Pediatric brain tumors

Association analysis of genetic polymorphisms of METTL3 with clinical outcomes in a Chinese pediatric population with primary brain tumors

BACKGROUND

Methyltransferase-like 3 (METTL3) regulates numerous biological processes and diverse cancers.

OBJECTIVE

To explore the frequency distribution of METTL3 rs1061026, rs1139130, and rs1263801 polymorphisms, and their potential impacts on clinical outcomes and chemotherapy-induced toxicities in a cohort of Chinese pediatric patients diagnosed with primary brain tumors (PBTs).

METHODS

Genotyping for three investigated SNPs was performed in 107 pediatric patients with PBTs using the Sequenom MassARRAY iPLEX platform. Serum METTL3 levels were determined by Enzyme-Linked Immunosorbent Assay. Serum methotrexate (MTX) concentrations were quantified utilizing fluorescence polarization immunoassay.

RESULTS

The three investigated SNPs were not significantly associated with the risks of relapse and metastasis after adjusting all confounders. Compared to individuals with the rs1139130 GG genotype, GA genotype carriers exhibited a significantly higher risk of oral mucositis (adjusted OR: 7.504; 95 % CI, 1.931-29.436; P = 0.004). The rs1139130 GA (adjusted OR: 5.091; 95 % CI, 1.351-19.176; P = 0.016) and AA (adjusted OR: 9.588; 95 % CI, 1.769-51.949; P = 0.009) genotype carriers exhibited a significantly lower risk of fever than GG genotype carriers. The median dose-normalized MTX concentrations at 42 h were lower with borderline significance in children with rs1061026 GT and GG genotypes (0.004 μmol/L per g/m2) than the TT genotype carriers (0.006 μmol/L per g/m2, P = 0.048). Patients with the rs1139130 GA genotype had significantly higher median serum METTL3 protein levels (59.91 ng/mL) than GG genotype carriers (44.57 ng/mL, P = 0.015).

CONCLUSION

This study demonstrated the association of the rs1139130 polymorphism with the development of oral mucositis and fever and the rs1061026 polymorphism with MTX exposure.

Intra-tumoral hemorrhage after endoscopic third ventriculostomy in a child with WNT-activated medulloblastoma: case report and literature review

Intratumoral hemorrhage is a known complication of cerebrospinal fluid (CSF) drainage surgeries, such as ventriculoperitoneal shunts or external ventricular drainage, which are usually associated with upward herniation of the posterior fossa contents. In contrast, this is extremely rare after an endoscopic third ventriculostomy (ETV). This technique should drain the CSF in a more physiological way by limiting the pressure gradient between the infratentorial and supratentorial compartments, thus avoiding upward herniation of the tumor and intratumoral hemorrhage. Only three cases of intratumoral hemorrhage after ETV have been reported in the literature. Here, we describe a 9-year-old boy affected by hydrocephalus secondary to a large posterior fossa tumor who presented intratumoral hemorrhage after ETV. He required urgent hematoma evacuation and tumor removal. Histological and molecular diagnosis was WNT-activated medulloblastoma, a tumor associated with an increased risk of hemorrhage.

Evaluation of Acute Ataxia in the Pediatric Emergency Department: Etiologies and Red Flags

BACKGROUND

We aimed to evaluate patients with acute ataxia and to determine the warning clinical factors in the early prediction of neurological emergencies.

METHOD

Patients with a history of balance and gait coordination disorder and clinically diagnosed as acute ataxia in pediatric emergency department were included in the study. As a result of final diagnosis, the characteristics of patients with and without clinically urgent neurological pathology (CUNP) were compared. CUNP was defined as any nervous system disorder requiring early diagnosis and prompt medical or surgical treatment and/or intensive care unit admission to prevent disabling or life-threatening evolution.

RESULTS

Eighty-eight patients with a median age of 5 years were included in the study (37 [42%] patients with CUNP and 51 [58%] without CUNP). In the CUNP group, the median age of patients and symptom duration were significantly higher (P < 0.001 and P = 0.011, respectively). The most common etiologies were acute post/parainfectious cerebellar ataxias (n = 40 [45.4%]), acute cerebellitis (n = 9 [10.2%]), and Guillain-Barré syndrome (n = 8 [9%]). Hyporeflexia/areflexia and dysmetria were associated with a higher risk of CUNP. Headache, loss of consciousness, and visual dysfunction were the findings appearing exclusively in patients with CUNP.

CONCLUSIONS

The most common etiologies in acute ataxia are benign and transient, whereas life-threatening conditions may occur rarely and may require urgent intervention. Older age; prolonged symptom duration; focal neurological deficits such as hemiparesis, hyporeflexia, and visual impairment; and nonspecific findings such as loss of consciousness and headache are the most striking "red flags" of a potential neurological emergency and should alert clinicians to CUNP.

