Neuropsychological Performance and Its Predictors in the Early Treatment Phase of Non-CNS Pediatric Cancer

BACKGROUND

Pediatric cancer survivors can experience neuropsychological problems in the long term. Less is known about neuropsychological performance and its possible predictors in the early treatment phase of non-central nervous system (CNS) cancers.

PROCEDURE

This study describes the neuropsychological performance of 104 children with leukemia (n = 43), lymphoma (n = 29), or a non-CNS solid tumor (n = 33) aged 5-18 years at diagnosis (M = 11.78, SD = 3.71, 48% female), 4.52 months (SD = 0.77) after diagnosis. Using one-sample t-tests, measures of IQ, attention, memory, working memory, verbal fluency, processing speed, and reading were compared to age-matched norm scores. Individual comparisons were performed with paired t-tests, comparing participants' neuropsychological scores to their estimated IQ (EIQ). Multiple regression analyses related medical factors, pre-existing developmental vulnerabilities, and family psychosocial risk to neuropsychological outcomes, corrected for age at diagnosis, sex, and EIQ.

RESULTS

EIQ was significantly above the population mean (M = 105.25, SD = 12.15, p < 0.05), and most neuropsychological outcomes were within the average range compared to age-matched norms. Compared to their EIQ, however, participants' scores were on average significantly lower for almost all neuropsychological outcomes (p < 0.05). Medical factors, developmental vulnerabilities, and family psychosocial risk were not associated with neuropsychological outcomes (p > 0.05) in multivariable models. In a follow-up analysis, family psychosocial risk was related to memory (p < 0.05).

CONCLUSIONS

Children with non-CNS cancers perform within the average range on most neuropsychological tests. However, most scores are lower than participants' EIQ, revealing potential vulnerabilities. Family psychosocial risk may relate to memory. Future studies should include longitudinal follow-up and alternative predictors to clarify what contributes to early neuropsychological difficulties.

Fine Motor Impairment and Its Impact on Social Outcomes in Survivors of Pediatric Acute Lymphoblastic Leukemia: St. Jude Lifetime Cohort Study

AOBJECTIVE

The impact of fine motor impairment among adult survivors of childhood acute lymphoblastic leukemia (ALL) on life after treatment is unknown.

METHODS

This study evaluated prevalence and utilized multivariate logistic regression to identify risk factors for fine motor impairment among survivors of ALL, and associations with educational attainment and social independence. Latent class analysis defined social independence (independent, moderately independent, dependent), using employment, independent living, personal care assistance, routine need assistance, driver's license status, and marital status inputs.

RESULTS

Among 875 survivors who were ≥ 25 years old (age when most adults achieve independence) and ≥ 5 years from diagnosis (mean = 28.97 years), 33.6% had fine motor impairment, with scores at or below the 10th percentile of the scores of community controls (n = 460) on fine motor components of the physical performance test and the grooved peg-board test. Survivors exposed to cranial radiation had more fine motor impairment than those without (45.8% vs 20.2%). Male sex (exposed: odds ratio [OR] = 2.55, 95% confidence interval [CI] = 1.65-3.92; unexposed: OR = 3.02, 95% CI = 1.69-5.38) and lower scores on the Wechsler abbreviated scale of intelligence (exposed: OR = 0.46, 95% CI = 0.36-0.58; unexposed: OR = 0.43, 95% CI = 0.31-0.58) were risk factors for neuropathy. A 1-point-higher total neuropathy score was associated with 8% (95% CI = 1%-17%) increased odds of fine motor impairment. Fine motor impairment was associated with less than a college education (less than high school: OR = 2.23, 95% CI = 1.20-4.14; high school diploma/general equivalency diploma: OR = 2.66, 95% CI = 1.65-4.30; vocational education: OR = 2.07, 95% CI = 1.38-3.13) and less social independence (moderately independent: OR = 1.80, 95% CI = 1.15-2.83; dependent: OR = 2.65, 95% CI = 1.25-5.64).

CONCLUSION

Fine motor impairment in survivors of childhood ALL may interfere with optimal educational attainment and social independence.

IMPACT

Early identification of survivors at risk for fine motor impairment, with timely intervention, may improve long-term outcomes.

Identifying fine motor difficulties in children with acute lymphoblastic leukemia: a scoping review

PURPOSE

Survival rates for children diagnosed with acute lymphoblastic leukemia (ALL) have increased significantly over recent decades, and thus attention shifted toward understanding the adverse effects of cancer treatment. Chemotherapy has side effects that could affect muscle state and diminish motor performance. This scoping review was conducted to map the breadth of evidence for different tools used in fine motor skills assessment, the extent of upper extremity strength, and fine motor performance, highlighting the potential risk factors that may influence these skills.

METHODS

In March 2023, full-text studies that examined fine motor performance and/or upper extremity strength were identified via searches in PubMed, Science Direct, Scopus, Web of Science, and PEDro databases. The titles and abstracts of selected studies were screened according to the inclusion and exclusion criteria.

RESULTS

The search yielded initial 418 citations and 26 peer-reviewed articles were finally included in the review. Considerable heterogeneity was observed regarding the methods of evaluating fine motor skills. The results of this review indicate that children and adolescents with ALL experienced fine motor limitations and upper extremity weakness either during or after cessation of treatment.

CONCLUSION

This scoping review presents a broad overview of the literature addressing fine motor difficulties in the pediatric population with ALL. Results accentuate the need to incorporate strengthening and occupational therapy training to preserve muscle strength and minimize future fine motor problems along the course of chemotherapeutic treatment. Little evidence was reported regarding the risk factors that may impair muscle strength and motor performance.

Neuropsychological task outcomes among survivors of childhood acute lymphoblastic leukemia in Malaysia

This study intended to explore the neuropsychological ramifications in childhood acute lymphoblastic leukemia (ALL) survivors in Malaysia and to examine treatment-related sequelae. A case-control study was conducted over a 2-year period. Seventy-one survivors of childhood ALL who had completed treatment for a minimum of 1 year and were in remission, and 71 healthy volunteers were enlisted. To assess alertness (processing speed) and essential executive functioning skills such as working memory capacity, inhibition, cognitive flexibility, and sustained attention, seven measures from the Amsterdam Neuropsychological Tasks (ANT) program were chosen. Main outcome measures were speed, stability and accuracy of responses. Mean age at diagnosis was 4.50 years (SD ± 2.40) while mean age at study entry was 12.18 years (SD ± 3.14). Survivors of childhood ALL underperformed on 6 out of 7 ANT tasks, indicating poorer sustained attention, working memory capacity, executive visuomotor control, and cognitive flexibility. Duration of treatment, age at diagnosis, gender, and cumulative doses of chemotherapy were not found to correlate with any of the neuropsychological outcome measures. Childhood ALL survivors in our center demonstrated significantly poorer neuropsychological status compared to healthy controls.

Neurocognitive and psychosocial outcomes in survivors of childhood leukemia with Down syndrome

OBJECTIVE

The primary aim of this study was to assess the feasibility of a developmentally tailored neurocognitive assessment in survivors of childhood acute leukemia with Down syndrome (DS-leukemia). A secondary aim was to compare outcomes in the DS-leukemia group to a historical comparison group of individuals with DS and no history of childhood cancer.

