Despite harboring histologic features similar to older patients, infants with GBM exhibit improved survival and respond more favorably to surgery and chemotherapy. To highlight this tumor's unique behavior, we report the case of a survivor of infantile GBM who developed a recurrent tumor in the surgical bed 6 months after diagnosis. The tumor was ultimately resected and was a ganglioglioma. This case shows both a favorable clinical outcome to an infantile GBM and this tumor's natural history.

Modulating autophagy as a therapeutic strategy for the treatment of paediatric high-grade glioma

Paediatric high-grade gliomas (pHGG) represent a therapeutically challenging group of tumors. Despite decades of research, there has been minimal improvement in treatment and the clinical prognosis remains poor. Autophagy, a highly conserved process for recycling metabolic substrates is upregulated in pHGG, promoting tumor progression and evading cell death. There is significant crosstalk between autophagy and a plethora of critical cellular pathways, many of which are dysregulated in pHGG. The following article will discuss our current understanding of autophagy signaling in pHGG and the potential modulation of this network as a therapeutic target.

In vitro neurosphere formation correlates with poor survival in glioma

Sphere formation is an indicator of tumor aggressiveness independent of the tumor grade; however, its relation to progression-free survival (PFS) is less known. This study was designed to assess the neurosphere forming ability among low grade glioma (LGG) and high-grade glioma (HGG), its stem cell marker expression, and correlation to PFS. Tumor samples of 140 patients, including (LGG; n = 67) and (HGG; n = 73) were analyzed. We used sphere forming assay, immunofluorescence, and immunohistochemistry to characterize the tumors. Our study shows that, irrespective of the pathological sub type, both LGG and HGG formed neurospheres in vitro under conventional sphere forming conditions. However, the number of neurospheres formed from tumor tissues were significantly higher in HGG compared to LGG (P < 0.0001). Different grades of glioma were further characterized for the expression of stem cell marker proteins and lineage markers. When neurospheres were analyzed, CD133 positive cells were identified in addition to CD15 and nestin positive cells in both LGG and HGG. When these neurospheres were subjected to differentiation, cells positive for GFAP and β-tubulin III were observed. Expression of stem cell markers and β-tubulin III were prominent in HGG compared to LGG, whereas GFAP expression was higher in LGG than in HGG. Kaplan-Meier survival analysis demonstrated that neurosphere forming ability was significantly associated with shorter PFS (P < 0.05) in both LGG and HGG. Our results supports earlier studies that neurosphere formation may serve as a definitive indicator of stem cell population within the tumor and thus a better predictor of PFS than the tumor grades alone. © 2018 IUBMB Life, 71(1):244-253, 2019.

Does the interval from tumour surgery to radiotherapy influence survival in paediatric high grade glioma?

PURPOSE

Paediatric high grade glioma (pHGG) are rare. Following maximum safe resection, children >3 years with HGG receive radiotherapy as standard of care. Whether the interval from tumour surgery to radiotherapy (ISRT) influences survival is disputed in adults with glioblastoma, data for children are lacking. This retrospective single-centre analysis investigates a possible impact of ISRT on survival in paediatric patients with HGG.

METHODS

Survival was analysed in patients aged 3-19 years with non-pontine HGG.

RESULTS

Thirty-eight patients were included (female:male 19:19) with a median age of 11.0 years (3.4-17.7). Seventeen patients had grade 3 and 21 grade 4 glioma. Gross total resection was achieved in 26.3%, partial resection in 36.8% and 36.8% underwent biopsy only. All patients received concomitant and adjuvant chemotherapy. Fifty percent (n = 19) started irradiation ≤17 days (median interval 12 days [range 5-17]), 50% thereafter (median 28 days [range 19-78]). More patients with grade 4 tumours were irradiated shortly after surgery. ISRT (as a continuous variable and dichotomised into two groups by the median ISRT of 18 days) did not significantly influence overall survival (OS) or progression-free survival (PFS). Higher extent of resection (EOR), lower tumour grade as well as chemotherapy with temozolomide had a significant positive impact on OS and PFS in univariate analysis and (except for the effect of temozolomide on PFS) also in multivariable analysis.

CONCLUSIONS

ISRT did not influence survival in pHGG. In view of upcoming targeted treatment options in pHGG the present data suggest that it is safe to perform molecular analyses within a 4-week timeframe before radiotherapy.

National cancer database analysis of outcomes in pediatric glioblastoma

Glioblastoma in children is an aggressive disease with no defined standard therapy. We evaluated hospital‐based demographic and survival patterns obtained through the National Cancer Database to better characterize children with glioblastoma. Our study identified 1173 patients from 0 to 19 years of age between 1998 and 2011. Comparisons were made among demographics, clinical characteristics, treatment, and survival variables. Fifty‐four percent of patients were over 10 years of age. Approximately 80% of patients underwent either partial or complete resection. Adjuvant therapy was used variably, and its use increased with patient age. Forty‐eight percent of patients received the combination of surgery, radiation, and chemotherapy, and 4% did not receive any treatment. As expected, patients ≤5 years of age had better 5‐year survival than those ages 6–10 (P = 0.01) or 11–19 years (P = 0.0077). Other factors associated with poor survival included black race and central tumor location. Better outcomes were associated with treatment that included surgery, radiotherapy, and chemotherapy compared to any other treatment combinations. Radiotherapy had no impact on survival in the 0 to 10‐year‐old age group, but was associated with improved survival for patients 11–19 years. We report an extensive demographic and survival analysis of pediatric glioblastoma. The observed differences likely reflect variances in tumor biology and likelihood of treatment receipt. Improved survival was associated with the use of surgery, radiotherapy, and chemotherapy. Radiation therapy was not associated with survival in patients younger than 10 years of age.

