Longitudinal follow-up of the intellectual and academic functioning of children receiving central nervous system-prophylactic chemotherapy for leukemia: a four-year final report

Cytokines in Pediatric Pilocytic Astrocytomas: A Clinico-Pathological Study

Pilocytic astrocytomas (PCA) are WHO Grade I tumors with a favorable prognosis. Surgical resection is usually curative. Nonetheless, progressive and/or metastatic disease occurs in 20% of patients. For these patients, treatment options are limited. The role of the immune system in PCA has not previously been reported. We hypothesize that the circulating cytokines contribute to tumorigenicity in PCA. This is an exploratory study with a focus on the identification of circulating cerebrospinal (CSF) cytokines associated with PCA. The primary objective is to demonstrate that CSF cytokines will be differentially expressed in the subset of PCAs that are difficult to treat in comparison to their surgically amendable counterparts. This is a single-institution, retrospective study of prospectively collected data. Patients with a confirmed histological diagnosis of PCA who have simultaneous intraoperative CSF sampling are included. Cerebrospinal fluid samples are subjected to multiplex cytokine profiling. Patient-derived PCA lines from selected patients in the same study cohort are cultured. Their cell culture supernatants are collected and interrogated using the sample multiplex platform as the CSF. A total of 8 patients are recruited. There were two patients with surgically difficult tumors associated with leptomeningeal involvement. Multiplex profiling of the cohort’s CSF samples showed elevated expressions of IFN-γ, IL-2, IL-12p70, IL-1β, IL-4, and TNF-α in these two patients in comparison to the remaining cohort. Next, primary cell lines derived from the same PCA patients demonstrated a similar trend of differential cytokine expression in their cell culture supernatant in vitro. Although our findings are preliminary at this stage, this is the first study in pediatric PCAs that show cytokine expression differences between the two groups of PCA with different clinical behaviors.

Auditory attention late effects in pediatric acute lymphoblastic leukemia

This study sought to characterize auditory attention functioning among pediatric Acute Lymphoblastic Leukemia (ALL) survivors treated on a chemotherapy-only protocol, given previous literature suggesting late impact on sustained visual attention. We hypothesized similar deficits would be observed in auditory attention relative to previous literature indicating weakness with aspect of visual attention in this population. Survivors (n = 107, 53 females, M = 12.80 years) completed the Conners Continuous Auditory Test of Attention (CATA). Parents completed the Behavior Assessment System for Children, Second Edition and reported educational performance and services via structured questionnaire. Results indicated several CATA indices associated with sustained auditory attention were significantly worse than normative data, though group means were average. Reflecting individual variability in performance, 50% of the sample performed worse than one standard deviation from the mean on at least one CATA variable. Parent report of attention did not differ from normative means for the sample. Parent-report data indicated that 60% of the sample utilized academic support services, with a large proportion of survivors having utilized special education services. Poorer performance with sustained auditory attention was associated with poor academic outcomes. Greater methotrexate exposure and younger age at diagnosis were risk factors for inattentiveness. No gender differences were identified on direct assessment of auditory attention or parent report of attention, though male gender was associated with poorer educational performance. Findings suggest that auditory attention is an at-risk cognitive domain following treatment for pediatric ALL, and that an association exists between auditory attention and school performance in this population.

Brain morphology and information processing at the completion of chemotherapy-only treatment for pediatric acute lymphoblastic leukemia

Background: Approximately 50% of survivors of childhood acute lymphoblastic leukemia (ALL) demonstrate cognitive impairments. However, the trajectory of change and contributing neuropathology is unclear, limiting our ability to tailor intervention content and timing. This study aimed to explore information processing abilities and brain morphology early post-treatment for pediatric ALL. Procedure: Twenty-one children at the end of ALL treatment and 18 controls underwent neuropsychological assessment. A subset also completed structural magnetic resonance imaging. Results: A principal component analysis generated two cognitive factors: information processing capacity and information processing speed. Compared to control group, the ALL group displayed deficits in capacity, but not speed. No group differences were identified in morphology. No relationship was identified between capacity or speed and morphology. Conclusion: Early cognitive intervention should target information processing abilities using a system-wide approach. Future studies should employ alternative imaging techniques sensitive to white-matter microstructure when exploring pathology underlying information processing deficits.

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.

