Ketogenic diet treatment in recurrent diffuse intrinsic pontine glioma in children: A safety and feasibility study.

BACKGROUND: The mean overall survival rate of children with diffuse intrinsic pontine glioma (DIPG) is 9-11 months, with current standard treatment with fractionated radiotherapy and adjuvant chemotherapy. So far, novel therapeutic strategies have not yet resulted in significantly better survival. The main source of energy for glioblastoma cells is glucose. Therefore, metabolic alterations induced by the use of the extremely carbohydrate-restricted ketogenic diet (KD) as adjuvant therapy are subject of interest in cancer research. PROCEDURE: This study explores the safety and feasibility of the KD in children with recurrent DIPG and no remaining treatment options. Safety was defined as the number of adverse effects. Feasibility was defined as the number of patients who were able to use the KD for three months. Coping of patients and parents was measured with questionnaires. RESULTS: Three of 14 children referred to our hospital between 2010 and 2015 were included. Two patients completed the study, and one died before the end of the study. Hospitalizations were needed for placing a nasogastric tube (n = 1) and epileptic seizures (n = 1). Adverse effects related to the diet were mild and transient. Parents were highly motivated during the study. CONCLUSION: Use of KD is safe and feasible, but the effect on survival has to be proven in a larger cohort of children who start the KD earlier after diagnosis, preferably as adjuvant therapy to fractionated radiotherapy.

Determinants of impairments in functioning, fatigue, and participation ability in pediatric brain tumor survivors.

BACKGROUND: Pediatric brain tumor survivors (PBTS) experience disease- and treatment-related sequelae. We aimed to investigate the occurrence of participation limitations, impairments in functioning, fatigue, and the association between patient, tumor- and treatment-related factors and these outcomes. METHODS: Children (4-18 years) after treatment for a brain tumor between 2005 and 2014 at the Erasmus Medical Center, Rotterdam, the Netherlands, were eligible. The parent-reported Child and Family Follow-up Survey developed to measure participation and impairments in functioning in youth with acquired brain injury, was used. Fatigue was assessed using the Pediatric Quality of Life Inventory Multidimensional Fatigue Scale. Associations with patient, tumor- and treatment-related factors were explored using univariable analyses. RESULTS: Ninety-one PBTS (median age: 11.3 years [range: 9.5-14.1], time since treatment: 3.9 years [range: 4-6.2]) were included (response rate: 55%). Participation limitations were reported in 53% and were associated with impairments in functioning (15-67%) (P ≤ .01) and fatigue (P ≤ .03).Parent- and child-reported fatigue was increased compared to normative values (P ≤ .02). History of hydrocephalus was associated with increased fatigue (P ≤ .04). Younger age at diagnosis and longer time since diagnosis were associated with impairments in functioning and cognitive fatigue (P < .05).Participation limitations, impairments in functioning and fatigue were similar in PBTS who were <3 or ≥3 years since completion of treatment. CONCLUSION: More than half of PBTS reported limited participation ability, which is associated with impairments in functioning and fatigue. The complication hydrocephalus seems to lead to more fatigue. Participation limitations, impairments in functioning and fatigue appear not to diminish in the longer term.

Various components of the insulin-like growth factor system in tumor tissue, cerebrospinal fluid and peripheral blood of pediatric medulloblastoma and ependymoma patients.