Patient and treatment factors associated with survival among pediatric glioblastoma patients: A Surveillance, Epidemiology, and End Results study

Glioblastoma (GBM) is a rare malignancy in children. The United States Surveillance, Epidemiology, and End Results (SEER) database allows large-scale analyses of clinical characteristics and prognostic features. We used it to study patients aged <20 years with histologically confirmed GBM (2000-2010) and examined the relationship between patient demographics, tumor characteristics, patterns of treatment, and outcomes. The primary outcome was disease-specific survival. 302 subjects were identified, with median age 11 years. Median follow-up was 32 months (95% CI 27-39). 34.4% had gross total resection (GTR). 61% underwent radiation after surgery (17% of subjects <3 years, 67% of those aged 4-19 years). Median survival and 2-year survival rates were 20 months and 46.9%, respectively. In multivariate analyses, age, tumor location, extent of resection, and year of diagnosis were significantly associated with the primary outcome. Compared to those aged 0-4 years, subjects aged 5-9 years and 10-14 years had higher risk of mortality. Infratentorial tumor location (HR 2.0, 95% CI 1.2-3.3, p = 0.007) and subtotal resection (HR 2.04, 95% CI 1.4-3.0, p < 0.001) were associated with increased mortality. Later year of diagnosis was significantly associated with decreased risk of death (HR 0.93, 95% CI 0.9-0.99, p = 0.031). There was no association between sex, race, region, or tumor size and the primary outcome. Repeat analyses examining all-cause mortality identified the same risk factors as for CNS cancer-specific mortality. Younger age, supratentorial location, GTR, and later year of diagnosis were associated with improved survival.

Recent perspectives of molecular aberrations in pediatric high-grade glioma

Pediatric high-grade glioma (HGG), including diffuse intrinsic pontine glioma (DIPG) are highly aggressive tumors with no effective cures. Lack of understanding of the molecular biology of these tumors, in part due to lack of well-characterized pre-clinical models, is a great challenge in the development of novel therapies. Recent studies have shown that pediatric HGG short-term cell cultures retain many of the tumor characteristics in vivo and at present one of the best choices for in-vivo experimental studies. The present review article would put light on novel genetic and epigenetic changes in pediatric HGG that might, act as a gold standard potential biomarkers and/or therapeutic targets in near future.

High-grade glioma in very young children: a rare and particular patient population

In the past years, pediatric high-grade gliomas (HGG) have been the focus of several research articles and reviews, given the recent discoveries on the genetic and molecular levels pointing out a clinico-biological uniqueness of the pediatric population compared to their adult counterparts with HGG. On the other hand, there are only scarce data about HGG in very young children (below 3 years of age at diagnosis) due to their relatively low incidence. However, the few available data suggest further distinction of this very rare subgroup from older children and adults at several levels including their molecular and biological characteristics, their treatment management, as well as their outcome. This review summarizes and discusses the current available knowledge on the epidemiological, neuropathological, genetic and molecular data of this subpopulation. We discuss these findings and differences compared to older patients suffering from the same histologic disease. In addition, we highlight the particular clinical and neuro-radiological findings in this specific subgroup of patients as well as their current management approaches and treatment outcomes.

Outcome of young children with high-grade glioma treated with irradiation-avoiding intensive chemotherapy regimens: Final report of the Head Start II and III trials

PURPOSE

To report the final analysis of survival outcomes for children with newly diagnosed high-grade glioma (HGG) treated on the "Head Start" (HS) II and III protocols with chemotherapy and intent to avoid irradiation in children <6 years old.

PATIENTS AND METHODS

Between 1997 and 2009, 32 eligible children were enrolled in HS II and III with anaplastic astrocytoma (AA, n = 19), glioblastoma multiforme (GBM, n = 11), or other HGG (n = 2). Central pathology review was completed on 78% of patients. Patients with predominantly brainstem tumors were excluded. Patients were to be treated with single induction chemotherapy regimen C, comprising four cycles of vincristine, carboplatin, and temozolomide. Following induction, patients underwent marrow-ablative chemotherapy and autologous hematopoietic cell rescue. Irradiation was used for patients with residual tumor after consolidation or >6 years old or at the time of tumor progression.

RESULTS

The 5-year event-free survival (EFS) and overall survival (OS) for all HGG patients were 25 ± 8% and 36 ± 9%, respectively. The EFS at 5 years for patients with AA and GBM were 24 ± 11% and 30 ± 16%, respectively (P = 0.65). The OS at 5 years for patients with AA and GBM was 34 ± 12% and 35 ± 16%, respectively (P = 0.83). Children <36 months old experienced improved 5-year EFS and OS of 44 ± 17% and 63 ± 17%, compared with children 36-71 months old (31 ± 13% and 38 ± 14%) and children >72 months old (0% and 13 ± 12%).

CONCLUSIONS

Irradiation-avoiding treatment strategies should be evaluated further in young children with HGG given similar survival rates to older children receiving standard irradiation-containing therapies.

Case Report of Spontaneous Resolution of a Congenital Glioblastoma

Glioblastoma multiforme (GBM) is a rare, highly aggressive brain tumor associated with a poor outcome in both children and adults. Treatment usually involves a combination of surgical resection, chemotherapy, and radiotherapy, but ultimately it is incurable. Evidence suggests that congenital GBM may have a better prognosis with improved survival compared with GBM in older children. We describe the first known report of spontaneous resolution of a congenital GBM without any systemic therapy. A limited debulking procedure was performed at diagnosis, and the residual tumor underwent spontaneous resolution over the following 21 months. The patient remains in remission, with no tumor recurrence after 5 years of follow-up. Despite the tumor regressing, the patient has had an adverse neurologic outcome, with severe developmental delay and seizures. This case suggests that congenital GBM may be a separate biological entity much like neuroblastomas in infants, and therefore associated with better outcomes and even spontaneous resolution.

Sex, Age, Anatomic Location, and Extent of Resection Influence Outcomes in Children With High-grade Glioma

BACKGROUND

Survival duration and prognostic factors in adult high-grade glioma have been comprehensively analyzed, but less is known about factors contributing to overall survival (OS) and progression-free survival (PFS) in pediatric patients.

OBJECTIVE

To identify these factors in the pediatric population.

METHODS

We retrospectively reviewed institutional databases evaluating all patients ≤21 years with high-grade glioma treated between 1988 and 2010. Kaplan-Meier curves and log-rank statistics were used to compare groups univariately. Multivariate analyses were completed using Cox proportional hazards regression models.

RESULTS

Ninety-seven patients were identified with a median age of 11 years. Median OS was 1.7 years, and median PFS was 272 days. Location was significant for OS (P < .001). Patients with gross total resection (GTR) had a median OS of 3.4 years vs 1.6 years for subtotal resection and 1.3 years for biopsy patients (P < .001). Female patients had improved OS (P = .01). Female patients with GTR had a mean OS of 8.1 years vs 2.4 years for male patients with GTR and 1.4 years for all other female patients and male patients (P = .001). PFS favored patients ≤3 and ≥13 years and females (P = .003 and .001).

CONCLUSION

OS was significantly correlated with the location of the tumor and the extent of resection. GTR significantly improved overall survival for both glioblastoma multiforme and anaplastic astrocytoma patients, and female patients showed a much larger survival benefit from GTR than male patients.

