A 3-year follow-up of the intellectual and academic functioning of children receiving central nervous system prophylactic chemotherapy for leukemia

The Psychoneuroimmunology of Stress Regulation in Pediatric Cancer Patients

Stress is a ubiquitous experience that can be adaptive or maladaptive. Physiological stress regulation, or allostasis, can be disrupted at any point along the regulatory pathway resulting in adverse effects for the individual. Children with cancer exhibit significant changes to these pathways in line with stress dysregulation and long-term effects similar to those observed in other early-life stress populations, which are thought to be, in part, a result of cytotoxic cancer treatments. Children with cancer may have disruption to several steps in the stress-regulatory pathway including cognitive-affective function, neurological disruption to stress regulatory brain regions, altered adrenal and endocrine function, and disrupted tissue integrity, as well as lower engagement in positive coping behaviours such as physical activity and pro-social habits. To date, there has been minimal study of stress reactivity patterns in childhood illness populations. Nor has the role of stress regulation in long-term health and function been elucidated. We conclude that consideration of stress regulation in childhood cancer may be crucial in understanding and treating the disease.

Cognitive function of children and adolescent survivors of acute lymphoblastic leukemia: A meta-analysis

Pediatric cancer and its treatment may have an impact on the neurocognitive functions of childhood cancer survivors (CCS). The aim of the present meta-analysis was to compare the intelligence quotient (IQ) scores between CCS of acute lymphoblastic leukemia (ALL) and controls. A comprehensive electronic search identified original research articles that reported scores of the Wechsler Intelligence Scale (WISC; WISC-III, WISC-IV and WISC-R) for children and adolescents, aged 6-16 years at evaluation, survivors of ALL and healthy controls. The included CCS had completed anticancer treatment and were in remission at the time of assessment. A total of 16 studies were included in the meta-analysis, out of 128 extracted studies, and involved a total of 1,676 children and adolescents: 991 CCS (ALL) and 685 healthy controls. Among the studies, a random effects model revealed a moderate estimate of effect size [standardized mean difference (SMD), -0.78; 95% CI, -1.05 to -0.50], indicating that the WISC scores for total IQ were significantly lower in the CCS than in the controls. The mean total IQ range was 85.2-107.2 in the CCS and 88.4-114.1 in the controls. The difference in the mean total IQ between controls and CCS ranged from -13.8 to 20.6. As regards the WISC scores for verbal IQ, 11 studies were included. A random effects model revealed a moderate estimate of effect size (SMD, -0.71; 95% CI, -1.05 to -0.38), indicating that the WISC scores for verbal IQ were significantly lower in the CCS than in the controls. Among the 9 studies that had available data for performance IQ scores, a fixed effect model revealed a moderate estimate of effect size (SMD, -0.80; 95% CI, -1.09 to -0.52), indicating that the WISC scores for performance IQ were significantly lower in the CCS than in the controls. As the survival rates of children and adolescents with ALL are steadily increasing, regular, lifelong follow-up for neurocognitive late effects is imperative in order to improve their education and employment prospects and overall, their quality of life.

Visual Attention and Math Performance in Survivors of Childhood Acute Lymphoblastic Leukemia

Objective

Attentional and academic difficulties, particularly in math, are common in survivors of childhood acute lymphoblastic leukemia (ALL). Of cognitive deficits experienced by survivors of childhood ALL, attention deficits may be particularly responsive to intervention. However, it is unknown whether deficits in particular aspects of attention are associated with deficits in math skills. The current study investigated relationships between math calculation skills, performance on an objective measure of sustained attention, and parent- and teacher-reported attention difficulties.

Method

Twenty-four survivors of childhood ALL (Mage = 13.5 years, SD = 2.8 years) completed a computerized measure of sustained attention and response control and a written measure of math calculation skills in the context of a comprehensive clinical neuropsychological evaluation. Parent and teacher ratings of inattention and impulsivity were obtained.

Results

Visual response control and visual attention accounted for 26.4% of the variance observed among math performance scores after controlling for IQ (p < .05). Teacher-rated, but not parent-rated, inattention was significantly negatively correlated with math calculation scores.

Conclusions

Consistency of responses to visual stimuli on a computerized measure of attention is a unique predictor of variance in math performance among survivors of childhood ALL. Objective testing of visual response control, rather than parent-rated attentional problems, may have clinical utility in identifying ALL survivors at risk for math difficulties.

Neurocognitive Predictors of Academic Outcomes Among Childhood Leukemia Survivors

BACKGROUND

Acute lymphoblastic leukemia is the most common pediatric cancer, and survival approaches 90%. Acute lymphoblastic leukemia survivors are more likely than healthy peers or siblings to experience academic underachievement, yet little is known about neurocognitive predictors of academic outcomes.

OBJECTIVES

Objectives were to compare neurocognitive abilities to age-adjusted standardized norms, examine change over time in neurocognitive abilities, and establish neurocognitive predictors of academic outcomes.

METHODS

Seventy-one children were followed over the course of therapy. Cognitive abilities were assessed during induction when the child was in remission (baseline) and annually for 3 years (years 1, 2, and 3). Reading and mathematics abilities were assessed at year 3.

RESULTS

Fine motor dexterity was significantly below age-adjusted norms at all data points but showed improvement over time. Baseline visual-motor integration was within the reference range but significantly declined by year 3, and mean scores at years 2 and 3 were significantly below age-adjusted norms. Verbal short-term memory was significantly below age-adjusted norms at all assessments. Visual-motor integration predicted reading and mathematics abilities. Verbal short-term memory predicted reading abilities, and visual short-term memory predicted mathematics abilities.

