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

Processing speed in patients with pediatric cancer: Psychosocial considerations

Pediatric cancer treatments may contribute to slower processing, while cultural considerations (e.g., SES) can influence outcomes and tend to be disproportionately lower in racial/ethnic minorities. Given increased risk for certain cancers in Hispanic/Latine children and rising Spanish exposure in the United States, the purpose of this study was to examine differences in processing speed between cancer survivors based on household language exposure: English vs. mixed language (ML; i.e. monolingual Spanish-speaking or bilingual Spanish/English-speaking). 128 patients ages 8-21 with leukemia/lymphoma completed screening. As expected, SES was lower in patients from ML households based on parental education (U = 355.00, p<.001) and estimated household income (U = 1031.500, p<.001). Despite this, processing speed (assessed using the written and oral trials of the Symbol Digit Modalities Test; SDMT) was average (SDMT-W x̅=-.13, SDMT-O x̅=.32), with no significant differences between language groups (F(2,120)=0.966, p=.384). Post-hoc analyses revealed time since diagnosis did not predict performance on oral trial for either group or the whole sample, while poorer performance on written trial was noted among the English-only group when further from diagnosis (SDMT-W F(1,57)=7.829, p=.007). Stable ML group trajectory regardless of time since diagnosis may reflect resiliency among children with Spanish exposure.

Cognitive performance and brain volume among survivors of pediatric hematological malignancies: a case-control study

BACKGROUND

Cognitive dysfunction may be one of the hazardous late effects among survivors of pediatric hematological malignancies. Our study aimed to explore cognitive performance and assess the global and regional brain volume changes in survivors of hematological malignancies.

METHODS

This case-control study was conducted on 68 survivors of hematological malignancies, with a median follow-up period of 2 years (ranging from 1 to 6.2 years). Stanford-Binet Test was used for cognitive assessment. A quantitative volumetric assessment of the brain was done using the NeuroQuant Brain Magnetic Resonance. Age and sex-matched 68 children were selected as a comparison group.

RESULTS

Cancer survivors showed significantly lower levels of IQ and their subtests than the control group. Global brain atrophy was observed in the majority of the survivors. Many risk factors significantly affected different IQ subtests, such as radiotherapy (RTH), high cumulative doses of methotrexate (MTX), and prednisone. At the same time, low white matter volume (WMV) was observed with higher cumulative doses of MTX and anthracyclines.

CONCLUSIONS

Hematological malignancies have a negative impact on cognition. Neurocognitive impairment and related brain changes were evident in those who received RTH, HDMTX, or high cumulative doses of steroids.

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.

Convergent validity, academic correlates and age- and SES-based normative data for the d2 Test of attention in children

The d2, test of attention is one of the most used neuropsychological tests to measure attention in clinical and research settings. To date, no studies have examined neither its convergent and divergent validity in children nor its relationship with academic skills at school age. The aims of the present study were: (1) to examine the convergent and divergent validity of the d2 Test in a non-clinical pediatric population, (2) to explore the relationship between d2 task performance and academic skills (i.e., math, reading and writing abilities) and (3) to develop normative data for Spanish-speaking children (n = 360 8- to 12-year-old children) stratified by age and socioeconomic status (SES). Pearson's correlation and Structural Equation Models (SEM) were used to analyze the d2 Test validity and its relationship with academic skills. A between-subjects factorial MANOVA was used to examine differences among SES (Middle, Low), age (8-10, 11-12), and sex (male, female). Findings revealed a significant relationship between d2 task performance and all attention and executive functions (EF) measures under analysis providing evidence of good convergent validity. Furthermore, SEM results showed that attention has direct effects on math and reading and writing skills. Finally, our study confirms the influence of age and SES on d2 task performance and provides normative data for middle- and low-SES children. These results have important implications for the assessment of attention functions in clinical and research settings in children with typical and atypical development.

Age- and Intravenous Methotrexate-Associated Leukoencephalopathy and Its Neurological Impact in Pediatric Patients with Lymphoblastic Leukemia

Simple Summary

In this study, we investigated standardized post-chemotherapy magnetic resonance (MR) scans for leukoencephalopathy and patient- and treatment-related risk factors in childhood leukemia patients. As prevalence numbers are limited, our study provides the required estimations for this population. Furthermore, we demonstrate that younger patients might be more at-risk for development of leukoencephalopathy (LE), and that a higher intravenous methotrexate (IV-MTX) dose has a cumulative toxic effect, while the number of intrathecal administrations was not significantly associated with the extent of LE. This can suggest we should modify chemotherapeutic treatment regimens by decreasing the number of IV-MTX applications, with special attention for younger patients.