Genetic Analysis of Diffuse High-Grade Astrocytomas in Infancy Defines a Novel Molecular Entity

Pediatric high-grade gliomas are considered to be different when compared to adult high-grade gliomas in their pathogenesis and biological behavior. Recently, common genetic alterations, including mutations in the H3F3A/ATRX/DAXX pathway, have been described in approximately 30% of the pediatric cases. However, only few cases of infant high-grade gliomas have been analyzed so far. We investigated the molecular features of 35 infants with diffuse high-grade astrocytomas, including 8 anaplastic astrocytomas [World Health Organization (WHO) grade III] and 27 glioblastomas (WHO grade IV) by immunohistochemistry, multiplex ligation probe-dependent amplification (MLPA), pyrosequencing of glioma-associated genes and molecular inversion probe (MIP) assay. MIP and MLPA analyses showed that chromosomal alterations are significantly less frequent in infants compared with high-grade gliomas in older children and adults. We only identified H3F3A K27M in 2 of 34 cases (5.9%), with both tumors located in the posterior fossa. PDGFRA amplifications were absent, and CDKN2A loss could be observed only in two cases. Conversely, 1q gain (22.7%) and 6q loss (18.2%) were identified in a subgroup of tumors. Loss of SNORD located on chromosome 14q32 was observed in 27.3% of the infant tumors, a focal copy number change not previously described in gliomas. Our findings indicate that infant high-grade gliomas appear to represent a distinct genetic entity suggesting a different pathogenesis and biological behavior.

Comparison of survival between the UK and US after surgery for most common pediatric CNS tumors

BACKGROUND

We report a population-based study examining long-term outcomes for common pediatric CNS tumors comparing results from the UK with the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) data set and with the literature. No such international study has previously been reported.

METHODS

Data between 1996 and 2005 from the UK National Registry of Childhood Tumours (NRCT) and the SEER registry were analyzed. We calculated actuarial survival at each time point from histological diagnosis, with death from any cause as the endpoint. Kaplan-Meier estimation and log-rank testing (Cox proportional hazards regression analysis) were used to calculate survival differences among tumor subtypes, adjusting for age at diagnosis.

RESULTS

Population-based outcomes for each tumor type are presented. Overall age-adjusted survival, stratifying for histology (combining pilocytic astrocytoma, anaplastic astrocytoma, glioblastoma, primitive neuroectodermal tumor, medulloblastoma, and ependymoma), is significantly lower for NRCT than SEER (hazard ratio 0.71, P < .001) and at 1, 5, and 10 years. Both NRCT and SEER outcomes are worse than those reported from trials.

CONCLUSION

Analyzing data from comprehensive registries minimizes bias associated with trials and institutional studies. The reasons for the poorer outcomes in children treated in the UK are unclear. Likewise, the differences in outcomes between patients in trials and those not in trials need further investigation. We recommend that all children with CNS tumors be recruited into studies-even if these are observational studies. We also suggest that registries be suitably funded to publish independent outcome data (including morbidity) at both a national and an institutional level.

Highly compacted pH-responsive DNA nanoparticles mediate transgene silencing in experimental glioma

Complex genetic mutations are common in brain cancer, making gene therapy an attractive approach to repair or modulate altered genes and cellular pathways. Non-viral gene vectors can offer DNA delivery without the risk of immunogenicity and/or insertional mutagenesis that are common with viral vectors. We developed pH-responsive DNA nanoparticles, CH₁₂K₁₈PEG_5k, by inserting a poly-L-histidine segment between PEG and poly-L-lysine to engineer a triblock copolymer. CH₁₂K₁₈PEG_5k DNA nanoparticles trafficked through clathrin-dependent endocytosis (CME) as the primary pathway in mouse glioblastoma (GBM) cells, and protected plasmid DNA from both DNase-mediated and acidic lysosomal degradation. CH₁₂K₁₈PEG_5k DNA nanoparticles effectively silenced a tumor-specific transgene (firefly luciferase) following direct injection into mouse intracranial GBM. Toxicity and histological analysis showed no evidence of acute or delayed inflammatory responses. These results demonstrate the utility of using this DNA nanoparticle-based technology for delivering genes to tumor cells as a possible therapeutic approach for patients with brain cancer.

Benefit from prolonged dose-intensive chemotherapy for infants with malignant brain tumors is restricted to patients with ependymoma: a report of the Pediatric Oncology Group randomized controlled trial 9233/34

BACKGROUND

The randomized controlled Pediatric Oncology Group study 9233 tested the hypothesis that dose-intensive (DI) chemotherapy would improve event-free survival (EFS) for children <3 years of age with newly diagnosed malignant brain tumors.

METHODS

Of 328 enrolled eligible patients, diagnoses were medulloblastoma (n = 112), ependymoma (n = 82), supratentorial primitive neuroectodermal tumor (sPNET, n = 38) and other malignant brain tumors (n = 96), and were randomized to 72 weeks of standard dose chemotherapy (Regimen A, n = 162) or DI chemotherapy (Regimen B, n = 166). Radiation therapy (RT) was recommended for patients with evidence of disease at completion of chemotherapy or who relapsed within 6 months of chemotherapy completion.

RESULTS

Distributions of EFS for Regimens A and B were not significantly different (P = 0.32) with 2- and 10-year rates of 22.8% ± 3.3% and 15.4% ± 3.7%, and 27.1% ± 3.4% and 20.8% ± 3.8%, respectively. Thus, the study hypothesis was rejected. While distributions of EFS and OS were not significantly different between Regimens A and B for patients with medulloblastoma and sPNET, DI chemotherapy resulted in significantly improved EFS distribution (P = .0011) (2-year EFS rates of 42.1% vs. 19.6% with SD chemotherapy), but not OS distribution, for patients with centrally confirmed ependymoma. The degree of surgical resection affected EFS, OS or both for most tumor groups. Approximately 20%, 40% and 20% of patients with medulloblastoma, ependymoma treated with DI chemotherapy, and sPNET, respectively appear to have been cured without RT. Of 11 toxic deaths on study, 10 occurred on the DI chemotherapy arm.

CONCLUSIONS

Prolonged dose-intensive chemotherapy given to infants with malignant brain tumors resulted in increased EFS only for patients with ependymoma.

Neuropathological and neuroradiological spectrum of pediatric malignant gliomas: correlation with outcome

BACKGROUND

The diagnostic accuracy and reproducibility for glioma histological diagnosis are suboptimal.

OBJECTIVE

To characterize radiological and histological features in pediatric malignant gliomas and to determine whether they had an impact on survival.