Epidemiology of pediatric central nervous system tumors in Uyghur: experience from a single center

PURPOSE

Retrospective analysis of clinical and epidemiological characteristics of central nervous system (CNS)tumors in Uyghur children from a single center in Xinjiang.

METHODS

Between January 2013 and December 2021, 243 children (0-17 years old) with a clear pathological type of CNS tumor are collected and analyzed for tumor size, grade, and category, as well as their relationship with the child's gender, age, and region of origin according to the 2021 edition of the new WHO CNS tumor classification.

OUTCOME

The 243 cases of CNS tumors in Uyghur children are predominantly from rural areas, with 144 cases (59.26%) of supratentorial tumors and 129 cases (53.09%) of low-grade tumors. With an overall male-to-female ratio of 1.43:1, a peak age of incidence of 6 to 8 years.

CONCLUDING

The present study is based on a 9-year analysis of pediatric CNS data from a single center, and the center is the largest tertiary hospital in Xinjiang with large numbers of admitted patients, which may reflect some extent the clinical characteristics and epidemiological features characteristics of pediatric CNS tumors in Uyghur in Xinjiang.

The Complexity of the Blood-Brain Barrier and the Concept of Age-Related Brain Targeting: Challenges and Potential of Novel Solid Lipid-Based Formulations

Diseases that affect the Central Nervous System (CNS) are one of the most exciting challenges of recent years, as they are ubiquitous and affect all ages. Although these disorders show different etiologies, all treatments share the same difficulty represented by the Blood-Brain Barrier (BBB). This barrier acts as a protective system of the delicate cerebral microenvironment, isolating it and making extremely arduous delivering drugs to the brain. To overtake the obstacles provided by the BBB it is essential to explore the changes that affect it, to understand how to exploit these findings in the study and design of innovative brain targeted formulations. Interestingly, the concept of age-related targeting could prove to be a winning choice, as it allows to consider the type of treatment according to the different needs and peculiarities depending on the disease and the age of onset. In this review was considered the prospective contribution of lipid-based formulations, namely Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs), which have been highlighted as able to overcome some limitations of other innovative approaches, thus representing a promising strategy for the non-invasive specific treatment of CNS-related diseases.

NeuroD1 Dictates Tumor Cell Differentiation in Medulloblastoma

Tumor cells are characterized by unlimited proliferation and perturbed differentiation. Using single-cell RNA sequencing, we demonstrate that tumor cells in medulloblastoma (MB) retain their capacity to differentiate in a similar way as their normal originating cells, cerebellar granule neuron precursors. Once they differentiate, MB cells permanently lose their proliferative capacity and tumorigenic potential. Differentiated MB cells highly express NeuroD1, a helix-loop-helix transcription factor, and forced expression of NeuroD1 promotes the differentiation of MB cells. The expression of NeuroD1 in bulk MB cells is repressed by trimethylation of histone 3 lysine-27 (H3K27me3). Inhibition of the histone lysine methyltransferase EZH2 prevents H3K27 trimethylation, resulting in increased NeuroD1 expression and enhanced differentiation in MB cells, which consequently reduces tumor growth. These studies reveal the mechanisms underlying MB cell differentiation and provide rationales to treat MB (potentially other malignancies) by stimulating tumor cell differentiation.

Cheng et al. demonstrate that medulloblastoma cells retain the capacity to undergo differentiation. The differentiation of tumor cells is regulated by NeuroD1 expression, which is repressed by H3K27me3 in tumor cells. EZH2 inhibitors suppress medulloblastoma growth by stimulating tumor cell differentiation.

Recent advances in iron oxide nanoparticles for brain cancer theranostics: from in vitro to clinical applications

Introduction: Today, the development of multifunctional nanoplatforms is more seriously considered in the field of cancer theranostics.Areas covered: In this respect, nanoparticles provide several advantages over the routine, conventional diagnostic methods, and treatments. Due to the expedient properties of iron oxide nanoparticles, such as being readily modified, great payload potential, intrinsic magnetic qualification, considerable biocompatibility, and overwhelming response to targeting strategies, these nanoparticles can be considered good candidates for application as diagnostic contrast agents and drug/gene delivery vehicles, while also being incorporated into hyperthermia-based approaches. Interestingly, these agents are detectable with routine imaging modalities such as magnetic resonance imaging.Expert opinion: Therefore, combining the traditional diagnostics and therapies with nanotechnological approaches may leave a positive impact on the survival rate of patients with cancer. This review summarizes the application of magnetic iron oxide nanoparticles in both in vitro and in vivo models of brain tumors.

