Core deficits and quality of survival after childhood medulloblastoma: a review

Psychosocial and executive functioning late effects in pediatric brain tumor survivors after proton radiation

PURPOSE

Pediatric brain tumor survivors can experience detrimental effects from radiation treatment. This cross-sectional, large cohort study examined late psychosocial and executive functioning effects in pediatric patients treated ≥ 3 years after proton radiation therapy (PRT).

METHODS

Parents of 101 pediatric brain tumor survivors completed the Behavior Assessment System for Children and the Behavior Rating Inventory of Executive Function. Standard scores were compared to published normative means, rates of impairment (T-score > 65) were calculated, and demographic and clinical characteristics were examined.

RESULTS

Mean age at PRT was 8.12 years and mean interval from PRT to assessment was 6.05 years. Half were female (49.5%), 45.5% received craniospinal irradiation (CSI), and 58.4% were diagnosed with infratentorial tumors. All mean T-scores were within normal range. Mean T-scores were significantly elevated compared to the norm on the withdrawal, initiate, working memory, and plan/organize scales. Rates of impairment were notably high in working memory (24.8%), initiate (20.4%), withdrawal (18.1%), and plan/organize (17.0%). Greater withdrawal was significantly associated with CSI and also with chemotherapy and diagnosis of hearing loss. Mean T-scores were significantly lower than the norm on the hyperactivity, aggression, conduct problems, and inhibition scales. No significant problems were identified with social skills or depression. Interval since treatment was not correlated with any scale.

CONCLUSION

Although psychosocial and executive functioning was within the normal range, on average, social withdrawal and metacognitive executive functioning (working memory, initiating, planning/organizing) were areas of concern. Targeted yearly screening and proactive executive skill and social interventions are needed for this population.

Identification of a prognosis-related phagocytosis regulator gene signature in medulloblastoma

Objectives

The aims of this study were to screen for phagocytosis regulator-related genes in tissue samples from children with medulloblastoma (MB) and to construct a prognostic model based on those genes.

Methods

Differentially expressed genes between the MB and control groups were identified using the GSE50161 dataset from the Gene Expression Omnibus database. Prognosis-related phagocytosis regulator genes were selected from the GSE85217 dataset. Intersecting genes of the two datasets (differentially expressed prognosis-related phagocytosis regulator genes) were submitted to unsupervised cluster analysis to identify disease subtypes, after which the association between the subtypes and the immune microenvironment was analyzed. A prognostic risk score model was constructed, and functional, immune-related, and drug sensitivity analyses were performed.

Results

In total, 23 differentially expressed prognosis-related phagocytosis regulator genes were identified, from which two disease subtypes (clusters 1 and 2) were classified. The prognoses of the patients in cluster 2 were significantly worse than those of the patients in cluster 1. The immune microenvironment differed significantly between the two subtypes. Finally, 10 genes (FAM81A, EZR, NDUFB9, RCOR1, FOXO4, NHLRC2, KIF23, PTPN6, SMAGP, and MED13) were selected to establish the prognostic risk score model. The prognosis in the low-risk group was better than that in the high-risk group. The model genes NDUFB9 and PTPN6 were positively correlated with M2 macrophages.

Conclusion

Ten key phagocytosis regulator genes were screened to construct a prognostic model for MB. These genes may serve as key biomarkers for predicting the prognosis of patients with this type of brain cancer.

Multifunctional Fluoropolymer-Engineered Magnetic Nanoparticles to Facilitate Blood-Brain Barrier Penetration and Effective Gene Silencing in Medulloblastoma

Patients with brain cancers including medulloblastoma lack treatments that are effective long-term and without side effects. In this study, a multifunctional fluoropolymer-engineered iron oxide nanoparticle gene-therapeutic platform is presented to overcome these challenges. The fluoropolymers are designed and synthesized to incorporate various properties including robust anchoring moieties for efficient surface coating, cationic components to facilitate short interference RNA (siRNA) binding, and a fluorinated tail to ensure stability in serum. The blood-brain barrier (BBB) tailored system demonstrates enhanced BBB penetration, facilitates delivery of functionally active siRNA to medulloblastoma cells, and delivers a significant, almost complete block in protein expression within an in vitro extracellular acidic environment (pH 6.7) - as favored by most cancer cells. In vivo, it effectively crosses an intact BBB, provides contrast for magnetic resonance imaging (MRI), and delivers siRNA capable of slowing tumor growth without causing signs of toxicity - meaning it possesses a safe theranostic function. The pioneering methodology applied shows significant promise in the advancement of brain and tumor microenvironment-focused MRI-siRNA theranostics for the better treatment and diagnosis of medulloblastoma.

Intra-tumoral T cells in pediatric brain tumors display clonal expansion and effector properties

Brain tumors in children are a devastating disease in a high proportion of patients. Owing to inconsistent results in clinical trials in unstratified patients, the role of immunotherapy remains unclear. We performed an in-depth survey of the single-cell transcriptomes and clonal relationship of intra-tumoral T cells from children with brain tumors. Our results demonstrate that a large fraction of T cells in the tumor tissue are clonally expanded with the potential to recognize tumor antigens. Such clonally expanded T cells display enrichment of transcripts linked to effector function, tissue residency, immune checkpoints and signatures of neoantigen-specific T cells and immunotherapy response. We identify neoantigens in pediatric brain tumors and show that neoantigen-specific T cell gene signatures are linked to better survival outcomes. Notably, among the patients in our cohort, we observe substantial heterogeneity in the degree of clonal expansion and magnitude of T cell response. Our findings suggest that characterization of intra-tumoral T cell responses may enable selection of patients for immunotherapy, an approach that requires prospective validation in clinical trials.