CONCLUSIONS

Central nervous system-directed therapy is associated with specific neurocognitive problems. Visual-spatial skills and verbal and visual short-term memory predict academic outcomes.

IMPLICATIONS FOR PRACTICE

Early assessment of visual-spatial perception and short-term memory can identify children at risk of academic problems. Children who are at risk of academic problems could benefit from a school-based individual educational program and/or educational intervention.

Oxidative Changes in Cerebral Spinal Fluid Phosphatidylcholine during Treatment for Acute Lymphoblastic Leukemia

Central nervous system (CNS) treatment contributes to improved long-term disease-free survival from childhood acute lymphoblastic leukemia (ALL) by sigificantly decreasing the rate of disease relapse. Methotrexate (MTX), a drug commonly used for CNS treatment, has been associated with cognitive and academic problems, white-matter changes, perfusion defects, and brain atrophy. This study investigated oxidative stress as a possible mechanism of chemotherapyinduced CNS injury. Unoxidized and oxidized components of phosphatidylcholine (PC), the most prevalent phospholipid in CNS cellular membranes, were measured in cerebral spinal fluid (CSF) samples obtained from 21 children diagnosed with low (n = 7), standard (n= 7), or high (n= 7) risk ALL. Children with high-risk ALL received the most MTX, especially during the most intensive phase of treatment (consolidation). Phospholipids were extracted from CSF samples obtained at diagnosis and during the induction, consolidation, and continuation treatment phases. Unoxidized and oxidized PC were measured by normalphase high-performance liquid chromatography at 2 ultraviolet wavelengths (206 and 234 nm, respectively). Data were analyzed by 2-way repeated-measures analysis of variance. Results support the hypotheses that the highest levels of oxidized PC would be observed during the most intensive phase of ALL therapy and in the high-risk ALL group. Findings provide preliminary evidence for chemotherapy-induced oxidative stress inCNSmembrane phospholipids.

Chemotherapy-induced neurotoxicity in pediatric solid non-CNS tumor patients: An update on current state of research and recommended future directions

Neurocognitive sequelae are known to be induced by cranial radiotherapy and central-nervous-system-directed chemotherapy in childhood Acute Lymphoblastic Leukemia (ALL) and brain tumor patients. However, less evidence exists for solid non-CNS-tumor patients. To get a better understanding of the potential neurotoxic mechanisms of non-CNS-directed chemotherapy during childhood, we performed a comprehensive literature review of this topic. Here, we provide an overview of preclinical and clinical studies investigating neurotoxicity associated with chemotherapy in the treatment of pediatric solid non-CNS tumors. Research to date suggests that chemotherapy has deleterious biological and psychological effects, with animal studies demonstrating histological evidence for neurotoxic effects of specific agents and human studies demonstrating acute neurotoxicity. Although the existing literature suggests potential neurotoxicity throughout neurodevelopment, research into the long-term neurocognitive sequelae in survivors of non-CNS cancers remains limited. Therefore, we stress the critical need for neurodevelopmental focused research in children who are treated for solid non-CNS tumors, since they are at risk for potential neurocognitive impairment.

Caregiver Sexual and HPV Communication Among Female Survivors of Childhood Cancer

Human papillomavirus (HPV) vaccination is recommended for all female survivors of childhood cancer; yet, it is underused. Parent-child sexual communication and health care provider recommendation for HPV vaccination influence familial vaccination decisions. However, caregivers may be less likely to discuss sexual health issues with survivors as compared to healthy peers. Therefore, this study compared mothers of daughters with/without history of childhood cancer on measures of sexual communication, HPV-specific communication, and health care provider recommendation for HPV vaccination, and examined the effects of sociodemographic and medical factors on these measures. There were no differences between mothers of survivors/noncancer survivors on the outcomes (Ps > .05). Among all mothers, daughter's age was associated with sexual communication (Ps < .05). Household income and daughter's age were associated with health care provider recommendation for vaccination (Ps < .05). Among mothers of survivors, daughter's age at diagnosis was associated with sexual communication, HPV-specific communication, and health care provider recommendation for vaccination (Ps < .05). Findings have implications for the role of health care providers as advocates for mother-daughter sexual communication and HPV vaccination, especially among survivors of childhood cancer.

The Association Between Motor Skills and Academic Achievement Among Pediatric Survivors of Acute Lymphoblastic Leukemia

OBJECTIVE

Assess the association between fine motor (FM) and visual-motor integration (VMI) skills and academic achievement in pediatric acute lymphoblastic leukemia (ALL) survivors.

METHODS

In this 28-site cross-sectional study of 256 children in first remission, a mean of 8.9 ± 2.2 years after treatment for standard-risk precursor-B ALL, validated measures of FM, VMI, reading, math, and intelligence were administered at mean follow-up age of 12.8 ± 2.5 years. 

RESULTS

 VMI was significantly associated with written math calculation ability (p < .0069) after adjusting for intelligence (p < .0001). VMI was more strongly associated with math in those with lower intelligence (p = .0141). Word decoding was also significantly associated with VMI but with no effect modification by intelligence. FM skills were not associated with either reading or math achievement.

CONCLUSION

These findings suggest that VMI is associated with aspects of math and reading achievement in leukemia survivors. These skills may be amenable to intervention.

Late effects of treatment in survivors of childhood cancer from a tertiary cancer center in South India

Background:

Improved survival after childhood cancer is attributed to intensive, aggressive therapy, adverse sequelae of which can manifest months to years after completion of treatment. There is little information about the late adverse effects of both childhood cancer and its therapy in survivors in India.

Aim:

To determine the long-term sequelae associated with therapy in childhood cancer survivors attending a tertiary cancer center in India.