Cognitive Changes in Cancer Survivors

Advances in cancer treatments have led to substantially improved survival for patients with cancer. However, many patients experience changes in cognition as a side effect of both cancer and cancer treatment. This occurs with both central nervous system (CNS) tumors and non-CNS tumors and in both children and adults. Studies of patients with non-CNS cancer have shown that cancer-related cognitive impairment (CRCI), which can include changes in memory, executive function, attention, and processing speed, occurs in up to 30% of patients prior to any treatment and in up to 75% of patients during treatment. A subset of patients with non-CNS and CNS cancer appear to be at higher risk for CRCI, so much research has gone into identifying who is vulnerable. Risk factors for CRCI in adults include cognitive reserve, age, genetic factors, and ethnicity; risk factors for children include genetic factors, female sex, younger age at diagnosis, chemotherapy dose, and both dose and field size for radiation. Although the field has made substantial strides in understanding and treating CRCI, more research is still needed to improve outcomes for both pediatric and adult cancer survivors.

The efficacy of cognitive interventions for improving cognitive performance and academic achievement in children after cancer treatment: A systematic review

Academic decline has been reported in children after cancer treatment, believed to be as a result of cognitive impairment. Cognitive interventions may improve both the present and future outcomes for children after cancer treatment by improving cognitive and/or academic performance. This review aimed to examine the efficacy of cognitive interventions in children who had received cancer treatment. A systematic search of the PsycInfo and PubMed databases was conducted in May 2015 to identify studies in which cognitive interventions were conducted with children who had undergone cancer treatment and were under the age of 21. Cognitive or academic outcomes needed to be reported pre- and post-intervention to meet the inclusion criteria. Eleven studies were included in this review. Computerized and home-based cognitive interventions were found to be most successful at improving cognitive skills. However, few cognitive interventions assessed academic achievement specifically. Future cognitive intervention research studies should include measures of academic achievement outcomes, because academic achievement and cognitive outcomes may differ. Future research regarding the effectiveness of early, home-based and computerized intervention is warranted.

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.

Intellectual development of childhood ALL patients: a multicenter longitudinal study

BACKGROUND

In childhood acute lymphoblastic leukemia (ALL), radiotherapy for CNS prophylaxis is not used in frontline therapy anymore. Standard treatment for ALL nowadays consists of polychemotherapy. Therefore, assessment of potential chemotherapy-induced cognitive side effects becomes important. Although neurotoxicity was demonstrated in cross-sectional studies, longitudinal studies remain scarce.

PROCEDURE

We evaluated intellectual development of 94 pediatric ALL patients between 1990 and 1997, diagnosed before the age of 12 years, treated according to the European Organisation for Research and Treatment of Cancer Children's Leukemia Group 58881 protocol. Three assessments of the Wechsler Intelligence Scale for Children Revised were performed since diagnosis, according to age. Using repeated measures regression analysis, we investigated the effect of gender (low versus increased) risk group, parents' education, age at diagnosis, intelligence quotient (IQ) subscale (verbal (VIQ) versus performance (PIQ) intelligence), and test session.

RESULTS

PIQ scores were lower than VIQ at baseline (-5.3 points on average, p = 0.0032), yet PIQ increased more strongly (PIQ: +3.9 points per test session; VIQ: +0.8, p = 0.0079), so this baseline difference disappeared (p = 0.0079). There were no clear effects of gender (girls: +0.6 points; p = 0.78) or risk group (low risk: +1.5 points; p = 0.49), but IQ scores were higher when one parent had followed higher education (+9.5 points, p < 0.0001). Finally, diagnosis at younger age predicted lower IQ scores (-1.3 points per year, p = 0.0009).

CONCLUSION

Given that IQ scores did not decline, our findings demonstrate a stable pattern. However, the lower PIQ scores at baseline may indicate that performance functioning is vulnerable to acute neurotoxicity. Also, lower scores for younger patients highlight the stronger impact of the disease and/or treatment at younger age.Copyright © 2016 John Wiley & Sons, Ltd.

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.

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.

Symptoms of attention-deficit/hyperactivity disorder in long-term survivors of childhood leukemia

BACKGROUND

Survivors of childhood acute lymphoblastic leukemia (ALL) sometimes have clinical features that suggest attention-deficit/hyperactivity disorder (ADHD), though few studies have examined specific symptoms in survivors.

PROCEDURE

Long-term survivors of childhood ALL (n = 161) received a neurological examination, while parents completed rating scales to establish formal criteria for ADHD. Symptom profiles were generated and compared across demographic and treatment characteristics, as well as medical tests associated with brain pathology.

RESULTS

Prevalence rates of ADHD were similar in survivors (10.5%) compared to those reported in the general population (7-10%). However, 25.5% of survivors reported symptoms that impair functioning in multiple settings, with attention problems being most common. These symptoms were associated with cranial radiation therapy (CRT) (mean inattentive symptoms [SD] = 3.6 [3.19] for group treated with CRT vs. 1.6 [2.40] for non-CRT group, P = 0.0006), and survivors who demonstrated impaired anti-saccades during the neurologic exam (mean inattentive symptoms [SD] = 3.4 [3.29] for those with impaired anti-saccades vs. 1.4 [2.41] for those with normal anti-saccades; P = 0.0004).