METHODS

Survivors of DS-leukemia (n = 43; 56% male, mean [SD] age at diagnosis = 4.3 [4.5] years; age at evaluation = 15 [7.9] years) completed a neurocognitive assessment battery that included direct measures of attention, executive function, and processing speed, and proxy ratings of attention problems and executive dysfunction. Direct assessment outcomes were compared to a historical comparison cohort of individuals with DS and no history of childhood cancer (DS-control; n = 117; 56% male, mean [SD] age at evaluation = 12.7 [3.4] years).

RESULTS

Rates of valid task completion ranged from 54% to 95%, suggesting feasibility for most direct assessment measures. Compared to the DS-control group, the DS-leukemia group had significantly lower completion rates on measures of executive function (p = 0.008) and processing speed (p = 0.018) compared to the DS-control group. There were no other significant group differences in completion rates. Compared to the DS-control group, the DS-leukemia group had significantly more accurate performance on two measures of executive function (p = 0.032; p = 0.005). Compared to the DS-control group, the DS-leukemia group had significantly more problems with executive function as identified on proxy ratings (6.5% vs. 32.6%, p = <0.001).

CONCLUSION

Children with Down syndrome (DS) are at increased risk for developing acute leukemia compared to the general population but are systematically excluded from neurocognitive outcome studies among leukemia survivors. This study demonstrated the feasibility of evaluating neurocognitive late effects in leukemia survivors with DS using novel measures appropriate for populations with intellectual developmental disorder.

REhabilitation Approaches in CHildren with cerebellar mutism syndrome (REACH): An international cross-disciplinary survey study

OBJECTIVE

Pediatric cerebellar mutism syndrome (pCMS) can occur following resection of a posterior fossa tumor and, although some symptoms are transient, many result in long-lasting neurological deficits. A multi-disciplinary rehabilitation approach is often used in cases of pCMS; however, there have been no clinical trials to determine gold standards in rehabilitation practice in this population, which remains a research priority. The purpose of this study was to identify and compare intervention practices used in pCMS throughout the disciplines of occupational and physical therapy, speech-language pathology, and neuropsychology across geographic regions.

METHODS

A 55-question e-survey was created by an international multidisciplinary research group made up of members of the Posterior Fossa Society and sent to rehabilitation professionals in pediatric neuro-oncology centers in the US, Canada, and Europe.

RESULTS

Although some differences in the type of intervention used in pCMS were identified within each discipline, many of the targeted interventions including dose, frequency, and intensity were similar within disciplines across geographic regions. In addition, there were common themes identified across disciplines regarding challenges in the rehabilitation of this population.

CONCLUSION

These results provide a foundation of current practices on which to build future intervention-based clinical trials.

Impaired neurocognitive functioning 3 months following diagnosis of high-risk acute lymphoblastic leukemia: A report from the Children's Oncology Group

PURPOSE

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer diagnosis. Cognitive late effects develop in 20%-40% of ALL survivors, but the course of declines is unclear. The aim of this paper is to characterize cognitive functioning, and its association with patient-reported outcomes, early in treatment.

PATIENTS AND METHODS

A total of 483 children with high-risk ALL, aged 6-12 years at diagnosis, consented to the neurocognitive study embedded in a prospective therapeutic trial, Children's Oncology Group (COG) AALL1131. A computerized neurocognitive battery (Cogstate) was administered 3 months post diagnosis assessing reaction time, visual attention, working memory, visual learning, and executive functioning. Parent-reported executive functioning and patient-reported physical symptoms were also collected.

RESULTS

Data from 390 participants (mean age at diagnosis = 9.2 years, 55.4% male) were obtained. Relatively few patients reported pain (16.0%) or nausea (22.6%), but a majority (68.5%) reported feeling at least some fatigue at testing. Mean Cogstate Z-scores were within normal limits across tasks; however, rates of impairment (Z-scores ≤ -1.5) for reaction time, working memory, visual learning, and visual attention were all higher than expected compared to the standardization sample. Patients reporting fatigue were significantly more likely to have impaired reaction time and visual attention compared to those reporting no fatigue.

CONCLUSION

Findings support feasibility of computerized cognitive assessments and suggest higher-than-expected rates of impaired cognitive performance early during treatment for pediatric ALL, notably within 3 months of diagnosis, suggesting intervention efforts may be indicated. These results also highlight acute factors that may impact reliability of "baseline" assessments conducted soon after diagnosis.

Feasibility of serial neurocognitive assessment using Cogstate during and after therapy for childhood leukemia

PURPOSE

Neurocognitive impairment is frequently observed among survivors of childhood acute lymphoblastic leukemia (ALL) within the domains of attention, working memory, processing speed, executive functioning, and learning and memory. However, few studies have characterized the trajectory of treatment-induced changes in neurocognitive function beginning in the first months of treatment, to test whether early changes predict impairment among survivors. If correct, we hypothesize that those children who are most susceptible to early impairment would be ideal subjects for clinical trials testing interventions designed to protect against treatment-related neurocognitive decline.

METHODS

In this pilot study, we prospectively assessed neurocognitive functioning (attention, working memory, executive function, visual learning, and processing speed), using the Cogstate computerized battery at six time points during the 2 years of chemotherapy treatment and 1-year post-treatment (Dana-Farber Cancer Institute ALL Consortium protocol 11-001; NCT01574274).

RESULTS

Forty-three patients with ALL consented to serial neurocognitive testing. Of the 31 participants who remained on study through the final time point, 1 year after completion of chemotherapy, 28 (90%) completed at least five of six planned Cogstate testing time points. Performance and completion checks indicated a high tolerability (≥ 88%) for all subtests. One year after completion of treatment, 10 of 29 patients (34%) exhibited neurocognitive function more than 2 standard deviations below age-matched norms on one or more Cogstate subtests.

CONCLUSIONS

Serial collection of neurocognitive data (within a month of diagnosis with ALL, during therapy, and 1-year post-treatment) is feasible and can be informative for evaluating treatment-related neurocognitive impairment.

The Impact of Intensified CNS-Directed Therapy on Neurocognitive Outcomes in Survivors of Childhood Acute Lymphoblastic Leukemia Treated Without Cranial Irradiation

PURPOSE

Findings from St Jude Total Therapy Study 16 (Total 16) showed early intensification of triple intrathecal therapy (ITT) improved CNS disease control for children with newly diagnosed acute lymphoblastic leukemia (ALL) at the greatest risk of CNS relapse. We examined the impact of this treatment on end-of-therapy neurocognitive outcomes.

METHODS

Between 2007 and 2017, 400 (83.5%) of 479 eligible patients treated with Total 16 risk-directed chemotherapy completed protocol-directed neurocognitive testing at the end of therapy. Intensified ITT was defined as ≥ 21 cumulative doses for patients with low-risk ALL (n = 70/194) and ≥ 27 doses for those with standard-to-high risk ALL (n = 81/206).