METHODS

We retrospectively reviewed a series of 96 pediatric malignant gliomas. All histological samples were blindly and independently reviewed and classified according to World Health Organization 2007 and Sainte-Anne classifications. Radiological features were reviewed independently. Statistical analyses were performed to investigate the relationship between clinical, radiological, and histological features and survival.

RESULTS

Cohort median age was 7.8 years; median follow-up was 4.8 years. Tumors involved cerebral hemispheres or basal ganglia in 82% of cases and brainstem in the remaining 18%. After histopathological review, low-grade gliomas and nonglial tumors were excluded (n = 27). The World Health Organization classification was not able to demonstrate differences between groups and patients survival. The Sainte-Anne classification identified a 3-year survival rate difference between the histological subgroups (oligodendroglioma A, oligodendroglioma B, malignant glioneuronal tumors, and glioblastomas; P = .02). The malignant glioneuronal tumor was the only glioma subtype with specific radiological features. Tumor location was significantly associated with 3-year survival rate (P = .005). Meningeal attachment was the only radiological criteria associated with longer survival (P = .02).

CONCLUSION

The Sainte-Anne classification was better able to distinguish pediatric malignant gliomas in terms of survival compared with the World Health Organization classification. In this series, neither of these 2 histological classifications provided a prognostic stratification of the patients.

ADAR2 editing activity in newly diagnosed versus relapsed pediatric high-grade astrocytomas

Background

High-grade (WHO grade III and IV) astrocytomas are aggressive malignant brain tumors affecting humans with a high risk of recurrence in both children and adults. To date, limited information is available on the genetic and molecular alterations important in the onset and progression of pediatric high-grade astrocytomas and, even less, on the prognostic factors that influence long-term outcome in children with recurrence. A-to-I RNA editing is an essential post-transcriptional mechanism that can alter the nucleotide sequence of several RNAs and is mediated by the ADAR enzymes. ADAR2 editing activity is particularly important in mammalian brain and is impaired in both adult and pediatric high-grade astrocytomas. Moreover, we have recently shown that the recovered ADAR2 activity in high-grade astrocytomas inhibits in vivo tumor growth. The aim of the present study is to investigate whether changes may occur in ADAR2-mediated RNA editing profiles of relapsed high-grade astrocytomas compared to their respective specimens collected at diagnosis, in four pediatric patients.

Methods

Total RNAs extracted from all tumor samples and controls were tested for RNA editing levels (by direct sequencing on cDNA pools) and for ADAR2 mRNA expression (by qRT-PCR).

Results

A significant loss of ADAR2-editing activity was observed in the newly diagnosed and recurrent astrocytomas in comparison to normal brain. Surprisingly, we found a substantial rescue of ADAR2 editing activity in the relapsed tumor of the only patient showing prolonged survival.

Conclusions

High-grade astrocytomas display a generalized loss of ADAR2-mediated RNA editing at both diagnosis and relapse. However, a peculiar Case, in complete remission of disease, displayed a total rescue of RNA editing at relapse, intriguingly suggesting ADAR2 activity/expression as a possible marker for long-term survival of patients with high-grade astrocytomas.

ABT-263 enhances sensitivity to metformin and 2-deoxyglucose in pediatric glioma by promoting apoptotic cell death

Pediatric high grade glioma is refractory to conventional multimodal treatment, highlighting a need to develop novel efficacious therapies. We investigated tumor metabolism as a potential therapeutic target in a panel of diverse pediatric glioma cell lines (SF188, KNS42, UW479 and RES186) using metformin and 2-deoxyglucose. As a single agent, metformin had little effect on cell viability overall. SF188 cells were highly sensitive to 2-deoxyglucose however, combination of metformin with 2-deoxyglucose significantly reduced cell proliferation compared to either drug alone in all cell lines tested. In addition, the combination of the two agents was associated with a rapid decrease in cellular ATP and subsequent AMPK activation. However, increased cell death was only observed in select cell lines after prolonged exposure to the drug combination and was caspase independent. Anti-apoptotic BCL-2 family proteins have been indicated as mediators of resistance against metabolic stress. Therefore we sought to determine whether pharmacological inhibition of BCL-2/BCL-xL with ABT-263 could potentiate apoptosis in response to these agents. We found that ABT-263 increased sensitivity to 2-deoxyglucose and promoted rapid and extensive cell death in response to the combination of 2-deoxyglucose and metformin. Furthermore, cell death was inhibited by the pan-caspase inhibitor, z-VAD-FMK suggesting that ABT-263 potentiated caspase-dependent cell death in response to 2-deoxyglucose or its combination with metformin. Overall, these data provide support for the concept that targeting metabolic and anti-apoptotic pathways may be an effective therapeutic strategy in pediatric glioma.

Gliomas in children

OPINION STATEMENT

Gliomas are the most common brain tumor in children and represent nearly 50 % of all pediatric central nervous system (CNS) tumors. They are a heterogeneous group of diseases, ranging from highly malignant and frequently fatal to histologically benign and curable by surgery alone. A uniform treatment approach to these tumors is not practical, due to their histological and biological heterogeneity. Low-grade gliomas (LGGs) are best treated with maximally safe surgical resection, generally achievable for hemispheric or cerebellar locations. Patients with deep midline, optic pathway/hypothalamic, and brain stem locations should undergo subtotal resection or biopsy only. If a complete resection is not feasible, subtotal resection followed by adjuvant chemotherapy or radiotherapy is the standard approach; however, observation alone with serial neuroimaging is used in some asymptomatic, surgically inaccessible lesions. Chemotherapy is used first-line in cases of residual or progressive disease, to avoid or delay radiation therapy and its associated side effects. Regimens demonstrating objective responses and increased progression free survival (PFS) include carboplatin and vincristine (CV), thioguanine/procarbazine/CCNU/vincristine (TPCV), or weekly vinblastine. High-grade gliomas (HGGs) are less common in children than in adults, though are similar in their aggressive clinical behavior, resistance to therapy, and dismal outcomes. There is not a single "standard of care" therapy for non-metastatic HGGs, but generally accepted is an aggressive attempt at a complete surgical resection, followed by multimodality therapy with focal radiation and chemotherapy. The use of temozolomide (TMZ) during and following radiotherapy is common, though it appeared not to improve the outcome in a cooperative group clinical trial when compared to an historical control cohort. The angiogenesis inhibitor bevacizumab, used alone or in combination with irinotecan, is also commonly used as maintenance therapy after radiation. Current trials are prospectively comparing TMZ to newer agents (vorinostat, bevacizumab) in a randomized phase II trial. Brainstem gliomas are a unique category of childhood gliomas. Approximately 80 % of childhood brainstem gliomas arise within the pons as diffuse intrinsic pontine gliomas (DIPG). When biopsied, these are usually HGGs and carry a dismal prognosis. Standard therapy is focal radiation (54-58 Gy), preferably on a clinical trial testing concurrent chemotherapy or biologic agent. No standard chemotherapy agent has impacted survival. The remaining 20 % of brainstem gliomas are low-grade, arise in the midbrain, dorsal medulla, or cervicomedullary junction, and are indolent in nature with a much better prognosis. Improvement in the outcome of all childhood gliomas will require increased knowledge of the underlying biology of these tumors, in order to treat with more biologically based and precise therapies.