Cancer and Tumor-Associated Childhood Stroke: Results From the International Pediatric Stroke Study

BACKGROUND

The prevalence of cancer among children with stroke is unknown. This study sought to evaluate cancer- and tumor-associated childhood ischemic stroke in a multinational pediatric stroke registry.

METHODS

Children aged 29 days to less than 19 years with arterial ischemic stroke or cerebral sinovenous thrombosis enrolled in the International Pediatric Stroke Study between January 2003 and June 2019 were included. Data including stroke treatment and recurrence were compared between subjects with and without cancer using Wilcoxon rank sum and chi-square tests.

RESULTS

Cancer or tumor was present in 99 of 2968 children (3.3%) with arterial ischemic stroke and 64 of 596 children (10.7%) with cerebral sinovenous thrombosis. Among children in whom cancer type was identified, 42 of 88 arterial ischemic stroke cases (48%) had brain tumors and 35 (40%) had hematologic malignancies; 45 of 58 cerebral sinovenous thrombosis cases (78%) had hematologic malignancies and eight (14%) had brain tumors. Of 54 cancer-associated arterial ischemic stroke cases with a known cause, 34 (63%) were due to arteriopathy and nine (17%) were due to cardioembolism. Of 46 cancer-associated cerebral sinovenous thrombosis cases with a known cause, 41 (89%) were related to chemotherapy-induced or other prothrombotic states. Children with cancer were less likely than children without cancer to receive antithrombotic therapy for arterial ischemic stroke (58% vs 80%, P = 0.007) and anticoagulation for cerebral sinovenous thrombosis (71% vs 87%, P = 0.046). Recurrent arterial ischemic stroke (5% vs 2%, P = 0.04) and cerebral sinovenous thrombosis (5% vs 1%, P = 0.006) were more common among children with cancer.

CONCLUSIONS

Cancer is an important risk factor for incident and recurrent childhood stroke. Stroke prevention strategies for children with cancer are needed.

Surgical approaches in pediatric neuro-oncology

Tumors of the central nervous system comprise nearly a quarter of all childhood cancers and are the most frequent solid tumor in the pediatric population. The most common location is in the posterior fossa, but tumors can occur anywhere intracranially. The spectrum of lesions encountered varies, from being completely benign and requiring surveillance alone to being highly malignant and requiring aggressive treatment in the form of surgery and adjuvant therapy. The extent of resection plays a crucial role in the oncological outcome of many of these tumors. A variety of surgical approaches are available for the spectrum of lesions encountered. This review focuses on summarizing the location, types, and neurosurgical management strategies for pediatric brain intracranial brain tumors. Here, we discuss neurosurgical approaches for a variety of brain tumors and regions, including the management of tumors of the posterior fossa, brainstem, pineal region, intraventricular region, sellar and suprasellar regions, optic pathway and hypothalamus, and supratentorial hemispheres.

Leukotriene Synthesis Is Critical for Medulloblastoma Progression

PURPOSE

Here, we examined the role of leukotrienes, well-known inflammatory mediators, in the tumorigenesis of hedgehog pathway-associated medulloblastoma, and tested the efficacies of antagonists of leukotriene biosynthesis in medulloblastoma treatment.Experimental Design: We examined the leukotriene levels in medulloblastoma cells by ELISA. We next tested whether leukotriene synthesis in medulloblastoma cells relied on activation of hedgehog pathway, or the presence of hedgehog ligand secreted by astrocytes. We then investigated whether leukotriene mediated hedgehog-induced Nestin expression in tumor cells. The functions of leukotriene in tumor cell proliferation and tumor growth in medulloblastoma were determined through knocking down 5-lipoxygenase (a critical enzyme for leukotriene synthesis) by shRNAs, or using 5-lipoxygenase-deficient mice. Finally, the efficacies of antagonists of leukotriene synthesis in medulloblastoma treatment were tested in vivo and in vitro.

RESULTS

Leukotriene was significantly upregulated in medulloblastoma cells. Increased leukotriene synthesis relied on hedgehog ligand secreted by astrocytes, a major component of medulloblastoma microenvironment. Leukotriene stimulated tumor cells to express Nestin, a cytoskeletal protein essential for medulloblastoma growth. Genetic blockage of leukotriene synthesis dramatically suppressed medulloblastoma cell proliferation and tumor growth in vivo. Pharmaceutical inhibition of leukotriene synthesis markedly repressed medulloblastoma cell proliferation, but had no effect on proliferation of normal neuronal progenitors. Moreover, antagonists of leukotriene synthesis exhibited promising tumor inhibitory efficacies on drug-resistant medulloblastoma.

