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1.  Impact of tumor location and pathological discordance on survival of children with midline high-grade gliomas treated on Children’s Cancer Group high-grade glioma study CCG-945 
Journal of neuro-oncology  2014;121(3):573-581.
Children with high-grade glioma (HGG) have a poor prognosis compared to those with low-grade glioma (LGG). Adjuvant chemotherapy may be beneficial, but its optimal use remains undetermined. Histology and extent of resection are important prognostic factors. We tested the hypothesis that patients with midline HGG treated on Children’s Cancer Group Study (CCG) CCG-945 have a worse prognosis compared to the entire group. Of 172 children eligible for analysis, 60 had midline tumors primarily localized to the thalamus, hypothalamus and basal ganglia. Time-to-progression and death were determined from the date of initial diagnosis, and survival curves were calculated. Univariate analyses were undertaken for extent of resection, chemotherapy regimen, anatomic location, histology, proliferation index, MGMT status and p53 over-expression. For the entire midline tumor group, 5-year PFS and OS were 18.3 ± 4.8 and 25 ± 5.4 %, respectively. Many patients only had a biopsy (43.3 %). The sub-groups with near/total resection and hypothalamic location appeared to have better PFS and OS. However, the effect of tumor histology on OS was significant for children with discordant diagnoses on central pathology review of LGG compared to HGG. Proliferative index (MIB-1 > 36 %), MGMT and p53 over-expression correlated with poor outcomes. Children treated on CCG-945 with midline HGG have a worse prognosis when compared to the entire group. The midline location may directly influence the extent of resection. Central pathology review and entry of patients on clinical trials continue to be priorities to improve outcomes for children with HGG.
doi:10.1007/s11060-014-1669-x
PMCID: PMC4323766  PMID: 25431150
Childhood malignant gliomas; Anaplastic astrocytoma; Glioblastoma multiforme; Chemotherapy; Midline tumors; Thalamus; Hypothalamus; Basal ganglia
2.  Management of children with brain tumors in Paraguay 
Neuro-Oncology  2012;15(2):235-241.
Background
Cure rates among children with brain tumors differ between low-income and high-income countries. To evaluate causes of these differences, we analyzed aspects of care provided to pediatric neuro-oncology patients in a low middle-income South American country.
Methods
Three methods were used to evaluate treatment of children with brain tumors in Paraguay: (1) a quantitative needs assessment questionnaire for local treating physicians, (2) site visits to assess 3 tertiary care centers in Asunción and a satellite clinic in an underdeveloped area, and (3) interviews with health care workers from relevant disciplines to determine their perceptions of available resources. Treatment failure was defined as abandonment of therapy, relapse, or death.
Results
All 3 tertiary care facilities have access to chemotherapy and pediatric oncologists but lack training and tools for neuropathology and optimal neurosurgery. The 2 public hospitals also lack access to appropriate radiological tests and timely radiotherapy. These results demonstrate disparities in Paraguay, with rates of treatment failure ranging from 37% to 83% among the 3 facilities.
Conclusions
National and center-specific deficiencies in resources to manage pediatric brain tumors contribute to poor outcomes in Paraguay and suggest that both national and center-specific interventions are warranted to improve care. Disparities in Paraguay reflect different levels of governmental and philanthropic support, program development, and socio-economic status of patients and families, which must be considered when developing targeted strategies to improve management. Effective targeted interventions can serve as a model to develop pediatric brain tumor programs in other low- and middle-income countries.
doi:10.1093/neuonc/nos291
PMCID: PMC3548583  PMID: 23197688
brain tumors; children; low-income country; Paraguay
3.  Myeloablative Chemotherapy with Autologous Bone Marrow Rescue in Children and Adolescents with Recurrent Malignant Astrocytoma: Outcome Compared with Conventional Chemotherapy: A Report from the Children’s Oncology Group 
Pediatric blood & cancer  2008;51(6):806-811.
Purpose
Children and adolescents with malignant astrocytomas recurring after initial treatment have a dismal prognosis, with only rare patients surviving one year beyond recurrence. The purpose of this study was to attempt to improve their survival.