Materials and Methods:

We studied 155 consecutive survivors of childhood cancer who were ≤14 years at the time of diagnosis and had completed 3 years of follow-up. The study included a complete history and clinical examination, with specific investigations to detect organ toxicity. Quality of life (QOL) was assessed from responses to a standardized questionnaire. Neurocognitive assessment was carried out in 20 survivors with an adaptation of the revised Wechsler adult intelligence scale for adults and the Malins intelligence scale for children.

Results:

The late effects included impaired fertility in 38 patients (24.5%), impaired growth pattern in 7 (4.5%), endocrine dysfunction in 7 (4.5%) and second malignancy in 2 (1.2%). Three of the 20 patients assessed had severe neurocognitive impairment. A high QOL was reported by 60% of survivors and an “average” QOL by 38%.

Conclusion:

Our study showed that most survivors had a good QOL and our results will help clinicians to better monitor childhood cancer survivors in countries with limited resources.

F2-isoprostanes: a measure of oxidative stress in children receiving treatment for leukemia

Acute lymphoblastic leukemia (ALL) is the most prevalent and curable cancer among children and adolescents less than 15 years of age in the United States. Essential for cure of childhood ALL is prophylactic treatment of the central nervous system (CNS), with methotrexate (MTX) being the most widely used drug in this treatment. While CNS treatment has contributed to long-term disease-free survival, resulting declines in academic abilities have been reported. There is growing evidence that CNS treatment with MTX increases oxidative stress, a potential mechanism of CNS injury. This article reports changes in oxidative stress, measured by the biomarker F2-isoprostane (F2-IsoP), in the cerebrospinal fluid (CSF) in 47 children with ALL during the first 18 months of treatment. The number of CSF samples ranged from 5 to 14 during postinduction and from 1 to 9 during continuation. Total doses of intrathecal MTX during postinduction were significantly correlated with the mean and highest concentrations of F2-IsoP during postinduction and the mean concentration of F2-IsoP during continuation. F2-IsoP concentrations during postinduction and continuation were higher in children who received more than six doses of intrathecal MTX. New therapies for a highly curable disease such as childhood leukemia have the potential to be individualized in the future, requiring reliable molecular and biochemical markers, such as oxidative stress indicators. Innovative use of biomarkers has the potential to increase our understanding of treatment-related toxicities and associated symptoms and to inform future therapeutic approaches for optimizing cure and quality of life among children with leukemia.

Comparison of intelligence quotient in children surviving leukemia who received different prophylactic central nervous system treatments

Background:

Neurocognitive deficits and decrease in intelligence quotient (IQ) is one of the complication of prophylactic central nervous system (CNS) treatment in acute lymphoblastic leukemia (ALL) patients. In this study, we compare the IQ in survivors of ALL that were treated with different prophylactic CNS treatments.

Materials and Methods:

We compared 43 long-term survivors of ALL: 21 survivors with intrathecal methotrexate (IT MTX) as CNS prophylaxis, 22 with IT MTX+1800-2400 rads cranial irradiation and 20 healthy controls. The IQ was measured using the Raven's test in these patients.

Results:

Raven's test revealed significant differences in IQ between the survivors of ALL that were treated with IT MTX, IT MTX plus cranial irradiation and control group. There was no significant difference in the IQ with respect to sex, age and irradiation dose.

Conclusion:

We can that reveal that CNS prophylaxis treatment, especially the combined treatment, is associated with IQ score decline in ALL survivors. Therefore,a baseline and an annual assessment of their educational progress are suggested.

Mathematics intervention for prevention of neurocognitive deficits in childhood leukemia

BACKGROUND

Despite evidence that CNS treatment is associated with cognitive and academic impairment, interventions to prevent or mitigate these problems are limited. The purpose was to determine if early intervention can prevent declines in mathematics abilities.

PROCEDURES

Fifty-seven children with ALL were enrolled and randomized to a Mathematics Intervention or Standard Care. Subjects completed neurocognitive assessments prior to the intervention, post-intervention, and 1 year later. Parents received written results and recommendations for use with their school. The Mathematics Intervention was based on Multiple Representation Theory and delivered individually over 1 year.

RESULTS

Thirty-two of 57 subjects completed the study and were included in data analyses. These 32 subjects completed all neurocognitive assessments and, for those in the Intervention Group, 40-50 hours of the Mathematics Intervention. There were no group differences on relevant demographic variables; risk stratification; number of intrathecal methotrexate injections; or high dose systemic methotrexate. Significant improvements in calculation and applied mathematics from Baseline to Post-Intervention (P = 0.003 and 0.002, respectively) and in visual working memory from Baseline to 1 year Follow-up (P = 0.02) were observed in the Intervention but not the Standard Care Group. Results from repeated measures ANOVA demonstrated significant between group differences for applied mathematics [F(2,29) = 12.47, P < 0.001] and visual working memory [F(2,29) = 5.53, P = 0.009].

CONCLUSIONS

The Mathematics Intervention improved mathematics abilities and visual working memory compared to standard care. Future studies are needed to translate the Mathematics Intervention into a "virtual" delivery method more readily available to parents and children.

Neurodevelopmental functioning in very young children undergoing treatment for non-CNS cancers

OBJECTIVE

We initiated a prospective study of very young children with cancer, in comparison with matched healthy children, to investigate neurodevelopmental consequences of non-CNS cancers and treatment.

METHODS

A total of 61 children (≤42 months) with non-CNS cancers and 61 matched controls underwent an identical age-appropriate neuropsychological test battery.

