Differential trajectories of neurocognitive functioning in females versus males following treatment for pediatric brain tumors

Genetic predictors of neurocognitive outcomes in survivors of pediatric brain tumors

BACKGROUND

Neurocognitive deficits are common in pediatric brain tumor survivors. The use of single nucleotide polymorphism (SNP) analysis in DNA repair genes may identify children treated with radiation therapy for brain tumors at increased risk for treatment toxicity and adverse neurocognitive outcomes.

MATERIALS

The Human 660W-Quad v1.0 DNA BeadChip analysis (Illumina) was used to evaluate 1048 SNPs from 59 DNA repair genes in 46 subjects. IQ testing was measured by the Wechsler Intelligence Scale for Children. Linear regression was used to identify the 10 SNPs with the strongest association with IQ scores while adjusting for radiation type.

RESULTS

The low vs high IQ patient cohorts were well matched for time from first treatment to most recent IQ, first treatment age, sex, and treatments received. 5 SNPs on 3 different genes (CYP29, XRCC1, and BRCA1) and on 3 different chromosomes (10, 19, and 17) had the strongest association with most recent IQ score that was not modified by radiation type. Furthermore, 5 SNPs on 4 different genes (WRN, NR3C1, ERCC4, RAD51L1) on 4 different chromosomes (8, 5, 16, 14) had the strongest association with change in IQ independent of radiation type, first IQ, and years between IQ measures.

CONCLUSIONS

SNPs offer the potential to predict adverse neurocognitive outcomes in pediatric brain tumor survivors. Our results require validation in a larger patient cohort. Improving the ability to identify children at risk of treatment related neurocognitive deficits could allow for better treatment stratification and early cognitive interventions.

Genetic Predictors of Neurocognitive Outcomes in Survivors of Pediatric Brain Tumors

Purpose

Neurocognitive deficits are common in pediatric brain tumor survivors. The use of single nucleotide polymorphism (SNP) analysis in DNA repair genes may identify children treated with radiation therapy for brain tumors at increased risk for treatment toxicity and adverse neurocognitive outcomes.

Methods

The Human 660W-Quad v1.0 DNA BeadChip analysis (Illumina) was used to evaluate 1048 SNPs from 59 DNA repair genes in 46 subjects. IQ testing was measured by the Wechsler Intelligence Scale for Children. Linear regression was used to identify the 10 SNPs with the strongest association with IQ scores while adjusting for radiation type.

Results

The low vs high IQ patient cohorts were well matched for time from first treatment to most recent IQ, first treatment age, gender, and treatments received. 5 SNPs on 3 different genes (CYP29, XRCC1, and BRCA1) and on 3 different chromosomes (10, 19, and 17) had the strongest association with most recent IQ score that was not modified by radiation type. Furthermore, 5 SNPs on 4 different genes (WRN, NR3C1, ERCC4, RAD51L1) on 4 different chromosomes (8, 5, 16, 14) had the strongest association with change in IQ independent of radiation type, first IQ, and years between IQ measures.

Conclusions

SNP polymorphisms offer potential to predict adverse neurocognitive outcomes in pediatric brain tumor survivors. Our results require validation in a larger patient cohort. Improving the ability to identify children at risk of treatment related neurocognitive deficits could allow for better treatment stratification and early cognitive interventions.

Comparison of Neurocognitive Functioning and Fine Motor Skills in Pediatric Cancer Survivors and Healthy Children