Abstract

Methotrexate (MTX) is associated with leukoencephalopathy (LE) in children treated for lymphoblastic leukemia/lymphoma (ALL/LBL). However, large-scale studies with systematic MR acquisition and quantitative volumetric lesion information remain limited. Hence, the prevalence of lesion burdens and the potential risk factors of LE in this population are still inconclusive. FLAIR-MRI scans were acquired at the end of treatment in children who were treated for ALL/LBL, which were quantitatively analyzed for LE. Voxels were assigned to the lesion segmentation if indicated by two raters. Logistic and linear regression models were used to test whether lesion presence and size were predicted by risk factors such as age at diagnosis, gender, intrathecal (IT-) or intravenous (IV-)MTX dose, CNS invasion, and acute neurological events. Patients with a pre-existing neurological condition or low-quality MR scan were excluded from the analyses. Of the 129 patients, ten (8%) suffered from CNS invasion. Chemotherapy-associated neurological events were observed in 13 patients (10%) during therapy, and 68 patients (53%) showed LE post-treatment. LE was more frequent in cases of lower age and higher cumulative IV-MTX doses, while the extent of LE and neurological symptoms were associated only with IV-MTX doses. Neurological events were not significantly associated with LE, even though symptomatic patients demonstrated a higher ratio of LE (n = 9/13) than asymptomatic patients (n = 59/116). This study suggests leukoencephalopathy frequently occurs in both symptomatic and asymptomatic leukemia patients. Younger children and patients treated with higher cumulative IV-MTX doses might need more regular screening for early detection and follow-up of associated sequelae.

Within 5-year off-chemotherapy: How the cardio-respiratory response to exercise is related to energy expenditure, fatigue, and adiposity in children with acute lymphoblastic leukaemia?

OBJECTIVE

To explore the cardio-respiratory response to exercise and examine the relationships among specific measures of cardio-respiratory function, energy expenditure (EE), fatigue and adiposity in children survivors of acute lymphoblastic leukaemia (ALL).

METHODS

Seventy survivors of ALL (13.31 ± 2.60 years) and 34 controls from the siblings (12.71 ± 2.36 years) participated and were assessed for submaximal and maximal exercise capacity, body composition, EE and fatigue.

RESULTS

ALL survivors had significantly lower submaximal (VO₂ ; p = 0.002) and maximal (VO_2peak ; p ˂ 0.001) cardio-respiratory capacity than their controls. At the submaximal exercise test, EE was significantly lower in ALL survivors (p < 0.001), but the heart rate (HR) was significantly higher (p = 0.005). The VO₂ and HR were significantly correlated [r (95%CI) = 0.689 (0.542 to 0.795), p < 0.001]. The VO_2peak negatively associated with adiposity [r (95%CI) = -0.368 (-0.554 to -0.145), p = 0.002]. Fatigue significantly correlated with the VO_2peak [r (95%CI) = 0.581 (0.401 to 0.718), p < 0.001] and adiposity [r (95%CI) = -0.303 (-0.502 to 0.073), p = 0.012].

CONCLUSION

Children survivors of ALL experience low cardio-respiratory fitness within 5-year off-chemotherapy. Associations exist between measures of cardio-respiratory fitness, EE, fatigue and adiposity. However, it has not yet been proven whether these are cause or effect.

Long-term brain status and cognitive impairment in children treated for high-risk acute lymphoblastic leukemia with and without allogeneic hematopoietic stem cell transplantation: A single-center study

AIM

The aim of the study was to assess long-term consequences of central nervous system (CNS) prophylaxis in patients with high-risk ALL (HR-ALL) treated according to ALL IC-BFM 2002 and to compare observed abnormalities in patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) with those who received only prophylactic CNS irradiation (12 Gy) and with control group.

PATIENTS AND METHODS

We studied 29 patients with HR-ALL in CR1 after treatment according to protocol ALL IC-BFM 2002 (14 with allo-HSCT conditioned with fractionated total body irradiation [FTBI] and 15 without HSCT) and 16 children with newly diagnosed ALL (control group). The median time from therapy completion to evaluation was 5 years. To assess brain status, volumetric T1-weighted sequences of magnetic resonance imaging were used. Neuropsychological assessment based on battery neuropsychological tests.

RESULTS

Transplanted patients had significantly lower volumes of white and gray matter (P = .048 and P < .001) and also of subcortical structures, including the thalamus (P < .001), the hippocampus (P = .007), the putamen (P = .011), the globus pallidus (P = .001), and the accumbens (P < .001). In addition, these patients had generally lower cognitive performance, especially in vocabulary (P = .011), visuospatial ability (P = .047), executive functions and attention (P = .034; P = .002; P = .048), and processing speed (P = .049 and P = .037). The thalamus volume is correlated with neuropsychological performance in verbal functions (P < .001), executive functions (P < .001 and P = .024), and processing speed (P < .001).

CONCLUSIONS

In pediatric patients treated for ALL, FTBI-based preparative regimen preceding allo-HSCT causes reduction of subcortical structure volumes and decline in cognitive performance. The observed long-term structural and functional CNS sequelae are significantly more pronounced in transplanted HR-ALL patients than in those treated with prophylactic CNS- radiotherapy only.

