Chemotherapy and attentional dysfunction in survivors of childhood acute lymphoblastic leukemia: effect of treatment intensity

Feasibility of baseline neurocognitive assessment using Cogstate during the first month of therapy for childhood leukemia

PURPOSE

Neurocognitive impairment is frequently observed among acute lymphoblastic leukemia (ALL) survivors within the domains of intelligence, attention, processing speed, working memory, learning, and memory. However, few have investigated treatment-induced changes in neurocognitive function during the first months of treatment. Additionally, dysfunction during treatment may be preceded by changes in biomarkers measured within cerebrospinal fluid (CSF). Identification of acute declines in neurocognitive function, as well as predictive genotypes or biomarkers, could guide therapeutic trials of protective interventions.

METHODS

This study collects CSF while prospectively assessing neurocognitive functioning (working memory, executive function, learning, processing speed, and attention) of ALL patients using the Cogstate computerized battery at six time points during and after the 2 years of leukemia treatment on a Dana-Farber Cancer Institute ALL Consortium trial.

RESULTS

Baseline data collected during the first 3 weeks of induction chemotherapy indicate reliable data as all subjects (N = 34) completed Cogstate baseline testing, while completion and performance checks indicate that 100 % of subjects completed testing and complied with test requirements. The majority (85 %) exhibited normal function compared with age peers. Preliminary analysis of CSF biomarkers (folate, homocysteine, 8-isoprostane, and myelin basic protein) similarly reveals values at baseline within expected normal ranges.

CONCLUSIONS

The first month of induction therapy for ALL is a reliable baseline for detecting treatment-induced changes in neurocognitive functioning. Consequently, serial data collection might identify subgroups of ALL patients at increased risk for neurocognitive decline, warranting proactive interventions to improve their level of functioning both during treatment and into survivorship.

Cognitive, behaviour, and academic functioning in adolescent and young adult survivors of childhood acute lymphoblastic leukaemia: a report from the Childhood Cancer Survivor Study

BACKGROUND

Survivors of childhood acute lymphoblastic leukaemia (ALL) are at risk for neurocognitive deficits that affect development in adolescence and young adulthood, and influence educational attainment and future independence. We examined a large and diverse cohort of survivors to identify risk predictors and modifiers of these outcomes.

METHODS

In this cohort study, cognitive and behaviour symptoms were assessed via a standardised parent questionnaire for 1560 adolescent survivors of ALL diagnosed between 1970 and 1999. Clinically significant symptoms (≥90th percentile) and learning problems were compared between survivors and a sibling cohort. Multivariable regression models were used to examine associations with demographic and treatment characteristics. Models were adjusted for inverse probability of sampling weights to reflect undersampling of ALL survivors in the expansion cohort. In a subset of survivors with longitudinal data (n=925), we examined associations between adolescent symptoms or problems and adult educational attainment.

FINDINGS

Compared with siblings, survivors treated with chemotherapy only were more likely to demonstrate headstrong behaviour (155 [19%] of 752 survivors vs 88 [14%] of 610 siblings, p=0·010), inattention-hyperactivity (15 [19%] vs 86 [14%], p<0·0001), social withdrawal (142 [18%] vs 75 [12%], p=0·002), and had higher rates of learning problems (191 [28%] vs 76 [14%], p<0·0001). In multivariable models among survivors, increased cumulative dose of intravenous methotrexate (ie, >4·3 g/m²) conferred increased risk of inattention-hyperactivity (relative risk [RR] 1·53, 95% CI 1·13-2·08). Adolescent survivors with cognitive or behaviour problems and those with learning problems were less likely to graduate from college as young adults than adolescent survivors without cognitive or behaviour problems.

INTERPRETATION

Although modern therapy for childhood ALL has eliminated the use of cranial radiation therapy, adolescent survivors treated with chemotherapy only remain at increased risk for cognitive, behaviour, and academic problems that adversely affect adult education outcomes.

FUNDING

National Cancer Institute, American Lebanese-Syrian Associated Charities.

Adverse neuropsychological effects associated with cumulative doses of corticosteroids to treat childhood acute lymphoblastic leukemia: A literature review

Corticosteroids (CS) are an essential component of childhood acute lymphoblastic leukemia treatments (cALL). Although there is evidence that daily doses of CS can have neuropsychological effects, few studies have investigated the role of cumulative doses of CS in short- and long-term neuropsychological effects in cALL. The aims of this review were to identify the measures used for documenting adverse neuropsychological effects (ANEs) of CS treatment and to study the association between cumulative doses of CS and the presence of ANEs. Twenty-two articles met the inclusion criteria. A variety of measures were used to evaluate outcomes in the domains of emotion, behaviour, neurocognition, and fatigue/sleep. The results suggest that we cannot conclude in favour of an association between the cumulative dosage of CS and ANEs. Yet, several factors including the heterogeneity of measures used to evaluate outcomes and reporting biases may limit the scope of the results. We offer several recommendations that could help improve the future published evidence on ANEs in relation to CS treatment in cALL.

Effects of Intraventricular Methotrexate on Neuronal Injury and Gene Expression in a Rat Model

Central nervous system (CNS)-directed treatment for acute lymphoblastic leukemia, used to prevent disease recurrence in the brain, is essential for survival. Systemic and intrathecal methotrexate, commonly used for CNS-directed treatment, have been associated with cognitive problems during and after treatment. The cortex, hippocampus, and caudate putamen, important brain regions for learning and memory, may be involved in methotrexate-induced brain injury. Objectives of this study were to (1) quantify neuronal degeneration in selected regions of the cortex, hippocampus, and caudate putamen and (2) measure changes in the expression of genes with known roles in oxidant defense, apoptosis/inflammation, and protection from injury. Male Sprague Dawley rats were administered 2 or 4 mg/kg of methotrexate diluted in artificial cerebrospinal fluid (aCSF) or aCSF only into the left cerebral lateral ventricle. Gene expression changes were measured using customized reverse transcription (RT)2 polymerase chain reaction arrays. The greatest percentage of degenerating neurons in methotrexate-treated animals was in the medial region of the cortex; percentage of degenerating neurons in the dentate gyrus and cornu ammonis 3 regions of the hippocampus was also greater in rats treated with methotrexate compared to perfusion and vehicle controls. There was a greater percentage of degenerating neurons in the inferior cortex of control versus methotrexate-treated animals. Eight genes involved in protection from injury, oxidant defense, and apoptosis/inflammation were significantly downregulated in different brain regions of methotrexate-treated rats. To our knowledge, this is the first study to investigate methotrexate-induced injury in selected brain regions and gene expression changes using a rat model of intraventricular drug administration.

