Assessing We-Disease Appraisals of Health Problems: Development and Validation of the We-Disease Questionnaire.

In couples dealing with health problems, we-disease appraisals can influence dyadic coping strategies to alleviate distress. This study describes the development and validation of a self-report scale to assess we-disease appraisals of health problems. The newly developed We-Disease Questionnaire (WDQ) was administered in three samples: parents of children with type 1 diabetes (n = 240) or cancer (n = 125) and individuals with visual impairment and their partners (n = 216). Reliability was measured by coefficient omega. To assess construct validity, correlations with other measures of individual and dyadic adjustment were examined. Descriptive statistics across all samples were compared. A 4-item version of the WDQ demonstrated good reliability and validity and showed meaningful associations with established scales. We-disease appraisals were highest among parents of children with cancer and lowest among couples with visual impairment. The WDQ is a reliable and valid measure that can be used across different health problems.

Treatment of NF1-Associated Optic Pathway/Hypothalamic Gliomas in Patients With Diencephalic Syndrome.

Diencephalic syndrome is usually associated with tumors in the hypothalamic region, rarely occurring in patients with neurofibromatosis type 1 (NF1)-associated gliomas. We describe the clinical presentation and response to treatment in 3 patients with NF1 presenting with diencephalic syndrome as first symptom of optic pathway/hypothalamic glioma (OPHG). Because of the rarity of this constellation, knowledge about the clinical course and best treatment options for patients with NF1-associated OPHG and diencephalic syndrome is still limited. All 3 patients showed good response to treatment with normalization of body mass index and decrease in tumor volume within 6 months.

Discovery of a small molecule ligand of FRS2 that inhibits invasion and tumor growth.

PURPOSE: Aberrant activation of the fibroblast growth factor receptor (FGFR) family of receptor tyrosine kinases drives oncogenic signaling through its proximal adaptor protein FRS2. Precise disruption of this disease-causing signal transmission in metastatic cancers could stall tumor growth and progression. The purpose of this study was to identify a small molecule ligand of FRS2 to interrupt oncogenic signal transmission from activated FGFRs. METHODS: We used pharmacophore-based computational screening to identify potential small molecule ligands of the PTB domain of FRS2, which couples FRS2 to FGFRs. We confirmed PTB domain binding of molecules identified with biophysical binding assays and validated compound activity in cell-based functional assays in vitro and in an ovarian cancer model in vivo. We used thermal proteome profiling to identify potential off-targets of the lead compound. RESULTS: We describe a small molecule ligand of the PTB domain of FRS2 that prevents FRS2 activation and interrupts FGFR signaling. This PTB-domain ligand displays on-target activity in cells and stalls FGFR-dependent matrix invasion in various cancer models. The small molecule ligand is detectable in the serum of mice at the effective concentration for prolonged time and reduces growth of the ovarian cancer model in vivo. Using thermal proteome profiling, we furthermore identified potential off-targets of the lead compound that will guide further compound refinement and drug development. CONCLUSIONS: Our results illustrate a phenotype-guided drug discovery strategy that identified a novel mechanism to repress FGFR-driven invasiveness and growth in human cancers. The here identified bioactive leads targeting FGF signaling and cell dissemination provide a novel structural basis for further development as a tumor agnostic strategy to repress FGFR- and FRS2-driven tumors.

Real-time drug testing of paediatric diffuse midline glioma to support clinical decision making: The Zurich DIPG/DMG centre experience.

BACKGROUND: Children diagnosed with diffuse midline gliomas (DMG) have an extremely poor overall survival: 9-12 months from diagnosis with currently no curative treatment options. Given DMG molecular heterogeneity, surgical biopsies are needed for molecular profiling and as part of enrolment into molecular-based and precision medicine type clinical interventions. In this study, we describe the results of real time profiling and drug testing at the diffuse intrinsic pontine glioma/DMG Research Centre at University Children's Hospital Zurich. METHOD: Biopsies were taken using a frame based stereotactic robot system (NeuroMate®, Renishaw) at University Children's Hospital Zurich. Tissue samples were evaluated to confirm diagnosis by H3K27M and H3K27 trimethylation loss. Genomic analyses were done using a variety of platforms (INFORM, Oncomine, UCSF500 gene panel). Cell lines were developed by mechanical tissue dissociation and verified by either sequencing or immunofluorescence staining confirming H3K27M mutation and used afterwards for drug testing. RESULTS: Twenty-five robot-assisted primary biopsies were successfully performed. Median hospital stay was 2 days (range 1-4 days). Nine low-passage patient-derived cells were developed, whereas 8 cell lines were used to inform response to clinically relevant drugs. Genome and RNA expression were used to further guide treatment strategies with targeted agents such as dual PI3K/mTOR inhibitor paxalisib. CONCLUSION: We established a systematic workflow for safe, robot-assisted brainstem biopsies and in-house tissue processing, followed by real-time drug testing. This provides valuable insights into tumour prognostic and individual treatment strategies targeting relevant vulnerabilities in these tumours in a clinically meaningful time frame.

