Addressing Neurocognitive Late Effects in Pediatric Cancer Survivors: Current Approaches and Future Opportunities

Post-traumatic stress, sleep, and neurocognitive problems in children newly diagnosed with a pediatric brain tumor

BACKGROUND

Children diagnosed with brain tumors are at risk to develop neurocognitive problems. Post-traumatic stress and sleep have been associated with poorer neurocognitive outcomes in the general population, and could be potential targets for intervention in brain tumor patients. Therefore, this study examined neurocognitive functioning in children newly diagnosed with a brain tumor and the associations between posttraumatic stress and sleep with neurocognitive outcomes.

METHODS

Children 6-16 years old who were newly diagnosed with a brain tumor completed questionnaires on post-traumatic stress and sleep, actigraphy for sleep, and tests for neurocognitive outcomes. One-sample t-tests and chi-square tests were used to compare neurocognitive scores with age norms. Multivariable regression examined associations between post-traumatic stress, sleep, demographics, and medical factors associated with neurocognitive functioning.

RESULTS

Of all eligible children, 60 patients with newly diagnosed brain tumors were included, at an average of 51 days after diagnosis (67% male, mean = 11.5 years at diagnosis). Compared to age norms, patients with brain tumors scored lower on measures of attention, inhibition, and verbal memory (meanZ = -0.40 to -0.98, p < .05). History of obstructive hydrocephalus was associated with poorer attention (p < .05) and processing speed (p < .05), posterior fossa tumor location was associated with poorer working memory (p < .01), and starting chemotherapy or radiotherapy treatment before the assessment was associated with poorer verbal memory (p < .05). Post-traumatic stress and sleep were not associated with neurocognitive outcomes at this phase (p > .20).

CONCLUSION

A subgroup of children with newly diagnosed brain tumors shows deficits in neurocognitive functioning, which highlights the importance of early monitoring to identify children at-risk for problems. Hydrocephalus, posterior fossa tumor location, and starting treatment, but not post-traumatic stress and sleep, are associated with poorer neurocognitive performance at this phase. Longitudinal research will be important for identifying biopsychosocial factors that may be associated with cognition over time.

Risk factors for domain-specific neurocognitive outcome in pediatric survivors of a brain tumor in the posterior fossa-Results of the HIT 2000 trial

BACKGROUND

Neurocognition can be severely affected in pediatric brain tumor survivors. We analyzed the association of cognitive functioning with radiotherapy dose, postoperative cerebellar mutism syndrome (pCMS), hydrocephalus, intraventricular methotrexate (MTX) application, tumor localization, and biology in pediatric survivors of a posterior fossa tumor.

METHODS

Subdomain-specific neurocognitive outcome data from 279 relapse-free survivors of the HIT-2000 trial (241 medulloblastoma and 38 infratentorial ependymoma) using the Neuropsychological Basic Diagnostic tool based on Cattell-Horn-Carroll's model for intelligence were analyzed.

RESULTS

Cognitive performance 5.14 years (mean; range = 1.52-13.02) after diagnosis was significantly below normal for all subtests. Processing speed and psychomotor abilities were most affected. Influencing factors were domain-specific: CSI-dose had a strong impact on most subtests. pCMS was associated with psychomotor abilities (β = -0.25 to -0.16) and processing speed (β = -0.32). Postoperative hydrocephalus correlated with crystallized intelligence (β = -0.20) and short-term memory (β = -0.15), age with crystallized intelligence (β = 0.15) and psychomotor abilities (β = -0.16 and β = -0.17). Scores for fluid intelligence (β = -0.23), short-term memory (β = -0.17) and visual processing (β = -0.25) declined, and scores for selective attention improved (β = 0.29) with time after diagnosis.

CONCLUSIONS

The dose of CSI was strongly associated with neurocognitive outcomes. Low psychomotor abilities and processing speed both in patients treated with and without CSI suggest a strong contribution of the tumor and its surgery on these functions. Future research therefore should analyze strategies to both reduce CSI dose and toxicity caused by other treatment modalities.

The paradigm of total body irradiation in acute lymphoblastic leukaemia: Therapeutic effectiveness versus the challenges of toxicity

INTRODUCTION

Total body irradiation (TBI) is part of the myeloablative conditioning for hematopoietic stem cell transplantation (HSCT) in malignant hematologic disorders. This therapy has recently shown improved survival in acute lymphoblastic leukemia (ALL) compared to chemotherapy-based regimens. However, side effects are a significant limitation, especially in the pediatric population.