Types and Influence of Social Support on School Engagement of Young Survivors of Leukemia

The present study aimed to describe and explore the influence of social support on the school engagement of young survivors of pediatric leukemia. Fifty-three young Quebecers, previously diagnosed and treated for leukemia, completed a questionnaire measuring their school engagement and participated in an interview focusing on the support offered by four groups of relations with regard to school: parents, siblings, friends, and other nonprofessional relations. The interview responses revealed that parents were perceived to be the primary source of informational and emotional support, with support also provided to a lesser extent by friends, siblings, and members of the extended family. Inferential analyses indicated that young survivors report a higher school engagement score when they perceive themselves as receiving support from a greater number of groups of relations, especially from friends or siblings.

Neurocognitive and Patient-Reported Outcomes in Adult Survivors of Childhood Osteosarcoma

IMPORTANCE

This study provides the first objective data documenting neurocognitive impairment in long-term survivors of childhood osteosarcoma.

OBJECTIVE

To examine neurocognitive, neurobehavioral, emotional, and quality-of-life outcomes in long-term survivors of childhood osteosarcoma.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional cohort study at an academic research hospital, with prospective treatment and chronic health predictors. Outcome data were collected from June 2008 to August 2014. Data analysis was completed in April 2015. Survivors of osteosarcoma recruited from the St Jude Lifetime Cohort Study were compared with community controls.

MAIN OUTCOMES AND MEASURES

Neurocognitive function, neurobehavioral symptoms, emotional distress, and quality of life. Outcomes were examined in relation to pharmacokinetic indices of methotrexate exposure and current chronic health conditions, which were assessed through medical examination and coded according to Common Terminology Criteria for Adverse Events, Version 4.03.

RESULTS

Eighty survivors of osteosarcoma (mean [SD] age, 38.9 [7.6] years; time since diagnosis, 24.7 [6.6] years; 42% female) were compared with 39 community controls (age, 39.0 [11.7] years; 56% female). Survivors demonstrated lower mean scores in reading skills (-0.21 [95% CI, -0.32 to -0.10] vs 0.05 [95% CI, -0.13 to 0.23]; P = .01), attention (-0.78 [95% CI, -1.32 to -0.24] vs 0.24 [95% CI, -0.07 to 0.55]; P = .002), memory (-0.24 [95% CI, -0.48 to 0] vs 0.27 [95% CI, -0.08 to 0.62]; P = .01), and processing speed (-0.15 [95% CI, -0.35 to 0.05] vs 0.74 [95% CI, 0.44 to 1.03]; P < .001). Results of pharmacokinetic analysis showed that high-dose methotrexate maximum plasma concentration (estimate = 0; P = .48), median clearance (estimate = -0.11; P = .76), and median/cumulative exposure (estimate = 0; P = .45) were not associated with neurocognitive outcomes. Any grade 3 or 4 Common Terminology Criteria for Adverse Events cardiac, pulmonary, or endocrine condition was associated with poorer memory (t = 2.93; P = .006) and slower processing speed (t = 3.03; P = .002). Survivor-reported poor general health was associated with decreased sustained attention (estimate = 0.24; P = .05) and processing speed (estimate = 0.34; P = .005).

CONCLUSIONS AND RELEVANCE

Long-term survivors of osteosarcoma are at risk for neurocognitive impairment, which is related to current chronic health conditions and not to original treatment with high-dose methotrexate. Prospective longitudinal studies are needed to identify onset and progression of impairment to inform optimal interventions.

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.

Longitudinal Assessment of Neurocognitive Outcomes in Survivors of Childhood Acute Lymphoblastic Leukemia Treated on a Contemporary Chemotherapy Protocol

PURPOSE

Survivors of childhood acute lymphoblastic leukemia (ALL) treated with CNS-directed chemotherapy are at risk for neurocognitive deficits. Prospective longitudinal studies are needed to clarify the neurodevelopmental trajectory in this vulnerable population.

METHODS

Patients enrolled in the St. Jude Total Therapy Study XV, which omitted prophylactic cranial radiation therapy in all patients, completed comprehensive neuropsychological assessments at induction (n = 142), end of maintenance (n = 243), and 2 years after completion of therapy (n = 211). We report on longitudinal change in neurocognitive function and predictors of neurocognitive outcomes 2 years after completing therapy.

RESULTS

Neurocognitive function was largely age appropriate 2 years after completing therapy; however, the overall group demonstrated significant attention deficits and a significantly greater frequency of learning problems as compared with national normative data (all P ≤ .005). Higher-intensity CNS-directed chemotherapy conferred elevated risk for difficulties in attention, processing speed, and academics (all P ≤ .01). The rate and direction of change in performance and caregiver-reported attention difficulties differed significantly by age at diagnosis and sex. End-of-therapy attention problems predicted lower academic scores 2 years later, with small to moderate effect sizes (│r│= 0.17 to 0.25, all P ≤ .05).