Cooperation of Striatin 3 and MAP4K4 promotes growth and tissue invasion.

MAP4K4 is associated with increased motility and reduced proliferation in tumor cells, but the regulation of this dichotomous functionality remained elusive. We find that MAP4K4 interacts with striatin 3 and 4 (STRN3/4) and that STRN3 and MAP4K4 exert opposing functions in Hippo signaling and clonal growth. However, depletion of either STRN3 or MAP4K4 in medulloblastoma cells reduces invasion, and loss of both proteins abrogates tumor cell growth in the cerebellar tissue. Mechanistically, STRN3 couples MAP4K4 to the protein phosphatase 2A, which inactivates growth repressing activities of MAP4K4. In parallel, STRN3 enables growth factor-induced PKCθ activation and direct phosphorylation of VASPS157 by MAP4K4, which both are necessary for efficient cell invasion. VASPS157 directed activity of MAP4K4 and STRN3 requires the CNH domain of MAP4K4, which mediates its interaction with striatins. Thus, STRN3 is a master regulator of MAP4K4 function, and disruption of its cooperation with MAP4K4 reactivates Hippo signaling and represses tissue invasion in medulloblastoma.

No wrong decisions in an all-wrong situation. A qualitative study on the lived experiences of families of children with diffuse intrinsic pontine glioma.

BACKGROUND: Diffuse intrinsic pontine glioma (DIPG) is a rare, but lethal pediatric brain tumor with a median survival of less than 1 year. Existing treatment may prolong life and control symptoms, but may cause toxicity and side effects. In order to improve child- and family-centered care, we aimed to better understand the treatment decision-making experiences of parents, as studies on this topic are currently lacking. PROCEDURE: The data for this study came from 24 semistructured interviews with parents whose children were diagnosed with DIPG in two children's hospitals in Switzerland and died between 2000 and 2016. Analysis of the dataset was done using reflexive thematic analysis. RESULTS: For most parents, the decision for or against treatment was relatively straightforward given the fatality of the tumor and the absence of treatment protocols. Most of them had no regrets about their decision for or against treatment. The most distressing factor for them was observing their child's gradual loss of independence and informing them about the inescapability of death. To counter this powerlessness, many parents opted for complementary or alternative medicine in order to "do something." Many parents reported psychological problems in the aftermath of their child's death and coping strategies between mothers and fathers often differed. CONCLUSION: The challenges of DIPG are unique and explain why parental and shared decision-making is different in DIPG compared to other cancer diagnoses. Considering that treatment decisions shape parents' grief trajectory, clinicians should reassure parents by framing treatment decisions in terms of family's deeply held values and goals.

Republication: Targeting PI3KC2ß Impairs Proliferation and Survival in Acute Leukemia, Brain Tumours and Neuroendocrine Tumours.

BACKGROUND: Eight human catalytic phosphoinositide 3-kinase (PI3K) isoforms exist which are subdivided into three classes. While class I isoforms have been well-studied in cancer, little is known about the functions of class II PI3Ks. MATERIALS AND METHODS: The expression pattern and functions of the class II PI3KC2ß isoform were investigated in a panel of tumour samples and cell lines. RESULTS: Overexpression of PI3KC2ß was found in subsets of tumours and cell lines from acute myeloid leukemia (AML), glioblastoma multiforme (GBM), medulloblastoma (MB), neuroblastoma (NB), and small cell lung cancer (SCLC). Specific pharmacological inhibitors of PI3KC2ß or RNA interference impaired proliferation of a panel of human cancer cell lines and primary cultures. Inhibition of PI3KC2ß also induced apoptosis and sensitised the cancer cells to chemotherapeutic agents. CONCLUSION: Together, these data show that PI3KC2ß contributes to proliferation and survival in AML, brain tumours and neuroendocrine tumours, and may represent a novel target in these malignancies.

Spatial proteomics finds CD155 and Endophilin-A1 as mediators of growth and invasion in medulloblastoma.