Identification and validation of a metabolism-related gene signature for predicting the prognosis of paediatric medulloblastoma

Medulloblastoma (MB) is a malignant brain tumour that is highly common in children and has a tendency to spread to the brain and spinal cord. MB is thought to be a metabolically driven brain tumour. Understanding tumour cell metabolic patterns and characteristics can provide a promising foundation for understanding MB pathogenesis and developing treatments. Here, by analysing RNA-seq data of MB samples from the Gene Expression Omnibus (GEO) database, 12 differentially expressed metabolic-related genes (DE-MRGs) were chosen for the construction of a predictive risk score model for MB. This model demonstrated outstanding accuracy in predicting the outcomes of MB patients and served as a standalone predictor. An evaluation of functional enrichment revealed that the risk score showed enrichment in pathways related to cancer promotion and the immune response. In addition, a high risk score was an independent poor prognostic factor for MB in patients with different ages, sexes, metastasis stages and subgroups (SHH and Group 4). Consistently, the metabolic enzyme ornithine decarboxylase (ODC1) was upregulated in MB patients with poor survival time. Inhibition of ODC1 in primary and metastatic MB cell lines decreased cell proliferation, migration and invasion but increased immune infiltration. This study could aid in identifying metabolic targets for MB as well as optimizing risk stratification systems and individual treatment plans for MB patients via the use of a metabolism-related gene prognostic risk score signature.

Parent ratings of executive functioning in pediatric survivors of medulloblastoma and pilocytic astrocytoma

The present study compared parent-rated executive functioning in pediatric medulloblastoma (MB) and pilocytic astrocytoma (PA) survivors. Although standard care for both includes surgical resection, children with MB additionally receive chemotherapy and craniospinal irradiation. Given well-documented neurocognitive late effects associated with the latter, we anticipated poor parent-reported executive functioning in MB survivors. Parents/guardians of 36 MB survivors and 20 PA survivors completed the Behavior Rating Inventory of Executive Functioning (BRIEF). PA survivors were younger at diagnosis (t[51.97] = 3.07, p < .001, d = 0.86) and demonstrated higher IQ (t[54] = -3.51, p < .001, d = 0.95). However, relative to the MB group, the PA group was rated as having significantly more problems on all BRIEF scales (all p ≤ .05; d = 0.30 - 1.10), except the Shift scale. Additionally, all mean BRIEF scores for MB survivors were within normal limits, whereas for PA survivors, all mean BRIEF scores except for Organization of Materials were significantly discrepant from normative means. Overall, PA survivors were rated as demonstrating poorer executive function than MB survivors. Five theories are discussed as possible explanations for these surprising findings: two related to group differences, two related to potential sources of parental bias, and one related to the nature of questionnaire-based assessment. All these theories represent directions for future research. Parent questionnaires such as the BRIEF may have real-world implications for pediatric brain tumor survivors. Future research should explore factors affecting parent ratings of executive functioning in these populations, along with comparison to performance-based measures.

Transmorphic phage-guided systemic delivery of TNFα gene for the treatment of human pediatric medulloblastoma

Medulloblastoma is the most common childhood brain tumor with an unfavorable prognosis and limited options of harmful treatments that are associated with devastating long-term side effects. Therefore, the development of safe, noninvasive, and effective therapeutic approaches is required to save the quality of life of young medulloblastoma survivors. We postulated that therapeutic targeting is a solution. Thus, we used a recently designed tumor-targeted bacteriophage (phage)-derived particle, named transmorphic phage/AAV, TPA, to deliver a transgene expressing the tumor necrosis factor-alpha (TNFα) for targeted systemic therapy of medulloblastoma. This vector was engineered to display the double-cyclic RGD4C ligand to selectively target tumors after intravenous administration. Furthermore, the lack of native phage tropism in mammalian cells warrants safe and selective systemic delivery to the tumor microenvironment. In vitro RGD4C.TPA.TNFα treatment of human medulloblastoma cells generated efficient and selective TNFα expression, subsequently triggering cell death. Combination with the chemotherapeutic drug cisplatin used clinically against medulloblastoma resulted in augmented effect through the enhancement of TNFα gene expression. Systemic administration of RGD4C.TPA.TNFα to mice-bearing subcutaneous medulloblastoma xenografts resulted in selective tumor homing of these particles and consequently, targeted tumor expression of TNFα, apoptosis, and destruction of the tumor vasculature. Thus, our RGD4C.TPA.TNFα particle provides selective and efficient systemic delivery of TNFα to medulloblastoma, yielding a potential TNFα anti-medulloblastoma therapy while sparing healthy tissues from the systemic toxicity of this cytokine.