The insulin-like growth factor (IGF) system plays an important role in neuronal development and may contribute to the development of brain tumors. In this study, we studied mRNA expression levels of IGFs, insulin-like growth factor binding proteins (IGFBPs) and insulin-like growth factor receptors (IGFRs) in 27 pediatric medulloblastomas, 13 pediatric ependymomas and 5 control cerebella. Compared to normal cerebellum, mRNA levels of IGFBP-2 and IGFBP-3 were significantly increased in medulloblastomas and ependymomas. IGFBP-2 expression was indicative of poor prognosis in medulloblastomas, whereas IGFBP-3 mRNA levels were especially high in anaplastic ependymomas. IGFBP-5 and IGF-II mRNA levels were significantly increased in ependymomas compared to control cerebellum. Protein expression levels of IGFs and IGFBPs were analyzed in the cerebrospinal fluid (CSF) of 16 medulloblastoma, 4 ependymoma and 23 control patients by radioimmuno assay to determine whether they could be used as markers for residual disease after surgery. No aberrant CSF protein expression levels were found for ependymoma patients. In medulloblastoma patients, the IGFBP-3 protein levels were significantly higher than in ependymoma patients and controls. Moreover, enhanced levels of proteolytic fragments of IGFBP-3 were found in the CSF of medulloblastoma patients, being in concordance with a significantly increased IGFBP-3 proteolytic activity in the CSF of these patients. In conclusion, our data suggest that the IGF system is of importance in pediatric medulloblastomas and ependymomas. Larger studies should be conducted to validate the predictive values of the levels of intact IGFBP-3 and proteolytic fragments in CSF in the follow-up of medulloblastomas.

Differential expression and prognostic significance of SOX genes in pediatric medulloblastoma and ependymoma identified by microarray analysis.

The objective of this study was to identify differentially expressed and prognostically important genes in pediatric medulloblastoma and pediatric ependymoma by Affymetrix microarray analysis. Among the most discriminative genes, three members of the SOX transcription factor family were differentially expressed. Both SOX4 and SOX11 were significantly overexpressed in medulloblastoma (median, 11-fold and 5-fold, respectively) compared with ependymoma and normal cerebellum. SOX9 had greater expression in ependymoma (median, 16-fold) compared with normal cerebellum and medulloblastoma (p<0.001 for all comparisons). The differential expression of the SOX genes was confirmed at the protein level by immunohistochemical analysis. Survival analysis of the most discriminative probe sets for each subgroup showed that 35 and 13 probe sets were predictive of survival in patients with medulloblastoma and ependymoma, respectively. There was a trend toward better survival with increasing SOX4 expression in medulloblastoma. SOX9 expression was predictive for favorable outcome in ependymoma. The mRNA levels of BCAT1, a mediator of amino acid breakdown, were higher (median, 15-fold) in medulloblastoma patients with metastases compared with those without metastasized disease (p<0.01). However, the correlation between BCAT1 expression and metastatic medulloblastoma could not be confirmed at the protein level. The potential prognostic effect of the genes associated with outcome should be evaluated in ongoing studies using larger groups of patients. Furthermore, our findings support further analysis of the functional properties of the selected genes, especially SOX4 and BCAT1 for medulloblastoma and SOX9 for ependymoma, to evaluate the use of these genes as potential tumor markers, prognostic markers, and drug targets in pediatric brain tumors.

Increased total-Tau levels in cerebrospinal fluid of pediatric hydrocephalus and brain tumor patients.

Total Tau (t-Tau), hyperphosphorylated Tau (p-Tau(181P)) and beta-amyloid(1-42) in cerebrospinal fluid (CSF) have shown to be markers of neuronal and axonal degeneration in various neurological and neurodegenerative diseases. The aim of this study was to evaluate the influence of the presence of a brain tumor and hydrocephalus on t-Tau, p-Tau(181P) and beta-amyloid(1-42) levels in CSF of pediatric patients. t-Tau, p-Tau(181P) and beta-amyloid(1-42) levels were simultaneously quantified by xMAP technology in 22 lumbar and 15 ventricular CSF samples from newly diagnosed pediatric brain tumor patients and 39 lumbar and 12 ventricular CSF samples from pediatric patients without a brain tumor. t-Tau, p-Tau(181P) and beta-amyloid(1-42) levels in both lumbar and ventricular CSF were not significantly correlated with age. t-Tau levels in lumbar CSF were elevated in brain tumor patients, being especially high in medulloblastoma patients. Lumbar CSF p-Tau(181P) levels were lower in brain tumor patients compared to normal controls. Ventricular levels of t-Tau, p-Tau(181P) and beta-amyloid(1-42) were not significantly different between the brain tumor patients and non-tumor patients, but t-Tau levels were significantly increased in patients with radiological signs of hydrocephalus. Two patients with an infected ventriculo-peritoneal drain also had high CSF t-Tau levels. In conclusion, high t-Tau levels in CSF are found in pediatric patients with a brain tumor, patients with hydrocephalus and patients with a serious CNS infection, reflecting neuronal and axonal damage. Ongoing studies should determine whether these neurodegenerative markers in CSF can be used to monitor neuronal and axonal degeneration in these patients during therapy and long-term follow up.