CONCLUSIONS

Our findings reveal a novel signaling pathway that is critical for medulloblastoma cell proliferation and tumor progression, and that leukotriene biosynthesis represents a promising therapeutic target for medulloblastoma treatment.

Feasibility study of brain tumor delineation using immunolabeled gold nanorods

Effective treatment of patients with malignant brain tumors requires surgical resection of a high percentage of the bulk tumor. Surgeons require a method that enables delineation of tumor margins, which are not visually distinct by eye. In this study, the feasibility of using gold nanorods (GNRs) for this purpose is evaluated. Anti-Epidermal Growth Factor Receptor (anti-EGFR) conjugated GNRs are used to label human xenograft glioblastoma multiforme (GBM) tumors embedded within slices of brain tissues from healthy nude mice. The anti-EGFR GNRs exhibit enhanced absorption at red to near-infrared wavelengths, often referred to as the tissue optical window, where absorption from blood is minimal. To enable definition of molecular specificity and spatial accuracy of the label, the GNR absorption is compared with GFP fluorescence which is expressed by the GBM cells used here. This work demonstrates a simple but highly translational technique to classify normal and malignant brain tissue regions in open surgery applications using immunolabeled GNR contrast agents.

Overcoming the blood-brain barrier in chemotherapy treatment of pediatric brain tumors

Pediatric brain tumors are most common cancers in childhood and among the leading causes of death in children. Chemotherapy has been used as adjuvant (i.e. after) or neoadjuvant (i.e. before) therapy to surgery and radiotherapy for the management of pediatric brain tumors for more than four decades and gained more attention in the recent two decades. Although chemotherapy has demonstrated its effectiveness in the management of some pediatric brain tumors, failure or inactiveness of chemotherapy is commonly met in the clinics and clinical trials. Some of these failures might be attributed to the blood-brain barrier (BBB), limiting the penetration of systemically administered chemotherapeutics into pediatric brain tumors. Therefore, various strategies have been developed and used to address this issue. Herein, we review different methods reported in the literature to circumvent the BBB for enhancing the present of chemotherapeutics in the brain to treat pediatric brain tumors.

Development of an in-home standardized end-of-life treatment program for pediatric patients dying of brain tumors

PURPOSE

To evaluate an end-of-life (EOL) program related to specific outcomes (i.e., number of hospitalizations and place of death) for children with brain tumors.

DESIGN AND METHODS

From 1990 to 2005, a retrospective chart review was performed related to specified outcomes for 166 children with admission for pediatric brain tumors.

RESULTS

Patients who received the EOL program were hospitalized less often (n = 114; chi-square = 5.001 with df = 1, p <.05) than patients who did not receive the program.

PRACTICE IMPLICATIONS

An EOL program may improve symptom management and decrease required hospital admissions for children with brain tumors.

Nanoparticles for imaging and treating brain cancer

Brain cancer tumors cause disruption of the selective properties of vascular endothelia, even causing disruptions in the very selective blood-brain barrier, which are collectively referred to as the blood-brain-tumor barrier. Nanoparticles (NPs) have previously shown great promise in taking advantage of this increased vascular permeability in other cancers, which results in increased accumulation in these cancers over time due to the accompanying loss of an effective lymph system. NPs have therefore attracted increased attention for treating brain cancer. While this research is just beginning, there have been many successes demonstrated thus far in both the laboratory and clinical setting. This review serves to present the reader with an overview of NPs for treating brain cancer and to provide an outlook on what may come in the future. For NPs, just like the blood-brain-tumor barrier, the future is wide open.

Diffuse reflectance spectroscopy for in vivo pediatric brain tumor detection

The concept of using diffuse reflectance spectroscopy to distinguish intraoperatively between pediatric brain tumors and normal brain parenchyma at the edge of resection cavities is evaluated using an in vivo human study. Diffuse reflectance spectra are acquired from normal and tumorous brain areas of 12 pediatric patients during their tumor resection procedures, using a spectroscopic system with a handheld optical probe. A total of 400 spectra are acquired at the rate of 33 Hz from a single investigated site, from which the mean spectrum and the standard deviation are calculated. The mean diffuse reflectance spectra collected are divided into the normal and the tumorous categories in accordance with their corresponding results of histological analysis. Statistical methods are used to identify those spectral features that effectively separated the two tissue categories, and to quantify the spectral variations induced by the motion of the handheld probe during a single spectral acquisition procedure. The results show that diffuse reflectance spectral intensities between 600 and 800 nm are effective in terms of differentiating normal cortex from brain tumors. Furthermore, probe movements induce large variations in spectral intensities (i.e., larger standard deviation) between 400 and 600 nm.