CONCLUSIONS

The presence of a neurologically-based phenotype of attention problems in survivors of leukemia that is not fully captured by the syndrome of ADHD suggests that treatments specific to childhood ALL should be explored.

Nicotinamide inhibits alkylating agent-induced apoptotic neurodegeneration in the developing rat brain

BACKGROUND

Exposure to the chemotherapeutic alkylating agent thiotepa during brain development leads to neurological complications arising from neurodegeneration and irreversible damage to the developing central nerve system (CNS). Administration of single dose of thiotepa in 7-d postnatal (P7) rat triggers activation of apoptotic cascade and widespread neuronal death. The present study was aimed to elucidate whether nicotinamide may prevent thiotepa-induced neurodegeneration in the developing rat brain.

METHODOLOGY/PRINCIPAL FINDINGS

Neuronal cell death induced by thiotepa was associated with the induction of Bax, release of cytochrome-c from mitochondria into the cytosol, activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP-1). Post-treatment of developing rats with nicotinamide suppressed thiotepa-induced upregulation of Bax, reduced cytochrome-c release into the cytosol and reduced expression of activated caspase-3 and cleavage of PARP-1. Cresyl violet staining showed numerous dead cells in the cortex hippocampus and thalamus; post-treatment with nicotinamide reduced the number of dead cells in these brain regions. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) and immunohistochemical analysis of caspase-3 show that thiotepa-induced cell death is apoptotic and that it is inhibited by nicotinamide treatment.

CONCLUSION

Nicotinamide (Nic) treatment with thiotepa significantly improved neuronal survival and alleviated neuronal cell death in the developing rat. These data demonstrate that nicotinamide shows promise as a therapeutic and neuroprotective agent for the treatment of neurodegenerative disorders in newborns and infants.

Risk factors for cognitive decline in children treated for brain tumors

The long term effects of central nervous system therapy for children with brain tumors have been the subject of research since the 1970s. Many studies have demonstrated that children treated for brain tumors with surgery and standard radiation therapy have developed intellectual decline which is progressive over at least a decade. Risk factors for this cognitive deterioration have been identified and include perioperative complications, possibly hydrocephalus, high radiation dose, large volume radiation, chemotherapy (especially methotrexate), radiation vasculopathy and young age at the time of treatment. In an effort to reduce long-term neurotoxicity, efforts have been made to develop treatment regimens that reduce the impact of these risk factors. Some of these include reduced neuraxis radiation with and without adjuvant chemotherapy, conformal radiation, chemotherapy only protocols for children with optic pathway-hypothalamic tumors and a series of baby brain tumor studies in which chemotherapy (standard and high dose) has allowed radiation to be delayed, reduced or omitted. Whether these changes in therapy will ultimately improve the quality of life of the long-term survivors is uncertain. Close follow-up of these children will be required throughout their lives.

Very high-dose methotrexate (33.6 g/m2) as central nervous system preventive therapy for childhood acute lymphoblastic leukemia: results of National Cancer Institute/Children's Cancer Group trials CCG-191P, CCG-134P and CCG-144P

Between 1977 and 1991, the Children's Cancer Group and the National Cancer Institute conducted three trials of very high-dose methotrexate (33.6 g/m2; VHD-MTX) in place of cranial radiation (CRT) as central nervous system (CNS) preventive therapy, and assessed efficacy, acute toxicity and long-term neurocognitive outcome. CCG-191P compared VHD-MTX to CRT plus intrathecal methotrexate (IT-MTX) in 181 patients and demonstrated equivalent survival. However, patients treated with CRT had poorer performance on neurocognitive testing over time. CCG-134P evaluated the addition of intensified systemic and intrathecal therapy to VHD-MTX in 128 patients with high-risk acute lymphoblastic leukemia (ALL) and demonstrated reduced CNS relapse compared to the CCG-191P trial, but equivalent survival. CCG-144P compared VHD-MTX to IT-MTX alone in 175 patients with average-risk ALL and demonstrated equivalent survival. VHD-MTX was associated with significant toxicities, particularly neutropenia, transient hepatic dysfunction and sepsis. VHD-MTX achieved similar survival to other CNS-directed therapies without the long-term impact on intelligence, but with substantial acute toxicities.