RESULTS

Children with cancer manifested deficits compared to healthy controls in motor, mental, and language development, but were similar to controls in cognitive representational abilities and emotional relationships in interaction with their mothers. Better physician-rated health status at diagnosis and mother-rated behavioral status 1 month prior to assessment were associated with better motor and mental performance in the cancer group.

CONCLUSIONS

This study identifies deficits as well as spared functions in children with non-CNS cancers; the results suggest ways parents and healthcare professionals may plan specific remediations to enhance quality of life in young cancer survivors.

Neurodevelopmental sequelae of pediatric acute lymphoblastic leukemia and its treatment

This review will describe the neurocognitive outcomes associated with pediatric acute lymphoblastic leukemia (ALL) and its treatment. The literature is reviewed with the aim of addressing methodological issues, treatment factors, risks and moderators, special populations, relationship to neuroimaging findings, and directions for future research. It is concluded that neurocognitive outcomes for the majority of children with standard-risk ALL treated according to current chemotherapy protocols is relatively good, but subgroups of children are more significantly compromised. As medical treatments advance and survival rates continue to improve, neurocognitive outcomes and other quality of life indicators will become increasingly important. Preventing or ameliorating treatment-related neuropsychological sequelae represents the next major challenge in pediatric ALL.

Cognitive outcome in children and adolescents treated for acute lymphoblastic leukaemia with chemotherapy only

Objective: To examine cognitive outcome in children and adolescents with acute lymphoblastic leukaemia (ALL) in remission, treated with central nervous system prophylactic chemotherapy only.

Method: Thirty-five children and adolescents, age 8.4–15.3 years in long-term remission from ALL, 4.2–12.4 years post diagnosis, without relapse and no prediagnosis history of neurodevelopmental disorder were compared with 35 healthy controls matched for gender and age, on measures of intellectual functioning Wechsler Intelligence Scale for Children-Third Edition (WISC-III).

Results: All but two of the ALL survivors treated by chemotherapy only obtained WISC-III Total Intelligence Quotient (IQ) scores in the normal range (M = 95.3), but their scores were significantly below levels for their matched controls and below normative standards for WISC-III. The difference between patients and controls was significant at the p < 0.001 level for the following measures: Total IQ, Verbal IQ, Verbal Comprehension Index, Freedom from Distraction Index and three verbal subtest scores.

Conclusion: The results indicate long-term sequelae in global cognitive functions, and indicate that verbal function, processing speed, attention and complex visual-spatial problem solving may be affected in the chemotherapy only group.

A meta-analysis of the neuropsychological sequelae of chemotherapy-only treatment for pediatric acute lymphoblastic leukemia

BACKGROUND

Mixed findings on the neuropsychological sequelae of chemotherapy-only treatment for pediatric acute lymphoblastic leukemia (ALL), without radiation, indicate the need for a comprehensive meta-analytic review. The purpose of the current study was to conduct a meta-analysis assessing neuropsychological and academic functioning differences between children with ALL treated solely with chemotherapy and comparison groups.

PROCEDURE

Thirteen articles met inclusion criteria for the meta-analysis and were analyzed using a random effects model, weighted least squares methods.

RESULTS

Mean effect sizes were significantly different from zero for multiple domains of intelligence and academic achievement; processing speed; verbal memory; and some aspects of executive functioning and fine motor skills, indicating worse functioning in ALL survivors. Effect sizes for visual-motor skills and visual memory were not significantly different from zero.

CONCLUSIONS

Results support the presence of neuropsychological and academic sequelae for ALL survivors treated solely with chemotherapy and highlight the need for ongoing follow-up of children with ALL using a standardized neuropsychological test battery and research methodology.

Reduced frontal white matter volume in long-term childhood leukemia survivors: a voxel-based morphometry study

BACKGROUND AND PURPOSE

To our knowledge, no published studies have examined whole-brain regional differences to identify more discrete volumetric changes in the brains of childhood leukemia survivors. We used voxel-based morphometry (VBM) to examine regional gray and white matter differences in a group of long-term survivors of acute lymphoblastic leukemia (ALL) compared with a group of healthy controls. Differences in regional white matter volume were expected, given previous reports of white matter changes during treatment for ALL and reduced brain white matter volumes in long-term survivors. Follow-up analyses examined the relationship of regional brain volumes to cognitive function.

MATERIALS AND METHODS

We compared 9 long-term survivors of ALL with 14 healthy controls. Survivors of ALL were treated with systemic and intrathecal chemotherapy only. T1-weighted axial 3D spoiled gradient high-resolution images collected on a 1.5T MR imaging scanner were used for the VBM analysis. Neuropsychological evaluations were conducted within 2 months of the MR imaging to assess cognitive function.

RESULTS

VBM analysis revealed 2 specific regions of reduced white matter in the right frontal lobes of survivors of ALL compared with healthy controls. Survivors of ALL had lower performances on tests of attention, visual-constructional skills, mental flexibility, and math achievement compared with healthy individuals. Decreased performance on neuropsychological measures was associated with decreased regional white matter volumes. No differences were found between the groups with respect to gray matter regions.

CONCLUSION

These findings are consistent with previous literature describing the long-term cognitive, academic, and imaging findings of survivors of ALL and suggest that right frontal white matter is particularly vulnerable to disruption following intensive chemotherapy for ALL. Future studies should focus on further clarifying the white matter changes observed.

Scholastic Achievements of Childhood Leukemia Patients: A Nationwide, Register-Based Study

Purpose

Studies concerning the scholastic achievement of survivors of childhood leukemia have yielded controversial results. We studied the school marks of childhood leukemia survivors in a register-based study.