On the death Trk

The trk family of receptor tyrosine kinases supports survival and differentiation in the nervous system. Paradoxically it has also been shown that members of the trk family can induce cell death in pediatric tumor cells of neuronal origin. Moreover, TrkA and TrkC serve as good prognostic indicators in neuroblastoma and medulloblatoma, respectively. Although the possible linkage between these observations was intriguing, until recently there was limited insight on the mechanisms involved. Recent findings suggest that TrkA might influence neuronal cell death through stimulation of p75 cleavage. An alternative p75-independent mechanism was suggested by a newly discovered interaction between TrkA and CCM2 (the protein product of the gene cerebral cavernous malformation 2). Coexpression of CCM2 with TrkA induces cell death in medulloblastoma and neuroblastoma cells, and CCM2 expression levels correlate with those of TrkA and with good prognosis in neuroblastoma patients. Thus, mechanistic clues to the enigma of trk-induced cell death have begun to emerge. Detailed elucidation of these mechanisms and their in vivo physiological significance will be of keen interest for future research.

Update on diagnostic practice: tumors of the nervous system

CONTEXT

Changes in the practice of diagnosing brain tumors are formally reflected in the evolution of the World Health Organization classification. Beyond this classification, the practice of diagnostic pathology is also changing with the availability of new tests and the introduction of new treatment options.

OBJECTIVE

Glioblastomas, oligodendrogliomas, glioneuronal tumors, and primitive pediatric tumors are discussed in an exemplary way to illustrate these changes.

DATA SOURCES

Review of relevant publications through Medline database searches.

CONCLUSIONS

The example of glioblastomas shows how new predictive markers may help identify subgroups of tumors that respond to certain therapy regimens. The development of new treatment strategies also leads to different questions in the assessment of brain tumors, as seen in the example of pseudoprogression or the changes in tumor growth pattern in patients taking bevacizumab. Oligodendrogliomas illustrate how the identification of 1p/19q loss as a cytogenetic aberration aids our understanding of these tumors and changes diagnostic practice but also introduces new challenges in classification. Glioneuronal tumors are an evolving group of lesions. Besides a growing list of usually low-grade entities with well-defined morphologic features, these also include more poorly defined cases in which a component of infiltrating glioma is often associated with focal neuronal elements. The latter is biologically interesting but of uncertain clinical significance. Oligodendrogliomas and glioneuronal tumors both illustrate the importance of effective communication between the pathologist and the treating oncologist in the discussion of these patients. Finally, the discussion of primitive pediatric tumors stresses the clinical importance of the distinction between different entities, like atypical teratoid rhabdoid tumor, "central" (supratentorial) primitive neuroectodermal tumor, "peripheral" primitive neuroectodermal tumor, and medulloblastoma. In medulloblastomas, the recognition of different variants is emerging as a prognostic factor that may in the future also predict therapy responsiveness.

Current treatment approaches for infants with malignant central nervous system tumors

The management of brain tumors in very young children remains a challenge for neuro-oncologists in large part because of the greater vulnerability of the developing brain to treatment-related toxicity. Nearly three decades of infant brain tumor clinical trials have led to significant progress in the delineation of prognostic factors and improvements in outcome. Innovative strategies that employ high-dose chemotherapy, intrathecal chemotherapy, modified focal irradiation, or combinations of these have been used to delay or avoid the use of conventional craniospinal irradiation in order to minimize the risk for deleterious neurocognitive impairment in survivors. However, it is difficult to evaluate the impact of such approaches on intellectual and functional outcome, and results to date are limited. This review covers the most recent therapeutic advances for the most common histological subtypes of malignant infant brain tumors: medulloblastoma, supratentorial primitive neuroectodermal tumor, ependymoma, atypical teratoid rhabdoid tumor, choroid plexus carcinoma, and high-grade glioma. Survival and neurocognitive outcome are emphasized.

[Pediatric intensive care after brain tumor surgery]

INTRODUCTION

Primary brain tumors are the most common solid tumors in children. Surgery is the basis of treatment for these patients, who require postoperative admission to the ICU-P. The aim of this study was to at the epidemiology of brain tumors of patients admitted to our ICU-P and to analyze the progress of these children in the postoperative period.

PATIENTS AND METHODS

Retrospective-prospective study of children admitted to our unit after brain tumor surgery between January 1998 and January 2007. We collected information such as, personal details, clinical characteristics, type of intervention and postoperative period.