Molecular characterisation defines clinically-actionable heterogeneity within Group 4 medulloblastoma and improves disease risk-stratification

Group 4 tumours (MBGrp4) represent the majority of non-WNT/non-SHH medulloblastomas. Their clinical course is poorly predicted by current risk-factors. MBGrp4 molecular substructures have been identified (e.g. subgroups/cytogenetics/mutations), however their inter-relationships and potential to improve clinical sub-classification and risk-stratification remain undefined. We comprehensively characterised the paediatric MBGrp4 molecular landscape and determined its utility to improve clinical management. A clinically-annotated discovery cohort (n = 362 MBGrp4) was assembled from UK-CCLG institutions and SIOP-UKCCSG-PNET3, HIT-SIOP-PNET4 and PNET HR + 5 clinical trials. Molecular profiling was undertaken, integrating driver mutations, second-generation non-WNT/non-SHH subgroups (1-8) and whole-chromosome aberrations (WCAs). Survival models were derived for patients ≥ 3 years of age who received contemporary multi-modal therapies (n = 323). We first independently derived and validated a favourable-risk WCA group (WCA-FR) characterised by ≥ 2 features from chromosome 7 gain, 8 loss, and 11 loss. Remaining patients were high-risk (WCA-HR). Subgroups 6 and 7 were enriched for WCA-FR (p < 0·0001) and aneuploidy. Subgroup 8 was defined by predominantly balanced genomes with isolated isochromosome 17q (p < 0·0001). While no mutations were associated with outcome and overall mutational burden was low, WCA-HR harboured recurrent chromatin remodelling mutations (p = 0·007). Integration of methylation and WCA groups improved risk-stratification models and outperformed established prognostication schemes. Our MBGrp4 risk-stratification scheme defines: favourable-risk (non-metastatic disease and (i) subgroup 7 or (ii) WCA-FR (21% of patients, 5-year PFS 97%)), very-high-risk (metastatic disease with WCA-HR (36%, 5-year PFS 49%)) and high-risk (remaining patients; 43%, 5-year PFS 67%). These findings validated in an independent MBGrp4 cohort (n = 668). Importantly, our findings demonstrate that previously established disease-wide risk-features (i.e. LCA histology and MYC(N) amplification) have little prognostic relevance in MBGrp4 disease. Novel validated survival models, integrating clinical features, methylation and WCA groups, improve outcome prediction and re-define risk-status for ~ 80% of MBGrp4. Our MBGrp4 favourable-risk group has MBWNT-like excellent outcomes, thereby doubling the proportion of medulloblastoma patients who could benefit from therapy de-escalation approaches, aimed at reducing treatment induced late-effects while sustaining survival outcomes. Novel approaches are urgently required for the very-high-risk patients.

Executive and social functioning in pediatric posterior fossa tumor survivors and healthy controls

Background

Executive and social functioning difficulty is well established in pediatric brain tumor survivors. Few studies have compared posterior fossa (PF) tumor survivors in comparison to their peers. The relationship between attention, processing speed, working memory, fatigue, and executive and social functioning was investigated to better understand the factors that impact executive and social functioning in PF tumor populations.

Methods

Sixteen medulloblastomas, 9 low-grade astrocytomas (LGAs), and 17 healthy controls recruited from 4 sites completed measures of working memory and processing speed, and self-reported fatigue. One parent completed questionnaires on executive and social functioning.

Results

There were no significant differences among all 3 groups on parent-reported executive and social functioning; of note, parents of LGA survivors expressed greater concerns regarding behavioral and cognitive regulation than did parents of medulloblastoma survivors and healthy controls. Parent-reported attention was related to parent-reported emotion, behavior, and cognitive regulation. Worse self-reported fatigue was associated with greater emotional dysregulation for the 2 PF tumor groups.

Conclusions

Parents of PF tumor survivors described their children as performing similarly to their peers in most facets of executive and social functioning. While LGA survivors are traditionally thought to have more favorable outcomes, our finding of parent-reported executive functioning concerns to be worse for this group highlights the importance of long-term follow-up for all PF tumor survivors. Additionally, significant effects of attention on aspects of executive functioning in PF tumor survivors may inform current clinical practice and the future development of more effective interventions.

Initial Evidence for Positive Effects of a Psychological Preparation Program for MRI "iMReady" in Children with Neurofibromatosis Type I and Brain Tumors-How to Meet the Patients' Needs Best

To provide an effective alternative to sedation during MRI examinations in pediatric cancer and NF1 patients, the aims of the present study were to (1) exploratively evaluate a behavioral MRI training program, to (2) investigate potential moderators, as well as to (3) assess the patients' well-being over the course of the intervention. A total of n = 87 patients of the neuro-oncology unit (mean age: 6.83 years) underwent a two-step MRI preparation program, including training inside the scanner, and were recorded using a process-oriented screening. In addition to the retrospective analysis of all data, a subset of 17 patients were also analyzed prospectively. Overall, 80% of the children receiving MRI preparation underwent the MRI scan without sedation, making the success rate almost five times higher than that of a group of 18 children that opted out of the training program. Memory, attentional difficulties, and hyperactivity were significant neuropsychological moderators for successful scanning. The training was associated with favorable psychological well-being. These findings suggest that our MRI preparation could present an alternative to sedation of young patients undergoing MRI examinations as well as a promising tool for improving patients' treatment-related well-being.