Neurocognitive consequences of a paediatric brain tumour and its treatment: a meta-analysis

AIM

This meta-analysis provides a systematic review of studies into intellectual and attentional functioning of paediatric brain tumour survivors (PBTS) as assessed by two widely used measures: the Wechsler Intelligence Scale for Children (3rd edition; WISC-III) and the Conners' Continuous Performance Test (CPT).

METHOD

Studies were located that reported on performance of PBTS (age range 6-16y). Meta-analytic effect sizes were calculated for Full-scale IQ, Performance IQ, and Verbal IQ as measured by the WISC-III, and mean hit reaction time, errors of omission, and errors of commission as measured by the CPT. Exploratory analyses investigated the possible impacts of treatment mode, tumour location, age at diagnosis, and time since diagnosis on intelligence.

RESULTS

Twenty-nine studies were included: 22 reported on the WISC-III in 710 PBTS and seven on CPT results in 372 PBTS. PBTS performed below average (p(s) <0.001) on Full-scale IQ (Cohen's d=-0.79), Performance IQ (d=-0.90), and Verbal IQ (d=-0.54). PBTS committed more errors of omission than the norm (d=0.82, p<0.001); no differences were found for mean hit reaction time and errors of commission. Cranial radiotherapy, chemotherapy, and longer time since diagnosis were associated with lower WISC-III scores (p(s) <0.05).

INTERPRETATION

PBTS have seriously impaired intellectual functioning and attentiveness. Being treated with cranial radiotherapy and/or chemotherapy as well as longer time since diagnosis leads to worse intellectual functioning.

Gross total resection correlates with long-term survival in pediatric patients with glioblastoma

OBJECTIVE

Glioblastoma is a rare central nervous system neoplasm in pediatric patients. Few studies focused exclusively on this disease in this population. Available literature suggests that this disease behaves differently between pediatric and adult patients. We set out to study patients younger than 18 years of age, carrying the diagnosis of glioblastoma not of the brainstem, their clinical characteristics and clinical factors associated with clinical outcome.

METHODS

Thirty-seven pediatric patients with the diagnosis of glioblastoma not of the brainstem, who were treated in our institution from 1982-2011, were identified and studied retrospectively.

RESULTS

All patients underwent surgical intervention. Seventeen patients (45.9%) had gross total resection (GTR). Thirteen patients (35.1%) had subtotal resection and seven (18.9%) had biopsy. After surgery, 35 patients received radiation therapy (94.6%) and 34 patients (91.9%) received chemotherapy (various agents depending on the institutional protocols established at the time of treatment and family choice). Median follow-up time was 17.5 months, ranging from 0.5-186 months. The median overall survival is 18.7 months (95% confidence interval 15.7-21.8 months). The survival rate at 1, 2, and 5 years is 63.9%, 44.5%, and 17.6%, respectively. The median overall survival for patients with GTR is 45.1 months (95% confidence interval 27.5-62.8 months), 8.7 or 11.5 months for patients with subtotal resection or biopsy, respectively. GTR was accomplished only in patients with superficially located tumors.

CONCLUSIONS

GTR significantly associates with long-term survival in our population of pediatric patients with glioblastoma not of the brainstem.

Chemotherapy increases amenability of surgical resection in congenital glioblastoma

Brain tumors presenting in infancy, especially during the first 6 months of life, are often very large and highly vascular. It is generally accepted that gross total resection of the tumor affords the best outcome to the patient. However, tumor resection is frequently very challenging due to the risk of significant bleeding. We report two cases of congenital glioblastoma whose initial surgery was hampered by tumor hypervascularity and excessive blood loss, resulting in subtotal resection. Subsequent carboplatin-based chemotherapy led to a significant reduction in tumor size and vascularity, enabling safe gross total resection at second-look surgery. Based on these findings and a review of the literature, we recommend cytoreductive chemotherapy following diagnostic biopsy for infants presenting with large, highly vascular tumors, such as congenital glioblastoma, in lieu of aggressive upfront surgery, to increase the feasibility and facilitate safe gross total excision at second-look surgery.

Pediatric high grade glioma: a review and update on tumor clinical characteristics and biology

High grade gliomas (HGG) are one of the most common central nervous system (CNS) tumors encountered in adults, but they only represent approximately 8–12% of all pediatric CNS tumors. Historically, pediatric HGG were thought to be similar to adult HGG since they appear histologically identical; however, molecular, genetic, and biologic data reveal that they are distinct. Similar to adults, pediatric HGG are very aggressive and malignant lesions with few patients achieving long-term survival despite a variety of therapies. Initial treatment strategies typically consist of a gross total resection (GTR) when feasible followed by focal radiotherapy combined with chemotherapy. Over the last few decades, a wealth of data has emerged from basic science and pre-clinical animal models helping to better define the common biologic, genetic, and molecular make-up of these tumors. These data have not only provided a better understanding of tumor biology, but they have also provided new areas of research targeting molecular and genetic pathways with the potential for novel treatment strategies and improved patient outcomes. Here we provide a review of pediatric non-brainstem HGG, including epidemiology, presentation, histology, imaging characteristics, treatments, survival outcomes, and an overview of both basic and translational research. An understanding of all relevant pre-clinical tumor models, including their strengths and pitfalls is essential in realizing improved patient outcomes in this population.