Patients and Methods

Three hundred seventy-one patients with a diagnosis of leukemia before the age of 16 years who were born between 1974 and 1986 and alive on their 16th birthday were identified from the Finnish Cancer Registry. Five matched controls were sought for each patient from the Population Register Center of Finland. Information on the ninth-grade school report was obtained from Statistics Finland. The overall mark average and the marks (scale 4 to 10) for mother tongue, foreign language, mathematics, and physical education were compared between the patients and controls.

Results

The ninth-grade school report was obtained by 97.6% of the patients and 98.5% of the controls. The patients whose treatment included cranial irradiation had a lower overall mark average (mean difference, −0.24; 95% CI, −0.33 to −0.15) and lower marks for all assessed school subjects compared with their controls. Of the patients treated with chemotherapy alone, only the females with leukemia diagnosed before 7 years of age had lower school marks than their controls. The biggest difference was observed in the marks for foreign language among the irradiated females diagnosed at a young age (mean difference, −1.0; 95% CI, −1.25 to −0.74).

Conclusion

Leukemia treatment that includes cranial irradiation impairs scholastic achievement. It is noteworthy that treatment of leukemia with chemotherapy alone impairs school performance only in females diagnosed before school age.

Almost normal cognitive function in patients during therapy for childhood acute lymphoblastic leukemia without cranial irradiation according to ALL-BFM 95 and COALL 06-97 protocols: results of an Austrian-German multicenter longitudinal study and implications for follow-up

In a multicenter study the authors prospectively investigated neurocognitive function in childhood ALL patients. Sixty-six patients (mean age at diagnosis 7.9 +/- 3.6 years, 34 female), treated with repeated intrathecal and systemical methotrexate administrations without cranial irradiation, underwent psychometric testing for intelligence, concentration, and visual-motor integration postdiagnosis and after reinduction therapy. Although there was a statistically significant decline of intellectual function after reinduction therapy for younger patients and girls (IQ scores still within normative data range), there were no differences in visual-motor performance and concentration over the time of induction therapy. Thus, neurocognitive examination should focus on younger ALL patients and girls.

Post-treatment intellectual functioning in children treated for acute lymphoblastic leukaemia (ALL) with chemotherapy-only: A prospective, sibling-controlled study

Intellectual functioning (verbal, performance and full-scale IQ) in 43 children treated for acute lymphoblastic leukaemia (ALL) with chemotherapy-only was evaluated in a nationwide, prospective, sibling-controlled study. Intellectual assessment was performed at diagnosis and repeated shortly after cessation of 2 years treatment, including intrathecal and systemic chemotherapy. Using hierarchical regression analysis, patients' and siblings' (n=27) scores were longitudinally analysed and compared to assess possible changes and differences over time. At both assessments, before and after treatment, the patients showed average scores on intelligence tests compared to population norms. Longitudinal analysis and cross-sectional comparisons revealed no significant differences between patients and controls. Young patients showed a small relative decline, albeit not significant, on performance-IQ compared to healthy siblings. Despite intensive and potentially neurotoxic treatment, no evident negative effects on intelligence were found. However, it cannot be precluded that younger patients are at risk for a small decline in PIQ.

Family impact of neurodevelopmental late effects in survivors of pediatric cancer: review of research, clinical evidence, and future directions

Children and adolescents who have survived childhood cancer are vulnerable to late effects of their disease and treatment experience, including both physical and psychological sequelae. The neurodevelopmental (ND) sequelae (e.g., difficulties with attention, memory, information processing, and other executive functions) faced by children surviving central nervous system (CNS) cancers or CNS treatments can have a range of effects on their psychological adjustment and quality of life as they reintegrate into school and social settings. Survivors facing such difficulties may be influenced by their family environment, and these struggles may in turn impact the perceived burden of their parents and family system, suggesting a bidirectional framework for understanding the impact of ND late effects within the family. The current study summarizes the following: Findings of family outcomes in children with ND late effects of cancer treatment; evaluation of methodological and measurement issues; the importance of examining bidirectional family-child influences; and implications for future survivorship research and clinical care addressing the role of ND late effects from a systems perspective.

Cytosine arabinoside induces programmed endothelial cell death through the caspase-3 pathway

The anti-cancer effects of cytosine arabinoside (ARA-C) are well known. However, effects on nonmalignant cells have not been elucidated and may be important to understanding treatment-related toxicity. The purpose of this study was to examine the effect of ARA-C on nondividing vascular endothelial cells. The objectives were to determine the effects of ARA-C on cell viability and to ascertain whether ARA-C caused apoptosis in cultured vascular endothelial cells and hydrocortisone blunted caspase-3-induced apoptosis. Endothelial cells were cultured until confluent and mitotically quiescent then exposed to ARA-C (10(-7)to 10(-3) M) for 1 to 4 days. Some experiments involved cotreatment with hydrocortisone (10(-11),10(-10),10(-4), and 10(-3) M). Light microscopy and the colorimetric MTS assay were used to measure viability. Fluorescent annexin-V and DNA fragmentation assays were used to measure apoptosis, and a fluorescence-based enzymatic assay was used to measure caspase-3 activity, which is one pathway involved in the apoptosis cascade. Two-way ANOVA or the appropriate nonparametric test was used to determine statistical significance in studies of viability and apoptosis. Oneway ANOVA was used to determine statistical significance for caspase-3 activity. Viability was decreased with higher concentrations of ARA-C and increased days of treatment. The percentage of apoptotic cells increased with higher concentrations of ARA-C and increased days of treatment. ARA-C-treated samples showed DNA fragmentation, indicative of apoptosis. Caspase-3 activity increased after ARA-C addition; hydrocortisone blunted this increase. ARA-C caused apoptosis in nondividing endothelial cells in culture. Hydrocortisone may protect against ARA-C-induced apoptosis by reducing caspase-3 activity.