Background: The late treatment outcomes of pediatric brain tumors and of hematopoietic and lymphoid tissue tumors are an important focus of both rehabilitation and research. Neurocognitive and motor disorders induce further learning problems impeding social-emotional adaptation throughout a whole lifespan. Core deficits in short-term and working memory, visuospatial constructional ability, verbal fluency, and fine motor skills underlie distorted intellectual and academic achievement. This study aimed to assess the individual differences in cognitive ability and fine motor skills of pediatric tumor survivors and the age-matched healthy controls. Methods: A total of 504 tumor survivors after treatment and 646 age-matched healthy controls underwent neurocognitive and fine motor assessments. Findings: The group of tumor survivors scored significantly worse in both neurocognitive and fine motor skill in compared with the healthy control group. The pediatric brain tumor survivors (PBT group) performed worse in cognitive (p < 0.001 for verbal fluency and p < 0.001 for visuospatial constructional ability) and motor tests (p < 0.001) compared to the healthy controls. Hematopoietic and Lymphoid Tissues tumors survivors (THL group) performed worse in verbal fluency (p < 0.01) and visuospatial constructional test (p < 0.001) compared to the control group. Furthermore, the PBT group had worse results in visuospatial constructional ability (p < 0.05) and fine motor (p < 0.001) ability than the THL group. Significant differences between females and males were found in fine motor test performance in the PBT group (p < 0.05), as well as in verbal fluency (p < 0.01) and visuospatial constructional ability (p < 0.01) in the control group. Neurocognitive and fine motor skill characteristics in the THL group did not correlate with age.

Processing efficiency in pediatric cancer survivors: A review and operationalization for outcomes research and clinical utility

OBJECTIVE

Childhood cancer and cancer-related treatments disrupt brain development and maturation, placing survivors at risk for cognitive late effects. Given that assessment tools vary widely across researchers and clinicians, it has been daunting to identify distinct patterns in outcomes across diverse cancer types and to implement systematic neurocognitive screening tools. This review aims to operationalize processing efficiency skill impairment-or inefficient neural processing as measured by working memory and processing speed abilities-as a worthwhile avenue for continued study within the context of childhood cancer.

METHODS

A comprehensive literature review was conducted to examine the existing research on cognitive late effects and biopsychosocial risk factors in order to conceptualize processing efficiency skill trends in childhood cancer survivors.

RESULTS

While a frequently reported pattern of neurobiological (white matter) and cognitive (working memory and processing speed) disruption is consistent with processing efficiency skill impairment, these weaknesses have not yet been fully operationalized in this population. We offer a theoretical model that highlights the impacts of a host of biological and environmental factors on the underlying neurobiological substrates of cancer survivors that precede and may even predict long-term cognitive outcomes and functional abilities following treatment.

CONCLUSION

The unified construct of processing efficiency may be useful in assessing and communicating neurocognitive skills in both outcomes research and clinical practice. Deficits in processing efficiency may serve as a possible indicator of cognitive late effects and functional outcomes due to the unique relationship between processing efficiency skills and neurobiological disruption following cancer treatment. Continued research along these lines is crucial for advancing childhood cancer outcomes research and improving quality of life for survivors.

Comparison of neuropsychological functioning in pediatric posterior fossa tumor survivors: Medulloblastoma, low-grade astrocytoma, and healthy controls

BACKGROUND

Neuropsychological comparison of medulloblastoma (MB) and cerebellar low-grade astrocytoma (LGA) survivors to controls can clarify treatment-related neurocognitive late effects. While both brain tumor groups undergo surgery to the posterior fossa, children with MB additionally receive craniospinal irradiation with boost and chemotherapy. This study provides an updated comparison of neuropsychological functioning in these two groups and examines effects of demographic risk factors upon outcomes.

PROCEDURE

Forty-two children (16 MB, nine LGA, and 17 controls) completed measures of intellectual functioning, verbal learning/memory, visual-motor integration, and fine-motor functioning. The effects of age at diagnosis, time since diagnosis, gender, fatigue, and social status on neuropsychological functioning were examined.

RESULTS

MB survivors demonstrated the worst neurocognitive late effects, but they were less severe and extensive than in prior studies. LGA survivors' mean scores were below normative expectations in working memory, processing speed, and fine-motor functioning. In this overall sample, processing speed difficulties were independent of fine-motor functioning and fatigue. Higher parental education was associated with better intellectual functioning, working memory, delayed recall, and visual-motor integration. Neuropsychological function was not associated with gender, age at diagnosis, or time since diagnosis.

CONCLUSION

The results support that contemporary treatment approaches with craniospinal irradiation plus boost and chemotherapy confer the greatest risk for late effects, while surgical resection is associated with subtle but important neurocognitive difficulties. Ultimately, this study furthers our understanding of factors impacting neuropsychological function in pediatric MB and LGA survivors and contributes to empirical support for close monitoring and targeted interventions into survivorship.

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.