Possible differentiation of cerebral glioblastoma into pleomorphic xanthoastrocytoma: an unusual case in an infant

The authors describe an infant girl who, at 10 months of age, presented with a large right parietooccipital tumor causing increased intracranial pressure, mass effect, and midline shift. The tumor was completely resected, and the entirety of the histology was consistent with glioblastoma. She was subsequently placed on adjuvant high-dose chemotherapy consisting of carboplatin, vincristine, and temozolomide, according to Head Start III, Regimen C. Three months after the complete resection, tumor recurrence was noted on MR imaging, during the third cycle of chemotherapy, and biopsy revealed malignant astrocytoma. Given the recurrence and the patient's intolerance to chemotherapy, a palliative course was pursued. Unexpectedly, the patient was alive and had made significant developmental improvements 18 months into palliation. Subsequently, however, signs of increased intracranial pressure developed and imaging demonstrated a very large new tumor growth at the site of prior resection. The recurrence was again fully resected, but microscopy surprisingly revealed pleomorphic xanthoastrocytoma throughout. The clinicopathological and genetic features of this girl's unusual neoplasm are detailed and potential pathogenic hypotheses are explored in this report.

Resection and Immunotherapy for Recurrent Grade III Glioma

Background. Despite surgery, radiotherapy, and chemotherapy, the prognosis of relapsed grade III gliomas remains poor. After promising results of immunotherapy in grade IV gliomas, we investigated its safety and efficacy in recurrent grade III gliomas. Methods. Thirty-nine patients received vaccines containing dendritic cells loaded with autologous tumor lysate after tumor resection. Progression-free survival (PFS) and overall survival (OS) were compared with those obtained after temozolomide (TMZ) treatment as found in the literature. Results. Median PFS and OS were 4.6 and 20.5, 3.4 and 18.8, 7.8 and 13.3 months in recurrent grade III astrocytoma, oligodendroglioma, and oligoastrocytoma, respectively. Compared with TMZ, no grade III/IV toxicity was reported and median OS tended to be higher although there was no difference in median PFS. The perceived benefit of immunotherapy was more pronounced in astrocytic tumors. Conclusions. We provide the first description of immunotherapy in recurrent grade III glioma as safe, promising, and feasible.

Treatment of high-grade glioma in children and adolescents

Pediatric high-grade gliomas (HGGs)--including glioblastoma multiforme, anaplastic astrocytoma, and diffuse intrinsic pontine glioma--are difficult to treat and are associated with an extremely poor prognosis. There are no effective chemotherapeutic regimens for the treatment of pediatric HGG, but many new treatment options are in active investigation. There are crucial molecular differences between adult and pediatric HGG such that results from adult clinical trials cannot simply be extrapolated to children. Molecular markers overexpressed in pediatric HGG include PDGFRα and P53. Amplification of EGFR is observed, but to a lesser degree than in adult HGG. Potential molecular targets and new therapies in development for pediatric HGG are described in this review. Research into bevacizumab in pediatric HGG indicates that its activity is less than that observed in adult HGG. Similarly, tipifarnib was found to have minimal activity in pediatric HGG, whereas gefitinib has shown greater effects. After promising phase I findings in children with primary CNS tumors, the integrin inhibitor cilengitide is being investigated in a phase II trial in pediatric HGG. Studies are also ongoing in pediatric HGG with 2 EGFR inhibitors: cetuximab and nimotuzumab. Other novel treatment modalities under investigation include dendritic cell-based vaccinations, boron neutron capture therapy, and telomerase inhibition. While the results of these trials are keenly awaited, the current belief is that multimodal therapy holds the greatest promise. Research efforts should be directed toward building multitherapeutic regimens that are well tolerated and that offer the greatest antitumor activity in the setting of pediatric HGG.

Characterization, treatment, and outcome of intracranial neoplasms in the first 120 days of life

Little is known about brain tumors in early infancy. Investigators reviewed the records of 27 patients (12 boys and 15 girls) diagnosed within 120 days of birth. The median age was 66 days (range, 0-110 days) at diagnosis. All patients underwent surgery; 18 received adjuvant chemotherapy, and 3 received adjuvant chemotherapy and radiation therapy. The median follow-up was 2.1 years (range, 0.2-21.6 years). At last encounter, 15 patients were alive, and 11 had no evidence of disease. Ten patients died of progressive disease, and 2 died of treatment-related complications. All survivors experienced late effects, including endocrine, neurologic, and cognitive deficits. Of the 13 patients who completed neurocognitive assessments, 7 had an IQ score less than 70. Children in whom brain tumors arise during early infancy can be cured with conventional therapy; however, contemporary approaches can adversely affect long-term function, and families need to be aware of these effects when making therapeutic decisions.

Challenging issues in pediatric oncology

Improvements in protocol-driven clinical trials and supportive care for children and adolescents with cancer have reduced mortality rates by more than 50% over the past three decades. Overall, the 5-year survival rate for patients with pediatric cancer has increased to approximately 80%. Recognition of the biological heterogeneity within specific subtypes of cancer, the discovery of genetic lesions that drive malignant transformation and cancer progression, and improved understanding of the basis of drug resistance will undoubtedly catalyze further advances in risk-directed treatments and the development of targeted therapies, boosting the cure rates further. Emerging new treatments include novel formulations of existing chemotherapeutic agents, monoclonal antibodies against cancer-associated antigens, and molecular therapies that target genetic lesions and their associated signaling pathways. Recent findings that link pharmacogenomic variations with drug exposure, adverse effects, and efficacy should accelerate efforts to develop personalized therapy for individual patients. Finally, palliative care should be included as an essential part of cancer management to prevent and relieve the suffering and to improve the quality of life of patients and their families.

Infant brain tumors: incidence, survival, and the role of radiation based on Surveillance, Epidemiology, and End Results (SEER) Data

PURPOSE

To evaluate the incidence of infant brain tumors and survival outcomes by disease and treatment variables.

METHODS AND MATERIALS

The Surveillance, Epidemiology, and End Results (SEER) Program November 2008 submission database provided age-adjusted incidence rates and individual case information for primary brain tumors diagnosed between 1973 and 2006 in infants less than 12 months of age.

RESULTS

Between 1973 and 1986, the incidence of infant brain tumors increased from 16 to 40 cases per million (CPM), and from 1986 to 2006, the annual incidence rate averaged 35 CPM. Leading histologies by annual incidence in CPM were gliomas (13.8), medulloblastoma and primitive neuroectodermal tumors (6.6), and ependymomas (3.6). The annual incidence was higher in whites than in blacks (35.0 vs. 21.3 CPM). Infants with low-grade gliomas had the highest observed survival, and those with atypical teratoid rhabdoid tumors (ATRTs) or primary rhabdoid tumors of the brain had the lowest. Between 1979 and 1993, the annual rate of cases treated with radiation within the first 4 months from diagnosis declined from 20.5 CPM to <2 CPM. For infants with medulloblastoma, desmoplastic histology and treatment with both surgery and upfront radiation were associated with improved survival, but on multivariate regression, only combined surgery and radiation remained associated with improved survival, with a hazard ratio for death of 0.17 compared with surgery alone (p = 0.005). For ATRTs, those treated with surgery and upfront radiation had a 12-month survival of 100% compared with 24.4% for those treated with surgery alone (p = 0.016). For ependymomas survival was higher in patients treated in more recent decades (p = 0.001).