Identification of novel biomarkers in pediatric primitive neuroectodermal tumors and ependymomas by proteome-wide analysis.

The aim of this study was to identify aberrantly expressed proteins in pediatric primitive neuroectodermal tumors (PNETs) and ependymomas. Tumor tissue of 29 PNET and 12 ependymoma patients was subjected to 2-dimensional difference gel electrophoresis. Gel analysis resulted in 79 protein spots being differentially expressed between PNETs and ependymomas (p < 0.01, fold change difference in expression >2). Three proteins, stathmin, annexin A1, and calcyphosine, were chosen for validation by immunohistochemistry. Stathmin was expressed 2.6-fold higher in PNETs than in ependymomas, and annexin A1 and calcyphosine were expressed 2.5- and 37.6-fold higher, respectively, in ependymomas. All PNETs showed strong staining for stathmin, and all ependymomas were strongly positive for annexin A1, whereas control tissues were negative. Calcyphosine immunoreactivity was observed in 59% of the ependymomas and was most profound in ependymoma tissue showing epithelial differentiation. mRNA expression levels of stathmin, annexin A1, and calcyphosine significantly correlated (Rs = 0.65 [p < 0.0001], Rs = 0.50 [p = 0.001], and Rs = 0.72 [p < 0.0001], respectively) with protein expression levels. In conclusion, using a proteome-wide approach, stathmin, annexin A1, and calcyphosine were successfully identified as tumor-specific proteins in pediatric PNETs and ependymomas. Ongoing studies are focused on characterizing the role of these proteins as tumor markers and potential drug targets in pediatric brain tumors.

Biallelic germline mutations of mismatch-repair genes: a possible cause for multiple pediatric malignancies.

BACKGROUND: Heterozygous defects in mismatch-repair (MMR) genes cause hereditary nonpolyposis colorectal cancer (HNPCC). In this syndrome, tumors typically arise from age 25 years onward. Case reports have shown that homozygosity or compound heterozygosity for MMR gene mutations can cause multiple tumors in childhood, sometimes combined with neurofibromatosis type I (NF1)-like features. Therefore, the authors studied the role of homozygosity or compound heterozygosity (CZ) for MMR gene defects in children with multiple primary tumors. METHODS: A database that contained all pediatric oncology patients who were seen between 1982 and 2003 at the author's institution was queried to identify patients aged <16 years with more than 1 tumor for whom tissue of at least 1 tumor was available. On isolated DNA, microsatellite instability (MSI) and immunohistochemistry of MMR proteins were assessed. RESULTS: In total, 15 patients with more than 1 tumor were identified. Abnormal test results were obtained in 2 of them, including 1 patient who was diagnosed at age 4 years with a glioblastoma (MSI-stable; no human mutL homolog 1 [MLH1] or postmeiotic segregation increased, Saccharomyces cerevisiae 2 [PMS2] expression) and a Wilms tumor (high MSI; no MLH1 or PMS2 expression). Apart from >6 cafe-au-lait spots, he had no other signs of NF1. The patient had CZ identified for a pathogenic MLH1 mutation (593delAG frameshift) and an unclassified MLH1 variant (Met35Asn). There was strong evidence that this unclassified variant was a pathogenic mutation. The second patient was diagnosed with a non-Hodgkin lymphoma (no tissue available) and an anaplastic oligodendroglioma (low MSI; no MSH6 expression) at age 4 years and 6 years, respectively. His brother had died of a medulloblastoma at age 6 years (low MSI, no MSH6 expression). Both boys had cafe-au-lait spots. Further genetic testing was not possible. CONCLUSIONS: Carriage of biallelic MMR gene defects can be associated with multiple malignancies in childhood that may differ from the standard spectrum of HNPCC tumor types. In 15 pediatric patients with multiple malignancies, the authors identified 1 clear case and 1 possible case of biallelic MMR gene defect. Recognition of the inherited nature of the tumors in these patients is important for counseling these patients and their families.