RESULTS

Compared with age-normative expectations, the overall group had significantly lower estimated intelligence quotient (P < .0001), attention (P = .0051), working memory (P = .0001), processing speed (P = .0002), fine motor speed (P = .0001), and math (P = .0087). Caregiver ratings of patient functioning showed elevated risk for problems in attention (P = .0173), executive function (P = .0001), and adaptive skills (P = .0001). Among the low-risk treatment group, there were no significant differences between patients treated with or without intensified ITT (all P's >.10). Among patients with standard-to-high risk ALL, those treated with intensified ITT had poorer working memory (P = .0328) and fine motor speed (P = .0403), and elevated ratings of inattention (P = .0189) and executive dysfunction (P = .0245). In the standard-to-high risk group, females treated with intensified ITT had lower working memory scores. Public insurance status was associated with worse neurocognitive outcomes in both treatment groups.

CONCLUSION

Standard-to-high risk patients treated with intensified ITT are at moderately increased risk for neurocognitive problems. The findings suggest a threshold effect for ITT exposure, which can inform the design of future clinical trials and approaches to neurocognitive monitoring and intervention.

Late effects of high-dose methotrexate treatment in childhood cancer survivors-a systematic review

BACKGROUND

High-dose methotrexate (HD-MTX) is used in the treatment of different childhood cancers, including leukemia, the most common cancer type and is commonly defined as an intravenous dose of at least 1 g/m² body surface area per application. A systematic review on late effects on different organs due to HD-MTX is lacking.

METHOD

We conducted a systematic literature search in PubMed, including studies published in English or German between 1985 and 2020. The population of each study had to consist of at least 75% childhood cancer survivors (CCSs) who had completed the cancer treatment at least twelve months before late effects were assessed and who had received HD-MTX. The literature search was not restricted to specific cancer diagnosis or organ systems at risk for late effects. We excluded case reports, case series, commentaries, editorial letters, poster abstracts, narrative reviews and studies only reporting prevalence of late effects. We followed PRISMA guidelines, assessed the quality of the eligible studies according to GRADE criteria and registered the protocol on PROSPERO (ID: CRD42020212262).

RESULTS

We included 15 out of 1731 identified studies. Most studies included CCSs diagnosed with acute lymphoblastic leukemia (n = 12). The included studies investigated late effects of HD-MTX on central nervous system (n = 10), renal (n = 2) and bone health (n = 3). Nine studies showed adverse outcomes in neuropsychological testing in exposed compared to non-exposed CCSs, healthy controls or reference values. No study revealed lower bone density or worse renal function in exposed CCSs. As a limitation, the overall quality of the studies per organ system was low to very low, mainly due to selection bias, missing adjustment for important confounders and low precision.

CONCLUSIONS

CCSs treated with HD-MTX might benefit from neuropsychological testing, to intervene early in case of abnormal results. Methodological shortcomings and heterogeneity of the tests used made it impossible to determine the most appropriate test. Based on the few studies on renal function and bone health, regular screening for dysfunction seems not to be justified. Only screening for neurocognitive late effects is warranted in CCSs treated with HD-MTX.

Functional Gains in Children Receiving Inpatient Rehabilitation After Brain Tumor Resection

OBJECTIVE

To examine whether children with brain tumors treated with resection benefit from inpatient rehabilitation and to explore what factors present at admission may predict better functional outcomes.

DESIGN

Retrospective cohort design.

SETTING

Pediatric inpatient rehabilitation unit.

PARTICIPANTS

Forty patients (N=40; ages 3-21y; 42.5% female) admitted to the rehabilitation unit between 2003 and 2015 after brain tumor resection.

INTERVENTIONS

Patients received multidisciplinary rehabilitation therapies as part of their admission to inpatient rehabilitation, including occupational, physical, and speech-language therapy.

MAIN OUTCOME MEASURES

Functional outcomes included the FIM for Children (WeeFIM) at discharge and 3-month follow-up as well as WeeFIM efficiency.

RESULTS

A repeated-measures analysis of variance using patient WeeFIM Developmental Functional Quotients (DFQs) at admission, discharge, and 3-month follow-up showed significant gains in total WeeFIM DFQ scores across time. Admission WeeFIM DFQ, time from surgery to admission, and age at admission provided the strongest model for predicting discharge and 3-month follow-up WeeFIM DFQ scores. Admission WeeFIM DFQ and time from surgery to admission provided the strongest model for predicting WeeFIM efficiency. Total Neurological Predictor Scale (NPS) at admission did not add predictive power to any of the 3 models over and above patient characteristics (admission WeeFIM DFQ, age at admission, time from surgery to admission).

CONCLUSIONS

Patients admitted to inpatient rehabilitation after brain tumor resection made significant functional gains (as measured by the WeeFIM) during inpatient rehabilitation and continued to make significant gains 3 months after discharge. Age and timing of admission provided the strongest models for predicting patient outcomes. The NPS did not predict functional outcomes after rehabilitation when controlling for other variables known to influence rehabilitation outcomes.

Longitudinal Trajectories of Neurocognitive Functioning in Childhood Acute Lymphoblastic Leukemia

OBJECTIVE

Children with acute lymphoblastic leukemia (ALL) are at risk for neurocognitive deficits, and examining individual variability is essential to understand these risks. This study evaluated latent longitudinal trajectories and risk factors of neurocognitive outcomes in childhood ALL.

METHODS

There were 233 participants with ALL who were enrolled on a phase 3, risk-stratified chemotherapy-only clinical trial (NCT00137111) and who completed protocol-directed neurocognitive assessments [47.6% female, mean (SD) = 6.6 (3.7) years]. Measures of sustained attention, learning/memory, and parent ratings of attention were completed during and after treatment. Longitudinal latent class analyses were used to classify participants into distinct trajectories. Logistic regression was used to identify predictors of class membership.

RESULTS

Within the overall group, attention performance was below age expectations across time (Conners Continuous Performance Test detectability/variability, p < 0.01); memory performance and parent ratings were below expectations at later phases (California Verbal Learning Test learning slope, p < 0.05; Conners Parent Rating Scale, Revised attention/learning, p < 0.05). Most participants (80-89%) had stable neurocognitive profiles; smaller groups showed declining (3-6%) or improving (3-11%) trajectories. Older age (p = 0.020), female sex (p = 0.018), and experiencing sepsis (p = 0.047) were associated with greater attention problems over time. Lower baseline IQ was associated with improved memory (p = 0.035) and fewer ratings of attention problems (p = 0.013) over time.

CONCLUSIONS

Most patients with ALL have stable neurocognitive profiles. Smaller groups have significant impairments shortly after diagnosis or have worsening performance over time. A tiered assessment approach, which includes consideration of individual and clinical risk factors, may be useful for monitoring neurocognitive functioning during treatment and survivorship.

Cerebrospinal Fluid Biomarkers in Childhood Leukemias

Involvement of the central nervous system (CNS) in childhood leukemias remains a major cause of treatment failures. Analysis of the cerebrospinal fluid constitutes the most important diagnostic pillar in the detection of CNS leukemia and relies primarily on cytological and flow-cytometry studies. With increasing survival rates, it has become clear that treatments for pediatric leukemias pose a toll on the developing brain, as they may cause acute toxicities and persistent neurocognitive deficits. Preclinical research has demonstrated that established and newer therapies can injure and even destroy neuronal and glial cells in the brain. Both passive and active cell death forms can result from DNA damage, oxidative stress, cytokine release, and acceleration of cell aging. In addition, chemotherapy agents may impair neurogenesis as well as the function, formation, and plasticity of synapses. Clinical studies show that neurocognitive toxicity of chemotherapy is greatest in younger children. This raises concerns that, in addition to injury, chemotherapy may also disrupt crucial developmental events resulting in impairment of the formation and efficiency of neuronal networks. This review presents an overview of studies demonstrating that cerebrospinal fluid biomarkers can be utilized in tracing both CNS disease and neurotoxicity of administered treatments in childhood leukemias.