CONCLUSION

Two years after chemotherapy-only treatment, neurocognitive function is largely age appropriate. Nonetheless, survivors remain at elevated risk for attention problems that impact real-world functioning. Attention problems at the end of therapy predicted decreased academics 2 years later, suggesting an amplified functional impact of discrete neurocognitive difficulties. Age at diagnosis and patient sex may alter neurocognitive development in survivors of childhood ALL treated with chemotherapy-only protocols.

Executive function deficits in pediatric cerebellar tumor survivors

BACKGROUND AND AIMS

Besides motor function the cerebellum subserves frontal lobe functions. Thus, we investigated executive functions in pediatric posterior fossa tumor survivors.

METHODS

We tested information processing, aspects of attention, planning and intelligence in 42 pediatric posterior fossa tumor survivors (mean age 14.63 yrs, SD 5.03). Seventeen low-grade tumor patients (LGCT) were treated with surgery only and 25 high-grade tumors patients (HGCT) received postsurgical adjuvant treatment. We evaluated simple reaction time, executive functioning, i.e. visuospatial memory, inhibition, and mental flexibility using the Amsterdam Neuropsychological Tasks program, whereas forward thinking was assessed with the Tower of London-test. Intelligence was determined using the Wechsler Intelligence Scale. Ataxia was assessed with the International Cooperative Ataxia Rating Scale.

RESULTS

About one third of each patient group showed forward thinking scores below one standard deviation of the norm. Impaired forward thinking correlated significantly with degree of ataxia (r = -0.39, p = 0.03) but not with fluid intelligence. Both patient groups exhibited executive function deficits in accuracy and reaction speed in more difficult tasks involving information speed and attention flexibility. Still, HGCT patients were significantly slower and committed more errors. Working memory was inferior in HGCT patients.

CONCLUSION

Pediatric cerebellar tumor survivors with different disease and treatment related brain damage exhibit similar patterns of impairment in executive functioning, concerning forward thinking, inhibition and mental flexibility. The deficits are larger in high-grade tumor patients. The pattern of function loss seen in both groups is most probably due to comparable lesions to cerebro-cerebellar circuits that are known to modulate critical executive functions.

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.

Monitoring and Assessment of Neuropsychological Outcomes as a Standard of Care in Pediatric Oncology

Central nervous system cancers or exposure to CNS-directed therapies increase risk for neuropsychological deficits. There are no accepted guidelines for assessment of neuropsychological functioning in this population. A multifaceted literature search was conducted and relevant literature reviewed to inform the guidelines. Studies of neuropsychological outcomes are widely documented in the pediatric oncology literature. There is strong evidence of need for neuropsychological assessment, but insufficient evidence to guide the timing of assessment, nor to recommend specific interventions. Children with brain tumors and others at high risk for neuropsychological deficits should be monitored and assessed for neuropsychological deficits.

Executive Dysfunction 25 Years after Treatment with Cranial Radiotherapy for Pediatric Lymphoid Malignancies

The first cohorts to survive childhood lymphoid malignancies treated with cranial irradiation are now aging into adulthood, and concerns are growing about the development of radiotherapy-induced cognitive deficits in the aging brain. These deficits are hypothesized to increase over time. Their impact on daily functioning of older survivors, and the accompanying need for interventions, should be anticipated. By describing a detailed profile of executive function deficits and their associations with age, specific targets for neuropsychological intervention can be identified. Fifty survivors of childhood lymphoid malignancies and 58 related controls were assessed with the Amsterdam Neuropsychological Tasks program. The survivors were on average 31.1 (4.9) years old, treated with 22.5 (6.8) Gy cranial irradiation, and examined on average 25.5 (3.1) years after diagnosis. The survivors showed significantly decreased response speed, irrespective of the task at hand. Furthermore, we found deficits in working memory capacity, inhibition, cognitive flexibility, executive visuomotor control, attentional fluctuations, and sustained attention. Older age was associated with poorer performance on executive visuomotor control and inhibition. On executive visuomotor control, 50% of female survivors performed more than 1.5 SD below average, versus 15.4% of male survivors. The combination of visuospatial working memory problems and decreasing executive visuomotor control could result in difficulty with learning new motor skills at older ages, like walking with a cane. Deterioration of executive control and inhibition may result in decreased behavioral and emotional regulation in aging survivors. Especially the deficiency in executive visuomotor control in female survivors should be considered for (prophylactic) intervention.

Neurocognitive outcome in survivors of childhood acute lymphoblastic leukemia: experience at a tertiary care hospital in Korea

This study was conducted to investigate long-term neurocognitive outcomes and to determine associated risk factors in a cohort of Korean survivors of childhood acute lymphoblastic leukemia (ALL). Forty-two survivors of ALL were compared with 42 healthy controls on measures of a neurocognitive test battery. We analysed potential risk factors (cranial irradiation, sex, age at diagnosis, elapsed time from diagnosis, and ALL risk group) on neurocognitive outcomes. ALL patients had lower, but non-significant full-scale intelligence quotient (FSIQ, 107.2±12.2 vs. 111.7±10.2), verbal intelligence quotient (VIQ, 107.7±13.6 vs. 112.2±11.4), and performance intelligence quotient (PIQ, 106.3±14.2 vs. 110.1±10.7) scores than healthy controls. However, patients treated with cranial irradiation performed significantly lower on FSIQ (102.2±8.1), VIQ (103.3±11.7), and PIQ (101.4±13.2) compared to non-irradiated patients and healthy controls. ALL patients also had poor attention, concentration, and executive functions. Among ALL survivors, cranial irradiation was a risk factor for poor FSIQ, being male was a risk factor for poor PIQ, and younger age was a risk factor for poor attention. Therefore, the delayed cognitive effects of ALL treatment and its impact on quality of life require continuing monitoring and management.