The composition of the plasma membrane (PM)-associated proteome of tumor cells determines cell-cell and cell-matrix interactions and the response to environmental cues. Whether the PM-associated proteome impacts the phenotype of Medulloblastoma (MB) tumor cells and how it adapts in response to growth factor cues is poorly understood. Using a spatial proteomics approach, we observed that hepatocyte growth factor (HGF)-induced activation of the receptor tyrosine kinase c-MET in MB cells changes the abundance of transmembrane and membrane-associated proteins. The depletion of MAP4K4, a pro-migratory effector kinase downstream of c-MET, leads to a specific decrease of the adhesion and immunomodulatory receptor CD155 and of components of the fast-endophilin-mediated endocytosis (FEME) machinery in the PM-associated proteome of HGF-activated MB cells. The decreased surface expression of CD155 or of the fast-endophilin-mediated endocytosis effector endophilin-A1 reduces growth and invasiveness of MB tumor cells in the tissue context. These data thus describe a novel function of MAP4K4 in the control of the PM-associated proteome of tumor cells and identified two downstream effector mechanisms controlling proliferation and invasiveness of MB cells.

Imipridones affect tumor bioenergetics and promote cell lineage differentiation in diffuse midline gliomas.

BACKGROUND: Pediatric diffuse midline gliomas (DMGs) are incurable childhood cancers. The imipridone ONC201 has shown early clinical efficacy in a subset of DMGs. However, the anticancer mechanisms of ONC201 and its derivative ONC206 have not been fully described in DMGs. METHODS: DMG models including primary human in vitro (n = 18) and in vivo (murine and zebrafish) models, and patient (n = 20) frozen and FFPE specimens were used. Drug-target engagement was evaluated using in silico ChemPLP and in vitro thermal shift assay. Drug toxicity and neurotoxicity were assessed in zebrafish models. Seahorse XF Cell Mito Stress Test, MitoSOX and TMRM assays, and electron microscopy imaging were used to assess metabolic signatures. Cell lineage differentiation and drug-altered pathways were defined using bulk and single-cell RNA-seq. RESULTS: ONC201 and ONC206 reduce viability of DMG cells in nM concentrations and extend survival of DMG PDX models (ONC201: 117 days, P = .01; ONC206: 113 days, P = .001). ONC206 is 10X more potent than ONC201 in vitro and combination treatment was the most efficacious at prolonging survival in vivo (125 days, P = .02). Thermal shift assay confirmed that both drugs bind to ClpP, with ONC206 exhibiting a higher binding affinity as assessed by in silico ChemPLP. ClpP activation by both drugs results in impaired tumor cell metabolism, mitochondrial damage, ROS production, activation of integrative stress response (ISR), and apoptosis in vitro and in vivo. Strikingly, imipridone treatment triggered a lineage shift from a proliferative, oligodendrocyte precursor-like state to a mature, astrocyte-like state. CONCLUSION: Targeting mitochondrial metabolism and ISR activation effectively impairs DMG tumorigenicity. These results supported the initiation of two pediatric clinical trials (NCT05009992, NCT04732065).

Central nervous system tumors in children under 5 years of age: a report on treatment burden, survival and long-term outcomes.

PURPOSE: The challenges of treating central nervous system (CNS) tumors in young children are many. These include age-specific tumor characteristics, limited treatment options, and susceptibility of the developing CNS to cytotoxic therapy. The aim of this study was to analyze the long-term survival, health-related, and educational/occupational outcomes of this vulnerable patient population. METHODS: Retrospective study of 128 children diagnosed with a CNS tumor under 5 years of age at a single center in Switzerland between 1990 and 2019. RESULTS: Median age at diagnosis was 1.81 years [IQR, 0.98-3.17]. Median follow-up time of surviving patients was 8.39 years [range, 0.74-23.65]. The main tumor subtypes were pediatric low-grade glioma (36%), pediatric high-grade glioma (11%), ependymoma (16%), medulloblastoma (11%), other embryonal tumors (7%), germ cell tumors (3%), choroid plexus tumors (6%), and others (9%). The 5-year overall survival (OS) was 78.8% (95% CI, 71.8-86.4%) for the whole cohort. Eighty-seven percent of survivors > 5 years had any tumor- or treatment-related sequelae with 61% neurological complications, 30% endocrine sequelae, 17% hearing impairment, and 56% visual impairment at last follow-up. Most patients (72%) attended regular school or worked in a skilled job at last follow-up. CONCLUSION: Young children diagnosed with a CNS tumor experience a range of complications after treatment, many of which are long-lasting and potentially debilitating. Our findings highlight the vulnerabilities of this population, the need for long-term support and strategies for rehabilitation, specifically tailored for young children.