Prevention of Brain Metastases

The incidence of brain metastases is projected to rise because survival rates of lung cancer, breast cancer, and melanoma continue to improve (1). The brain is being identified as a sanctuary site for harboring metastases despite excellent control of extracranial disease. This is thought to occur because the drug therapies that control extracranial disease have limited central nervous system (CNS) penetration. The development of brain metastases is a devastating diagnosis affecting both quality of life (QOL) and survival. Symptoms after diagnosis can include headache, nausea, vomiting, seizure, neurocognitive decline, and focal neurologic deficit. Some of these symptoms can be irreversible even after successful treatment of intracranial disease. Treatment of brain metastases often necessitates surgery and radiation. There have been some reports of systemic therapies offering an intracranial response however long-term data is lacking. These treatments for CNS metastases can also lead to neurocognitive sequelae impacting quality of life. Therefore, preventing disease from spreading to the brain is a topic that has generated much interest in oncology. Prophylactic cranial Irradiation (PCI) has been used in leukemia, small cell lung cancer (SCLC), and non-small cell lung cancer (NSCLC). While showing effectiveness in preventing intracranial disease development, its carries with it side effects of neurocognitive decline that can affect QOL. There are Clinical trials exploring novel delivery of PCI and concurrent neuroprotective drug therapy to try to mitigate these neurocognitive sequelae. These will be important trials to complete, as PCI has shown promise in controlling disease and prolonging survival in select patient populations. There are also drug therapies that have shown efficacy in preventing CNS metastases development. This review will explore the current therapies available to prevent CNS metastases.

Impaired Recent, but Preserved Remote, Autobiographical Memory in Pediatric Brain Tumor Patients

Medulloblastomas, the most common malignant brain tumor in children, are typically treated with radiotherapy. Refinement of this treatment has greatly improved survival rates in this patient population. However, radiotherapy also profoundly affects the developing brain and is associated with reduced hippocampal volume and blunted hippocampal neurogenesis. Such hippocampal (as well as extrahippocampal) abnormalities likely contribute to cognitive impairments in this population. While several aspects of memory have been examined in this population, the impact of radiotherapy on autobiographical memory has not previously been evaluated. Here we evaluated autobiographical memory in male and female patients who received radiotherapy for posterior fossa tumors (PFTs), including medulloblastoma, during childhood. Using the Children's Autobiographical Interview, we retrospectively assessed episodic and nonepisodic details for events that either preceded (i.e., remote) or followed (i.e., recent) treatment. For post-treatment events, PFT patients reported fewer episodic details compared with control subjects. For pretreatment events, PFT patients reported equivalent episodic details compared with control subjects. In a range of conditions associated with reduced hippocampal volume (including medial temporal lobe amnesia, mild cognitive impairment, Alzheimer's disease, temporal lobe epilepsy, transient epileptic amnesia, frontal temporal dementia, traumatic brain injury, encephalitis, and aging), loss of episodic details (even in remote memories) accompanies hippocampal volume loss. It is therefore surprising that pretreatment episodic memories in PFT patients with reduced hippocampal volume are retained. We discuss these findings in light of the anterograde and retrograde impact on memory of experimentally suppressing hippocampal neurogenesis in rodents.SIGNIFICANCE STATEMENT Pediatric medulloblastoma survivors develop cognitive dysfunction following cranial radiotherapy treatment. We report that radiotherapy treatment impairs the ability to form new autobiographical memories, but spares preoperatively acquired autobiographical memories. Reductions in hippocampal volume and cortical volume in regions of the recollection network appear to contribute to this pattern of preserved preoperative, but impaired postoperative, memory. These findings have significant implications for understanding disrupted mnemonic processing in the medial temporal lobe memory system and in the broader recollection network, which are inadvertently affected by standard treatment methods for medulloblastoma tumors in children.

Cognitive disability in adult patients with brain tumors

Cognitive dysfunction is common among patients with intracranial tumors. Most cognitive deficits are subtle, lack specificity, may mimic depression or other neurological disorders and may be recognized in retrospect by the physician. In certain cases, distinguishing between tumor recurrence and cognitive deficits that arise as a consequence of the treatment becomes challenging. Late treatment effects have also become an area of focus as the overall survival and prognosis of patients with brain tumors increases. New data has highlighted the importance of less toxic adjuvant therapies owing to their positive impact on prognosis and quality of life. Various experimental therapies and genetic influences on individual sensitivity towards injury are promising steps towards a better management strategy for cognitive dysfunction. In this literature review, we discuss cognitive dysfunction as a manifestation of intracranial tumors, treatment modalities such as radiotherapy, chemotherapy, surgery and their impact on cognition and patients' quality of life. We also discuss management options for cognitive dysfunction and emerging therapies.