Impact of Intrathecal Triple Therapy Versus Intrathecal Methotrexate on Disease-Free Survival for High-Risk B-Lymphoblastic Leukemia: Children's Oncology Group Study AALL1131

PURPOSE

The high-risk stratum of Children's Oncology Group Study AALL1131 was designed to test the hypothesis that postinduction CNS prophylaxis with intrathecal triple therapy (ITT) including methotrexate, hydrocortisone, and cytarabine would improve the postinduction 5-year disease-free survival (DFS) compared with intrathecal methotrexate (IT MTX), when given on a modified augmented Berlin-Frankfurt-Münster backbone.

PATIENTS AND METHODS

Children with newly diagnosed National Cancer Institute (NCI) high-risk B-cell acute lymphoblastic leukemia (HR B-ALL) or NCI standard-risk B-ALL with defined minimal residual disease thresholds during induction were randomly assigned to receive postinduction IT MTX or ITT. Patients with CNS3-status disease were not eligible. Postinduction IT therapy was given for a total of 21 to 26 doses. Neurocognitive assessments were performed during therapy and during 1 year off therapy.

RESULTS

Random assignment was closed to accrual in March 2018 after a futility boundary had been crossed, concluding that ITT could not be shown to be superior to IT MTX. The 5-year postinduction DFS and overall survival rates (± SE) of children randomly assigned to IT MTX versus ITT were 93.2% ± 2.1% v 90.6% ± 2.3% (P = .85), and 96.3% ± 1.5% v 96.7% ± 1.4% (P = .77), respectively. There were no differences in the cumulative incidence of isolated bone marrow relapse, isolated CNS relapse, or combined bone marrow and CNS relapse rates, or in toxicities observed for patients receiving IT MTX compared with ITT. There were no significant differences in neurocognitive outcomes for patients receiving IT MTX compared with ITT.

CONCLUSION

Postinduction CNS prophylaxis with ITT did not improve 5-year DFS for children with HR B-ALL. The standard of care for CNS prophylaxis for children with B-ALL and no overt CNS involvement remains IT MTX.

Motor functioning and associated cognitive outcomes in pediatric survivors of acute lymphoblastic leukemia

Pediatric acute lymphoblastic leukemia survivors are at risk for developing neurocognitive late effects following intensive medical treatment. Motor impairments have been highlighted as a common neurocognitive late effect, including fine-, gross-, and visual-motor skills. The severity of these motor deficits is variable in the existing literature, warranting additional investigations with more homogenous samples. In addition, there is an even greater paucity regarding the interrelations between motor deficits and the impact motor challenges may have on other domains of functioning, such as academics. Therefore, the present study aimed to characterize motor functioning in children who were treated for acute lymphoblastic leukemia with chemotherapy (n = 13) in comparison to healthy controls (n = 13). Additionally, this study investigated the relationship between primary (e.g., visual-spatial, fine-motor), secondary (e.g., visual-motor), and tertiary (e.g., academics) skills. The results revealed that oncology survivors had significantly lower fine- and gross-motor skills compared to healthy controls. No significant differences were observed between the groups on visual-perception and visual-motor tasks. Fine-motor functioning was significantly associated with visual-motor functioning in ALL survivors. Motor skills were not related to academic outcomes. The present findings provide evidence for motor impairments in pediatric ALL survivors, along with initial findings highlighting the cascading effect of primary motor impairments on other cognitive domains. This research sheds light on the need for clinical screening and intervention of motor skills in the survivorship population. Future research is warranted to examine the effect of motor deficits on cognitive and psychosocial functioning in pediatric oncology.

Childhood leukemia survivors exhibit deficiencies in sensory and cognitive processes, as reflected by event-related brain potentials after completion of curative chemotherapy: A preliminary investigation

Objective: The purpose of this study was to characterize post-chemotherapy sensory, memory, and attention abilities in childhood survivors of acute lymphoblastic leukemia (ALL) to better understand how treatment affects cognitive functioning. Methods: Eight ALL survivors and eight age-matched, healthy children between the ages of 5-11 years participated in the study. Among the ALL survivors, a median of 63 days (range 22-267 days) elapsed between completion of chemotherapy and this assessment. Sounds were presented in an oddball paradigm while recording the electroencephalogram in separate conditions of passive listening and active task performance. To assess different domains of cognition, we measured event-related brain potentials (ERPs) reflecting sensory processing (P1 component), working memory (mismatch negativity [MMN] component), attentional orienting (P3a), and target detection (P3b component) in response to the sounds. We also measured sound discrimination and response speed performance. Results: Relative to control subjects, ALL survivors had poorer performance on auditory tasks, as well as decreased amplitude of the P1, MMN, P3a, and P3b components. ALL survivors also did not exhibit the amplitude gain typically observed in the sensory P1 component when attending to the sound input compared to when passively listening. Conclusions: Atypical responses were observed in brain processes associated with sensory discrimination, auditory working memory, and attentional control in pediatric ALL survivors indicating deficiencies in all cognitive domains compared to age-matched controls. Significance: ERPs differentiated aspects of cognitive functioning, which may provide a useful tool for assessing recovery and risk of post-chemotherapy cognitive deficiencies in young children. The decreased MMN amplitude in ALL survivors may indicate (N-methyl D-aspartate) NMDA dysfunction induced by methotrexate, and thus provides a potential therapeutic target for chemotherapy-associated cognitive impairments.

Motor function in survivors of pediatric acute lymphoblastic leukemia treated with chemotherapy-only

BACKGROUND

Up to 43% of survivors of pediatric acute lymphoblastic leukemia (ALL) may exhibit fine-motor problems. Information on manual dexterity in this cohort is still limited.

OBJECTIVES

We tested survivors of childhood ALL treated with chemotherapy-only for fine-motor function in terms of drawing and handwriting abilities using a Digitizing Tablet (DT) with three tasks for drawing and handwriting of varying complexity, for ataxia using the International Cooperative Ataxia Rating Scale (ICARS), and for tremor and hand-eye coordination using the Nine Hole Steadiness Tester (NHST).

RESULTS

We examined a cohort of non-irradiated survivors (n = 31) after a median time of 3.5 years after end of therapy. In all tasks of the DT the cohort demonstrated significant (p < 0.05) impairment of speed, automation, and variability in at least two tasks and significantly more pressure. Impaired speed (SPV) inversely correlated with lag time since end of therapy. Dexterity performance of six survivors (19%) lay below the 5th percentile. No survivor exhibited ataxia, tremor, or impaired hand-steadiness.

CONCLUSION

Despite the absence of gross ataxia, tremor, and impaired hand-eye coordination, we nevertheless detected significant fine-motor impairment in a relevant number of survivors of childhood ALL. Prospective studies are needed to reveal the pathophysiological underpinnings and genetic risk factors for development of such deficits due to ALL and its treatment.