Neurocognitive Late Effects of Chemotherapy in Survivors of Acute Lymphoblastic Leukemia: Focus on Methotrexate

Childhood cancer survivors frequently experience long-lasting consequences of chemotherapy on health outcomes. Neurocognitive late effects of chemotherapy occur in 40 - 60% of acute lymphoblastic leukemia (ALL) survivors. These deficits affect mental health, school performance, job success, and are associated with poor quality of life, therefore presenting a clinical challenge for psychiatrists. However, not all cancer survivors are impacted by treatment in the same manner and emerging evidence suggests that genetic variation may modulate neurocognitive outcomes. Much like other complex psychopathologies, neurocognitive deficits in cancer survivors are the result of complex interactions between genetic and environmental variables. This review describes adverse neurocognitive outcomes observed in survivors of acute lymphoblastic leukemia (ALL) and discusses genetic variability in biochemical pathways targeted by chemotherapeutic agents as a possible mechanism contributing to psychopathology in ALL survivors.

Increase in oxidative stress as measured by cerebrospinal fluid lipid peroxidation during treatment for childhood acute lymphoblastic leukemia

Five-year survival from childhood acute lymphoblastic leukemia (ALL) approaches 90%, but 40% of survivors experience central nervous system (CNS) treatment-related cognitive problems. Despite considerable evidence for cognitive problems, less is known about mechanisms of neurological injury. Our purpose was to investigate oxidative stress, measured by lipid peroxidation, as a mechanism of CNS treatment-related neurological injury. The sample included 55 children (mean age at diagnosis=6.84 y, SD=3.40) who received intrathecal and intravenous chemotherapy for CNS-directed treatment according to Children's Oncology Group protocols. Glycerophospholipids were extracted from cerebrospinal fluid samples obtained at diagnosis and during intrathecal chemotherapy administration. Unoxidized and oxidized phosphatidylcholine (PC) and phosphatidylinositol (PI) were measured by normal phase high-performance liquid chromatography with diode array detection, and analyzed with a general linear model for repeated measures analysis of variance. Compared with the diagnostic cerebrospinal fluid sample, unoxidized and oxidized PC and PI increased significantly across treatment phases. Amount of intravenous methotrexate received was significantly correlated with oxidized PI, and age at time of ALL diagnosis was significantly associated with oxidized PC. These findings support our hypothesis that oxidative stress is a mechanism of neurological injury associated with CNS-directed treatment for ALL.

What are the long-term effects of treatment on survivors of childhood leukaemia? A review of the literature

Purpose

Key advances in cancer treatment have led to an increasing number of long-term cancer survivors. Knowledge of the long-term effects of cancer treatment on leukaemia survivors is to some degree limited. This article investigates the effects of the treatment of childhood leukaemia on the quality of life (QOL), the physical and the psychological wellbeing and general development of survivors. This article reviews current literature to examine existing gaps in knowledge and identify a potential focus of future research and clinical practice.

Materials and methods

Online systematic searching, along with historical searching took place in order to retrieve relevant primary research papers for the review. Strict inclusion and exclusion criteria were applied to the literature, to create a manageable amount of research papers.

Results

The extent of intellectual impairment among radiotherapy patients was significantly greater than those treated with chemotherapy only. Body composition, including endocrine function, is readily affected by cancer treatment. Early identification and interventions can greatly improve the QOL of survivors.

Conclusion

Further research into the effect of treatment modality on the extent of chronic effects, along with investigations into the needs of the whole family unit, is required. Future practice must take into account long-term implications while ensuring effective holistic care.

Executive function late effects in survivors of pediatric brain tumors and acute lymphoblastic leukemia

BACKGROUND

Survivors of pediatric brain tumors (BT) and acute lymphoblastic leukemia (ALL) are at risk for neurocognitive late effects related to executive function.

PROCEDURE

Survivors of BT (48) and ALL (50) completed neurocognitive assessment. Executive function was compared to estimated IQ and population norms by diagnostic group.

RESULTS

Both BT and ALL demonstrated relative executive function weaknesses. As a group, BT survivors demonstrated weaker executive functioning than expected for age. Those BT survivors with deficits exhibited a profile suggestive of global executive dysfunction, while affected ALL survivors tended to demonstrate specific rapid naming deficits.

CONCLUSION

Findings suggest that pediatric BT and ALL survivors may exhibit different profiles of executive function late effects, which may necessitate distinct intervention plans.

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.

Career readiness in adult survivors of childhood cancer: a report from the St. Jude Lifetime Cohort Study

PURPOSE

Adult survivors of childhood cancer experience difficulties in obtaining and maintaining employment. Employment-related challenges are associated with treatment-related health conditions and may also be related to vocational factors such as career readiness, skill acquisition, and work experience. Unfortunately, little is known about how treatment-, health-, and vocational-related factors interact to impact career development among childhood cancer survivors.

METHODS

Three hundred eighty-five adult survivors of childhood cancer (42.1% male, median age 38 years (21-62)), participating in the St. Jude Lifetime Cohort Study, completed a work experiences survey that included measures of career readiness and vocational identity. Logistic regression was used to compare characteristics of survivors in the low career readiness category to those in the medium or high career readiness category, and structural equation modeling (SEM) was utilized to evaluate associations between career readiness, vocational identity, treatment intensity, and physical/emotional health.

RESULTS

Low career readiness was prevalent in 17.4% of survivors. Univariate analysis did not identify any significant associations between cancer treatment-related factors and career readiness. Unemployed survivors (odds ratio (OR) 2.3, 95% confidence interval (CI) 1.2-4.5), those who were not college graduates (OR 3.0, 95% CI 1.6-5.6), and those who had no personal income (OR 5.9, 95% CI 1.7-30.9) were at increased risk of low career readiness. SEM indicated that associations between treatment intensity, physical health, age at diagnosis, and career readiness were mediated by emotional health and vocational identity. Sixty-three, 35, and 10% of the variance in career readiness, vocational identity, and emotional health, respectively, were explained by this theoretical model.