The Tumor Microenvironment of Medulloblastoma: An Intricate Multicellular Network with Therapeutic Potential

Medulloblastoma (MB) is a heterogeneous disease in which survival is highly affected by the underlying subgroup-specific characteristics. Although the current treatment modalities have increased the overall survival rates of MB up to 70-80%, MB remains a major cause of cancer-related mortality among children. This indicates that novel therapeutic approaches against MB are needed. New promising treatment options comprise the targeting of cells and components of the tumor microenvironment (TME). The TME of MB consists of an intricate multicellular network of tumor cells, progenitor cells, astrocytes, neurons, supporting stromal cells, microglia, immune cells, extracellular matrix components, and vasculature systems. In this review, we will discuss all the different components of the MB TME and their role in MB initiation, progression, metastasis, and relapse. Additionally, we briefly introduce the effect that age plays on the TME of brain malignancies and discuss the MB subgroup-specific differences in TME components and how all of these variations could affect the progression of MB. Finally, we highlight the TME-directed treatments, in which we will focus on therapies that are being evaluated in clinical trials.

Coming in from the cold: overcoming the hostile immune microenvironment of medulloblastoma

Medulloblastoma is an aggressive brain tumor that occurs predominantly in children. Despite intensive therapy, many patients die of the disease, and novel therapies are desperately needed. Although immunotherapy has shown promise in many cancers, the low mutational burden, limited infiltration of immune effector cells, and immune-suppressive microenvironment of medulloblastoma have led to the assumption that it is unlikely to respond to immunotherapy. However, emerging evidence is challenging this view. Here we review recent preclinical and clinical studies that have identified mechanisms of immune evasion in medulloblastoma, and highlight possible therapeutic interventions that may give new hope to medulloblastoma patients and their families.

Late side effects of cancer treatment in childhood cancer survivors

INTRODUCTION

Childhood cancers are usually treated with chemotherapy and radiation. Therefore, understanding the late side effects of such treatments is important to improve the quality of life in childhood cancer survivors. The present study aimed to investigate the late complications of treatments in childhood cancer survivors.

METHODS

This study is a retrospective descriptive study. A total number of 93 cases were enrolled in this study. These cases had a history of childhood cancer documented in their medical records at the Shafa Hospital, Ahvaz, Iran. The age range was 5.9-21.3 years and included 62 males and 31 female patients.

RESULTS

Many of the patients at this hospital with childhood cancer had experienced chemotherapy side effects as well as late effects of cancer therapy. Hypothyroidism is a late complication of therapy in thoracic cancers and head/neck tumors with relative frequencies of 23.1% and 12.5%, respectively. Scoliosis was observed in the patients undergoing the ABVD + COPP and 8/1 regimens with relative frequencies of 4% and 50%, respectively. Lower growth percentiles were also late side effects of cancer therapy. The highest relative frequency of growth retardation was observed in the <5 age group (46.7%). Restrictive lung changes had an overall relative frequency of 6.5% in male patients with all types of tumors. Sensorineural hearing loss was observed in patients with leukemia and Hodgkin lymphoma with relative frequencies of 8.7% and 24.0, respectively.

CONCLUSION

The occurrence of most side effects could be decreased through early diagnosis, dose adjustment of some drugs, and preventative measures.

Educational Pain Points for Pediatric Brain Tumor Survivors: Review of Risks and Remedies

Evolving treatment paradigms have led to increased survival rates for children diagnosed with a brain tumor, and this has increasingly shifted clinical and research focus to morbidity and quality of life among survivors. Among unfavorable outcomes, survivors of pediatric brain tumors are at risk for academic failure and low educational attainment, which may then contribute to lower health related quality of life, lower income and vocational status, and a greater likelihood of dependence on others in adulthood. Several specific risk factors for lower educational performance and attainment have been investigated. These are typically examined in isolation from one another which clouds understanding of the full range and potential interplay of contributors to educational difficulties. This review integrates and summarizes what is known about the direct and indirect barriers to educational success and performance (i.e., educational pain points) to enhance clinician knowledge of factors to consider when working with pediatric brain tumor survivors. Specific barriers to educational success include neurocognitive difficulties, school absences, psychosocial challenges, challenges to knowledge and communication, and physical and sensory difficulties. Finally, we discuss the current state of educational interventions and supports and offer recommendations for future research to improve educational outcomes for pediatric brain tumor survivors.

Hedgehog Pathway Inhibitors against Tumor Microenvironment

Targeting the hedgehog (HH) pathway to treat aggressive cancers of the brain, breast, pancreas, and prostate has been ongoing for decades. Gli gene amplifications have been long discovered within malignant glioma patients, and since then, inhibitors against HH pathway-associated molecules have successfully reached the clinical stage where several of them have been approved by the FDA. Albeit this success rate implies suitable progress, clinically used HH pathway inhibitors fail to treat patients with metastatic or recurrent disease. This is mainly due to heterogeneous tumor cells that have acquired resistance to the inhibitors along with the obstacle of effectively targeting the tumor microenvironment (TME). Severe side effects such as hyponatremia, diarrhea, fatigue, amenorrhea, nausea, hair loss, abnormal taste, and weight loss have also been reported. Furthermore, HH signaling is known to be involved in the regulation of immune cell maturation, angiogenesis, inflammation, and polarization of macrophages and myeloid-derived suppressor cells. It is critical to determine key mechanisms that can be targeted at different levels of tumor development and progression to address various clinical issues. Hence current research focus encompasses understanding how HH controls TME to develop TME altering and combinatorial targeting strategies. In this review, we aim to discuss the pros and cons of targeting HH signaling molecules, understand the mechanism involved in treatment resistance, reveal the role of the HH pathway in anti-tumor immune response, and explore the development of potential combination treatment of immune checkpoint inhibitors with HH pathway inhibitors to target HH-driven cancers.