Methods
Twenty-seven children and adolescents with malignant astrocytomas (17 glioblastoma multiforme and 10 anaplastic astrocytoma) following initial tumor progression, received myeloablative chemotherapy followed by autologous marrow rescue with one of three thiotepa and etoposide-based chemotherapy regimens, administered alone (n=11) or combined with carmustine (n=5) or carboplatin (n=11). Time to progression and death following myeloablative chemotherapy for these patients was compared non-randomly with outcome of a contemporaneously treated cohort of similar patients who received only conventional chemotherapy following initial tumor progression. The two cohorts were compared for age, histology, prior therapies, extent of surgical resection at progression and time from initial diagnosis to progression.
Results
Five of 27 children (two with glioblastoma multiforme and three with anaplastic astrocytoma) survive event-free from 8.3 to 13.3 years (median of 11.1 years) following myeloablative chemotherapy. Of 56 children with recurrent malignant astrocytoma who received conventional chemotherapy following initial progression, no patient survives. Differences in distributions of survival were not significant when stratified by surgical debulking (p=0.39). However, for patients who were surgically debulked, the survival distributions are significantly different (p=0.017).
Conclusions
Myeloablative chemotherapy with autologous marrow rescue can produce durable remissions in children and young adults with recurrent malignant gliomas, in the setting of minimal residual tumor burden achieved surgically.
doi:10.1002/pbc.21732
PMCID: PMC2844080  PMID: 18802947
Myeloablative chemotherapy; autologous bone marrow rescue; recurrent malignant astrocytoma
4.  High-dose chemotherapy with stem cell rescue as initial therapy for anaplastic oligodendroglioma: Long-term follow-up 
Neuro-Oncology  2006;8(2):183-188.
We previously reported a phase 2 trial of 69 patients with newly diagnosed anaplastic or aggressive oligodendroglioma who were treated with intensive procarbazine, CCNU (lomustine), and vincristine (PCV) followed by high-dose thiotepa with autologous stem cell rescue. This report summarizes the long-term follow-up of the cohort of 39 patients who received high-dose thiotepa with autologous stem cell support. Thirty-nine patients with a median age of 43 (range, 18–67) and a median KPS of 100 (range, 70–100) were treated. Surviving patients now have a median follow-up of 80.5 months (range, 44–142). The median progression-free survival is 78 months, and median overall survival has not been reached. Eighteen patients (46%) have relapsed. Neither histology nor prior low-grade oligodendroglioma correlated with risk of relapse. Persistent nonenhancing tumor at transplant was identified in our initial report as a significant risk factor for relapse; however, long-term follow-up has not confirmed this finding. Long-term neurotoxicity has developed only in those patients whose disease relapsed and required additional therapy; no patient in continuous remission has developed a delayed neurologic injury. This treatment strategy affords long-term disease control to a subset of patients with newly diagnosed anaplastic oligodendroglioma without evidence of delayed neurotoxicity or myelodysplasia.
doi:10.1215/15228517-2005-009
PMCID: PMC1871935  PMID: 16524945
anaplastic; chemotherapy; oligodendroglioma
5.  Elevated citrate in pediatric astrocytomas with malignant progression 
Neuro-Oncology  2011;13(10):1107-1117.
In vivo magnetic resonance spectroscopy (MRS) provides information about metabolite concentrations in tissue. Recently citrate was detected by MRS in subgroups of pediatric brain tumors. Citrate is an intermediate in the tricarboxylic acid (TCA) cycle and accumulates in tissue when the glycolytic rate exceeds the TCA cycle activity, a feature of malignant tumors. Currently, no practical indicators allow clinicians to predict risk for malignant progression of pediatric astrocytomas (World Health Organization [WHO] grade II). Medical records and citrate concentrations measured with in vivo MRS of 29 pediatric astrocytomas were reviewed. This included 6 patients with astrocytomas (WHO II) who had stable disease (indolent LGA) for >2 years, 7 with aggressive grade II astrocytomas (aggressive LGA), 13 with anaplastic astrocytomas (WHO III), and 3 with glioblastoma (WHO IV) with disease progression within 2 years. Citrate was observed in all patients with aggressive LGA, and the mean citrate concentration was significantly higher in this group than among those with indolent LGA (mean ± standard deviation, 4.1 ± 1.1 vs 0.6 ± 0.8 mmol/kg; P < .0001). There was no consistent pattern for citrate in anaplastic astrocytoma and glioblastoma, with citrate prominent in some lesions whereas undetectable in others. It is unclear whether citrate accumulation occurred because of fundamental defects of citrate regulation or was secondary to altered physiological conditions. Nonetheless, prominent citrate identified a subgroup of pediatric grade II astrocytomas destined for aggressive behavior. Citrate was not specific for poor outcome because it was not detectable in all high-grade astrocytomas. In high-grade astrocytoma, tumors with prominent citrate may constitute a metabolic subclass.