Adolescence and Socioeconomic Factors: Key Factors in the Long-Term Impact of Leukemia on Scholastic Performance-A LEA Study

OBJECTIVE

To evaluate the association between medical and social environmental factors and the risk of repeating a grade in childhood leukemia survivors.

STUDY DESIGN

A cross-sectional study of childhood leukemia survivors, recruited through the LEA cohort (Leucémie de l'Enfant et de l'Adolescent [French Childhood Cancer Survivor Study for Leukemia]) in 2014. An adjusted logistic regression model was used to identify variables linked to repeating a grade after the diagnosis among the survivors, and the rates of repeating a grade were compared between the survivors and their siblings using a multilevel logistic regression model.

RESULTS

The mean age at inclusion of the 855 participants was 16.2 ± 7.0 years, and the mean duration of follow-up from diagnosis to evaluation was 10.2 ± 6.2 years. After disease onset, 244 patients (28.5%) repeated a grade, with a median interval of 4 years (IQR, 2-8 years). Independent factors associated with repeating a grade were male sex (OR, 1.78; 95% CI, 1.21-2.60), adolescence (OR, 2.70; 95% CI, 1.63-4.48), educational support during the treatment period (OR, 3.79; 95% CI, 2.45-5.88), low parental education level (OR, 2.493; 95% CI, 1.657-3.750), and household financial difficulties (OR, 2.62; 95% CI, 1.607-4.28). Compared with siblings, survivors were at greater risk of repeating a grade (OR, 1.87; 95% CI, 1.48-2.35).

CONCLUSIONS

The most vulnerable patients seemed to be adolescents and those with parents of low socioeconomic status. Improving the schooling career of leukemia survivors will require that the medical community more carefully consider the social status of patients.

Chemotherapy and the pediatric brain

Survival rates of children with cancer are steadily increasing. This urges our attention to neurocognitive and psychiatric outcomes, as these can markedly influence the quality of life of these children. Neurobehavioral morbidity in childhood cancer survivors affects diverse aspects of cognitive function, which can include attention, memory, processing speed, intellect, academic achievement, and emotional health. Reasons for neurobehavioral morbidity are multiple with one major contributor being chemotherapy-induced central nervous system (CNS) toxicity. Clinical studies investigating the effects of chemotherapy on the CNS in children with cancer have reported causative associations with the development of leukoencephalopathies as well as smaller regional grey and white matter volumes, which have been found to correlate with neurocognitive deficits.Preclinical work has provided compelling evidence that chemotherapy drugs are potent neuro- and gliotoxins in vitro and in vivo and can cause brain injury via excitotoxic and apoptotic mechanisms. Furthermore, chemotherapy triggers DNA (deoxyribonucleic acid) damage directly or through increased oxidative stress. It can shorten telomeres and accelerate cell aging, cause cytokine deregulation, inhibit hippocampal neurogenesis, and reduce brain vascularization and blood flow. These mechanisms, when allowed to operate on the developing brain of a child, have high potential to not only cause brain injury, but also alter crucial developmental events, such as myelination, synaptogenesis, neurogenesis, cortical thinning, and formation of neuronal networks.This short review summarizes key publications describing neurotoxicity of chemotherapy in pediatric cancers and potential underlying pathomechanisms.

Brain structure, working memory and response inhibition in childhood leukemia survivors

INTRODUCTION

Survival rates for children with acute lymphoblastic leukemia (ALL) approach 95%. At the same time, there is growing concern that chemotherapy causes alterations in brain development and cognitive abilities. We performed MRI measurements of white and gray matter volume to explore how variation in brain structure may be related to cognitive abilities in ALL survivors and healthy controls.

METHODS

The sample included 24 male ALL survivors who had completed contemporary treatment 3-11 years prior, and 21 age- and sex-matched controls. Participants were between 8 and 18 years old. Working memory and motor response inhibition were measured with the N-Back and Stop Signal Tasks (SST), respectively. Participants underwent 3T structural MRI to assess white and gray matter volumes overall, lobe-wise, and in cortical and atlas-identified subcortical structures. Mental health was assessed with the Child Behavioral Checklist.

RESULTS

ALL survivors performed more poorly on measures of working memory and response inhibition than controls. Frontal and parietal white matter, temporal and occipital gray matter volume, and volumes of subcortical white and gray matter structures were significantly reduced in ALL survivors compared with controls. Significant structure-function correlations were observed between working memory performance and volume of the amygdala, thalamus, striatum, and corpus callosum. Response inhibition was correlated with frontal white matter volume. No differences were found in psychopathology.

CONCLUSIONS

Compared with controls, a reduction in volume across brain regions and tissue types, was detectable in ALL survivors years after completion of therapy. These structural alterations were correlated with neurocognitive performance, particularly in working memory. Confirming these observations in a larger, more representative sample of the population is necessary. Additionally, establishing the time course of these changes-and the treatment, genetic, and environmental factors that influence them-may provide opportunities to identify at-risk patients, inform the design of treatment modifications, and minimize adverse cognitive outcomes.

Long-term brain structural magnetic resonance imaging and cognitive functioning in children treated for acute lymphoblastic leukemia with high-dose methotrexate chemotherapy alone or combined with CNS radiotherapy at reduced total dose to 12 Gy

INTRODUCTION

The aim of this study was to assess the long-term side effects of central nervous system prophylaxis (high-dose chemotherapy alone vs chemotherapy and CNS radiotherapy) according to the ALL IC-BFM 2002.

METHODS

Thirty-tree children aged 6.7-19.9 years have been studied. The control group consisted of 12 children newly diagnosed with acute lymphoblastic leukemia. We assessed subcortical gray matter volume using automatic MRI segmentation and cognitive performance to identify differences between two therapeutic schemes and patients prior to treatment.

RESULTS

Patients treated with chemotherapy and CNS radiotherapy had smaller hippocampi than two other subgroups and lower IQ score than patients treated with chemotherapy alone. Both treated groups, whether with chemotherapy only or in combination with CNS radiotherapy, had significantly lower volumes of caudate nucleus and performed significantly worse on measures of verbal fluency in comparison with patients prior to treatment. There were no differences in the mean volumes of total white matter, total gray matter, thalamus, putamen, and amygdala between the studied groups.

CONCLUSION

In all children treated according to the ALL IC-BFM 2002 with high-dose chemotherapy, both decreased volume of selected subcortical structures and cognitive impairment was observed, especially in children who received chemotherapy in combination with reduced dose CNS radiotherapy. In all children treated according to the ALL IC-BFM 2002 with high-dose chemotherapy, both decreased volume of selected subcortical structures and cognitive impairment were observed, especially in children who received chemotherapy in combination with CNS radiotherapy.

Oxidative Stress, Motor Abilities, and Behavioral Adjustment in Children Treated for Acute Lymphoblastic Leukemia

PURPOSE/OBJECTIVES

To examine associations among oxidative stress, fine and visual-motor abilities, and behavioral adjustment in children receiving chemotherapy for acute lymphoblastic leukemia (ALL)
.

DESIGN

A prospective, repeated-measures design
.

SETTING

Two pediatric oncology settings in the southwestern United States.