Neuropsychological assessment of paediatric brain tumour survivors: Factors associated with assessment

AIM

Paediatric brain tumour survivors are at increased risk of neurocognitive deficits that affect their education. The aim of this study was to assess the proportion of brain tumour survivors who historically received a neuropsychological assessment and examine the demographic and treatment-related variables associated with neuropsychological assessment. A further aim was to determine the number and treatment profile of brain tumour survivors who would benefit from neuropsychological assessment.

METHODS

Data from the New Zealand Children's Cancer Registry including treatments received, was used to identify children treated for a brain tumour at Starship Children's Hospital between January 2009 and December 2015. Clinical records were examined for evidence of a neuropsychological assessment in the form of a written report. Logistic regression models were used to determine factors associated with receipt of an assessment.

RESULTS

Of the 132 brain tumour survivors, 37 (28.0%) had evidence of a neuropsychological assessment in their clinical records. In adjusted analysis, children who were treated with all three of surgery, chemotherapy and radiotherapy (n = 38) were more likely to have had an assessment (odds ratio: 12.90; 95% confidence interval: 4.76-34.93) than children who had either no treatment, chemotherapy alone, surgery alone or chemotherapy and surgery (n = 73). Treatment with radiotherapy alone or with either chemotherapy or surgery (n = 21) was not significantly associated with receipt of assessment (odds ratio = 2.40; 95% confidence interval: 0.69-8.37).

CONCLUSIONS

It is important to identify the number of children who might benefit from neuropsychological assessment to inform prioritisation within existing resource and plan for additional resource if required. With a focus on reducing late effects, it is imperative that neuropsychological assessment is an integral component of a paediatric brain tumour programme.

Impact of executive functioning on health-related quality of life of pediatric brain tumor survivors

BACKGROUND

Brain tumor survivors are at risk for significant late effects following treatment completion that may adversely impact health-related quality of life (HRQOL). The current study examines the relationship between executive functioning (EF) and HRQOL in pediatric brain tumor survivors within a longitudinal framework. We hypothesized that early deficits in EF would be related to less optimal HRQOL in this population.

PROCEDURE

The current study utilized retrospective medical chart review to identify neurocognitive correlates of HRQOL in 137 youth previously treated for a pediatric brain tumor. Participants completed the Pediatric Quality of Life Inventory (PedsQL) and neuropsychological assessment, including a well-validated measure of executive functioning (Behavior Rating Inventory of Executive Function; BRIEF). General linear regression and multivariate models were utilized to examine the relationship between child executive functioning and HRQOL.

RESULTS

Multiple domains of child executive functioning, as reported by parents on the BRIEF, significantly predicted parent-proxy reported HRQOL after controlling for demographic and medical covariates, including child intellectual functioning (IF). Similarly, after controlling for covariates, the BRIEF Cognitive Regulation Index was a significant predictor of self-reported physical and school functioning domains of HRQOL.

CONCLUSION

Current data demonstrate EF is a significant predictor of HRQOL during survivorship for youth previously diagnosed with a pediatric brain tumor. Results suggest that opportunities may exist to intervene and improve HRQOL of pediatric brain tumor survivors by targeting EF.

Histologic Correlates of Molecular Group 4 Pediatric Medulloblastoma: A Retrospective Canadian Review

INTRODUCTION

The World Health Organization currently classifies medulloblastoma (MB) into four molecular groups (WNT, SHH, Group 3 and Group 4) and four histologic subtypes (classic, desmoplastic nodular, MB with extensive nodularity, and large cell/anaplastic). "Classic" MB is the most frequent histology, but unfortunately it does not predict molecular group or patient outcome. While MB may exhibit additional histologic features outside of the traditional WHO subtypes, the clinical significance of such features, in a molecular context, is unclear.

METHODS

The clinicopathologic features of 120 pediatric MB were reviewed in the context of NanoString molecular grouping. Each case was evaluated for five ancillary histologic features, including: nodularity without desmoplasia (i.e., "biphasic", B-MB), rhythmic palisades, and focal anaplasia. Molecular and histological features were statistically correlated to clinical outcome using Chi-square, log-rank, and multivariate Cox regression analysis.

RESULTS

While B-MB (N = 32) and rhythmic palisades (N = 12) were enriched amongst non-WNT/SHH MB (especially Group 4), they were not statistically associated with outcome. In contrast, focal anaplasia (N = 12) was not associated with any molecular group, but did predict unfavorable outcome.

CONCLUSION

These data nominate B-MB as a surrogate marker of Groups 3 and particularly 4 MB, which may earmark a clinically significant subset of cases.

Functional Connectivity Networks and Their Recruitment During Working Memory Tasks in Adult Survivors of Childhood Brain Tumors