RESULTS

We reviewed 161 postoperative periods, corresponding to 134 patients (54.5% male). The mean age was 7 years and 8 months +/- 5 months. The most common location was the posterior fossa (44.8%). The most common histological type was low grade/intermediate astrocytoma (44.7%). The most frequent complication was diabetes insipidus (9.9%). Resection was complete in 58.4% patients. The median stay in the ICU-P was 2 days (0-61 days). 3 patients died after surgery.

CONCLUSIONS

The epidemiology of the group of patients admitted to our ICU-P is similar to the general population. The most common complication is diabetes insipidus.

Role of MRI in paediatric neurooncology

The investigation of children with suspected brain tumours has undergone major advances over the last few decades. MRI has become the primary imaging modality in the initial diagnosis and in follow up of established tumours. Some of the newer techniques are still in the evolutionary phase and not yet routinely used in all centres around the world. However, with the advent of the high field strength magnets and more sophisticated MRI techniques such as MR spectroscopy and MR perfusion, the potential for more rapid and accurate diagnosis is expanding.

Invasion suppressor cystatin E/M (CST6): high-level cell type-specific expression in normal brain and epigenetic silencing in gliomas

DNA hypermethylation-mediated gene silencing is a frequent and early contributor to aberrant cell growth and invasion in cancer. Malignant gliomas are the most common primary brain tumors in adults and the second most common tumor in children. Morbidity and mortality are high in glioma patients because tumors are resistant to treatment and are highly invasive into surrounding brain tissue rendering complete surgical resection impossible. Invasiveness is regulated by the interplay between secreted proteases (eg, cathepsins) and their endogenous inhibitors (cystatins). In our previous studies we identified cystatin E/M (CST6) as a frequent target of epigenetic silencing in glioma. Cystatin E/M is a potent inhibitor of cathepsin B, which is frequently overexpressed in glioma. Here, we study the expression of cystatin E/M in normal brain and show that it is highly and moderately expressed in oligodendrocytes and astrocytes, respectively, but not in neurons. Consistent with this, the CST6 promoter is hypomethylated in all normal samples using methylation-specific PCR, bisulfite genomic sequencing, and pyrosequencing. In contrast, 78% of 28 primary brain tumors demonstrated reduced/absent cystatin E/M expression using a tissue microarray and this reduced expression correlated with CST6 promoter hypermethylation. Interestingly, CST6 was expressed in neural stem cells (NSC) and markedly induced upon differentiation, whereas a glioma tumor initiating cell (TIC) line was completely blocked for CST6 expression by promoter methylation. Analysis of primary pediatric brain tumor-derived lines also showed CST6 downregulation and methylation in nearly 100% of 12 cases. Finally, ectopic expression of cystatin E/M in glioma lines reduced cell motility and invasion. These results demonstrate that epigenetic silencing of CST6 is frequent in adult and pediatric brain tumors and occurs in TICs, which are thought to give rise to the tumor. CST6 methylation may therefore represent a novel prognostic marker and therapeutic target specifically altered in TICs.

Outcome of pediatric pineoblastoma after surgery, radiation and chemotherapy

INTRODUCTION

Pineoblastomas are a category of supratentorial primitive neuroectodermal tumors (sPNETs) occurring in the pineal gland; some studies support the impression that patients with pineoblastomas have a worse prognosis than those with other sPNETs.

METHODS

We reviewed the medical records and tissue sections of all patients with the diagnosis of pineoblastoma that were treated at the Dana-Farber Cancer Institute/Children's Hospital Boston Pediatric Brain Tumor Program between 1986 and 2005.

RESULTS

Thirteen patients with the pathologic diagnosis of pineoblastoma were treated at our Hospital; 11 of these cases had complete records suitable for study. The median age was 8 years 8 months (5 F, 6 M). Surgical, radiation and chemotherapeutic regimens varied from case to case. Three patients had gross total resection and are alive and free of disease, versus four of eight with subtotal resection or biopsy only. Patients who received CSI and multi-agent chemotherapy had improved overall survival.

CONCLUSIONS

Seven of eleven patients with pineoblastoma are currently alive and free of disease, reflecting an improved outcome and longer survival than previously appreciated. Gross total surgical resection appeared to correlate with improved survival, as did treatment with craniospinal irradiation and multi-agent chemotherapy. Further study of this group of patients as a distinct diagnostic entity will be necessary to determine optimal therapy.

Surgical management of pediatric brain tumors

Brain tumors are the most common cause of cancer-related death and the second most common form of cancer in pediatric patients. Many of these tumors are treated primarily with surgery, either alone or in combination with radiation or chemotherapy. Recent advances have lead to greater survival and decreased morbidities in childhood brain tumor patients. A full understanding of the biology and primary treatment modalities for the particular tumor are essential for any professional treating these patients, including the neurosurgeon. Each tumor type has features in common with, and unique from, other tumors that need to be understood prior to undertaking a rational treatment plan. This article summarizes some of these features.