PATIENTS AND METHODS

We retrospectively analyzed the survival of patients with ALL who underwent an HSCT at a tertiary hospital between 1996 and 2009 (N = 69 HSCT in 57 patients). We differentiated a cohort that received TBI (N = 44) from another that did not (N = 25). Subsequently, we interviewed the survivors from the TBI group with a minimum of 10 years of follow-up (N = 18), asking about the presence of side effects.

RESULTS

The overall survival (OS) at 2 and 5 years was 79.1% and 65.2% respectively for the TBI group and 66.2% and 55.8% for the non-TBI group, although this difference was not significant (P=.31). The event-free survival (EFS) at 2 and 5 years was 77.3% and 63.6% respectively for the TBI group and 56% and 32% for the non-TBI group (P=.02). The probability of relapse (PR) at 2 years for those who received TBI was 10% compared to 28.6% for those who did not receive TBI (P=.005). Survivors who received TBI developed secondary neoplasms (39%), dyslipidemia (67%), cognitive impairments affecting memory (44%), recurrent respiratory infections (39%), thyroid abnormalities (45%), premature ovarian failure (89%), cataracts (22%), and psychological problems (44%). However, the quality of life, as self-assessed by the patients, was considered good for 83% of the participants..

CONCLUSIONS

Patients who received TBI had significantly higher EFS and lower PR. However, adverse effects are frequent and significant, although they do not subjectively affect quality of life.

[Formula: see text] The multifaceted role of neuropsychology in pediatric solid organ transplant: preliminary guidelines and strategies for clinical practice

The incidence of pediatric solid organ transplantation (SOT) has increased in recent decades due to medical and surgical advances as well as improvements in organ procurement. Survival rates for pediatric kidney, liver, and heart transplantation are above 85% but patients continue to experience complex healthcare needs over their lifetime. Long-term developmental and neuropsychological sequelae are becoming increasingly recognized in this population, although preliminary work is limited and deserves further attention. Neuropsychological weaknesses are often present prior to transplantation and may be related to underlying congenital conditions as well as downstream impact of the indicating organ dysfunction on the central nervous system. Neuropsychological difficulties pose risk for functional complications, including disruption to adaptive skill development, social-emotional functioning, quality of life, and transition to adulthood. The impact of cognitive dysfunction on health management activities (e.g., medication adherence, medical decision-making) is also an important consideration given these patients' lifelong medical needs. The primary aim of this paper is to provide preliminary guidelines and clinical strategies for assessment of neuropsychological outcomes across SOT populations for pediatric neuropsychologists and the multidisciplinary medical team, including detailing unique and shared etiologies and risk factors for impairment across organ types, and functional implications. Recommendations for clinical neuropsychological monitoring as well as multidisciplinary collaboration within pediatric SOT teams are also provided.

Awareness, access, and communication: provider perspectives on early intervention services for children with sickle cell disease

Purpose

This study aimed to identify determinants influencing the utilization of early intervention services among young children with sickle cell disease (SCD) based on perspectives from medical and early intervention providers.

Design and methods

Early intervention and medical providers from the catchment area surrounding St. Jude Children's Research Hospital and Washington University were recruited (20 total providers). Interviews were completed over the phone and audio recorded. All interviews were transcribed verbatim, coded, and analyzed using inductive thematic analysis.

Results

Three overarching themes were identified from both groups: Awareness (e.g., lack of awareness about the EI system and SCD), Access (e.g., difficulties accessing services), and Communication (e.g., limited communication between medical and early intervention providers, and between providers and families). Although these three themes were shared by medical and early intervention providers, the differing perspectives of each produced subthemes unique to the two professional fields.

Conclusions

Early intervention services can limit the neurodevelopmental deficits experienced by young children with SCD; however, most children with SCD do not receive these services. The perspectives of early intervention and medical providers highlight several potential solutions to increase early intervention utilization among young children with SCD.

Artificial and natural interventions for chemotherapy- and / or radiotherapy-induced cognitive impairment: A systematic review of animal studies

BACKGROUND

Cancer survivors frequently experience cognitive impairments. This systematic review assessed animal literature to identify artificial (pharmaceutical) or natural interventions (plant/endogenously-derived) to reduce treatment-related cognitive impairments.

METHODS

PubMed, EMBASE, PsycINFO, Web of Science, and Scopus were searched and SYRCLE's tool was used for risk of bias assessment of the 134 included articles.

RESULTS

High variability was observed and risk of bias analysis showed overall poor quality of reporting. Results generally showed positive effects in the intervention group versus cancer-therapy only group (67% of 156 cognitive measures), with only 15 (7%) measures reporting cognitive impairment despite intervention. Both artificial (61%) and natural (75%) interventions prevented cognitive impairment. Artificial interventions involving GSK3B inhibitors, PLX5622, and NMDA receptor antagonists, and natural interventions utilizing melatonin, curcumin, and N-acetylcysteine, showed most consistent outcomes.