Anti-leukemic treatment-induced neurotoxicity in long-term survivors of childhood acute lymphoblastic leukemia: impact of reduced central nervous system radiotherapy and intermediate- to high-dose methotrexate

The aim of the study was to evaluate the long-term neurodevelopmental consequences of currently applied acute lymphoblastic leukemia (ALL) therapy containing chemotherapy alone or combined with 12 Gy radiotherapy. Seventy-nine children aged 6.3-21.7 years diagnosed with ALL and treated according to ALL IC-BFM 2002 have been studied. The control group consisted of 23 children newly diagnosed with ALL. We assessed subcortical gray matter volume using automatic MRI segmentation and cognitive performance to identify differences between three therapeutic schemes and patients prior to treatment. Irradiated patients had smaller selected subcortical volumes than those treated with chemotherapy alone and than the controls, while the chemotherapy group had similar volumes as the control one. In neurocognitive assessment, irradiated children performed worse in major domains than the control group. There were no significant results for patients after high dose chemotherapy without radiotherapy. There was a significant relationship between full scale IQ together with verbal learning and volumes of hippocampus, amygdala, and pallidum. In all children treated for ALL, both decreased volume of selected subcortical structures and cognitive impairment were observed, especially in children who were irradiated.

Altered brain function in new onset childhood acute lymphoblastic leukemia before chemotherapy: A resting-state fMRI study

OBJECTIVE

Cognitive impairments had been reported in childhood acute lymphoblastic leukemia, what caused the impairments needed to be demonstrated, chemotherapy-related or the disease itself. The primary aim of this exploratory investigation was to determine if there were changes in brain function of children with acute lymphoblastic leukemia before chemotherapy.

METHODS

In this study, we advanced a measure named regional homogeneity to evaluate the resting-state brain activities, intelligence quotient test was performed at same time. Using regional homogeneity, we first investigated the resting state brain function in patients with new onset childhood acute lymphoblastic leukemia before chemotherapy, healthy children as control.

RESULTS

The decreased ReHo values were mainly founded in the default mode network and left frontal lobe, bilateral inferior parietal lobule, bilateral temporal lobe, bilateral occipital lobe, precentral gyrus, bilateral cerebellum in the newly diagnosed acute lymphoblastic leukemia patients compared with the healthy control. While in contrast, increased ReHo values were mainly shown in the right frontal lobe (language area), superior frontal gyrus-R, middle frontal gyrus-R and inferior parietal lobule-R for acute lymphoblastic leukemia patients group. There were no significant differences for intelligence quotient measurements between the acute lymphoblastic leukemia patient group and the healthy control in performance intelligence quotient, verbal intelligence quotient, total intelligence quotient.

CONCLUSION

The altered brain functions are associated with cognitive change and language, it is suggested that there may be cognition impairment before the chemotherapy. Regional homogeneity by functional magnetic resonance image is a sensitive way for early detection on brain damage in childhood acute lymphoblastic leukemia.

Chronic hepatitis C virus infection and neurocognitive function in adult survivors of childhood cancer

BACKGROUND

Cancer survivors transfused with blood products before reliable screening for hepatitis C virus (HCV) are at risk for infection. This study examined the impact of HCV on neurocognitive function and health-related quality of life (HRQOL) among adult survivors of childhood cancer.

METHODS

Neurocognitive testing was conducted for 836 adult survivors of childhood cancer (mean age, 35 years [standard deviation, 7.4 years]; time since diagnosis, 29 years [standard deviation, 6.2 years]) who received blood products before universal HCV screening. No differences were observed between confirmed HCV-seropositive survivors (n = 79) and HCV-seronegative survivors (n = 757) in the primary diagnosis or neurotoxic therapies. Multivariate regression models were used to compare functional outcomes between seropositive and seronegative survivors.

RESULTS

Compared with seronegative survivors, seropositive survivors demonstrated lower performance on measures of attention (P < .001), processing speed (P = .008), long-term verbal memory (P = .01), and executive function (P = .001). After adjustments for sex, age at diagnosis, and treatment exposures, seropositive survivors had a higher prevalence of impairment in processing speed (prevalence ratio [PR], 1.3; 95% confidence interval [CI], 1.1-1.6) and executive functioning (PR, 1.3; 95% CI, 1.1-1.6). Differences were not associated with the treatment of HCV or the presence of liver cirrhosis. Seropositive survivors reported worse general HRQOL (PR, 1.6; 95% CI, 1.2-2.1), which was associated with the presence of liver cirrhosis (P = .001).

CONCLUSIONS

Survivors of childhood cancer with a history of HCV infection are at risk for neurocognitive impairment and reduced HRQOL beyond the known risks associated with neurotoxic cancer therapies. Cancer 2017;123:4498-505. © 2017 American Cancer Society.