Effects of chemotherapy on neurocognitive function in children with acute lymphoblastic leukemia: a critical review of the literature

Chemotherapy-only treatment has increasingly become the standard of treatment for childhood acute lymphoblastic leukemia (ALL). The objective of this review is to assess the present state of knowledge of the neurocognitive effects of central nervous system (CNS)-directed chemotherapy in children with ALL, and to formulate directions for future research. We performed a review of studies published since 1997, that included an ALL group treated with chemotherapy only and a control group. Twenty-one studies met our inclusion criteria. There is evidence of subtle long-term neurocognitive deficits survivors of childhood ALL after treatment with chemotherapy only. These involve mainly processes of attention and of executive functioning, while global intellectual function is relatively preserved. Young age at diagnosis and female sex emerged as risk factors.

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.

Neurocognitive late effects of chemotherapy in children: the past 10 years of research on brain structure and function

Advances in the treatment of childhood cancers have greatly improved survivorship. Success has not come without cost, however, as survivors are at risk for late effects of treatment, including neurocognitive late effects (e.g., difficulties with thinking and reasoning). In the advent of chemotherapy-only protocols, researchers are examining neurocognitive sequelae of these agents to understand the specific role of chemotherapy in neurocognitive changes and the mechanism through which these occur. In this review, we examine the state of the literature on neurocognitive late effects after chemotherapy and their proposed neural mechanisms.

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.

A meta-analysis of the neurocognitive sequelae of treatment for childhood acute lymphocytic leukemia

BACKGROUND

Impaired neurocognitive functioning is one increasingly recognized long-term consequence of childhood ALL treatment. However, research findings have been inconsistent regarding the domains affected and the degree to which they are compromised.

PROCEDURE

A comprehensive meta-analytic review of the long-term neurocognitive effects of childhood ALL was conducted. Studies were included if they were published in English, reported original quantitative data on the post-treatment neurocognitive functioning of childhood ALL patients in first remission and control groups, and used neurocognitive measures with adequate psychometric properties and published normative data.

RESULTS

Data from 28 empirical studies yielding 13 effect sizes across nine domains were extracted and analyzed. All effects were negative (g = -0.34 to -0.71), demonstrating that ALL survivors consistently experienced significant deficits in intellectual functioning, academic achievement, and specific neurocognitive abilities compared to control groups. The role of potential moderators, including treatment with cranial irradiation, age at time of diagnosis, and time since treatment ended, was examined. However, no effects emerged as clearly and consistently moderated by these variables.

CONCLUSIONS

The results from this meta-analysis suggest that declines in both global and specific areas of areas of neurocognitive functioning occur as a result of contemporary ALL treatment. Such deficits have significant implications for survivors' academic achievement and overall quality of life. Neurocognitive assessment plays a critical role in determining what remedial or specialized instruction is needed in childhood ALL survivors and should be included as a standard part of long-term follow-up care.

Delayed neurotoxicity associated with therapy for children with acute lymphoblastic leukemia

Most children diagnosed today with acute lymphoblastic leukemia (ALL) will be cured. However, treatment entails risk of neurotoxicity, causing deficits in neurocognitive function that can persist in the years after treatment is completed. Many of the components of leukemia therapy can contribute to adverse neurologic sequelae, including craniospinal irradiation, nucleoside analogs, corticosteroids, and antifolates. In this review, we describe the characteristic radiographic findings and neurocognitive deficits seen among survivors of childhood ALL. We summarize what is known about the pathophysiology of delayed treatment-related neurotoxicity, with a focus on the toxicity resulting from pharmacologic disruption of folate physiology within the central nervous system. Finally, we suggest testable strategies to ameliorate the symptoms of treatment-related neurotoxicity or decrease its incidence.

Cognitive changes in children treated for acute lymphoblastic leukemia with chemotherapy only according to the Pediatric Oncology Group 9605 protocol

The purpose of this study was to examine cognitive functioning and neuroimaging in children with leukemia treated with the Pediatric Oncology Group 9605 protocol at the Children's Hospital of Eastern Ontario. Mean age at diagnosis was 4.88 +/- 2.54 years. The mean (n = 24) Wechsler Verbal and Performance IQ fell in the low-average range (87.33 +/- 15.69 and 84.83 +/- 19.11, respectively). Mean (n = 20) Verbal and Visual Memory Indexes of 82.95 +/- 15.46 and 88.30+/- 10.80, respectively, were obtained. The proportion of scores on measures of intelligence and memory falling > 1 SD below the normative mean was substantially higher than expected. Paired t-test suggested that Wechsler Verbal IQ and memory remained stable, whereas Wechsler Performance IQ declined significantly. The results of growth curve analyses replicated these findings and suggested a significant adverse effect of cumulative dosage of intrathecal methotrexate on estimated Wechsler Performance IQ. Although only two children experienced seizures, 78% of the group showed leukoencephalopathy on at least one magnetic resonance image. Reliance on seizures as a predictor of leukoencephalopathy might underestimate the incidence of neurotoxicity.