SAMPLE

89 children with ALL were followed from diagnosis to the end of chemotherapy.

METHODS

Serial cerebrospinal fluid samples were collected during scheduled lumbar punctures and analyzed for oxidative stress biomarkers. Children completed fine motor dexterity, visual processing speed, and visual-motor integration measures at three time points. Parents completed child behavior ratings at the same times.

MAIN RESEARCH VARIABLES

Oxidative stress, fine motor dexterity, visual processing, visual-motor integration, and behavioral adjustment
.

FINDINGS

Children with ALL had below-average fine motor dexterity, visual processing speed, and visual-motor integration following the induction phase of ALL therapy. By end of therapy, visual processing speed normalized, and fine motor dexterity and visual-motor integration remained below average. Oxidative stress measures correlated with fine motor dexterity and visual-motor integration. Decreased motor functioning was associated with increased hyperactivity and anxiety
.

CONCLUSIONS

Oxidative stress occurs following chemo-therapy for childhood ALL and is related to impaired fine motor skills and visual symptoms
.

IMPLICATIONS FOR NURSING

Early intervention should be considered to prevent fine motor and visual-spatial deficits, as well as behavioral problems.

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.

Neurocognitive Outcome in Very Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia After Treatment with Chemotherapy Only

BACKGROUND

There is a concern regarding long-term cognitive late effects after treatment for acute lymphoblastic leukemia (ALL). The present study assessed neuropsychological function in very long-term childhood ALL survivors treated with chemotherapy only. We also investigated associations between neurocognitive performance and individual treatment load.

PROCEDURE

One-hundred and twelve adult ALL survivors, diagnosed 1970-2002 before age 16 and treated with chemotherapy only, and 100 comparison peers underwent neuropsychological tests covering processing speed, executive functions, working memory, and verbal learning and memory. Individual cumulative doses of cytostatic agents were extracted from the medical records for each patient.

RESULTS

Mean age at diagnosis for survivors was 6.3 years and mean follow-up time was 22.6 years. There was no difference in general intellectual ability between survivors and comparison peers. However, survivors performed significantly more poorly in the neurocognitive domains' processing speed (P = 0.003, Cohen's d 0.48), executive functions, and working memory (both P < 0.001, Cohen's d 0.81-0.95). Among survivors, the rates of poor neurocognitive performance (>1.5 SD below control mean) for processing speed was 22%, executive functions 31%, working memory 34%, and verbal learning and memory 16%. Comparing survivors with poor versus normal neurocognitive performance, we found no difference with respect to cumulative doses of any of the cytostatic agents, age at diagnosis, or gender.

CONCLUSIONS

Very long-term survivors of childhood ALL treated exclusively with chemotherapy showed no impairment in general intellectual ability, but significantly poorer performance in several neurocognitive domains than comparison peers. However, no associations emerged between neurocognitive impairment and treatment burden.

Chemotherapy-only treatment effects on long-term neurocognitive functioning in childhood ALL survivors: a review and meta-analysis

Children treated for ALL without cranial radiation display significant IQ deficits of 6 to 8 points compared with healthy controls. Moderate deficits occur in other neurocognitive domains including working memory, information processing speed, and fine motor functioning.

Motor performance in children and adolescents with cancer at the end of acute treatment phase

Reduced motor performance may particularly limit reintegration into normal life after cessation of treatment in pediatric cancer patients. This study aimed at analyzing motor performance at the end of the acute treatment phase and reveals potential risk factors for motor deficits. A childhood cancer population with different tumor entities was assessed with the MOON test, which allows for comparison with age- and gender-matched reference values of healthy children, at the end of the acute treatment phase. Forty-seven patients were tested at 7.0 ± 2.6 months after diagnosis. Significant reductions of motor performance affected muscular explosive strength (P < 0.001), handgrip strength (P < 0.001), muscular endurance of legs (P = 0.035), hand-eye coordination (P < 0.001), static balance (P = 0.003), speed (P = 0.012), and flexibility (P < 0.001). Loss of upper extremity coordination did not achieve statistical significance. Associations between single motor deficits and the tumor entity, age, body mass index, and inactivity during treatment were revealed, whereas no associations were found for gender and vincristine application.

CONCLUSION

Overall, motor performance was low in the patient group studied. We recommend that individualized exercise interventions to attenuate motor deficits and promote physical activity are needed during cancer treatment in order to enhance motor performance and improve social participation during and after cancer therapy.

Developing interventions for cancer-related cognitive dysfunction in childhood cancer survivors

Survivors of childhood cancer frequently experience cancer-related cognitive dysfunction, commonly months to years after treatment for pediatric brain tumors, acute lymphoblastic leukemia (ALL), or tumors involving the head and neck. Risk factors for cancer-related cognitive dysfunction include young age at diagnosis, treatment with cranial irradiation, use of parenteral or intrathecal methotrexate, female sex, and pre-existing comorbidities. Limiting use and reducing doses and volume of cranial irradiation while intensifying chemotherapy have improved survival and reduced the severity of cognitive dysfunction, especially in leukemia. Nonetheless, problems in core functional domains of attention, processing speed, working memory and visual-motor integration continue to compromise quality of life and performance. We review the epidemiology, pathophysiology and assessment of cancer-related cognitive dysfunction, the impact of treatment changes for prevention, and the broad strategies for educational and pharmacological interventions to remediate established cognitive dysfunction following childhood cancer. The increased years of life saved after childhood cancer warrants continued study toward the prevention and remediation of cancer-related cognitive dysfunction, using uniform assessments anchored in functional outcomes.

Visuomotor function in children treated for acute lymphoblastic leukaemia with chemotherapy only

This study aimed to evaluate visuomotor function in children treated for acute lymphoblastic leukaemia (ALL). The performance of 64 children, 1-7 years post-chemotherapy for ALL, was compared to that of their healthy peers (n = 56) on visuomotor integration (VMI) and motor coordination (MC) tasks. Children posttreatment for ALL displayed significantly reduced VMI, but not MC, performances as compared to controls. Children treated on chemotherapy-only ALL regimes are at heightened risk for visuomotor integration deficits. Monitoring of visuomotor skills and implementation of appropriate interventions targeting higher level visuomotor integration skills should form an important component of any ALL long-term effects program.

A 50-year journey to cure childhood acute lymphoblastic leukemia

The 50th anniversary of Seminars in Hematology coincides with the 50th anniversary of St. Jude Children's Research Hospital, and both milestones are inexorably linked to studies contributing to the cure of childhood acute lymphoblastic leukemia (ALL). We thought it fitting, therefore, to mark these events by traveling back in time to point out some of the achievements, institutions, study groups, and individuals that have made cure of childhood ALL a reality. In many instances, progress was driven by new ideas, while in others it was driven by new experimental tools that allowed more precise assessment of the biology of leukemic blasts and their utility in selecting therapy. We also discuss a number of contemporary advances that point the way to exciting future directions. Whatever pathways are taken, a clear challenge will be to use emerging genome-based or immunologic-based treatment options in ways that will enhance, rather than duplicate or compromise, recent gains in outcome with classic cytotoxic chemotherapy. The theme of this journey serves as a reminder of the chief ingredient of any research directed to a catastrophic disease such as ALL. It is the audacity of a small group of investigators who confronted a childhood cancer with the goal of cure, not palliation, as their mindset.