CONCLUSION

The incidence of infant brain tumors has been stable since 1986. Survival outcomes varied markedly by histology. For infants with medulloblastoma and ATRTs, improved survival was observed in patients treated with both surgery and early radiation compared with those treated with surgery alone.

Clinical outcome in pediatric glial and embryonal brain tumors correlates with in vitro multi-passageable neurosphere formation

BACKGROUND

Cultured brain tumors can form neurospheres harboring tumorigenic cells with self renewal and differentiation capacities. Renewable neurosphere formation has clinical predictive value in adult malignant gliomas, yet its prognostic role for pediatric brain tumors is unknown.

METHODS

Established neurosphere conditions were used for culturing samples from glial, embryonal and mixed glioneuronal tumors from 56 pediatric patients. Potential associations between neurosphere formation and clinical outcome were analyzed retrospectively.

RESULTS

Thirty-seven percent of all samples formed renewable neurospheres. Analysis of available clinical outcome data from 51 patients demonstrated significantly increased hazard ratios (HR) for both disease progression (HR = 9.9, P < 0.001) and death (HR = 16.6, P < 0.01) in the neurosphere forming group. Furthermore, neurosphere formation correlated with adverse progression free survival (PFS) in glial and embryonal tumors, but not in mixed glioneuronal tumors. Overall survival (OS) was significantly worse for neurosphere-forming patients with embryonal tumors, as a group and amongst the subgroup with medulloblastoma, but not in the glial group. Multivariate analysis showed that neurosphere formation was associated with diminished PFS and OS independent of age, gender, or treatment. Neurosphere formation was an independent predictor of diminished PFS of glial tumors after adjusting for grade. Multivariate analysis, adjusting for both Ki67 staining and neurosphere formation, demonstrated that neurosphere formation remained predictive of progression whereas Ki67 did not.

CONCLUSIONS

Neurosphere formation is more predictive of pediatric brain tumor progression than semi-quantitative Ki67 staining. Pediatric brain tumor derived neurospheres may provide a predictive model for preclinical explorations.

Distinct molecular signatures in pediatric infratentorial glioblastomas defined by aCGH

Glioblastomas (GBM) are rare in children, but reportedly have more varied outcome which suggests differences in tumor etiology compared to typical GBM of adults. To investigate this we performed high resolution array comparative genomic hybridization (aCGH) analysis on three pediatric infratentorial GBM, ages 3.5, 7 and 14 years. Two of these tumors occurred in the brainstem and one in the spinal cord. While histologically typical, one brainstem tumor showed mainly pleomorphic astrocytic cells, whereas the other brainstem and spinal tumors showed a GFAP positive small cell component. Whole chromosomal gains (#1 and #2) and loss (#20) were seen only in the pleomorphic brainstem GBM, which also showed a high level of segmental genomic copy number changes. Segmental loss involving chromosome 8 was seen in all three tumors (Chr8;133039446-136869494, Chr8;pter-3581577, and Chr8;pter-30480019 respectively), whereas loss involving chromosome 16 was seen in only 2 cases with small cell components (Chr16;31827239-qter and Chr16;pter-29754532). Segmental gain of chromosome 7 was shared only between the 2 brainstem cases (Chr7;17187166-qter and Chr7;69824947-qter). Chromosome 17 showed segmental gain of 17q in the backdrop of loss of 17p only in case 1. Segmental gain of chromosome 1q was seen only in case 2. The spinal GBM showed a relatively stable karyotype with a unique loss of Chr19;32848902-qter. None of the frequent losses, gains and amplifications known to occur in adult GBM were identified, suggesting that pediatric infratentorial glioblastomas show a molecular karyotype that was more characteristic of pediatric embryonal tumors than adult GBM.

Initial experience involving treatment and retreatment with carmustine wafers in combination with oral temozolomide: long-term survival in a child with relapsed glioblastoma multiforme

BACKGROUND

Glioblastomas occur infrequently in children, and the prognosis is better than for glioblastomas seen in adults. Aggressive treatment is justified in pediatric patients.

OBSERVATIONS

We present the case of a 6-year-old child with malignant posterior temporal glioma treated with surgery, radiotherapy, local chemotherapy with carmustine wafers, and oral therapy with temozolomide, both at initial diagnosis and at relapse 18 months later. After 6 years, the patient seems healthy with no focal neurologic signs, and imaging studies show no evidence of disease.

CONCLUSION

Multimodal therapy was found to have a very positive outcome for a child with malignant glioma.

Integrated molecular genetic profiling of pediatric high-grade gliomas reveals key differences with the adult disease

PURPOSE

To define copy number alterations and gene expression signatures underlying pediatric high-grade glioma (HGG).

PATIENTS AND METHODS

We conducted a high-resolution analysis of genomic imbalances in 78 de novo pediatric HGGs, including seven diffuse intrinsic pontine gliomas, and 10 HGGs arising in children who received cranial irradiation for a previous cancer using single nucleotide polymorphism microarray analysis. Gene expression was analyzed with gene expression microarrays for 53 tumors. Results were compared with publicly available data from adult tumors.

RESULTS

Significant differences in copy number alterations distinguish childhood and adult glioblastoma. PDGFRA was the predominant target of focal amplification in childhood HGG, including diffuse intrinsic pontine gliomas, and gene expression analyses supported an important role for deregulated PDGFRalpha signaling in pediatric HGG. No IDH1 hotspot mutations were found in pediatric tumors, highlighting molecular differences with adult secondary glioblastoma. Pediatric and adult glioblastomas were clearly distinguished by frequent gain of chromosome 1q (30% v 9%, respectively) and lower frequency of chromosome 7 gain (13% v 74%, respectively) and 10q loss (35% v 80%, respectively). PDGFRA amplification and 1q gain occurred at significantly higher frequency in irradiation-induced tumors, suggesting that these are initiating events in childhood gliomagenesis. A subset of pediatric HGGs showed minimal copy number changes.