Concordance of parent-, teacher- and self-report ratings on the Conners 3 in adolescent survivors of cancer

Survivors of childhood cancer are at risk for attention problems. The objectives of this study were to assess concordance between parent-, teacher-, and self-report ratings on a measure of attention (Conners Rating Scales, 3rd ed.; Conners, 2008) in adolescent survivors of childhood cancer and to examine associations with a performance-based task. The Conners 3 was completed by 80 survivors of pediatric cancer (39 brain tumor, 41 acute lymphoblastic leukemia; ages 12–17; at least 1 year posttreatment; 51.3% male) as well as their parents and 1 teacher. In addition, survivors completed a continuous performance test. Parents and teachers demonstrated moderate agreement on most subscales; however, agreement was weaker than would be expected based on the normative sample. Agreement between self- and proxy ratings was more variable. The strongest associations for all raters were observed on the Learning Problems subscale. There were significant mean differences between parent and teacher ratings, with parents reporting more problems across subscales. Only self-ratings of Inattention were significantly associated with the continuous performance test (omission errors). Agreement across raters in assessment of attentional functioning in adolescent survivors of childhood cancer is modest. Findings support the need to obtain multiple ratings of behavior, including both proxy- and self-report, when assessing youth with cancer, particularly adolescents.

Self-Esteem and Academic Difficulties in Preadolescents and Adolescents Healed from Paediatric Leukaemia

Adolescents with cancer may demonstrate problems in their self-esteem and schooling. This study aims to screen the preadolescents and adolescents more at risk in their self-esteem perception and schooling difficulties post-five years from the end of therapy. Twenty-five paediatric ex-patients healed from leukaemia were recruited at the Haematology-Oncologic Clinic (University of Padua). The mean age of the children was 13.64 years (Standard Deviation (SD)) = 3.08, range = 10-19 years), most were treated for acute lymphoblastic leukaemia (ALL) (84%) and relatively equally distributed by gender. They filled in the Multidimensional Self-Esteem Test, while parents completed a questionnaire on their child's schooling. Global self-esteem was mostly below the 50 percentile (58.5%), especially regarding interpersonal relationships (75%). An independent sample t-test showed significant mean differences on the emotionality scale (t = 2.23; degree of freedom (df) = 24; p = 0.03) and in the bodily experience scale (t = 3.02; df = 24; p = 0.006) with survivors of Acute Myeloid Leukaemia (AML) having lower scores. An Analysis of Variance (ANOVA) showed significant mean differences in the bodily experience scale (F = 12.31; df = 2, p = 0.0001) depending on the survivors' assigned risk band. The parent reports showed that 43.5% of children had difficulties at school. Childhood AML survivors with a high-risk treatment were more at risk in their self-esteem perceptions. Preventive interventions focusing on self-esteem and scholastic wellbeing are suggested in order to help their return to their normal schedules.

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.

Impaired brain metabolism and neurocognitive function in childhood leukemia survivors despite complete hormone supplementation in adulthood

Cranial radiotherapy is a known risk factor for neurocognitive impairment in survivors of childhood acute lymphoblastic leukemia (ALL). Understanding the nature of cognitive dysfunction during adulthood in ALL survivors is important as it has an impact on major life situations. Thirty-eight (21 women) ALL survivors were investigated 34 years after diagnosis. Median-age was 38 (27-46) years. All were treated with a CRT dose of 24Gy and 11 years (3-13) of complete hormone supplementation. Comparisons were made to 29 matched controls. Assessments of magnetic resonance spectroscopy (white and grey matter metabolic alterations), brain volume and neuropsychological tests were performed. ALL survivors demonstrate a generally lower performance in neuropsychological tests. ALL survivors scored lower than controls in vocabulary (p<0.001), memory (p<0.001), learning capacity (p<0.001), spatial ability (p<0.001), executive functions and attention (p<0.001) 34 years after ALL treatment. Compared to controls ALL survivors had reduced white matter (WM) (492 vs 536cm³, p<0.001) and grey matter (GM) volumes (525 vs 555cm³, p=0.001). ALL survivors had lower levels of WM N-acetyl aspartate/creatin (NAA/Cr) (1.48 vs 1.63, p=0.004), WM NAA+NAAG (N-acetylaspartylglutamate)/Cr (1.61 vs 1.85, p<0.001) and lower levels of GM NAA/Cr (1.18 vs 1.30, p=0.001) and GM NAA+NAAG/Cr (1.28 vs 1.34, p=0.01) compared to controls. ALL survivors had higher levels in WM MI (Myoinositol)/NAA (0.65 vs 0.56, p=0.01) concentrations compared to controls. There was a significantly negative correlation of years since ALL diagnosis to WM NAA+NAAG/Cr (r=-0.4, p=0.04) in ALL survivors. The present study shows impaired brain metabolism detected by MRS, reduced brain volumes and neurocognitive impairment in childhood ALL survivors treated with cranial radiotherapy and chemotherapy, despite complete hormone substitution. We also report an impairment of metabolites correlated to time since treatment and a progressive impairment in sustained attention, suggesting an accelerated aging in the irradiated brain. Following these survivors many decades, or throughout life, after treatment with cranial radiotherapy and chemotherapy is highly warranted for a broader understanding of long-term outcome in this patient group.