CONCLUSIONS

The results of this study indicate that individuals who reported low levels of career readiness were more likely to be unemployed and earn less than US$40,000 per year and were less likely to graduate from high school. The final structural model indicates that vocational identity and emotional health accounted for the indirect effect of treatment intensity, age at diagnosis, and physical health on career readiness.

IMPLICATIONS FOR CANCER SURVIVORS

Addressing career readiness may be important to improve employment outcomes for adult survivors of childhood cancer.

Does dexamethasone induce more neuropsychological side effects than prednisone in pediatric acute lymphoblastic leukemia? A systematic review

Steroid-induced neuropsychological side effects impact quality of life in children with acute lymphoblastic leukemia. Dexamethasone induces more metabolic side effects than prednisone. To evaluate whether dexamethasone also leads to more neuropsychological side effects, we reviewed all available literature. Randomized controlled trials with neuropsychological function as the primary or secondary outcome did not show clinically meaningful differences between dexamethasone and prednisone on cognition, mood or behavior.

Prognostic factors that increase the risk for reduced white matter volumes and deficits in attention and learning for survivors of childhood cancers

OBJECTIVE

In children, CNS-directed cancer therapy is thought to result in decreased cerebral white matter volumes (WMV) and subsequent neurocognitive deficits. This study was designed as a prospective validation of the purported reduction in WMV, associated influential factors, and its relationship to neurocognitive deficits in a very large cohort of both acute lymphoblastic leukemia (ALL) and malignant brain tumors (BT) survivors in comparison to an age similar cohort of healthy sibling controls.

PROCEDURES

The effects of host characteristics and CNS treatment intensity on WMV were investigated in 383 childhood cancer survivors (199 ALL, 184 BT) at least 12 months post-completion of therapy and 67 healthy siblings that served as a control group. t-Tests and multiple variable linear models were used to assess cross-sectional WMV and its relation with neurocognitive function.

RESULTS

BT survivors had lower WMV than ALL survivors, who had less than the control group. Increased CNS treatment intensity, younger age at treatment, and greater time since treatment were significantly associated with lower WMV. Additionally, cancer survivors did not perform as well as the control group on neurocognitive measures of intelligence, attention, and academic achievement. Reduced WMV had a larger impact on estimated IQ among females and children treated at a younger age.

CONCLUSIONS

Survivors of childhood cancer that have undergone higher intensity therapy at a younger age have significantly less WMV than their peers and this difference increases with time since therapy. Decreased WMV is associated with significantly lower scores in intelligence, attention, and academic performance in survivors.

Consequences of cancer treatments on adult hippocampal neurogenesis: implications for cognitive function and depressive symptoms

The human brain is capable of generating new functional neurons throughout life, a phenomenon known as adult neurogenesis. The generation of new neurons is sustained throughout adulthood due to the proliferation and differentiation of adult neural stem cells. This process in humans is uniquely located in the subgranular zone of the dentate gyrus in the hippocampus. Adult hippocampal neurogenesis (AHN) is thought to play a major role in hippocampus-dependent functions, such as spatial awareness, long-term memory, emotionality, and mood. The overall aim of current treatments for cancer (such as radiotherapy and chemotherapy) is to prevent aberrant cell division of cell populations associated with malignancy. However, the treatments in question are absolutist in nature and hence inhibit all cell division. An unintended consequence of this cessation of cell division is the impairment of adult neural stem cell proliferation and AHN. Patients undergoing treatment for cancerous malignancies often display specific forms of memory deficits, as well as depressive symptoms. This review aims to discuss the effects of cancer treatments on AHN and propose a link between the inhibition of the neurogenetic process in the hippocampus and the advent of the cognitive and mood-based deficits observed in patients and animal models undergoing cancer therapies. Possible evidence for coadjuvant interventions aiming to protect neural cells, and subsequently the mood and cognitive functions they regulate, from the ablative effects of cancer treatment are discussed as potential clinical tools to improve mental health among cancer patients.

Neurocognitive and neuroradiologic central nervous system late effects in children treated on Pediatric Oncology Group (POG) P9605 (standard risk) and P9201 (lesser risk) acute lymphoblastic leukemia protocols (ACCL0131): a methotrexate consequence? A report from the Children's Oncology Group

Concerns about long-term methotrexate (MTX) neurotoxicity in the 1990s led to modifications in intrathecal (IT) therapy, leucovorin rescue, and frequency of systemic MTX administration in children with acute lymphoblastic leukemia. In this study, neurocognitive outcomes and neuroradiologic evidence of leukoencephalopathy were compared in children treated with intense central nervous system (CNS)-directed therapy (P9605) versus those receiving fewer CNS-directed treatment days during intensive consolidation (P9201). A total of 66 children from 16 Pediatric Oncology Group institutions with "standard-risk" acute lymphoblastic leukemia, 1.00 to 9.99 years at diagnosis, without evidence of CNS leukemia at diagnosis were enrolled on ACCL0131: 28 from P9201 and 38 from P9605. Magnetic resonance imaging scans and standard neuropsychological tests were performed ≥2.6 years after the end of treatment. Significantly more P9605 patients developed leukoencephalopathy compared with P9201 patients (68%, 95% confidence interval 49%-83% vs. 22%, 95% confidence interval 5%-44%; P=0.001) identified as late as 7.7 years after the end of treatment. Overall, 40% of patients scored <85 on either Verbal or Performance IQ. Children on both studies had significant attention problems, but P9605 children scored below average on more neurocognitive measures than those treated on P9201 (82%, 14/17 measures vs. 24%, 4/17 measures). This supports ongoing concerns about intensive MTX exposure as a major contributor to CNS late effects.

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.