Impact of chemotherapy for childhood leukemia on brain morphology and function

OBJECTIVE

Using multidisciplinary treatment modalities the majority of children with cancer can be cured but we are increasingly faced with therapy-related toxicities. We studied brain morphology and neurocognitive functions in adolescent and young adult survivors of childhood acute, low and standard risk lymphoblastic leukemia (ALL), which was successfully treated with chemotherapy. We expected that intravenous and intrathecal chemotherapy administered in childhood will affect grey matter structures, including hippocampus and olfactory bulbs, areas where postnatal neurogenesis is ongoing.

METHODS

We examined 27 ALL-survivors and 27 age-matched healthy controls, ages 15-22 years. ALL-survivors developed disease prior to their 11th birthday without central nervous system involvement, were treated with intrathecal and systemic chemotherapy and received no radiation. Volumes of grey, white matter and olfactory bulbs were measured on T1 and T2 magnetic resonance images manually, using FIRST (FMRIB's integrated Registration and Segmentation Tool) and voxel-based morphometry (VBM). Memory, executive functions, attention, intelligence and olfaction were assessed.

RESULTS

Mean volumes of left hippocampus, amygdala, thalamus and nucleus accumbens were smaller in the ALL group. VBM analysis revealed significantly smaller volumes of the left calcarine gyrus, both lingual gyri and the left precuneus. DTI data analysis provided no evidence for white matter pathology. Lower scores in hippocampus-dependent memory were measured in ALL-subjects, while lower figural memory correlated with smaller hippocampal volumes.

INTERPRETATION

Findings demonstrate that childhood ALL, treated with chemotherapy, is associated with smaller grey matter volumes of neocortical and subcortical grey matter and lower hippocampal memory performance in adolescence and adulthood.

Intellectual functioning of childhood leukemia survivors--relation to Tau protein--a marker of white matter injury

PURPOSE

Chemo- and radiotherapy used in acute lymphoblastic leukemia (ALL) can influence on brain functioning in the future. In a prospective study we analysed the cognitive functions of ALL survivors in relation to Tau protein as a marker of white matter injury.

MATERIAL AND METHODS

Thirty-one survivors of childhood ALL (6.3 years after diagnosis); without the signs of CNS involvement, treated with chemotherapy alone, rested in first remission; underwent Intelligence tests- Wechsler Intelligence Scales (WISC-R, WAIS-R). Their results were analyzed in relation to the levels of Tau in cerebrospinal fluid (CSF) obtained during the treatment.

RESULTS

The analysis showed that all survivors attained the average scores in intelligence tests. A negative correlation was found between methotrexate (MTX) doses and Freedom from Distractibility (FFD). Females had higher values of Performance Intelligence Quotient (PIQ) than males. A negative correlation was noted of Tau protein levels obtained from the last CSF with: Total and Verbal Intelligence Quotient, PIQ, Perceptual Organisation Index and FFD but not with Verbal Comprehension Index.

CONCLUSION

Our results suggest the possibility of white matter injury during the treatment for ALL with chemotherapy alone. Elevated Tau protein level in CSF at the end of treatment might indicate future difficulties in neurocognitive functioning.

Motor functioning during and following treatment with chemotherapy for pediatric acute lymphoblastic leukemia

This systematic review evaluated empirical studies examining motor skills in children during and following treatment for acute lymphoblastic leukemia. Most studies indicated that children on-treatment display poorer gross and fine motor abilities than healthy peers, but generally have intact visual-motor integration skills. Studies have reported gross motor difficulties in 5-54% of survivors. There is some limited evidence for long-term fine motor deficits. The evidence for visual-motor integration difficulties in the survivor population is less consistent. Larger studies with a longitudinal design are needed to further specify the onset and timing of motor difficulties and ascertain risk factors.

Gross and fine motor skills in children treated for acute lymphoblastic leukaemia

OBJECTIVE

Chemotherapy treatment for acute lymphoblastic leukaemia (ALL) may disrupt motor development, with suggestions that gross and fine motor deficits are different depending on time since treatment.

METHODS

Thirty-seven participants aged between 2.5 to 5 years at the time of diagnosis were assessed using the Movement Assessment Battery for Children, 2nd Edition (MABC-2) and the Bruininks-Oseretsky Test of Motor Proficiency, 2nd Edition, Short Form (BOT-2 SF), and divided into groups (i.e., months-off-treatment): (1) 0-12, (2) 13-24, and (3) 25-60 for comparison.

RESULTS

MABC-2 and BOT-2 SF mean total scores fell within the average range. Twenty-six percent of the sample performed in the impaired range on the MABC-2. Group 2 had significantly lower Manual Dexterity scores than the normative population and lower BOT-2 SF scores than Group 1.

CONCLUSION

Most children treated for ALL display appropriate motor skills, yet around a quarter experience general motor difficulties. Time-off-treatment did not affect the prevalence of motor impairments on any measure.

Reduced neuroanatomic volumes in long-term survivors of childhood acute lymphoblastic leukemia

PURPOSE

To compare regional brain volumes in adult long-term survivors of childhood acute lymphoblastic leukemia (ALL) and healthy controls.

PATIENTS AND METHODS

We investigated 130 survivors of childhood ALL diagnosed between 1970 and 2002 with magnetic resonance imaging (MRI) and neuropsychological testing at a median of 22.5 years after diagnosis. Morphometric analyses including whole-brain segmentation were performed using a validated automated procedure; 130 healthy adults served as controls.

RESULTS

Compared with healthy controls, ALL survivors showed significantly smaller volumes of cortical gray matter, cerebral white matter, amygdala, caudate, hippocampus, thalamus, and estimated intracranial volume. Effect sizes ranged from small to medium. The strongest effect was found for the caudate, which on average was 5.2% smaller in ALL survivors. Caudate volumes were also smaller when controlling for intracranial volume, suggesting a specific effect. Neither age at diagnosis nor treatment variables such as radiation therapy or drug dose had a major impact on neuroanatomic volumes. Neuropsychological assessment revealed reduced processing speed, executive function, and verbal learning/memory in survivors compared with controls but no difference in estimated general intellectual ability. In ALL survivors, but not in controls, neuropsychological test results correlated with volumes of cortical gray matter, caudate, and thalamus as well as intracranial volume.

CONCLUSION

Structural MRI of long-term survivors of childhood ALL demonstrated smaller volumes of multiple brain structures compared with healthy controls. Because of possible selection biases, these results must be interpreted with caution. Future studies are required to clarify the significance of these findings and the neurobiologic mechanisms involved.

Pediatric acute lymphoblastic leukemia: where are we going and how do we get there?

Improved supportive care, more precise risk stratification, and personalized chemotherapy based on the characteristics of leukemic cells and hosts (eg, pharmacokinetics and pharmacogenetics) have pushed the cure rate of childhood acute lymphoblastic leukemia to near 90%. Further increase in cure rate can be expected from the discovery of additional recurrent molecular lesions, coupled with the development of novel targeted treatment through high-throughput genomics and innovative drug-screening systems. We discuss specific areas of research that promise to further refine current treatment and to improve the cure rate and quality of life of the patients.