Cognition, psychosocial functioning, and health-related quality of life among childhood cancer survivors.

Long-term sequelae of cancer and its treatment render childhood cancer (CC) survivors vulnerable to cognitive and behavioural difficulties and likely affect their quality of life (QoL). Our aim was to compare levels of cognition, psychosocial functioning, and health-related QoL of CC survivors to healthy controls and examine the associations between these three domains. Seventy-eight CC survivors (age range = 7-16 years, ≥ one year since cancer treatment) and 56 healthy controls were included. Cognition (i.e., fluid intelligence, executive functions, memory, processing speed, and selective attention), psychosocial functioning, and health-related QoL were assessed using standardized tests and questionnaires. The cognitive performance, parent-reported psychosocial behaviour, and health-related QoL of the CC survivors were within the normative range. However, working memory was significantly poorer in survivors than controls, and visuospatial working memory below the normative range was more commonly observed among survivors than among controls. Processing speed significantly predicted survivors' performance in executive functions. Among survivors, greater peer problems were significantly associated with poorer cognitive functions and health-related QoL. Despite the evidence for good intellectual functioning, which might point towards adequate reserves, in some survivors, domain-specific difficulties may emerge years after cancer relating to psychosocial development and QoL.

Therapeutic implications of improved molecular diagnostics for rare CNS embryonal tumor entities: results of an international, retrospective study.

BACKGROUND: Only few data are available on treatment-associated behavior of distinct rare CNS embryonal tumor entities previously treated as "CNS-primitive neuroectodermal tumors" (CNS-PNET). Respective data on specific entities, including CNS neuroblastoma, FOXR2 activated (CNS NB-FOXR2), and embryonal tumors with multilayered rosettes (ETMR) are needed for development of differentiated treatment strategies. METHODS: Within this retrospective, international study, tumor samples of clinically well-annotated patients with the original diagnosis of CNS-PNET were analyzed using DNA methylation arrays (n = 307). Additional cases (n = 66) with DNA methylation pattern of CNS NB-FOXR2 were included irrespective of initial histological diagnosis. Pooled clinical data (n = 292) were descriptively analyzed. RESULTS: DNA methylation profiling of "CNS-PNET" classified 58 (19%) cases as ETMR, 57 (19%) as high-grade glioma (HGG), 36 (12%) as CNS NB-FOXR2, and 89(29%) cases were classified into 18 other entities. Sixty-seven (22%) cases did not show DNA methylation patterns similar to established CNS tumor reference classes. Best treatment results were achieved for CNS NB-FOXR2 patients (5-year PFS: 63% ± 7%, OS: 85% ± 5%, n = 63), with 35/42 progression-free survivors after upfront craniospinal irradiation (CSI) and chemotherapy. The worst outcome was seen for ETMR and HGG patients with 5-year PFS of 18% ± 6% and 22% ± 7%, and 5-year OS of 24% ± 6% and 25% ± 7%, respectively. CONCLUSION: The historically reported poor outcome of CNS-PNET patients becomes highly variable when tumors are molecularly classified based on DNA methylation profiling. Patients with CNS NB-FOXR2 responded well to current treatments and a standard-risk CSI-based regimen may be prospectively evaluated. The poor outcome of ETMR across applied treatment strategies substantiates the necessity for evaluation of novel treatments.

The Working Memory Network and Its Association with Working Memory Performance in Survivors of non-CNS Childhood Cancer.

Childhood cancer and its treatment puts survivors at risk of low working memory capacity. Working memory represents a core cognitive function, which is crucial in daily life and academic tasks. The aim of this functional MRI (fMRI) study was to examine the working memory network of survivors of childhood cancer without central nervous system (CNS) involvement and its relation to cognitive performance. Thirty survivors (aged 7-16 years, ≥ 1 year after cancer treatment) and 30 healthy controls performed a visuospatial working memory task during MRI, including a low- and a high-demand condition. Working memory performance was assessed using standardized tests outside the scanner. When cognitive demands increased, survivors performed worse than controls and showed evidence for slightly atypical working memory-related activation. The survivor group exhibited hyperactivation in the right-hemispheric superior parietal lobe (SPL) in the high- compared to the low-demand working memory condition, while maintaining their performance levels. Hyperactivation in the right SPL coincided with poorer working memory performance outside the scanner in survivors. Even in survivors of childhood cancer without CNS involvement, we find neural markers pointing toward late effects in the cerebral working memory network.AbbreviationsfMRI: Functional magnetic resonance imaging; CNS: Central nervous system; MNI: Montreal Neurological Institute; SES: Socioeconomic status; SPL: Superior parietal lobe.