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.

Lithium increases proliferation of hippocampal neural stem/progenitor cells and rescues irradiation-induced cell cycle arrest in vitro

Radiotherapy in children causes debilitating cognitive decline, partly linked to impaired neurogenesis. Irradiation targets primarily cancer cells but also endogenous neural stem/progenitor cells (NSPCs) leading to cell death or cell cycle arrest. Here we evaluated the effects of lithium on proliferation, cell cycle and DNA damage after irradiation of young NSPCs in vitro.

NSPCs were treated with 1 or 3 mM LiCl and we investigated proliferation capacity (neurosphere volume and bromodeoxyuridine (BrdU) incorporation). Using flow cytometry, we analysed apoptosis (annexin V), cell cycle (propidium iodide) and DNA damage (γH2AX) after irradiation (3.5 Gy) of lithium-treated NSPCs.

Lithium increased BrdU incorporation and, dose-dependently, the number of cells in replicative phase as well as neurosphere growth. Irradiation induced cell cycle arrest in G₁ and G₂/M phases. Treatment with 3 mM LiCl was sufficient to increase NSPCs in S phase, boost neurosphere growth and reduce DNA damage. Lithium did not affect the levels of apoptosis, suggesting that it does not rescue NSPCs committed to apoptosis due to accumulated DNA damage.

Lithium is a very promising candidate for protection of the juvenile brain from radiotherapy and for its potential to thereby improve the quality of life for those children who survive their cancer.

Utility of the General Ability Index (GAI) and Cognitive Proficiency Index (CPI) with survivors of pediatric brain tumors: Comparison to Full Scale IQ and premorbid IQ estimates

INTRODUCTION

Pediatric brain tumor survivors are at risk for working memory and processing speed impairment. The General Ability Index (GAI) provides an estimate of intellectual functioning that is less influenced by working memory and processing speed than a Full Scale IQ (FSIQ). The Cognitive Proficiency Index (CPI) provides a measure of efficient information processing derived from working memory and processing speed tasks. We examined the utility of the GAI and CPI to quantify neurocognitive outcomes in a sample of pediatric brain tumor survivors.

METHOD

GAI, CPI, and FSIQ scores from the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) were examined for 57 pediatric brain tumor survivors (ages 6-16 years) treated with cranial radiation therapy (RT).

RESULTS

GAI scores were higher than FSIQ and CPI scores, both p < .001. Lower CPI scores were associated with history of craniospinal irradiation and time since RT. Lower FSIQ and GAI scores were associated with higher RT dose and time since RT. The rate of clinically significant GAI-FSIQ discrepancies in our sample was greater than that observed in the WISC-IV standardization sample, p < .001. Estimated premorbid IQ scores were higher than GAI, p < .01, and FSIQ scores, p < .001.

CONCLUSIONS

Pediatric brain tumor survivors exhibit weaker cognitive proficiency than that expected for age, while general reasoning ability remains relatively spared. The GAI may be useful to quantify the intellectual potential of a survivor when appropriate accommodations are in place for relative cognitive proficiency weaknesses. The CPI may be a particularly sensitive outcome measure of treatment-related cognitive change in this population.

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.

Standard of Care for Neuropsychological Monitoring in Pediatric Neuro-Oncology: Lessons From the Children's Oncology Group (COG)

As the mortality of pediatric cancers has decreased, focus on neuropsychological morbidities of treatment sequelae have increased. Neuropsychological evaluations are essential diagnostic tools that assess cognitive functioning and neurobiological integrity. These tests provide vital information to support ongoing medical care, documenting cognitive morbidity and response to interventions. We frame standards for neuropsychological monitoring of pediatric patients with CNS malignancy or who received cancer-directed therapies involving the CNS and discuss billing for these services in the United States in the context of clinical research. We describe a cost-effective, efficient model of neuropsychological monitoring that may increases access to neuropsychological care.

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.

Treatment of young children with CNS-positive acute lymphoblastic leukemia without cranial radiotherapy

BACKGROUND

Due to the long-term sequelae of cranial radiotherapy (CRT), contemporary treatment protocols for children with acute lymphoblastic leukemia (ALL) aim to limit the use of prophylactic CRT. For patients with central nervous system (CNS) involvement with ALL at diagnosis, the use of CRT remains common. Children <5 years of age are a particularly challenging subgroup in whom the consequences of CRT can be devastating.