Natural progression of an unresected supratentorial ependymoma

Ependymomas are rare gliomas that have been associated with a poor outcome despite aggressive therapy including surgery, chemotherapy and radiation therapy. We present a case report of a 16-year-old male with an untreated supratentorial ependymoma that lay dormant for 15 years without significant morbidity. Supratentorial ependymomas are thought to have a better outcome than infratentorial ependymomas, primarily because of the increased likelihood of achieving a gross total resection in the supratentorial space. Our case report suggests that the improved outcome may be due in part to the biologically benign nature of some supratentorial ependymomas. This highly unusual case illustrates the unpredictable heterogeneity of pediatric ependymomas.

Cerebellar lesion studies of cognitive function in children and adolescents - limitations and negative findings

An increasing number of human lesion and functional brain imaging studies appear to support the hypothesis that the cerebellum contributes to a wide range of non-motor functions, including attention, language and visuospatial functions. Various abnormalities have been reported in standard neuropsychological tests in children and adolescents who have been treated for cerebellar tumors. This review focuses on limitations of lesion studies and negative findings in children and adolescents with focal cerebellar lesions. Frequently cited early findings have not been replicated in later studies or have been explained by motor components of the tasks. Such discrepancies may relate to a number of methodological problems. In addition to impaired motor function, it is unclear to what extent deficits in neuropsychological tests are caused by unspecific effects such as increased intracranial pressure and depression. Effects of extracerebellar lesions are frequently not considered. Although a role of the cerebellum in specific aspects of non-motor functions seems obvious it is still an open question which cognitive functions are involved, why and to what extent. It is a matter of ongoing discussion whether or not cognitive dysfunction belongs to the symptoms of cerebellar disease. Overall, disorders appear to be mild and far less frequent than disorders observed following lesions of cerebral areas. The aim of the review is to demonstrate that many findings frequently cited to support cerebellar involvement in cognition are insufficient to prove the hypothesis. There is ongoing need of well-controlled lesion studies, which show that disorders are due to cerebellar lesions independent of motor dysfunction and other confounding factors.

Ataxias

Gait disorders in elderly individuals are a major cause of falls and their attendant morbidities. Ataxia is one of the neurologic components of fall risk, as are inattention or confusion, visual impairment, vestibular impairment, subcortical white matter disease, parkinsonism, weakness, sensory loss, orthostasis or arrhythmia with alterations in blood pressure, pain, medication use, and environmental hazards. Ataxia in the geriatric population has many causes. Correctly identifying them can improve clinicians' ability to offer treatment and management strategies to patients and their families. The goals should be safe mobility and preserved activities of daily living.

An analysis of SEER data of increasing risk of secondary malignant neoplasms among long-term survivors of childhood brain tumors

BACKGROUND

Advances made in treatment of a childhood brain cancer have extended the lives of many children and adolescents. Treatment success, however, brings the opportunity to assess late effects; most worrying among these are secondary malignant neoplasms (SMN). Even though the cumulative incidence is quite small, long-term follow-up is required because treatment-induced cancers can occur years after initial treatment.

PROCEDURE

The purpose of this project was to determine what treatments and what host characteristics of children treated for a primary brain cancer are associated with an increase in the risk of a SMN in long-term survivors. Data were analyzed from 2,056 5-year survivors, of primary brain cancer in the surveillance, epidemiology, and end results (SEER) database between 1973 and 1998. Thirty-nine patients developed a SMN. Cox regression models were used to evaluate the independent contribution of a number of risk factors.

RESULTS

The most important risk factor for developing a SMN in 5-year survivors was the era in which the primary cancer was treated. Compared to treatment prior to 1979, patients treated between 1979 and 1984 had a 4.7-fold increase in risk (P = 0.001), while those treated after 1985 had a 6.7-fold increase in risk. (P = 0.002). Patients treated most recently carry the greatest risk of SMN development even after controlling for radiotherapy. This could be due to the increase in intensive treatment compared to earlier years.

CONCLUSION

Although the absolute excess risk of SMN remains quite low, continued surveillance is needed to evaluate long-term effects of new therapies for primary brain tumors.