Background: Assessments of functional connectivity of default mode network (DMN) and positive task-related networks (TRNs) using independent component analysis (ICA) may help describe long-term effects of childhood brain tumors and adjuvant treatments. Methods: Aiming to identify potential neuronal markers that may aid in prognosis and inform interventions to optimize outcomes, this study used ICA to evaluate the presence of functional connectivity networks and their recruitment during a letter n-back task in 23 adult survivors of childhood posterior fossa tumors (9 low grade, 14 high grade) at least 5 years past diagnosis compared with 40 age- and sex-matched healthy peers. Results: DMN components generally demonstrated increasing disengagement as task difficulty increased, and relationships between effective DMN disengagement and improved performance were observed in healthy controls (HCs). Low-grade brain tumor survivors (LGS) demonstrated unique patterns in DMN recruitment that suggested increased involvement of the medial prefrontal cortex in LGS during tasks. TRN components generally demonstrated increasing engagement, which was related to improved task performance in HCs for one executive control network (ECN) component. High-grade brain tumor survivors (HGS) demonstrated distinct challenges recruiting an ECN component at more difficult task levels and showed a relationship between recruitment of another ECN component and task performance, indicating a potential compensatory mechanism for some HGS. Conclusions: Findings suggest the importance of cognitive intervention in both survivor groups and the necessity to track LGS despite their cognitive abilities often resembling those of their healthy peers. Impact statement Distinct functional connectivity patterns were identified between both adult survivor of childhood brain tumor groups and peers during attention and working memory tasks, reflecting different damage and recovery from treatment. Survivors of low-grade tumors demonstrated unique patterns of recruitment of default mode network components in the context of similar cognitive abilities, whereas survivors of high-grade tumors demonstrated poorer cognitive abilities and may be utilizing compensatory executive control network components in the face of challenging tasks. Long-term clinical follow-up and cognitive remediation is warranted for both groups, including low grade cerebellar tumor patients who have traditionally not been monitored as closely.

Resection of cerebellar tumours causes widespread and functionally relevant white matter impairments

Several diffusion tensor imaging studies reveal that white matter (WM) lesions are common in children suffering from benign cerebellar tumours who are treated with surgery only. The clinical implications of WM alterations that occur as a direct consequence of cerebellar disease have not been thoroughly studied. Here, we analysed structural and diffusion imaging data from cerebellar patients with chronic surgical lesions after resection for benign cerebellar tumours. We aimed to elucidate the impact of focal lesions of the cerebellum on WM integrity across the entire brain, and to investigate whether WM deficits were associated with behavioural impairment in three different motor tasks. Lesion symptom mapping analysis suggested that lesions in critical cerebellar regions were related to deficits in savings during an eyeblink conditioning task, as well as to deficits in motor action timing. Diffusion imaging analysis of cerebellar WM indicated that better behavioural performance was associated with higher fractional anisotropy (FA) in the superior cerebellar peduncle, cerebellum's main outflow path. Moreover, voxel‐wise analysis revealed a global pattern of WM deficits in patients within many cerebral WM tracts critical for motor and non‐motor function. Finally, we observed a positive correlation between FA and savings within cerebello‐thalamo‐cortical pathways in patients but not in controls, showing that saving effects partly depend on extracerebellar areas, and may be recruited for compensation. These results confirm that the cerebellum has extended connections with many cerebral areas involved in motor/cognitive functions, and the observed WM changes likely contribute to long‐term clinical deficits of posterior fossa tumour survivors.

Hebrew version of the Jansari assessment of Executive Functions for Children (JEF-C©): Translation, adaptation and validation

The Jansari assessment of Executive Functions for Children (JEF-C^©) is a non-immersive computerized assessment of executive functions (EFs). This study aimed to create a cross-culturally adapted Hebrew version, JEF-C(H)^© and to assess reliability and validity in the Israeli context. Forty typically developing Israeli children and adolescents, aged 11-18 years, were assessed with JEF-C(H)^©. In addition, participants and their parents filled in the Behaviour Rating Inventory of Executive Function (BRIEF). JEF-C(H)^© was found to be feasible in Israeli children and adolescents. The internal consistency was acceptable (Cronbach's alpha = 0.79). Most of the JEF-C(H)^© subtests and the Average score showed significant positive moderate to high correlations with age, ranging from 0.40 to 0.78 demonstrating construct validity. Multiple significant correlations were also found between the JEF-C(H)^© Average score and the BRIEF indices as well as total score in the Parent and Self-report questionnaires. These preliminary findings support the reliability and validity of this version. Current findings demonstrate the potential clinical utility of JEF-C(H)^© as an ecologically valid tool for Israeli children and adolescents in the assessment of EFs.

The role of cerebellum in the child neuropsychological functioning

This chapter proposes a review of neuropsychologic and behavior findings in pediatric pathologies of the cerebellum, including cerebellar malformations, pediatric ataxias, cerebellar tumors, and other acquired cerebellar injuries during childhood. The chapter also contains reviews of the cerebellar mutism/posterior fossa syndrome, reported cognitive associations with the development of the cerebellum in typically developing children and subjects born preterm, and the role of the cerebellum in neurodevelopmental disorders such as autism spectrum disorders and developmental dyslexia. Cognitive findings in pediatric cerebellar disorders are considered in the context of known cerebellocerebral connections, internal cellular organization of the cerebellum, the idea of a universal cerebellar transform and computational internal models, and the role of the cerebellum in specific cognitive and motor functions, such as working memory, language, timing, or control of eye movements. The chapter closes with a discussion of the strengths and weaknesses of the cognitive affective syndrome as it has been described in children and some conclusions and perspectives.