doi:10.1093/neuonc/nor087
PMCID: PMC3177657  PMID: 21771868
astrocytoma; citrate; metabolism; MR spectroscopy; pediatrics
6.  Mismatch Repair Deficiency Is an Uncommon Mechanism of Alkylator Resistance in Pediatric Malignant Gliomas: A Report From the Children's Oncology Group 
Pediatric blood & cancer  2010;55(6):1066-1071.
Background
Alkylating agents are commonly used in the treatment of childhood malignant gliomas. Overexpression of O6-methylguanine-DNA methyltransferase (MGMT)constitutes an important mechanism for resistance to such agents, and MGMT status has been associated with outcome in several recent trials. Deficiency in mismatch repair (MMR)function has been implicated in preclinical studies as an additional potential mechanism of resistance to methylating agents, such as temozolomide, independent of tumor MGMT status. However, the frequency of this abnormality as a clinical resistance mechanism in childhood malignant gliomas has not been well characterized.
Methods
To address this issue, we examined the frequency of microsatellite instability (MSI), a marker of defective MMR, in a series of 68 tumors, derived from newly diagnosed patients treated on the Children's Cancer Group 945 study, and the Children's Oncology Group ACNS0126 and 0423 studies. MSI was assessed using a panel of six microsatellite markers, including BAT-25, BAT-26, CAT-25, D2S123, D5S346, and D17S250. MGMT immunoreactivity was assessed in parallel to allow comparison of the relative incidence of MGMT overexpression and MSI.
Results
Only three tumors had high-level MSI involving three or more markers; the remainder had no MSI at any of the loci examined. These children did not have unusual features in terms of their outcome. In contrast to the infrequency of MSI, 25 tumors (37%)exhibited MGMT overexpression as assessed by immunohistochemistry. None of the tumors with MSI exhibited overexpression of MGMT.
Conclusion
MMR deficiency is an infrequent contributor to initial alkylator resistance in children with malignant gliomas. Pediatr Blood Cancer.
doi:10.1002/pbc.22634
PMCID: PMC3036982  PMID: 20589656
anaplastic glioma; childhood; glioblastoma; MGMT; microsatellite instability; mismatch repair; treatment resistance
7.  High-dose carboplatin, thiotepa, and etoposide with autologous stem cell rescue for patients with previously irradiated recurrent medulloblastoma† 
Neuro-Oncology  2010;12(3):297-303.
Recurrent medulloblastoma is highly lethal in previously irradiated patients. Previously irradiated patients with M-0–M-3 recurrences who achieved a minimal disease state prior to protocol enrollment received carboplatin (Calvert formula with area under the curve = 7 mg/mL min, maximum 500 mg/m2/day) on days −8 to −6, and thiotepa (300 mg/m2/day) and etoposide (250 mg/m2/day) on days −5 to −3, followed by autologous stem cell rescue (ASCR) on day 0. Twenty-five patients, aged 7.6–44.7 years (median 13.8 years) at ASCR, were treated. Three (12%) died of treatment-related toxicities within 30 days of ASCR, due to multiorgan system failure (n = 2) and aspergillus infection with veno-occlusive disease (n = 1). Tumor recurred in 16 at a median of 8.5 months (range 2.3–58.5 months). Six are event-free survivors at a median of 151.2 months post-ASCR (range 127.2–201.6 months). The Kaplan–Meier estimate of median overall survival is 26.8 months (95% CI: 11.9–51.1 months) and of event-free survival (EFS) and overall survival are both 24% (95% CI: 9.8%–41.7%) at 10 years post-ASCR. M-0 (vs M-1 + ) recurrence prior to protocol, lack of tissue confirmation of relapse, and initial therapy of radiation therapy (RT) alone (vs RT + chemotherapy) were not significantly associated with better EFS (P = .33, .34, and .27, respectively). Trends toward better EFS were noted in patients (n = 5) who received additional RT as part of their retrieval therapy (P = .07) and whose recurrent disease was demonstrated to be sensitive to reinduction chemotherapy (P = .09). This retrieval strategy provides long-term EFS for some patients with previously irradiated recurrent medulloblastoma. The use of additional RT may be associated with better outcome.
doi:10.1093/neuonc/nop031
PMCID: PMC2940591  PMID: 20167818
chemotherapy; hematopoietic stem cell transplantation; medulloblastoma
8.  Metabolism of diffuse intrinsic brainstem gliomas in children 
Neuro-Oncology  2008;10(1):32-44.