Long-term effects of radiation therapy on cognitive and endocrine function in children with leukemia and brain tumors

BACKGROUND

As the number of long-term survivors of childhood cancer has grown, it has become increasingly clear that central nervous system therapy may have serious long-term effects on cognition and endocrine function. These complications have been studied most extensively in children with brain tumors and leukemia.

REVIEW SUMMARY

Children with acute lymphoblastic leukemia previously treated with cranial irradiation are at risk for cognitive decline. Chemotherapy-only regimens, which rely on high-dose frequently administered methotrexate, are also associated with producing cognitive dysfunction. Children irradiated for brain tumors are even more vulnerable. Risk factors include perioperative morbidity, young age, large-volume high-dose cranial irradiation, supra-tentorial location of tumor, moyamoya syndrome, and leukoencephalopathy. Cognitive decline is progressive over at least a decade. The most common radiation-induced endocrinopathies are hypothyroidism and growth hormone deficiency. Treatment effects on growth are multifactorial and include growth hormone deficiency,spinal shortening, precocious puberty, undetected hypothyroidism,and poor nutrition. Fifty percent to 80% of children treated with craniospinal radiation for brain tumors will experience growth failure. In hopes of reducing neurotoxicity, current treatments limit the dose and volume of radiation while adding chemotherapy. Results have not been uniformly positive, however, and may increase toxicity in some cases.

CONCLUSIONS

The standard of care in 2004 is that children who have been treated for brain tumors and leukemia should be monitored for cognitive and endocrine dysfunction. Until effective non-neurotoxic treatment is identified, long-term effects assessments are essential to maximize the quality of life of survivors of childhood cancer.

Evaluating Survivors of Pediatric Cancer

The past 3 decades have seen tremendous improvements in the survival of children diagnosed with cancer, with the 5-year survival rate approaching 80%. This improvement in survival has resulted in a growing population of childhood cancer survivors. Use of cancer therapy at an early age can produce complications that may not become apparent until years later. Approximately two thirds of the survivors of childhood cancer experience at least one late effect and about one fourth experience a late effect that is severe or life-threatening, although psychosocial issues in survivors and family members are often underestimated and may be more prevalent. Long-term complications in childhood cancer survivors, such as impairment in growth and development, neurocognitive dysfunction, cardiopulmonary compromise, endocrine dysfunction, renal impairment, gastrointestinal dysfunction, musculoskeletal sequelae, and subsequent malignancies, are related not only to the specific therapy used but also may be determined by individual host characteristics. We review the known late effects in survivors of childhood in order to suggest reasonable starting points for the evaluation of specific long-term problems in this unique but growing population.

Attention and information processing in survivors of childhood acute lymphoblastic leukemia treated with chemotherapy only

BACKGROUND

Omitting radiotherapy for central nervous system (CNS) prophylaxis has improved the overall quality of life for long-term survivors of childhood acute lymphoblastic leukemia (ALL). However, recent reports suggest minor cognitive impairment in survivors who received chemotherapy only.

PROCEDURE

This study focused on attentional functioning and speed of information processing in 23 children previously treated for ALL according to EORTC 58881 and EORTC 58951 protocol. Patients received intrathecal methotrexate combined with high doses intravenous methotrexate as CNS prophylaxis. Cognitive functioning was assessed with the Amsterdam Neuropsychological Tasks, a computerized attention assessment program. Variables of both speed and accuracy of the patients were compared with those obtained from 23 age- and sex-matched control children.

RESULTS

Patients were equal to control children concerning baseline speed, sustained attention, response inhibition, and response organization. However, they were significantly slower than controls in three tasks: encoding, memory search letters, and focused attention 4-letters. Interactions with the difficulty of the task were found. There were no differences in number or type of errors between groups on all tasks.

CONCLUSIONS

ALL survivors treated with chemotherapy have specific information processing difficulties. They process information slower than control children, especially when more information has to be processed or when attention has to be focused precisely. In spite of being slower, patients are equally accurate compared to control children.

Online exclusive: behavioral adjustment of children and adolescents with cancer: teacher, parent, and self-report

PURPOSE/OBJECTIVES

To describe behavioral adjustment in children and adolescents with acute lymphoblastic leukemia (ALL) and to determine whether behavioral adjustment is correlated with cognitive and academic abilities.

DESIGN

Descriptive, cross-sectional design.

SETTING

Two pediatric oncology treatment centers.

SAMPLE

47 children and adolescents who had been receiving ALL therapy for at least one year or who were off therapy for no more than three years and their parents and teachers. Wechsler Intelligence Scale for Children-Revised (WISC-R) and Wide Range Achievement Test-Revised (WRAT-R) data were available on a subset of 17 subjects.

METHODS

Parent, teacher, and self-report Behavioral Assessment System for Children (BASC) ratings were used to measure behavioral adjustment. WISC-R measured cognitive abilities, and WRAT-R measured academic abilities. Demographic, family, and treatment-related data also were collected.

MAIN RESEARCH VARIABLES

Behavioral adjustment and cognitive and academic abilities.

FINDINGS

At least 20% of teacher ratings for somatization, learning problems, leadership, and study skills; parent ratings for somatization, adaptability, attention problems, withdrawal, anxiety, social skills, and depression; and self-report ratings for anxiety and attitude to school were in the at-risk range (i.e., presence of significant problems that require treatment). The majority of teacher BASC ratings were correlated significantly with WISC-R and WRAT-R scores. Self-report depression and social stress ratings were correlated significantly with some WISC-R and WRAT-R scores. Treatment-related experiences such as body image alterations and mental and emotional problems were associated with problematic behaviors, including depression, somatization, withdrawal, and social stress.