Anticancer agents are potent neurotoxins in vitro and in vivo

Neurotoxicity of anticancer agents complicates treatment of children with cancer. We investigated neurotoxic effects of common cytotoxic drugs in neuronal cultures and in the developing rat brain. When neurons were exposed to cisplatin (5-100 microM), cyclophosphamide (5-100 microM), methotrexate (5-100 microM), vinblastin (0.1-1 microM), or thiotepa (5-100 microM), a concentration-dependent neurotoxic effect was observed. Neurotoxicity was potentiated by nontoxic glutamate concentrations. The N-methyl-D-aspartate receptor antagonist MK 801 (10 microM), the AMPA receptor antagonists GYKI 52466 (10 microM) and NBQX (10 microM), and the pancaspase inhibitor Ac-DEVD-CHO (1 nM) ameliorated neurotoxicity of cytotoxic drugs. To investigate neurotoxicity in vivo, we administered to 7-day-old rats the following: cisplatin (5-15 mg/kg i.p.), cyclophosphamide (200-600 mg/kg i.p.), thiotepa (15-45 mg/kg), or ifosfamide (100-500 mg/kg) and their brains were analyzed at 4 to 24 hours. Cytotoxic drugs produced widespread lesions within cortex, thalamus, hippocampal dentate gyrus, and caudate nucleus in a dose-dependent fashion. Early histological analysis demonstrated dendritic swelling and relative preservation of axonal terminals, which are morphological features indicating excitotoxicity. After longer survival periods, degenerating neurons displayed morphological features consistent with active cell death. These results demonstrate that anticancer drugs are potent neurotoxins in vitro and in vivo; they activate excitotoxic mechanisms but also trigger active neuronal death.

Attentional ability among survivors of leukaemia treated without cranial irradiation

BACKGROUND

Previous research has indicated that children who have received treatment for leukaemia which includes cranial irradiation exhibit deficits in their ability to focus attention. It has been suggested that the use of cranial irradiation may have a role to play in long term sequelae.

AIMS

To investigate neuropsychological functioning among children treated for leukaemia without cranial irradiation.

METHODS

In a cross sectional study, 17 leukaemic patients and their sibling controls were assessed using a neuropsychological model of attention. All were treated on the UKALL XI protocol and none had received cranial irradiation. Participants completed the Arithmetic subtest and Digit Span subtest of the Weschler Intelligence Scale for Children-Revised to assess focus-encode elements of attention; the Coding subtest and the Speed of Information subtest of the BAS to assess focus-execute aspects of attention; the VIGIL computerised battery to assess sustain elements of attention; and the Wisconsin Card Sorting test to assess the ability to shift attention.

RESULTS

These children did not exhibit the deficits witnessed in previous cohorts, and were performing at comparable levels to their controls on all measures of attention

CONCLUSIONS

These findings suggest that children who have received treatment for leukaemia without the use of cranial irradiation do not show the neuropsychological insult found in earlier treatment groups.

Childhood cancer patients at school

The aim of this study was to assess the school-related problems of childhood cancer patients. A cross-sectional questionnaire study for school-aged children with extracranial malignancies, in the area of Turku University Hospital serving around 1000000 people. Siblings, healthy pupils and teachers were studied as controls. 43 patients responded. None of the patients or controls was placed in special educational programmes. However, 30.8% of the patients, 15.7% of the controls and 3.7% of the siblings had required extra tutoring. The patients' results differed statistically from both the siblings' (P=0.022) and the controls' (P=0.041) results. The school marks in mathematics (P=0.05) and in foreign languages (P=0.06) tended to be worse for the patients than for the healthy controls. Bullying was reported by 31.7% of the patients, 10.9% of controls (P=0.0012) and 8.3% of the siblings (P=0.056). The biggest problem faced by the cancer patients was bullying-the patients reported approximately 3 times as much bullying as the healthy children did. It seems that there are still several aspects which need to be reconsidered when these children return to school or start their school-life as survivors of childhood cancer. Some proposals are presented.

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.

Complications of treatment of paediatric malignancies

Advances in surgical techniques, radiotherapy and chemotherapy have led to improved survival for children with solid tumours and leukaemia. However, the treatment has also resulted in increased side effects both in the short and long term. This article outlines the complications which may arise as a result of treatment under the headings of surgery; chemotherapy; radiotherapy; organ specific complications; infection and graft-v-host disease.