Functional outcome after low-grade astrocytoma treatment in childhood.

BACKGROUND: The relatively high survival rate of patients with low-grade astrocytoma necessitates increasing attention to physical and psychosocial outcomes. The objective of the current study was to investigate functional outcomes among children who were treated for low-grade or pilocytic astrocytoma in different areas of the brain. METHODS: Functional outcomes were evaluated in the following domains: impairments, disabilities, handicaps, and quality of life (QOL). In a consecutive series, 38 children were included. Follow-up ranged from 3 years and 7 months to 11 years and 4 months after diagnosis. RESULTS: Approximately 61% of children had impairments and 10% had a severe disability. Handicaps were found in the domains of relationships, school, and behavior. Children who were treated for supratentorial tumors required significantly more special education, and children who were treated for infratentorial tumors had significantly more behavioral and social problems. QOL was decreased significantly in all domains except emotions. Children who had a diagnosis in adolescence reported a lower QOL in social functioning compared with younger children. Data analysis revealed that some deficits suddenly became apparent years after diagnosis. CONCLUSIONS: At long-term follow-up, children who had low-grade or pilocytic astrocytomas were found to have poor functional outcomes, depending on tumor site, age, and recurrence. Children without deficits may develop severe cognitive, social, and behavioral deficits years after diagnosis, because of the phenomenon of "growing into deficit." Therefore, the authors suggest a long-term follow-up of children who are treated for low-grade or pilocytic astrocytomas at a young age to detect and subsequently offer support focused on the medical and cognitive impairments as well as on the behavioral and social consequences of their disease.

Identification of apolipoprotein A-II in cerebrospinal fluid of pediatric brain tumor patients by protein expression profiling.

BACKGROUND: Our aim was to detect differences in protein expression profiles of cerebrospinal fluid (CSF) from pediatric patients with and without brain tumors. METHODS: We used surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry and Q10 ProteinChip arrays to compare protein expression profiles of CSF from 32 pediatric brain tumor patients and 70 pediatric control patients. A protein with high discriminatory power was isolated and identified by subsequent anion-exchange and reversed-phase fractionation, gel electrophoresis, and mass spectrometry. The identity of the protein was confirmed by Western blotting and immunohistochemistry. RESULTS: Of the 247 detected protein peak clusters, 123 were differentially expressed between brain tumor and control patients with a false discovery rate of 1%. Double-loop classification analysis gave a mean prediction accuracy of 88% in discriminating brain tumor patients from control patients. From the 123 clusters, a highly overexpressed protein peak cluster in CSF from brain tumor patients was selected for further analysis and identified as apolipoprotein A-II. Apolipoprotein A-II expression in CSF was correlated with the CSF albumin concentration, suggesting that the overexpression of apolipoprotein A-II is related to a disrupted blood-brain barrier. CONCLUSIONS: SELDI-TOF mass spectrometry can be successfully used to find differentially expressed proteins in CSF of pediatric brain tumor and control patients. Apolipoprotein A-II is highly overexpressed in CSF of pediatric brain tumor patients, which most likely is related to a disrupted blood-brain barrier. Ongoing studies are aimed at finding subtype specific proteins in larger groups of pediatric brain tumor patients.