Accelerated aging, decreased white matter integrity, and associated neuropsychological dysfunction 25 years after pediatric lymphoid malignancies

PURPOSE

CNS-directed chemotherapy (CT) and cranial radiotherapy (CRT) for childhood acute lymphoblastic leukemia or lymphoma have various neurotoxic properties. This study aimed to assess their impact on the maturing brain 20 to 30 years after diagnosis, providing a much stronger perspective on long-term quality of life than previous studies.

PATIENTS AND METHODS

Ninety-three patients treated between 1978 and 1990 at various intensities, with and without CRT, and 49 healthy controls were assessed with magnetic resonance diffusion tensor imaging (DTI) and neuropsychological tests. Differences in fractional anisotropy (FA)-a DTI measure describing white matter (WM) microstructure-were analyzed by using whole brain voxel-based analysis.

RESULTS

CRT-treated survivors demonstrated significantly decreased FA compared with controls in frontal, parietal, and temporal WM tracts. Trends for lower FA were seen in the CT-treated survivors. Decreases in FA correlated well with neuropsychological dysfunction. In contrast to the CT group and controls, the CRT group showed a steep decline of FA with age at assessment. Younger age at cranial irradiation and higher dosage were associated with worse outcome of WM integrity.

CONCLUSION

CRT-treated survivors show decreased WM integrity reflected by significantly decreased FA and associated neuropsychological dysfunction 25 years after treatment, although effects of CT alone seem mild. Accelerated aging of the brain and increased risk of early onset dementia are suspected after CRT, but not after CT.

Long-term effects of cranial irradiation and intrathecal chemotherapy in treatment of childhood leukemia: a MEG study of power spectrum and correlated cognitive dysfunction

Background

Prophylaxis to prevent relapses in the central nervous system after childhood acute lymphoblastic leukemia (ALL) used to consist of both intrathecal chemotherapy (CT) and cranial irradiation (CRT). CRT was mostly abolished in the eighties because of its neurotoxicity, and replaced with more intensive intrathecal CT. In this study, a group of survivors treated with CRT before 1983 and another group treated without CRT thereafter are investigated 20–25 years later, giving a much stronger perspective on long-term quality of life than previous studies. The outcomes will help to better understand these groups’ current needs and will aid in anticipating late effects of prophylactic CRT that is currently applied for other diseases. This study evaluates oscillatory neuronal activity in these long-term survivors. Power spectrum deviations are hypothesized to correlate with cognitive dysfunction.

Methods

Resting state eyes-closed magnetoencephalography (MEG) recordings were obtained from 14 ALL survivors treated with CT + CRT, 18 treated with CT alone and 35 controls. Relative spectral power was calculated in the δ, θ, α1, α2, β and γ frequency bands. The Amsterdam Neuropsychological Tasks (ANT) program was used to assess cognition in the executive functions domain. MEG data and ANT scores were correlated.

Results

In the CT + CRT group, relative θ power was slightly increased (p = 0.069) and α2 power was significantly decreased (p = 0.006). The CT + CRT group performed worse on various cognitive tests. A deficiency in visuomotor accuracy, especially of the right hand, could be clearly associated with the deviating regional θ and α2 powers (0.471 < r < 0.697). A significant association between decreased regional α2 power and less attentional fluctuations was found for CT + CRT patients as well as controls (0.078 < r < 0.666). Patients treated with CT alone displayed a power spectrum similar to controls, except for a significantly increased level of left frontal α2 power (p = 0.030).

Conclusions

The tendency towards global slowing of brain oscillatory activity, together with the fact that dementia has been reported as a late effect of CRT and the neuropsychological deficiencies currently present, suggest that the irradiated brain might be aging faster and could be at risk for early‐onset dementia. The CT group showed no signs of early aging.

Cognitive outcomes following contemporary treatment without cranial irradiation for childhood acute lymphoblastic leukemia

BACKGROUND

Treatment of acute lymphoblastic leukemia (ALL) has included the use of prophylactic cranial irradiation in up to 20% of children with high-risk disease despite known cognitive risks of this treatment modality.

METHODS

Patients enrolled on the St Jude ALL Total Therapy Study XV, which omitted prophylactic cranial irradiation in all patients, were assessed 120 weeks after completion of consolidation therapy (n = 243) using a comprehensive cognitive battery. χ(2) analysis was used to compare the percentage of below-average performers among the entire ALL patient group to the expected rate based on the normative sample. Univariate logistic regression was used to estimate the effect of intensity of chemotherapy (treatment arm), age at diagnosis, and sex on the probability of below-average performance. All statistical tests were two-sided.

RESULTS

Overall, the ALL group had a statistically significantly higher risk for below-average performance on a measure of sustained attention (67.31% more than 1 SD below the normative mean for omission errors, P < .001) but not on measures of intellectual functioning, academic skills, or memory. Patients given higher intensity chemotherapy were at greater risk for below-average performance compared with those given lower intensity therapy on measures of processing speed (27.14% vs 6.25%, P = .009) and academic abilities (Math Reasoning: 18.60% vs 3.90%, P = .008; Word Reading: 20.00% vs 2.60%, P = .007; Spelling: 27.91% vs 3.90%, P = .001) and had higher parent-reported hyperactivity (23.00% vs 9.84%, P = .018) and learning problems (35.00% vs 16.39%, P = .005). Neither age at diagnosis nor sex was associated with risk for below-average cognitive performance.

CONCLUSIONS

Omitting cranial irradiation may help preserve global cognitive abilities, but treatment with chemotherapy alone is not without risks. Caregiver education and development of interventions should address both early attention deficits and cognitive late effects.

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.

Population-based exploration of academic achievement outcomes in pediatric acute lymphoblastic leukemia survivors

OBJECTIVE

Examine academic achievement among pediatric acute lymphoblastic leukemia survivors diagnosed during the years 1993-2008.