CONCLUSIONS

Both artificial and natural interventions may prevent cognitive impairment in rodents, which merit consideration in future clinical trials. Greater consistency in design is needed to enhance the generalizability across studies, including timing of cognitive tests and description of treatments and interventions.

Verschlimmbesserung: Craniospinal Radiotherapy Is Essential in WNT Medulloblastoma Patients

Standard-risk WNT medulloblastoma patients have an excellent prognosis (>90% progression-free survival) using the combination of standard dose craniospinal radiotherapy (CSI) (23.4 Gy) followed by platinum and alkylator based chemotherapy. A recent pilot study that attempted to completely omit radiotherapy was terminated early as all patients (n = 3) relapsed rapidly (on treatment or within 6 months of completing treatment). The study highlights that therapy is the most important prognostic factor, with CSI still required to cure even the most favorable subgroup of medulloblastoma patients. See related article by Cohen et al., p. 5031.

Radiotherapy-Induced Neurocognitive Impairment Is Driven by Heightened Apoptotic Priming in Early Life and Prevented by Blocking BAX

Although external beam radiotherapy (xRT) is commonly used to treat central nervous system (CNS) tumors in patients of all ages, young children treated with xRT frequently experience life-altering and dose-limiting neurocognitive impairment (NI) while adults do not. The lack of understanding of mechanisms responsible for these differences has impeded the development of neuroprotective treatments. Using a newly developed mouse model of xRT-induced NI, we found that neurocognitive function is impaired by ionizing radiation in a dose- and age-dependent manner, with the youngest animals being most affected. Histologic analysis revealed xRT-driven neuronal degeneration and cell death in neurogenic brain regions in young animals but not adults. BH3 profiling showed that neural stem and progenitor cells, neurons, and astrocytes in young mice are highly primed for apoptosis, rendering them hypersensitive to genotoxic damage. Analysis of single-cell RNA sequencing data revealed that neural cell vulnerability stems from heightened expression of proapoptotic genes including BAX, which is associated with developmental and mitogenic signaling by MYC. xRT induced apoptosis in primed neural cells by triggering a p53- and PUMA-initiated, proapoptotic feedback loop requiring cleavage of BID and culminating in BAX oligomerization and caspase activation. Notably, loss of BAX protected against apoptosis induced by proapoptotic signaling in vitro and prevented xRT-induced apoptosis in neural cells in vivo as well as neurocognitive sequelae. On the basis of these findings, preventing xRT-induced apoptosis specifically in immature neural cells by blocking BAX, BIM, or BID via direct or upstream mechanisms is expected to ameliorate NI in pediatric patients with CNS tumor.

SIGNIFICANCE

Age- and differentiation-dependent apoptotic priming plays a pivotal role in driving radiotherapy-induced neurocognitive impairment and can be targeted for neuroprotection in pediatric patients.

Social determinants of cognitive outcomes in survivors of pediatric brain tumors treated with conformal radiation therapy

BACKGROUND

Social determinants of health including parental occupation, household income, and neighborhood environment are predictors of cognitive outcomes among healthy and ill children; however, few pediatric oncology studies have investigated this relationship. This study utilized the Economic Hardship Index (EHI) to measure neighborhood-level social and economic conditions to predict cognitive outcomes among children treated for brain tumors (BT) with conformal radiation therapy (RT).

METHODS

Two hundred and forty-one children treated on a prospective, longitudinal, phase II trial of conformal photon RT (54-59.4 Gy) for ependymoma, low-grade glioma, or craniopharyngioma (52% female, 79% white, age at RT = 7.76 ± 4.98 years) completed serial cognitive assessments (intelligence quotient [IQ], reading, math, and adaptive functioning) for ten years. Six US census tract-level EHI scores were calculated for an overall EHI score: unemployment, dependency, education, income, crowded housing, and poverty. Established socioeconomic status (SES) measures from the extant literature were also derived.

RESULTS

Correlations and non-parametric tests revealed EHI variables share modest variance with other SES measures. Income, unemployment, and poverty overlapped most with individual SES measures. Linear mixed models, accounting for sex, age at RT, and tumor location, revealed EHI variables predicted all cognitive variables at baseline and change in IQ and math over time, with EHI overall and poverty most consistent predictors. Higher economic hardship was associated with lower cognitive scores.