Progress in the development of effective therapies for diffuse intrinsic brainstem gliomas (DIBSGs) is compromised by the unavailability of tissue samples and the lack of noninvasive markers that can characterize disease status. The purpose of this study was to compare the metabolic profile of DIBSGs with that of astrocytomas elsewhere in the CNS and to determine whether the measurement of metabolic features can improve the assessment of disease status. Forty in vivo MR spectroscopy (MRS) studies of 16 patients with DIBSG at baseline and after radiation therapy were retrospectively reviewed. Control data for baseline studies of DIBSGs were obtained from 14 untreated regular and anaplastic astrocytomas. All spectra were acquired with single-voxel, short echo-time (35 ms), point-resolved spectroscopy. Absolute metabolite concentrations (mmol/kg) and lipid intensities (arbitrary units) were determined. At baseline, creatine and total choline (tCho) were significantly lower in DIBSGs than in astrocytomas elsewhere in the CNS (4.3 ± 1.1 vs. 7.5 ± 1.9 mmol/kg, p < 0.001; 1.9 ± 0.7 vs. 4.2 ± 2.6, p < 0.001). Serial MRS in individual subjects revealed increasing levels of tCho (p < 0.05) and lipids (p < 0.05) and reduced ratios of N-acetylaspartate, creatine, and myoinositol relative to tCho (all p < 0.01). Metabolic progression defined by increased tCho concentration in serial MRS preceded clinical deterioration by 2.4 ± 2.7 months (p < 0.04). Low tCho of DIBSG at baseline is consistent with low proliferative tumors. Subsequent metabolic changes that have been associated with malignant degeneration preceded clinical deterioration. MRS provides early surrogate markers for disease progression.
doi:10.1215/15228517-2007-042
PMCID: PMC2600836  PMID: 18003889
brainstem gliomas; disease progression; metabolism; MR spectroscopy; pediatrics
9.  The influence of central review on outcome associations in childhood malignant gliomas: results from the CCG-945 experience. 
Neuro-Oncology  2003;5(3):197-207.
To examine the influence of the pathology review mechanism on the results of analyses of therapeutic efficacy and biological prognostic correlates for pediatric high-grade gliomas, we evaluated the effects of using single-expert review or consensus review, as alternatives to institutional classification, in determining outcome results of a large randomized trial. The study group was the randomized cohort of Children's Cancer Group study 945, which compared efficacy of 2 chemotherapy regimens adjuvant to surgery and radiation. Trial eligibility required institutional histopathologic diagnosis of high-grade glioma. Sections of study tumors also were centrally reviewed, initially by a study review neuropathologist and subsequently by 5 neuropathologists, including the review pathologist. Reviews were independent, and reviewers were masked to clinical factors and outcomes, and consensus diagnoses of the panel were then established. Among 172 eligible patients, 42 tumors were classified as discordant on single-expert review and 51 on consensus review. Progression-free survival probabilities calculated for patients with tumors classified as high-grade gliomas by either single-expert or consensus review were inferior to those for the overall, institutionally diagnosed cohort. However, conclusions of the study regarding relative efficacy of treatment and clinical and molecular outcome correlates were unaffected by diagnosis method. Resection extent, proliferation index, and p53 expression were associated strongly with outcome, regardless of diagnosis method. However, comparisons between arms in which inclusion was determined by different review criteria for each arm caused spurious conclusions about efficacy differences between treatments. We conclude that the pathology review mechanism had little effect on within-trial comparisons of therapeutic effects or prognostic correlates in this randomized study, but strongly influenced survival distributions that were calculated for each treatment arm. These results support the implementation of expedited central review in therapeutic studies involving childhood malignant gliomas as a way to prospectively identify and exclude cases with discordant diagnoses and indicate the need for additional measures, such as molecular assessments, to increase the reproducibility of neuropathologic classification for these tumors.
doi:10.1215/S1152-8517-03-00009-7
PMCID: PMC1920685  PMID: 12816726

Results 1-9 (9)