Cortical Morphometry and Its Relationship with Cognitive Functions in Children after non-CNS Cancer.

Background: Childhood cancer survivors (Ccs) are at risk for cognitive late-effects, which might result from cortical alterations, even if cancer does not affect the brain. The study aimed to examine gray and white matter volume and its relationship to cognition. Methods: Forty-three Ccs of non-central nervous system cancers and 43 healthy controls, aged 7-16 years, were examined. Cognitive functions and fine motor coordination were assessed and T1-weighted images were collected for voxel-based morphometry. Results: Executive functions (p = .024, d = .31) were poorer in Ccs than controls, however still within the normal range. The volume of the amygdala (p = .011, ŋ2 = .117) and the striatum (p = .03, ŋ2 = .102) was reduced in Ccs. No significant structure-function correlations were found, neither in patients nor controls. Conclusion: Non-CNS childhood cancer and its treatment impacts on brain structures relevant to emotion processing.

Motor ability, physical self-concept and health-related quality of life in pediatric cancer survivors.

BACKGROUND: Cancer survivorship is frequently associated with severe late effects. However, research into pediatric cancer survivors on late effects in motor ability, physical self-concept and their relationship to quality of life is limited. METHODS: Using multiple regression analyses, 78 pediatric cancer survivors and 56 typically developing children were compared in motor ability, physical self-concept and health-related quality of life. In addition, mediational multi-group analyses between motor ability (independent variable), physical self-concept (mediator) and quality of life (dependent variable) were calculated. RESULTS: Pediatric cancer survivors had a lower motor ability (gHedges  = 0.863), a lower physical self-concept with regard to several scales of the PSDQ-S (gHedges  = 0.318-0.764) and a higher relative risk for a below average quality of life than controls (RR = 1.44). Children with a history of cancer involving the central nervous system showed poorer motor ability compared to those without central nervous system involvement (gHedges  = 0.591). Furthermore, the physical self-concept significantly mediated the relationship between motor ability and quality of life in pediatric cancer survivors but not in typically developing children. CONCLUSIONS: Results show the importance of monitoring and supporting the development of motor ability in the aftercare of pediatric cancer survivors. Physical activity interventions may be advisable to prevent physical activity-related late effects and potentially improve related psychosocial variables such as quality of life.

Impact of non-CNS childhood cancer on resting-state connectivity and its association with cognition.

INTRODUCTION: Non-central nervous system cancer in childhood (non-CNS CC) and its treatments pose a major threat to brain development, with implications for functional networks. Structural and functional alterations might underlie the cognitive late-effects identified in survivors of non-CNS CC. The present study evaluated resting-state functional networks and their associations with cognition in a mixed sample of non-CNS CC survivors (i.e., leukemia, lymphoma, and other non-CNS solid tumors). METHODS: Forty-three patients (off-therapy for at least 1 year and aged 7-16 years) were compared with 43 healthy controls matched for age and sex. High-resolution T1-weighted structural magnetic resonance and resting-state functional magnetic resonance imaging were acquired. Executive functions, attention, processing speed, and memory were assessed outside the scanner. RESULTS: Cognitive performance was within the normal range for both groups; however, patients after CNS-directed therapy showed lower executive functions than controls. Seed-based connectivity analyses revealed that patients exhibited stronger functional connectivity between fronto- and temporo-parietal pathways and weaker connectivity between parietal-cerebellar and temporal-occipital pathways in the right hemisphere than controls. Functional hyperconnectivity was related to weaker memory performance in the patients' group. CONCLUSION: These data suggest that even in the absence of brain tumors, non-CNS CC and its treatment can lead to persistent cerebral alterations in resting-state network connectivity.

Mechanisms of imipridones in targeting mitochondrial metabolism in cancer cells.