CONCLUSIONS

Youth with ALL are at risk for some behavioral adjustment problems, particularly anxiety, somatization, adaptability, attention, and withdrawal. Cognitive and academic abilities are associated with some dimensions of behavioral adjustment.

IMPLICATIONS FOR NURSING

Findings suggest the need for ongoing assessment of behavioral adjustment and cognitive and academic abilities of children with ALL. Behavioral interventions that target at-risk mannerisms, such as somatization, depression, anxiety, and social stress, are needed. Central nervous system treatment may contribute to behavioral adjustment problems, as well as to cognitive and academic problems. Strategies to improve academic abilities also may have a positive effect on behavioral adjustment.

CNS late-effects after ALL therapy in childhood. Part III: neuropsychological performance in long-term survivors of childhood ALL: impairments of concentration, attention, and memory

PURPOSE

To date, the event free survival (EFS) after treatment of childhood acute lymphoblastic leukemia (ALL) attains 80%. The survivor group is growing steadily. Therefore, the primary purpose of our study is to define the neuropsychological function and to describe which central nervous system (CNS) functions are impaired following the German ALL-BFM and COALL protocols for CNS-negative patients.

PATIENTS AND METHODS

In a cross-sectional multicenter study 121 subjects, long-term survivors of childhood ALL in first continuous complete remission were investigated. Seven years ago, the subjects were treated as standard or medium risk patients according to ALL-BFM 81, ALL-BFM 83, or COALL 82 protocols, receiving comparable treatments. According to different CNS-prophylaxes, two subgroups were compared in the study: the non-cranially irradiated MTX-group (methotrexate-group) (n = 38) and the cranially irradiated RT-group (radiotherapy-group) (with MTX i.th.) (n = 83). Intellectual and cognitive abilities of these groups were evaluated using standardized psychometric techniques. The Kaufman factors Verbal Comprehension, Perceptual Organisation and Freedom from Distractibility were calculated. Demographical and clinical data collected at the time of the diagnosis were compared between both groups. The different prognoses for patients within both groups were taken into account using a defined risk factor. Analysis of variance was conducted to relate intellectual performance to age, gender, and CNS-treatment.

RESULTS

The RT-group exhibited a lower Full Scale IQ than the MTX-group (101.2 +/- 15.9 vs. 109.9 +/- 14.9, P = 0.031). Particularly for the Kaufman factor Freedom from Distractibility the RT-group showed the lower scores (96.9 +/- 14.1 vs. 105.5 +/- 12.6, P = 0.037). Significant interactions between gender and CNS prophylactic treatment were observed for Full Scale IQ (P = 0.008), Verbal IQ (P = 0.012), Performance IQ (P = 0.024), Verbal Comprehension (P = 0.004), and Perceptual Organisation (P = 0.032).

CONCLUSIONS

Cranial irradiation in combination with MTX therapy was associated with deficits in attention, concentration, and the ability of sequencing and processing, measured by the Kaufman factor Freedom from Distractibility. Our results support the strategy of avoiding prophylactic CNS irradiation in low risk patients.

No major cognitive impairment in young children with acute lymphoblastic leukemia using chemotherapy only: a prospective longitudinal study

PURPOSE

To study, using serial neuropsychological assessment and evaluation of school achievement, persistent neuropsychological late effects in children treated for acute lymphoblastic leukemia (ALL) at a young age with chemotherapy only.

PATIENTS AND METHODS

Twenty consecutive patients underwent three evaluations, including 12 psychometric measures beside IQ. The authors applied strict methodology and a prospective-longitudinal design that started at diagnosis and extended to a median follow-up of 7 years. This report focuses on the outcome of the last evaluation. Test results were compared with healthy controls and to patients with ALL treated on a previous chemotherapy-only protocol. School achievement was evaluated in patients and their siblings.

RESULTS

At the last evaluation, significantly lower test scores in patients compared with controls were found for only 2 of 14 cognitive measures (1 intelligence and 1 attention measure). No great differences were seen between school achievement of patients and siblings. Compared with the previous chemotherapy protocol, a better outcome was seen in the current study group on two measures (one memory and one attention measure).

CONCLUSIONS

Children surviving ALL have no major cognitive impairment after chemotherapy, including intrathecal and high-dose intravenous methotrexate. The slightly better outcome in the current group may indicate possible adverse effects of more dexamethasone treatment in the previous group.

Slight cognitive impairment and magnetic resonance imaging abnormalities but normal school levels in children treated for acute lymphoblastic leukemia with chemotherapy only

OBJECTIVES

To investigate persistent neuropsychologic late effects in children treated for acute lymphoblastic leukemia at a young age with chemotherapy only by means of serial neuropsychologic assessments (NPAs), magnetic resonance imaging (MRI) of the brain, and evaluation of school levels.

STUDY DESIGN

Consecutive patients (n = 17) had 2 extensive NPAs (12 psychometric measures) after cessation of therapy. Test results were compared with those of both healthy control subjects and 28 previously treated children who received cranial irradiation. MRI findings were related to test scores. School levels were evaluated in the patients and their healthy siblings.

RESULTS

Initial participation (n = 17) and availability of the study group after 8 years of follow-up were 100%. Significant group differences between patients who received chemotherapy and healthy control subjects were found for memory and fine-motor functioning. The 17 patients combined showed 16 deficits on various test measures. MRI abnormalities were seen in 6 children, but these did not correlate with cognitive performance. No differences in school levels were seen when the patients who received chemotherapy were compared with their siblings. The current nonirradiated patients demonstrated significantly better test results and significantly fewer learning disabilities and MRI abnormalities than did the previously irradiated group.