PROCEDURE

This study retrospectively describes the overall (OS) and event-free survival (EFS) of young children (1-5 years) who were treated for CNS-positive ALL at the Hospital for Sick Children between 2000 and 2013.

RESULTS

Of a total of 19 patients, two were treated with upfront CRT, both as part of the conditioning regimen prior to HSCT. All patients received intensification of CNS-directed chemotherapy by triple intra-thecal chemotherapy (84.2%), use of dexamethasone in induction (57.9%) and maintenance (66.7%), and high-dose methotrexate (77.8%). The OS was 84.2 ± 8.4% and EFS was 79.0 ± 9.4% with a median follow-up time of 4.3 years (range, 2.6-8.2). The cumulative incidence of CNS relapse was 5.2 ± 5.1%.

CONCLUSIONS

We conclude that omission of CRT from the treatment of young children with ALL involving the CNS is associated with acceptable survival and avoids potentially devastating late effects in this group.

Neurocognitive outcomes in long-term survivors of childhood acute lymphoblastic leukemia treated on contemporary treatment protocols: A systematic review

The intensified administration of chemotherapeutic drugs has gradually replaced cranial radiation therapy (CRT) for the treatment of childhood acute lymphoblastic leukemia (ALL). While CRT is often implicated in neurocognitive impairment in ALL survivors, there is a paucity of the literature that evaluates the persistence of neurocognitive deficits in long-term survivors of pediatric ALL who were treated with contemporary chemotherapy-only protocols. Results from this systematic review concurred to the probable cognitive-sparing effect of chemotherapy-based protocols over CRT in long-term survivors. However, coupled with multiple intrinsic and extrinsic factors, survivors who received chemotherapy treatment still suffered from apparent cognitive impairment, particularly in the attention and executive function domains. Notably, there is evidence to suggest that the late neurotoxic effect of methotrexate on survivors' neurocognitive performance may be dose-related. This review also recommends future pharmacokinetic, neuroimaging and genetic studies to illuminate the multifactorial nature of this subject matter and discusses the potential value of neurochemical, physiological, inflammatory and genetic markers for the prediction of susceptibility to neurocognitive impairment in long-term survivors of childhood ALL.

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.

Survival of Mexican Children with Acute Lymphoblastic Leukaemia under Treatment with the Protocol from the Dana-Farber Cancer Institute 00-01

Our aim in this paper is to describe the results of treatment of acute lymphoblastic leukaemia (ALL) in Mexican children treated from 2006 to 2010 under the protocol from the Dana-Farber Cancer Institute (DFCI) 00-01. The children were younger than 16 years of age and had a diagnosis of ALL de novo. The patients were classified as standard risk if they were 1–9.9 years old and had a leucocyte count <50 × 10⁹/L, precursor B cell immunophenotype, no mediastinal mass, CSF free of blasts, and a good response to prednisone. The rest of the patients were defined as high risk. Of a total of 302 children, 51.7% were at high risk. The global survival rate was 63.9%, and the event-free survival rate was 52.3% after an average follow-up of 3.9 years. The percentages of patients who died were 7% on induction and 14.2% in complete remission; death was associated mainly with infection (21.5%). The relapse rate was 26.2%. The main factor associated with the occurrence of an event was a leucocyte count >100 × 10⁹/L. The poor outcomes were associated with toxic death during induction, complete remission, and relapse. These factors remain the main obstacles to the success of this treatment in our population.

Immediate treatment effects of high-dose methotrexate and cranial irradiation on neuropsychological functions of children treated for acute lymphoblastic leukemia at a regional cancer center

Context:

Overall cure rates for pediatric acute lymphoblastic leukemia (ALL) have improved; however, the neuropsychological sequelae of ALL treatment have not been adequately documented in India.

Aims:

The present study assesses the immediate effects of ALL treatment on neuropsychological functioning, at the Regional Cancer Center in Chennai, South India.

Materials and Methods:

Newly diagnosed with ALL patients (n = 24) (aged 6–15 years; 13M:11F) registered between March 2008 and February 2009 were included. Patients who had received high-dose methotrexate (HD-MTX) and cranial radiotherapy (CRT) as part of their treatment were enrolled for the study. Neurocognitive assessments were done to assess various functions such as performance intelligence, visuo-perception, visuo-spatial, perceptual organization, processing speed, planning, working memory, and immediate verbal memory (IVM) (Malin's intelligence scale); verbal fluency (ideation fluency test) and verbal attention (vigilance test). Three assessments were done during induction (baseline), after re-induction phase (second) and during the maintenance phase (third).

Results:

The patients performed significantly worse in the third assessment (mean duration from diagnosis 17.48 months) on performance intelligence quotient (PIQ), visuo-perception, visuo-spatial, processing speed, planning, IVM, verbal attention, and verbal fluency (P < 0.05), there were no significant changes observed in visuo-perceptual organization and working memory (P > 0.05). Significant difference was observed between age groups 6 and 10 (41.7%) and 11–15 years (58.3%) in perceptual organization, verbal fluency, and verbal attention (P < 0.05) and no gender difference was observed across the three assessments (P > 0.05).