Advances in the treatment of pediatric brain tumors

Brain tumors are a heterogeneous group of neoplasms with different origins, pathobiologies, treatments and prognoses. The collective contributions from the fields of neuro-oncology, neurosurgery, radiation oncology, neurology, neuropathology, neuroradiology and molecular biology have all led to significant advances in the treatment of certain brain tumors. Ideas from these fields, under the cooperative umbrella of clinical cancer trial consortia, have been tested in large-scale studies. As a result, patient survivals have increased markedly for these tumor types. Unfortunately, there are certain brain tumors in childhood, such as the diffuse intrinsic pontine glioma and atypical teratoid rhabdoid tumor, for which survival advantages have not been found. This review will discuss the current and possible future therapies of the most common pediatric brain tumors and highlight some of the novel imaging modalities that are used pre- and intraoperatively.

Fatal haemorrhage in medulloblastoma following ventricular drainage. Case report and review of the literature

Haemorrhage in medulloblastoma is reported to be very rare. The authors report a case of a 13-year-old boy who presented with headache, unsteadiness, diplopia and papilloedema due to posterior fossa medulloblastoma causing obstructive hydrocephalus. Six hours following placement of an external ventricular drain, he suddenly became comatose with respiratory arrest. The cause was marked upward herniation of the anterior vermis and downward herniation of the cerebellar tonsils due to massive spontaneous intratumoural haemorrhage extended into the ventricular system. This atypical clinical course of fatal haemorrhage in medulloblastoma after insertion of external ventricular drainage is reported and the literature discussed.

Brain tumors in children: evaluation and management

Brain and spinal cord tumors represent the most common solid tumors in children. Recent advances in imaging techniques, neurosurgical techniques, chemotherapy approaches, and radiation oncology have resulted in some improvement in overall survival and morbidity. However, the prognosis for many children with high-grade and malignant brain tumors remains guarded in terms of mortality and long-term sequelae. Given the rarity of tumors in children, patients are likely best served at tertiary center that can offer a comprehensive multidiscipline approach.

Comparison of gadobenate dimeglumine (Gd-BOPTA) with gadopentetate dimeglumine (Gd-DTPA) for enhanced MR imaging of brain and spine tumours in children

BACKGROUND

Gadobenate dimeglumine (Gd-BOPTA) demonstrates superior enhancement of brain tumours in adult patients than Gd-DTPA.

OBJECTIVE

To determine whether Gd-BOPTA has advantages over Gd-DTPA for enhanced MR imaging of paediatric brain and spine tumours.

MATERIALS AND METHODS

Sixty-three subjects, aged 6 months to 16 years, who were enrolled in a prospective, fully blinded, randomized parallel-group phase III clinical trial, received 0.1 mmol/kg doses of either Gd-BOPTA (n=29) or Gd-DTPA (n=34). The MR images were acquired before and within 10 min of contrast agent injection. The primary objective was to compare the difference from pre-dose to post-dose lesion visualization between Gd-BOPTA and Gd-DTPA. Lesion visualization was determined as the sum of individual scores for three criteria of lesion morphological characteristics (lesion border delineation, internal morphology, and contrast enhancement), each assessed qualitatively using 4-point scales. Quantitative evaluation compared changes in lesion-to-background (LBR) and contrast-to-noise (CNR) ratios and per cent enhancement. Monitoring for adverse events and evaluation of vital signs and laboratory values was performed.

RESULTS

Pre-dose to post-dose changes in lesion visualization were significantly better for Gd-BOPTA for both lesion level (2.68+/-2.17 vs. 1.05+/-1.90, P=0.0106) and patient level (2.55+/-2.18 vs. 1.14+/-1.68, P=0.0079) comparisons. The mean pre-dose to post-dose change in CNR was greater for Gd-BOPTA (9.13+/-15.36) than Gd-DTPA (2.18+/-9.90), but the difference was only marginally significant (P=0.0779; 95% CI: -0.553, 14.454) because of wide variations of signal intensity between lesions. Similar findings were obtained for LBR and per cent enhancement. No differences between the agents were noted in terms of safety parameters.

CONCLUSIONS

At an equivalent dose Gd-BOPTA is significantly better than Gd-DTPA for visualization of enhancing CNS tumours in paediatric patients.

Pediatric surgical neuro-oncology: current best care practices and strategies

Significant advances have been made in the diagnosis and treatment of childhood brain tumors. Gross total surgical resection combined with appropriate adjuvant therapies can achieve a high rate of disease control for low grade gliomas, ependymomas and medulloblastomas. High grade gliomas, tumors involving the optic apparatus or diencepahalic structures, diffuse brainstem lesions, and recurrent or metastatic disease still pose considerable therapeutic challenges. We review the current treatment strategies of the three most common types of pediatric brain tumors: gliomas, medulloblastomas and ependymomas, and discuss current and future diagnostic and therapeutic modalities.