CONCLUSION

Integrated molecular profiling showed substantial differences in the molecular features underlying pediatric and adult HGG, indicating that findings in adult tumors cannot be simply extrapolated to younger patients. PDGFRalpha may be a useful target for pediatric HGG, including diffuse pontine gliomas.

Primary postoperative chemotherapy without radiotherapy for treatment of brain tumours other than ependymoma in children under 3 years: results of the first UKCCSG/SIOP CNS 9204 trial

BACKGROUND

Radiotherapy is an effective adjuvant treatment for brain tumours arising in very young children, but it has the potential to damage the child's developing nervous system at a crucial time - with a resultant reduction in IQ leading to cognitive impairment, associated endocrinopathy and risk of second malignancy. We aimed to assess the role of a primary chemotherapy strategy in avoiding or delaying radiotherapy in children younger than 3 years with malignant brain tumours other than ependymoma, the results of which have already been published.

METHODS

Ninety-seven children were enrolled between March 1993 and July 2003 and, following diagnostic review, comprised: medulloblastoma (n=31), astrocytoma (26), choroid plexus carcinoma [CPC] (15), CNS PNET (11), atypical teratoid/rhabdoid tumours [AT/RT] (6) and ineligible (6). Following maximal surgical resection, chemotherapy was delivered every 14 d for 1 year or until disease progression. Radiotherapy was withheld in the absence of progression.

FINDINGS

Over all diagnostic groups the cumulative progression rate was 80.9% at 5 years while the corresponding need-for-radiotherapy rate for progression was 54.6%, but both rates varied by tumour type. There was no clear relationship between chemotherapy dose intensity and outcome. Patients with medulloblastoma presented as a high-risk group, 83.9% having residual disease and/or metastases at diagnosis. For these patients, outcome was related to histology. The 5-year OS for desmoplastic/nodular medulloblastoma was 52.9% (95% confidence interval (CI): 27.6-73.0) and for classic medulloblastoma 33.3% (CI: 4.6-67.6); the 5-year EFS were 35.3% (CI: 14.5-57.0) and 33.3% (CI: 4.6-67.6), respectively. All children with large cell or anaplastic variants of medulloblastoma died within 2 years of diagnosis. The 5-year EFS for non-brainstem high-grade gliomas [HGGs] was 13.0% (CI: 2.2-33.4) and the OS was 30.9% (CI: 11.5-52.8). For CPC the 5-year OS was 26.67% (CI: 8.3-49.6) without RT. This treatment strategy was less effective for AT/RT with 3-year OS of 16.7% (CI: 0.8-51.7) and CNS PNET with 1-year OS of 9.1% (CI: 0.5-33.3).

INTERPRETATION

The outcome for very young children with brain tumours is dictated by degree of surgical resection and histological tumour type and underlying biology as an indicator of treatment sensitivity. Overall, the median age at radiotherapy was 3 years and radiotherapy was avoided in 45% of patients. Desmoplastic/nodular sub-type of medulloblastoma has a better prognosis than classic histology, despite traditional adverse clinical features of metastatic disease and incomplete surgical resection. A subgroup with HGG and CPC are long-term survivors without RT. This study highlights the differing therapeutic challenges presented by the malignant brain tumours of early childhood, the importance of surgical approaches and the need to explore individualised brain sparing approaches to the range of malignant brain tumours that present in early childhood.

Prognostic significance of histological grading, p53 status, YKL-40 expression, and IDH1 mutations in pediatric high-grade gliomas

The objective of this study was to evaluate, in a series of 43 pediatric high-grade gliomas (21 anaplastic astrocytoma WHO grade III and 22 glioblastoma WHO grade IV), the prognostic value of histological grading and expression of p53 and YKL-40. Moreover, mutational screening for TP53 and IDH1 was performed in 27 of 43 cases. The prognostic stratification for histological grading showed no difference in overall (OS) and progression-free survival (PFS) between glioblastomas and anaplastic astrocytomas. Overexpression of YKL40 was detected in 25 of 43 (58%) cases, but YKL-40 expression was not prognostic in terms of OS and PFS. p53 protein expression was observed in 13 of 43 (31%) cases but was not prognostic. TP53 mutations were detected in five of 27 (18%) cases (four glioblastomas and one anaplastic astrocytoma). Patients with TP53 mutation had a shorter median OS (9 months) and PFS (8 months) than those without mutations (OS, 17 months; PFS, 16 months), although this trend did not reach statistical significance (p = 0.07). IDH1 mutations were not detected in any of the cases analyzed. Our results suggest that in pediatric high-grade gliomas: (i) histological grading does not have strong prognostic significance, (ii) YKL-40 overexpression is less frequent than adult high-grade gliomas and does not correlate with a more aggressive behavior, (iii) TP53 mutations but not p53 expression may correlate with a more aggressive behavior, and (iv) IDH1 mutations are absent. These observations support the concept that, despite identical histological features, the biology of high-grade gliomas in children differs from that in adults, and therefore different prognostic factors are needed.

Outcome and prognostic features in pediatric gliomas: a review of 6212 cases from the Surveillance, Epidemiology, and End Results database

BACKGROUND

Pediatric gliomas are rare and heterogeneous tumors. The Surveillance, Epidemiology, and End Results (SEER) database allows a large-scale analysis of the clinical characteristics and prognostic features of these tumors.

METHODS

The authors analyzed available SEER data on 6212 patients younger than 20 years at diagnosis of glioma (1973-2005), according to 4 age categories: <1 year, 1-3 years, 3-5 years, and 5-20 years.

RESULTS

The overall 5- and 10-year survival estimates were 71%+/-0.62% (standard error) and 68%+/-0.67%, respectively. Forty-one percent of gliomas were cerebral; the frequency of cerebellar tumors (22%-32% of gliomas) increased sharply after the first year of life. Of the tumors for which grade was available, 77% were low grade (grade I or II). Tumor grade emerged as the most significant independent prognostic factor in all age groups except the youngest age group, in which extent of resection was most significant. Surgery other than gross total resection was an adverse prognostic factor (hazard ratio, 2.18; 95% confidence interval, 1.78-2.67). Age<3 years predicted a greater likelihood of survival in patients with high-grade gliomas and brainstem tumors. Conversely, age<3 years predicted a lower likelihood of survival in patients with low-grade gliomas. Children aged<1 year received less radiotherapy than older patients (P<.0001) and were less likely to undergo gross total resection (P<.0001).

CONCLUSIONS

The survival of children with gliomas is influenced by histologic subtype, age, and extent of resection. Despite its limitations, the SEER database provides a useful tool for studies of rare tumors such as pediatric gliomas.