ONC201 is the first member of the imipridone family of anticancer drugs to enter the clinic for the treatment of diverse solid and hematologic cancers. A subset of pediatric and adult patients with highly aggressive brain tumors has shown remarkable clinical responses to ONC201, and recently, the more potent derivative ONC206 entered clinical trials as a single agent for the treatment of central nervous system (CNS) cancers. Despite the emerging clinical interest in the utility of imipridones, their exact molecular mechanisms are not fully described. In fact, the existing literature points to multiple pathways (e.g. tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) signaling, dopamine receptor antagonism, and mitochondrial metabolism) as putative drug targets. We have performed a comprehensive literature review and highlighted mitochondrial metabolism as the major target of imipridones. In support of this, we performed a meta-analysis of an ONC201 screen across 539 human cancer cell lines and showed that the mitochondrial caseinolytic protease proteolytic subunit (ClpP) is the most significant predictive biomarker of response to treatment. Herein, we summarize the main findings on the anticancer mechanisms of this potent class of drugs, provide clarity on their role, and identify clinically relevant predictive biomarkers of response.

Evaluation of Prognostic Factors and Role of Participation in a Randomized Trial or a Prospective Registry in Pediatric and Adolescent Nonmetastatic Medulloblastoma - A Report From the HIT 2000 Trial.

PURPOSE: We aimed to compare treatment results in and outside of a randomized trial and to confirm factors influencing outcome in a large retrospective cohort of nonmetastatic medulloblastoma treated in Austria, Switzerland and Germany. METHODS AND MATERIALS: Patients with nonmetastatic medulloblastoma (n = 382) aged 4 to 21 years and primary neurosurgical resection between 2001 and 2011 were assessed. Between 2001 and 2006, 176 of these patients (46.1%) were included in the randomized HIT SIOP PNET 4 trial. From 2001 to 2011 an additional 206 patients were registered to the HIT 2000 study center and underwent the identical central review program. Three different radiation therapy protocols were applied. Genetically defined tumor entity (former molecular subgroup) was available for 157 patients. RESULTS: Median follow-up time was 7.3 (range, 0.09-13.86) years. There was no difference between HIT SIOP PNET 4 trial patients and observational patients outside the randomized trial, with 7 years progression-free survival rates (PFS) of 79.5% ± 3.1% versus 78.7% ± 3.1% (P = .62). On univariate analysis, the time interval between surgery and irradiation (≤ 48 days vs ≥ 49 days) showed a strong trend to affect PFS (80.4% ± 2.2% vs 64.6% ± 9.1%; P = .052). Furthermore, histologically and genetically defined tumor entities and the extent of postoperative residual tumor influenced PFS. On multivariate analyses, a genetically defined tumor entity wingless-related integration site-activated vs non-wingless-related integration site/non-SHH, group 3 hazard ratio, 5.49; P = .014) and time interval between surgery and irradiation (hazard ratio, 2.2; P = .018) were confirmed as independent risk factors. CONCLUSIONS: Using a centralized review program and risk-stratified therapy for all patients registered to the study center, outcome was identical for patients with nonmetastatic medulloblastoma treated on and off the randomized HIT SIOP PNET 4 trial. The prognostic values of prolonged time to RT and genetically defined tumor entity were confirmed.

Effects of Cognitive Training and Exergaming in Pediatric Cancer Survivors-A Randomized Clinical Trial.

PURPOSE: Although most pediatric cancer patients survive, those who undergo anticancer treatments like chemotherapy and/or radiotherapy are at a high risk for late effects, such as cognitive deficits. To counteract these deficits, feasible and effective interventions are needed. The aim of this study was to compare the effects of working memory training, exergaming, and a wait-list control condition on cognitive functions in pediatric cancer survivors. METHODS: In a parallel-group randomized trial, 69 pediatric cancer survivors aged 7-16 yr (mean = 11.35, SD = 3.53) were randomly assigned to 8-wk working memory training, exergaming, or a wait-list control group. Each training course consisted of three 45-min training sessions per week. The primary outcome comprised the core executive functions (visual working memory, inhibition, switching), and the secondary outcomes included other cognitive domains (intelligence, planning, memory, attention, processing speed), motor abilities, and parent rating on their children's executive functions. Assessments were conducted both before and immediately after the interventions, and at 3-month follow-up. RESULTS: Linear mixed models revealed that participants in the working memory training group showed a linear improvement in visual working memory after training and at follow-up compared with the control group. No other intervention effects of either type of training could be detected. CONCLUSION: This study presents evidence that working memory training improves visual working memory in pediatric cancer survivors. Results show that near-transfer, but no far-transfer effects can be expected from working memory training. Multiple-component interventions tailored to fit the individual's cognitive profile are needed to best support cognitive development after cancer and its treatment.