METHOD

A deterministic linkage of the Iowa Cancer Registry and Iowa Testing Programs databases was performed and yielded 147 survivors. Achievement data, in the form of Iowa Percentile Rank scores, were obtained and analyzed by grade and content domain.

RESULTS

Children diagnosed before age 5 evidenced more underachievement than those diagnosed later (p = .05). Underachievement was noted in mathematics in grades 8 and 11 (p's < .05), in addition to a longitudinal decrease in scores from grades 4 through 11 (p = .01). No differences were found in academic achievement between males and females.

CONCLUSIONS

Utilization of a population-based approach with a nationally recognized, standardized instrument indicates that academic underachievement is subtle yet exists, most notably in mathematics.

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.

Folate pathway polymorphisms predict deficits in attention and processing speed after childhood leukemia therapy

BACKGROUND

Neurocognitive impairment occurs in 20-40% of childhood acute lymphoblastic leukemia (ALL) survivors, possibly mediated by folate depletion and homocysteine elevation following methotrexate treatment. We evaluated the relationship between folate pathway polymorphisms and neurocognitive impairment after childhood ALL chemotherapy.

PROCEDURE

Seventy-two childhood ALL survivors treated with chemotherapy alone underwent a neurocognitive battery consisting of: Trail Making Tests A (TMTA) and B (TMTB), Grooved Pegboard Test Dominant-Hand and Nondominant-Hand, Digit Span subtest, and Verbal Fluency Test. We performed genotyping for: 10-methylenetetrahydrofolate reductase (MTHFR 677C>T and MTHFR 1298A>C), serine hydroxymethyltransferase (SHMT 1420C>T), methionine synthase (MS 2756 A>G), methionine synthase reductase (MTRR 66A>G), and thymidylate synthase (TSER). Student's two sample t-test and analysis of covariance were used to compare test scores by genotype.

RESULTS

General impairment on the neurocognitive battery was related to MTHFR 1298A>C (P = 0.03) and MS 2756A>G (P = 0.05). Specifically, survivors with MTHFR 1298AC/CC genotypes scored, on average, 13 points lower on TMTB than those with MTHFR 1298AA genotype (P = 0.001). The MS 2756AA genotype was associated with a 12.2 point lower mean TMTA score, compared to MS 2756 AG/GG genotypes (P = 0.01). The TSER 2R/3R and 3R/3R genotypes were associated with an 11.4 point lower mean score on TMTB, compared to the TSER 2R/2R genotype (P = 0.03). Survivors with ≥6 folate pathway risk alleles demonstrated a 9.5 point lower mean TMTA score (P = 0.06) and 14.5 point lower TMTB score (P = 0.002) than survivors with <6 risk alleles.

CONCLUSIONS

Folate pathway polymorphisms are associated with deficits in attention and processing speed after childhood ALL therapy.

Physical and psychological outcome in long-term survivors of childhood malignant solid tumor in Japan

PURPOSE

Few studies have assessed physical and psychological status in long-term survivors of childhood solid tumors in Japan. For children with such diseases diagnosed and treated in our hospital, our purpose was to clarify the physical and psychological status of long-term survivors and their parents.

METHODS

Subjects were 56 patients who were diagnosed at our institution as having a childhood malignant solid tumor between 1982 and 2005 and had been alive for at least 5 years after treatment. Surveys were sent and returned by mail.

RESULTS

Of the 56 patients surveyed, 32 responded. The current health condition and psychosocial status of survivors were evaluated as good by their parents. However, psychological tests revealed psychosocial problems in 28.1% of the children. Severe posttraumatic stress associated with the child's disease and its treatment was present in 15.6% of the parents.

CONCLUSION

Physical status of long-term survivors of childhood malignant solid tumors was good in general. However, psychological tests revealed psychosocial problems in some of the children and posttraumatic stress in the parents. Considering the diversity of both the diseases and their clinical course, a qualitative study is warranted for further analysis.

Disruption of learning processes by chemotherapeutic agents in childhood survivors of acute lymphoblastic leukemia and preclinical models

OBJECTIVE

With the survival rate of acute lymphoblastic leukemia (ALL) surpassing 90 percent within this decade, new research is emerging in the field of late effects. A review of the research investigating the relationship of treatment regimens for ALL to specific late effect deficits, underlying mechanisms, and possible remediation is warranted to support continued studies.

METHODS

The clinical literature was briefly surveyed to describe the occurrence and topography of late effects, specifically neurocognitive deficits. Additionally, the preclinical literature was reviewed to uncover potential underlying mechanisms of these deficits. The advantages of using rodent models to answer these questions are outlined, as is an assessment of the limited number of rodent models of childhood cancer treatment.

RESULTS

The literature supports that childhood survivors of ALL exhibit academic difficulties and are more likely to be placed in a special education program. Behavioral evidence has highlighted impairments in the areas of attention, working memory, and processing speed, leading to a decrease in full scale IQ. Neurophysiological and preclinical evidence for these deficits has implicated white matter abnormalities and acquired brain damage resulting from specific chemotherapeutic agents commonly used during treatment.

CONCLUSIONS

The exact role of chemotherapeutic agents in learning deficits remains mostly unknown. Recommendations for an improved rodent model of learning deficits in childhood cancer survivors are proposed, along with suggestions for future directions in this area of research, in hopes that forthcoming treatment regimens will reduce or eliminate these types of impairments.

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.

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.