CONCLUSIONS

Neighborhood-level measures of socioeconomic conditions can help inform understanding of long-term cognitive and academic outcomes in survivors of pediatric BT. Future investigation of poverty's driving forces and the impact of economic hardship on children with other catastrophic diseases is needed.

Genetic susceptibility to cognitive decline following craniospinal irradiation for pediatric central nervous system tumors

BACKGROUND

Survivors of pediatric central nervous system (CNS) tumors treated with craniospinal irradiation (CSI) exhibit long-term cognitive difficulties. Goals of this study were to evaluate longitudinal effects of candidate and novel genetic variants on cognitive decline following CSI.

METHODS

Intelligence quotient (IQ), working memory (WM), and processing speed (PS) were longitudinally collected from patients treated with CSI (n = 241). Genotype-by-time interactions were evaluated using mixed-effects linear regression to identify common variants (minor allele frequency > 1%) associated with cognitive performance change. Novel variants associated with cognitive decline (P < 5 × 10-5) in individuals of European ancestry (n = 163) were considered replicated if they demonstrated consistent genotype-by-time interactions (P < .05) in individuals of non-European ancestries (n = 78) and achieved genome-wide statistical significance (P < 5 × 10-8) in a meta-analysis across ancestry groups.

RESULTS

Participants were mostly males (65%) diagnosed with embryonal tumors (98%) at a median age of 8.3 years. Overall, 1150 neurocognitive evaluations were obtained (median = 5, range: 2-10 per participant). One of the five loci previously associated with cognitive outcomes in pediatric CNS tumors survivors demonstrated significant time-dependent IQ declines (PPARA rs6008197, P = .004). Two variants associated with IQ in the general population were associated with declines in IQ after Bonferroni correction (rs9348721, P = 1.7 × 10-5; rs31771, P = 7.8 × 10-4). In genome-wide analyses, we identified novel loci associated with accelerated declines in IQ (rs116595313, meta-P = 9.4 × 10-9), WM (rs17774009, meta-P = 4.2 × 10-9), and PS (rs77467524, meta-P = 1.5 × 10-8; rs17630683, meta-P = 2.0 × 10-8; rs73249323, meta-P = 3.1 × 10-8).

CONCLUSIONS

Inherited genetic variants involved in baseline cognitive functioning and novel susceptibility loci jointly influence the degree of treatment-associated cognitive decline in pediatric CNS tumor survivors.

Physical activity and exercise for cancer-related cognitive impairment among individuals affected by childhood cancer: a systematic review and meta-analysis

BACKGROUND

Individuals affected by childhood cancer can have cognitive dysfunction that persists into adulthood and negatively affects quality of life. In this study, we aimed to evaluate the effects of physical activity and exercise on cognitive function among individuals affected by childhood cancer.

METHODS

In this systematic review and meta-analysis, we searched seven databases (CINAHL Plus, Cochrane Library, Embase, MEDLINE, PsycINFO, SPORTDiscus, and Web of Science) and two clinical trial registries (ClinicalTrials.gov and the International Clinical Trials Registry Platform) for randomised controlled trials (RCTs) and non-randomised studies of interventions (NRSIs) published (or registered) from database inception to Jan 30, 2022, with no language restrictions. We included studies that compared the effects of physical activity or exercise interventions with controls (no intervention or usual care) on cognitive function among individuals diagnosed with any type of cancer at age 0-19 years. Two reviewers (JDKB and FR) independently screened records for eligibility and searched references of the selected studies; extracted study-level data from published reports; and assessed study risk of bias of RCTs and NRSIs using the Cochrane risk of bias tool for randomised trials (RoB 2) and Risk Of Bias In Non-randomised Studies-of Interventions (ROBINS-I) tools, certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach, and any adverse events. We used intention-to-treat data and unpublished data if available. Cognitive function was assessed by standardised cognitive performance measures (primary outcome) and by validated patient-reported measures (secondary outcome). A random-effects meta-analysis model using the inverse-variance and Hartung-Knapp methods was used to calculate pooled estimates (Hedges' g) and 95% CI values. We estimated the heterogeneity variance by the restricted maximum likelihood method and calculated I² values to measure heterogeneity. We examined funnel plots and used Egger's regression test to assess for publication bias. This study is registered with PROSPERO, CRD42021261061.