Neuropsychological functioning in survivors of childhood medulloblastoma/CNS-PNET: The role of secondary medical complications

OBJECTIVE

To investigate the long-term cognitive consequences of malignant pediatric brain tumor and its treatment, and factors explaining variability in cognitive functioning among survivors. Method: A geographical cohort of survivors of pediatric medulloblastoma (MB) and supratentorial primitive neuroectodermal tumor (CNS-PNET), treated between 1974 and 2013, was invited to participate. Of the 63 surviving patients, 50 (79%) consented to participation. The participants were tested with a battery of neuropsychological tests covering a wide age range. Verbal cognition, nonverbal cognition, processing speed, attention, memory, executive functioning, and manual dexterity were assessed. The participants were between 5:5 and 51:11 years of age at time of assessment. Assessments took place on average 19 years after primary tumor resective surgery. Results: One participant had a severe intellectual disability. For the rest, IQ varied from 52 to 125, with a mean score of 88.0 (SD 19.7). Twenty-eight (56%) of the participants had full-scale IQ scores in the age-average range or above. Gender, age at operation, time since operation, the presence of secondary medical complications, and treatment variables explained 46% of the variability in IQ scores, F(4,44) =  9.5, p<.001. The presence of endocrine insufficiency in combination with either epilepsy and/or hydrocephalus was associated with lowered IQ, lowered processing speed, and memory impairments. Conclusion: Patients treated for childhood MB and CNS-PNET have a lifelong risk of medical sequelae, including impaired cognitive functioning. This study adds to the literature by demonstrating the importance of following neuropsychological functioning closely, especially processing speed, learning, and memory, in survivors who have multiple secondary medical complications.

Neurocognitive functioning and health-related quality of life in adult medulloblastoma patients: long-term outcomes of the NOA-07 study

Background

Combined radiochemotherapy followed by maintenance chemotherapy with cisplatin, lomustine and vincristine within the NOA-07 study resulted in considerable short-term toxicity in adult medulloblastoma patients. Here we investigated the long-term impact of this treatment, focusing on neurocognitive functioning and health-related quality of life (HRQoL).

Methods

Neurocognitive functioning and HRQoL scores over time were determined, and differences between the post-treatment and follow-up assessments were calculated up to 18 months for neurocognition and 60 months for HRQoL.

Results

28/30 patients were analyzed. The three preselected HRQoL scales (role, social and cognitive functioning) showed improved scores, to a clinically relevant extent (≥ 10 points), compared to post-treatment levels up to 30 months, but decreased afterwards. Z-scores for verbal working memory were worse during follow-up compared to post-treatment scores and remained impaired during 18 months follow-up (i.e. z-score below − 1 standard deviation). Attention was impaired post-treatment, and remained impaired to a clinically relevant extent during follow-up. Coordination/processing speed and lexical verbal fluency improved compared to post-treatment scores, and remained within the normal range thereafter. Other tests of verbal fluency were stable over time, with z-scores within the normal range.

Conclusions

This long-term follow-up study showed that the NOA-07 treatment regimen was not associated with a deterioration in HRQoL in the post-treatment period. Verbal working memory deteriorated, while other neurocognitive domains did not seem to be impacted negatively by the treatment.

Electronic supplementary material

The online version of this article (10.1007/s11060-020-03502-y) contains supplementary material, which is available to authorized users.

Quality of survival assessment in European childhood brain tumour trials, for children below the age of 5 years

The highest incidence rate of childhood brain tumours is in children below the age of five years, who are particularly vulnerable to the effects of treatments. The assessment of quality of survival (QoS) in multiple domains is essential to compare the outcomes for different tumour types and treatment regimens. The aim of this position statement is to present the domains of health and functioning to be assessed in children from birth to five years, to advance the collection of a common QoS data set in European brain tumour trials. The QoS group of the European Society of Paediatric Oncology (SIOP-E) Brain Tumour group conducted consensus discussions over a period of six years to establish domains of QoS that should be prioritised in clinical trials involving children under 5 years. The domains of health and functioning that were agreed to affect QoS included: medical outcomes (e.g. vision, hearing, mobility, endocrine), emotion, behaviour, adaptive behaviour, and cognitive functioning. As for children aged five years and older, a 'core plus' approach is suggested in which core assessments are recommended for all clinical trials. The core component for children from birth to three years includes indirect assessment which, in this age-group, requires proxy assessment by a parent, of cognitive, emotional and behaviour variables and both direct and indirect endocrine measures. For children from four years of age direct cognitive assessment is also recommended as 'core'. The 'plus' components enable the addition of assessments which can be selected by individual countries and/or by, age-, treatment-, tumour type- and tumour location-specific trials.

Intellectual, educational, and situation-based social outcome in adult survivors of childhood medulloblastoma

PURPOSE

To investigate intellectual and situation-based social outcome and educational achievement in adult survivors of childhood medulloblastoma and analyse factors influencing outcome Methods: We collected demographic, medical and cognitive data, and social and educational outcome at a mean time since the end of treatments of 14.9 years in 58 adults, aged 19-35 years, consecutively treated in a single cancer center between 1989 and 2005.

RESULTS

Ten survivors had severe intellectual disability, 12 were still studying, 23 had a regular employment and 13 were unemployed. Full Scale Intellectual Quotient, assessed 6.6 years after the end of treatments, ranged from 46 to 131. It was strongly associated with educational achievement and significantly lower in patients who experienced postoperative cerebellar mutism, and when parental education level was low.

CONCLUSION

These factors should be systematically considered at diagnosis in order to offer adequate and timely assessments and interventions.