Indices of language outcome 11 years after intrathecal chemotherapy for acute lymphoblastic leukemia: a sibling case-control study

Studies are emerging that suggest that major language indices do not differentiate children treated for acute lymphoblastic leukemia (ALL) with risk-adapted intrathecal chemotherapy (ITC) from control children matched on age, gender, and educational level. No study to date has controlled for cognitive environment, an important variable influencing language achievement and outcome. This case-control study applies the deconfounding principle by using a sibling as a control to investigate language outcomes in a male child 11 years after administration of ITC for ALL at the age of 2 years 3 months. A comprehensive behavioral language test battery failed to differentiate the siblings on current language performance when descriptively compared, but neurophysiological assessment revealed that the ITC-treated child required more time and elicited a smaller N400 component compared to his sibling during picture-word matching. The findings suggest that in the absence of pretreatment performance indices, comparison with sibling achievement may supplement what is known on posttreatment language skill development drawn from comparative studies using children matched on age, sex, and educational level drawn from the community. The study's findings offer pilot data of language outcomes following ITC beyond the early stage of survivorship. The benefits and limitations of using siblings in research where the cognitive environment is known to make an important contribution to skill development are discussed.

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.

Adverse effects of treatment in childhood acute lymphoblastic leukemia: general overview and implications for long-term cardiac health

Survival of childhood acute lymphoblastic leukemia (ALL) is one of the greatest medical success stories of the last four decades. Unfortunately, childhood ALL survivors experience medical late effects that increase their risk of morbidity and premature death, often due to heart and vascular disease. Research has helped elucidate the mechanisms and trajectory of direct damage to the heart from treatment exposure, particularly to anthracyclines, and has also contributed knowledge on the influences of related chronic conditions, such as obesity and insulin resistance on heart health in these survivors. This article summarizes the key issues associated with early morbidity and mortality from cardiac-related disease in childhood ALL survivors and suggests directions for interventions to improve long-term outcomes.

Neurocognitive outcome in survivors of pediatric cancer

PURPOSE OF REVIEW

There are more than 11 million survivors of pediatric cancers living in the US. The largest proportion had leukemia and the group most severely impacted by their cancer and their therapies are the survivors of central nervous system (CNS) tumors. This review describes the neurocognitive outcome for these groups and outlines work aimed at understanding the pathophysiology of and approach to ameliorating neurocognitive dysfunction.

RECENT FINDINGS

The impact of chemotherapy on children treated for leukemia without radiation has been elucidated and the differential impact of different radiation fields and doses among children with CNS malignancies has been described. Newer imaging techniques may predict damage earlier and animal models of chemotherapy-induced neurotoxicity may prove valuable in designing less toxic therapies or finding protective agents. Cognitive training programs, notably computerized programs that can be accessed at home, may be part of successful programs for minimizing neurotoxicity.

SUMMARY

This review seeks to describe the neurocognitive consequences of cancer and its therapy among pediatric patients treated for leukemia or a CNS tumor. The consequences of therapy with and without cranial radiation are described and information on potentially valuable animal models and imaging techniques are presented. The impact of host pharmacogenomics is outlined.

Cognitive reserve and brain volumes in pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is associated with long-term, progressive cognitive deficits and white matter injury. We measured global and regional white and gray matter as well as cognitive function and examined relationships between these variables and cognitive reserve, as indicated by maternal education level, in 28 young survivors of ALL and 31 healthy controls. Results indicated significantly reduced white matter volumes and cognitive testing scores in the ALL group compared to controls. Maternal education was inversely related to both global and regional white matter and directly related to gray matter in ALL and was directly related to both gray and white matter in controls, consistent with the cognitive reserve hypothesis. Cognitive performance was associated with different brain regions in ALL compared to controls. Maternal education was significantly positively correlated with working and verbal memory in ALL as well as processing speed and verbal memory in controls, improving models of cognitive outcome over medical and/or demographic predictors. Our findings suggest that cognitive reserve may be an important factor in brain injury and cognitive outcome in ALL. Additionally, children with ALL may experience some neural reorganization related to cognitive outcome.

Neurocognitive functioning in adult survivors of childhood non-central nervous system cancers

BACKGROUND We sought to measure self-reported neurocognitive functioning among survivors of non-central nervous system (CNS) childhood cancers, overall and compared with a sibling cohort, and to identify factors associated with worse functioning. METHODS In a retrospective cohort study, 5937 adult survivors of non-CNS cancers and 382 siblings completed a validated neuropsychological instrument with subscales in task efficiency, emotional regulation, organization, and memory. Scores were converted to T scores; scores in the worst 10% of siblings' scores (ie, T score > or =63) were defined as impaired. Non-CNS cancer survivors and siblings were compared with multivariable linear regression and log-binomial regression. Among survivors, log-binomial models assessed the association of patient and treatment factors with neurocognitive dysfunction. All statistical tests were two-sided. RESULTS Non-CNS cancer survivors had similar or slightly worse (<0.5 standard deviation) mean test scores for all four subscales than siblings. However, frequencies of impaired survivors were approximately 50% higher than siblings in task efficiency (13.0% of survivors vs 7.3% of siblings), memory (12.5% vs 7.6%), and emotional regulation (21.2% vs 14.4%). Impaired task efficiency was most often identified in patients with acute lymphoblastic leukemia who received cranial radiation therapy (18.1% with impairment), myeloid leukemia who received cranial radiation therapy (21.2%), and non-Hodgkin lymphoma (13.9%). In adjusted analysis, diagnosis age of younger than 6 years, female sex, cranial radiation therapy, and hearing impairment were associated with impairment. CONCLUSION A statistically and clinically significantly higher percentage of self-reported neurocognitive impairment was found among survivors of non-CNS cancers than among siblings.

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.

Long-term results of Dutch Childhood Oncology Group studies for children with acute lymphoblastic leukemia from 1984 to 2004

The Dutch Childhood Oncology Group (DCOG) has used two treatment strategies for children with acute lymphoblastic leukemia (ALL) based on Pinkel's St Jude Total Therapy or the Berlin-Frankfurt-Münster (BFM) backbone. In four successive protocols, 1734 children were treated. Studies ALL-6 and ALL-9 followed the Total Therapy approach; cranial irradiation was replaced by medium-dose methotrexate infusions and prolonged triple intrathecal therapy; dexamethasone was used instead of prednisone. Studies ALL-7 and ALL-8 had a BFM backbone, including more intensive remission induction, early reinduction and maintenance therapy without vincristine and prednisone pulses. The 5-year event-free survival and overall survival increased from 65.4 to 80.6% (P<0.001) and from 78.7 to 86.4% (P=0.07) in ALL-7 and ALL-9, respectively. In ALL-7 and ALL-8 National Cancer Institute (NCI) high-risk criteria, male gender, T-lineage ALL and high white blood cells (WBCs) predict poor outcome. In ALL-9 NCI criteria, gender, WBC >100 x 109/l, and T-lineage ALL have prognostic impact. We conclude that the chemotherapy-only approach in children with ALL in Total Therapy-based strategies and BFM-backbone treatment does not jeopardize survival and preserves cognitive functioning. This experience is implemented in the current DCOG-ALL-10 study using a BFM backbone and minimal residual disease-based stratification.