CONCLUSION

Treatment with chemotherapy only may be associated with some cognitive impairment. However, these children attained normal school levels.

Eine Übersicht über kognitiv, behaviorale und psychosoziale Langzeitfolgen nach pädiatrischen Hirntumoren

Zusammenfassung. In diesem Beitrag wird ein Überblick über die kognitiven, behavioralen und psychosozialen Langzeitfolgen bei Kindern und Jugendlichen mit Hirntumoren gegeben. In der Übersicht wird deutlich, daß die kognitiven Leistungen der pädiatrischen Hirntumor-Patienten (insb. nach Radiatio) deutlich stärker beeinträchtigt sind als bei Kindern mit Leukämieerkrankung nach ZNS-Bestrahlung. Verbunden damit, aber auch aufgrund der großen Häufigkeit von Verhaltensauffälligkeiten, wird die schulische Reintegration als schwierig beschrieben. Die massiven kognitiven Beeinträchtigungen und Verhaltensauffälligkeiten der Hirntumor-Kinder machen die Notwendigkeit der Konzeption und Evaluation von Rehabilitations- und Beratungsmaßnahmen für die betroffenen Kinder und ihre Eltern deutlich.

Cognitive consequences and central nervous system injury following treatment for childhood leukemia

OBJECTIVES

To determine the relationship between membrane damage and intellectual and academic abilities in children with acute lymphoblastic leukemia (ALL) and pilot test a math intervention for children with ALL who were affected.

DATA SOURCES

Research studies and review articles.

CONCLUSIONS

Despite the prophylactic central nervous system (CNS) treatment for long-term disease-free survival, many children with ALL subsequently experience declines in intellectual and academic skills.

IMPLICATIONS FOR NURSING PRACTICE

Improving academic abilities in children who have received CNS treatment is of high priority and may have longlasting implications on quality of life.

Methotrexate causes apoptosis in postmitotic endothelial cells

Methotrexate (MTX) is a commonly used chemotherapy agent for a variety of cancers. However, therapeutic levels are associated with numerous untoward effects such as central nervous system damage in children with acute lymphoblastic leukemia. The purpose of this study was to determine if MTX caused injury to endothelial cells using cultured bovine pulmonary artery endothelial cells as a model. Light microscopy showed gaps between cells and reduced numbers of endothelial cells after exposure to MTX (10(-9) to 10(-5) M), a range consistent with therapeutic drug levels. Proliferation and viability of subconfluent and confluent MTX-treated endothelial cells were measured by colorimetric (MTS) assay. There was a significant decline in cell numbers in MTX-treated subconfluent (growing) cells cultured after 4 days of MTX exposure compared to controls, as expected. However, there was also an unexpected decline in cell numbers in MTX-treated postmitotic endothelial cells after 1, 3, and 4 days of drug exposure. This suggested that MTX induced endothelial cell death. Fluorescent ApoAlert Enhanced Annexin-V binding demonstrated apoptosis in endothelial cells after 1 day of MTX exposure. Apoptosis was confirmed by a DNA fragment assay. This is apparently the first report of MTX-induced apoptosis of postmitotic, cultured endothelial cells. The findings suggest that apoptosis may be one mechanism of MTX-induced injury to endothelial cells.

Review of research studies that evaluated the impact of treatment for childhood cancers on neurocognition and behavioral and social competence: nursing implications

ISSUES AND PURPOSE

Given the increasing incidence of childhood cancer, increasing survivor rates, and documented incidence of sequelae, nurses need evidence on which to base interventions for families at risk. The authors review and critique research studies that evaluated the impact of treatment for childhood cancers. Implications for nursing practice are discussed.

CONCLUSIONS

Research to evaluate the effects of treatment on neurocognition and behavioral and social competency of children with cancer has produced conflicting results. Most studies found deleterious effects on all three areas associated with childhood cancer treatment. Some studies, however, found no differences between childhood cancer survivors and children on therapy compared to normative data or healthy controls.

PRACTICE IMPLICATIONS

Knowledge of the short- and long-term impact of treatment for childhood cancer on neurocognition and behavioral and social competence allows nurses to design interventions that mitigate neurocognitive effects, decrease behavioral problems, and improve social competence.

Social skills and psychological adjustment of child and adolescent cancer survivors

Social skills and psychological adjustment for survivors of childhood cancer were investigated. Cancer survivors included 42 children and adolescents ranging in age at evaluation from 6 to 18 years with a mean age of 13.1 years. Measures included teacher and parent ratings of social skills and adjustment and parent ratings of family functioning. The findings showed that social skills and psychological adjustment as rated by both parents and teachers were primarily associated with academic functioning. In addition, family cohesiveness was found to account for nearly one third of the variance in survivors' adjustment when rated by teachers, and length of time off treatment accounted for a significant percentage of the variance in children's adjustment when rated by parents. The findings underscore the importance of a multi-informant approach to the assessment of psychological adjustment of pediatric cancer survivors and demonstrate the role of learning difficulties and family functioning in influencing social skills and adjustment for these children and adolescents.

Identifying the educational implications of chronic illness in school children

Children and adolescents with chronic illness such as asthma, diabetes, and cancer are at the intersection of the health and education systems. At school, their health needs may be attended to by a school nurse, while their educational needs may be overlooked. This article helps school personnel become more proactive in identifying the educational implications of chronic illness in school children. The confusing array of terms used to refer to this population by health professionals and educators are clarified, and estimates of the size of the population are provided. The potential impact of some common disease processes, treatments, and medications are reviewed, as are the risks of chronic absenteeism. Suggestions for how school and health professionals can identify and work with this group of children are offered.