Neurocognitive and Psychosocial Outcomes in Pediatric Brain Tumor Survivors

The late neurocognitive and psychosocial effects of treatment for pediatric brain tumor (PBT) represent important areas of clinical focus and ongoing research. Neurocognitive sequelae and associated problems with learning and socioemotional development negatively impact PBT survivors' overall health-related quality of life, educational attainment and employment rates. Multiple factors including tumor features and associated complications, treatment methods, individual protective and vulnerability factors and accessibility of environmental supports contribute to the neurocognitive and psychosocial outcomes in PBT survivors. Declines in overall measured intelligence are common and may persist years after treatment. Core deficits in attention, processing speed and working memory are postulated to underlie problems with overall intellectual development, academic achievement and career attainment. Additionally, psychological problems after PBT can include depression, anxiety and psychosocial adjustment issues. Several intervention paradigms are briefly described, though to date research on innovative, specific and effective interventions for neurocognitive late effects is still in its early stages. This article reviews the existing research for understanding PBT late effects and highlights the need for innovative research to enhance neurocognitive and psychosocial outcomes in PBT survivors.

Neuropsychological consequences of childhood medulloblastoma and possible interventions: A review

BACKGROUND

Children who have been treated for a medulloblastoma often suffer long-term cognitive impairments that often negatively affect their academic performance and quality of life. In this article, we will review the neuropsychological consequences of childhood medulloblastoma and discuss the risk factors known to influence the presence and severity of these cognitive impairments and possible interventions to improve their quality of life.

METHODS

This narrative review was based on electronic searches of PubMed to identify all relevant studies.

RESULTS

Although many types of cognitive impairments often emerge during a child's subsequent development, the core cognitive domains that are most often affected in children treated for a medulloblastoma are processing speed, attention and working memory. The emergence and magnitude of these deficits varies greatly among patients. They are influenced by demographic (age at diagnosis, parental education), medical and treatment-related factors (perioperative complications, including posterior fossa syndrome, radiation therapy dose, etc.), and the quality of interventions such as school adaptations provided to the child or rehabilitation programs that focus on cognitive skills, behavior and psychosocial functioning.

CONCLUSION

These patients require specialized and coordinated multidisciplinary rehabilitation follow-up that provides timely and adapted assessments and culminates in personalized intervention goals being set with the patient and the family. Follow-up should be continued until referral to adult services.

Assessment of executive functions in children and adolescents with acquired brain injury (ABI) using a novel complex multi-tasking computerised task: The Jansari assessment of Executive Functions for Children (JEF-C©)

Objectives: The Jansari assessment of Executive Functions for Children (JEF-C^©) is a new non-immersive computerised assessment of executive functions. The objectives of the study were to test the feasibility and validity of JEF-C^© in children and adolescents with acquired brain injury (ABI). Methods: Twenty-nine patients with ABI aged 10-18 years and 30 age-and gender-matched controls were tested. Participants performed JEF-C^©, Wechsler Abbreviated Scale of Intelligence (WASI) and the Behavioural Assessment of the Dysexecutive Syndrome for Children (BADS-C), while parents completed the Behaviour Rating Inventory of Executive Function (BRIEF) questionnaire. Results: The JEF-C^© task proved feasible in patients with ABI. The internal consistency was medium (Cronbach's alpha = 0.62 and significant intercorrelations between individual JEF-C^© constructs). Patients performed significantly worse than controls on most of the JEF-C^© subscales and total score, with 41.4% of participants with ABI classified as having severe executive dysfunction. No significant correlations were found between JEF-C^© total score, the BRIEF indices, and the BADS-C. Significant correlations were found between JEF-C^© and demographic characteristics of the sample and intellectual ability, but not with severity/medical variables. Conclusion: JEF-C^© is a playful complex task that appears to be a sensitive and ecologically valid assessment tool, especially for relatively high-functioning individuals.

Long-term Survivors of Childhood Brain Tumors: Impact on General Health and Quality of Life

PURPOSE OF REVIEW

We review and summarize the key issues affecting general health and quality of life (QOL) of pediatric long-term survivors of brain tumors.

RECENT FINDINGS

Long-term survivors of brain tumors are at risk of considerable late morbidity and mortality. Lengthening survival in brain tumors has highlighted the deep impact of tumor and its treatment on the physical, psychological, functional, and social health and QOL of these survivors. Evolution in tumor therapy including surgery, radiotherapy, and systemic therapies, etc., has the potential to mitigate this impact to some extent. Sensitization of health staff, policy makers, and the primary designers of clinical trials towards integration of QOL end points while measuring survival in brain tumor patients is the need of the hour. New developments in tumor therapeutics must not only provide quantitative gain but also improve the quality of survival in these long-term survivors. While majority of the issues presented pertain to survivorship in pediatric brain tumor population, similar challenges are likely to exist in young adults surviving brain tumors as well.

Time knowledge difficulties following treatment for malignant cerebellar tumors

In children treated for malignant cerebellar tumors, there are only a few studies investigating temporal skills, despite the role of the cerebellum in time processing being generally acknowledged. Children's time knowledge has been defined as the correct representation and use of familiar time units. The present study compares time knowledge in 38 children treated for malignant cerebellar tumors (mean age 11.6 years) with 105 typically-developing (TD) children. The performances on all time knowledge subtests were significantly lower in the tumor group. The results also confirm a lower mean IQ in the children treated for cerebellar tumors, related to slower processing speed and poorer performance on working memory and non-verbal tasks. However, the lower IQ does not explain the considerable difficulties in the acquisition of time knowledge. These results are discussed in the light of the role of the cerebellum in time processing and in the context of two different models of temporal processing: the internal clock model and the neural network state model.