Oxidative stress and neurobehavioral problems in pediatric acute lymphoblastic leukemia patients undergoing chemotherapy

Neurobehavioral problems after chemotherapy treatment for pediatric acute lymphoblastic leukemia (ALL) have been a recent focus of investigation. This study extended previous research that suggested oxidative stress as a potential mechanism for chemotherapy-induced central nervous system injury by examining early markers of oxidative stress in relation to subsequent neurobehavioral problems. Oxidized and unoxidized components of phosphatidylcholine (PC) were measured in the cerebrospinal fluid of 87 children with ALL at diagnosis, induction, and consolidation. Behavioral assessments were conducted postconsolidation and at the end of chemotherapy. Results revealed a significant association between physiologic reactivity (high vs. low PC changes from diagnosis) and behavioral outcomes (high vs. low pathology). Elevated oxidized PC fraction change was predictive of increased problems with aggression at the end of therapy as well as postconsolidation adaptability. Furthermore, symptoms of hyperactivity systematically changed over time in relation to both unoxidized PC and oxidized PC fraction reactivity. These findings suggest that symptoms of behavioral problems occur early in the course of chemotherapy and that increases in the cerebrospinal fluid PC markers of oxidative stress during induction and consolidation may help to predict certain future behavioral problems.

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.

Health-related Quality of Life in Children with Cancer Undergoing Treatment: A First Look at the Singapore Experience

Introduction: With intensive chemotherapy and increased survival, quality of life in our paediatric population is of increasing concern. The aim of this study was to assess the children’s quality of life during the treatment process. Materials and Methods: Patients between the ages of 7 and 18 years old who are undergoing cancer treatment in the Division of Paediatric Haematology-Oncology, Department of Paediatrics, National University Health System, were identified. The child self-reported his/her health-related quality of life (HRQOL) using the PedsQL Paediatric Quality of Life Inventory and Cancer module as a validated assessment tool. Results: Thirty-two patients were enrolled over a 3-week period in November 2007. The median age was 11 years (range, 7 to 17). There was 1 non-responder (3%). Fourteen (45%) boys and 17 (55%) girls were interviewed. There were 8 (26%) and 23 (74%) patients with solid and haematologic malignancies, respectively. For the Cognitive Problem Dimension score, 86% of patients with haematologic malignancy and 50% of those with solid malignancy scored below the 75th percentile (82), [OR 0.72 (0.01-0.8), P = 0.03]. For the Physical Health Summary score, patients with solid malignancy scored worse, 25% below the 10th percentile, as compared to 4.3% of patients with haematologic malignancy. This is reflected by a worse Pain and Hurt Dimension score for patients with solid malignancy. For the Perceived Appearance Dimension score, patients with solid malignancy (75%) scored lower than the median score (67) compared to those with haematologic malignancy (44%). Conclusions: The domains of HRQOL are affected to different extents for the patients with solid and those with haematologic malignancy. This is most likely to be due to the differences in treatment strategies and clinical course. Healthcare professionals should be aware of the effects of treatment on HRQOL and take practical steps to address these issues. Key words: Childhood cancer, Self-reported health and well-being

Comparison of neurocognitive functioning in children previously randomly assigned to intrathecal methotrexate compared with triple intrathecal therapy for the treatment of childhood acute lymphoblastic leukemia

PURPOSE

For the majority of children with acute lymphoblastic leukemia (ALL), CNS prophylaxis consists of either intrathecal (IT) methotrexate or triple IT therapy (ie, methotrexate with both cytarabine and hydrocortisone). The long-term neurotoxicities of these two IT strategies have not yet been directly compared.

PATIENTS AND METHODS

In this multisite study, 171 children with standard-risk ALL, age 1 to 9.99 years at diagnosis, previously randomly assigned to IT methotrexate (n = 82) or to triple IT therapy (n = 89) on CCG 1952, underwent neurocognitive evaluation by a licensed psychologist at a mean of 5.9 years after random assignment.

RESULTS

Patients who received IT methotrexate had a mean Processing Speed Index that was 3.6 points lower, about one fourth of a standard deviation, than those who received triple IT therapy (P = .04) after analysis was adjusted for age, sex, and time since diagnosis. Likewise, 19.5% of children in the IT methotrexate group had a Processing Speed Index score in the below-average range compared with 6.9% in the triple IT therapy group (P = .02). Otherwise, the groups performed similarly on tests of full-scale intelligence quotient, academic achievement, attention/concentration, memory, and visual motor integration. The association of treatment with measures of cognitive functioning was not modified by sex or age at diagnosis. In the post-therapy period, there were no group differences in special education services, neurologic events, or use of psychotropic medications.

CONCLUSION

This study did not show any clinically meaningful differences in neurocognitive functioning between patients previously randomly assigned to IT methotrexate or triple IT therapy except for a small difference in processing speed in the IT methotrexate group.

Sex-specific attention problems in long-term survivors of pediatric acute lymphoblastic leukemia

BACKGROUND

Neurocognitive problems are a frequent outcome of chemotherapy for pediatric leukemia, although individual differences exist in patient outcome. Sex of the patient and age at diagnosis are 2 characteristics that have been associated with differential outcomes. The relation between these patient characteristics and specific attention deficits (ie, initiating, inhibiting, shifting, focusing, sustaining attention, and working memory) has not been well researched. The purpose of this study was to evaluate the pattern of attention problems in male and female long-term survivors of pediatric acute lymphoblastic leukemia (ALL).

METHODS

One hundred three long-term survivors (ie, >or=5 years from diagnosis; 51% boys, mean age at diagnosis of 3.9 years, and mean time since diagnosis 7.5 years) completed standardized measures of basic and complex attention skills related to anterior (ie, inhibition, shifting attention, working memory), posterior (ie, focusing), and subcortical brain systems (ie, sustaining).

RESULTS

Treatment intensity was related to sustained attention, with those patients treated on high-risk protocols displaying significantly lower performance. Girls performed worse than boys on measures related to the anterior attention system (ie, shifting attention, P<.042) and the subcortical attention system (ie, sustained attention, P<.001), whereas boys performed worse than girls on different measures of anterior control (ie, inhibition, P<.039; working memory, P<.003).

CONCLUSIONS

The results of this study suggest that children diagnosed with and treated for pediatric ALL perform poorly on select measures of attention and executive control, and that this performance is influenced by sex and treatment intensity.