FINDINGS

We screened 12 425 titles and abstracts, which resulted in full-text assessment of 131 potentially relevant reports. We evaluated 22 unique studies (16 RCTs and six NRSIs) with data on 1277 individuals affected by childhood cancer and low-to-moderate risk of bias. Of the 1277 individuals, 674 [52·8%] were male and 603 [47·2%] were female; median age at study start was 12 (IQR 11-14) years, median time since the end of cancer treatment was 2·5 (IQR -1·1 to 3·0) years, and median intervention period was 12 [IQR 10-24] weeks. There was moderate-quality evidence that, compared with control, physical activity and exercise improved cognitive performance measures (five RCTs; Hedges' g 0·40 [95% CI 0·07-0·73], p=0·027; I²=18%) and patient-reported measures of cognitive function (13 RCTs; Hedges' g 0·26 [0·09-0·43], p=0·0070; I²=40%). No evidence of publication bias was found. Nine mild adverse events were reported.

INTERPRETATION

There is moderate-certainty evidence that physical activity and exercise improves cognitive function among individuals affected by childhood cancer, which supports the use of physical activity for managing cancer-related cognitive impairment.

FUNDING

Research Impact Fund of Research Grants Council of the Hong Kong University Grants Committee (R7024-20) and Seed Fund for Basic Research of the University of Hong Kong.

COPYRIGHT

© 2022 Published by Elsevier Ltd. All rights reserved.

Sleep Disturbance and Its Association With Sluggish Cognitive Tempo and Attention in Pediatric Brain Tumor Survivors

Background

Pediatric brain tumor (PBT) survivors are at risk for developing sleep disturbances. While in other pediatric populations sleep disturbance has been associated with worse cognitive functioning, it is unclear to what extent this relationship generalizes to PBT survivors. The aim of the current study was to assess the relationship between sleep disturbance and aspects of cognition, including sluggish cognitive tempo (SCT) as well as attention and working memory.

Materials and Methods

Eighty-three PBT survivors 6–18 years of age who were at least 3 months post-treatment were included in the present cross-sectional study. Level of sleep disturbance was measured as a composite score reflecting various sleep problems as rated by caregivers. Cognitive measures included caregiver-ratings of sluggish cognitive tempo and attention problems, as well as performance-based cognitive measures assessing attention and executive functioning. Hierarchical regression analysis was used to assess associations between sleep and cognition.

Results

Of all caregivers, 32.5% reported one or more sleep disturbances as “very/often true” and over 68% of caregivers rated at least one sleep-related item as “somewhat true.” Of all cognitive variables, scores were most frequently impaired for SCT (30%). A higher level of sleep disturbance was associated with worse SCT and parent-rated attention problems. Associations between sleep and performance-based cognitive measures assessing attention and working memory were not statistically significant.

Conclusion

Findings of the current study highlight the importance of further investigation into the relationship between sleep and cognition in PBT survivors, which may assist efforts to maximize cognitive outcome and health-related quality of life in PBT survivors. The current study additionally suggests further investigation of SCT in this population is warranted, as it may be more sensitive to detecting possible associations with sleep disturbance relative to discrete measures that assess cognitive performance under ideal circumstances.

Neuropathic pain and neurocognitive functioning in children treated for acute lymphoblastic leukemia

ABSTRACT

Children with acute lymphoblastic leukemia (ALL) often experience treatment-related neurocognitive deficits and significant pain. Pain may exacerbate these cognitive impairments. This study examined neuropathic pain and neurocognitive outcomes in survivors of childhood ALL treated with contemporary therapy on a clinical trial (NCT00137111). There were 345 survivors (45% female, M = 6.9 years at diagnosis) who completed neurocognitive assessments including measures of sustained attention, learning and memory, and parent ratings of attention during at least one of 4 time points: on-therapy (Induction and Reinduction), end of therapy, and 2 years post-therapy. At-risk performance was defined as a score at least 1SD below the age-adjusted mean. Data on neuropathic pain (events, duration, and severity according NCI Common Toxicity Criteria) and pharmacologic pain management (opioids and gabapentin) were ascertained. Results showed that 135 survivors (39%) experienced neuropathic pain during treatment. Compared with those without pain, survivors with pain had greater memory impairments at end of therapy (California Verbal Learning Test [CVLT]-Total, 24% vs 12%, P = 0.046). Within the pain group, survivors who experienced a greater number of pain events (CVLT-Total = -0.88, P = 0.023) and those who were treated with opioids (versus gabapentin) had poorer learning and memory performance (CVLT-Total = -0.73, P = 0.011; Short Delay = -0.57, P = 0.024; Long Delay = -0.62, P = 0.012; and Learning Slope = -0.45, P = 0.042) across time points. These are considered medium-to-large effects (SD = 0.45-0.88). Neuropathic pain may be a risk factor for learning problems after therapy completion, and treatment for pain with opioids may also adversely affect neurocognitive performance. Therefore, patients who experience pain may require closer monitoring and additional intervention for neurocognitive impairment.

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.