Conclusions:

Combining HD MTX and CRT had an immediate effect on neuropsychological sequelae among the children with ALL, however, long-term evaluation is recommended to study the long-term effects.

Gamma deficits as a neural signature of cognitive impairment in children treated for brain tumors

Cognitive impairment is consistently reported in children treated for brain tumors, particularly in the categories of processing speed, memory, and attention. Although tumor site, hydrocephalus, chemotherapy, and cranial radiation therapy (CRT) are all associated with poorer function, CRT predicts the greatest deficits. There is a particularly high correlation between CRT and slowed information-processing speed. Cortical gamma-band oscillations have been associated with processing behaviorally relevant information; however, their role in the maintenance of cognition in individuals with processing deficits is unclear. We examined gamma oscillations using magnetoencephalography (MEG) in children undergoing CRT to test whether gamma characteristics can be a signature of cognitive impairment in this population. We collected resting-state data as well as data from baseline and active periods during two visual-motor reaction time tasks of varying cognitive loads from 18 healthy children and 20 patients. We found that only high-gamma oscillations (60-100 Hz), and not low-gamma oscillations (30-59 Hz), showed significant group differences in absolute power levels. Overall, compared with healthy children, patients showed the following: (1) lower total high-gamma (60-100 Hz) power during the resting state, as well as during task-related baseline and performance measures; (2) no change in gamma reactivity to increases in cognitive load; and (3) slower processing speeds both inside and outside MEG. Our findings show that high-gamma oscillations are disrupted in children after treatment for a brain tumor. The temporal dynamic of the high-gamma response during information processing may index cognitive impairment in humans with neurological injury.

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.

Clinical features and early treatment response of central nervous system involvement in childhood acute lymphoblastic leukemia

BACKGROUND

Central nervous system (CNS) involvement in childhood acute lymphoblastic leukemia (ALL) remains a therapeutic challenge.

PROCEDURE

To explore leukemia characteristics of patients with CNS involvement at ALL diagnosis, we analyzed clinical features and early treatment response of 744 patients on Nordic-Baltic trials. CNS status was classified as CNS1 (no CSF blasts), CNS2 (<5 leukocytes/µl CSF with blasts), CNS3 (≥5 leukocytes/µl with blasts or signs of CNS involvement), TLP+ (traumatic lumbar puncture with blasts), and TLP- (TLP with no blasts).

RESULTS

Patients with CNS involvement had higher leukocyte count compared with patients with CNS1 (P < 0.002). Patients with CNS3 more often had T-ALL (P < 0.001) and t(9;22)(q34;q11)[BCR-ABL1] (P < 0.004) compared with patients with CNS1. Among patients with CNS involvement headache (17%) and vomiting (14%) were most common symptoms. Symptoms or clinical findings were present among 27 of 54 patients with CNS3 versus only 7 of 39 patients with CNS2 and 15 of 75 patients with TLP+ (P < 0.001). The majority of patients with CNS involvement received additional induction therapy. The post induction bone marrow residual disease level did not differ between patients with CNS involvement and patients with CNS1 (P > 0.15). The 12-year event-free survival for patients with leukemic mass on neuroimaging did not differ from patients with negative or no scan (0.50 vs. 0.60; P = 0.7) or between patients with symptoms or signs suggestive of CNS leukemia and patients without such characteristics (0.50 vs. 0.61; P = 0.2).

CONCLUSION

CNS involvement at diagnosis is associated with adverse prognostic features but does not indicate a less chemosensitive leukemia.

Development of figurative language skills following central nervous system-directed chemotherapy delivered in early childhood

Central nervous system (CNS)-directed chemotherapy is delivered for the treatment of childhood acute lymphoblastic leukaemia (ALL). Figurative language deficits have been described in children following CNS-directed chemotherapy; however, comprehensive analysis of figurative interpretation errors, potentially providing clinical utility to assist with intervention planning, has never been performed. The present study aimed to compare the figurative language skills of seven children treated with CNS-directed chemotherapy for ALL before the age of 6 years (mean age at diagnosis 3 years 10 months) and a matched control group of children, using the Test of Language Competence-Expanded Edition (TLC-E) Figurative Language sub-test. It was hypothesised that the children treated with CNS-directed chemotherapy would demonstrate a decreased performance in and an alternative method of interpreting figurative language. The results suggest no negative effects of CNS-directed chemotherapy on figurative language. There were no statistically significant differences between groups for TLC-E Figurative Language sub-test composite scores and picture component errors, nor were there clinically significant differences observed from descriptive comparisons of individual case data and error analysis. As these skills continue to emerge beyond childhood, the need to monitor skill development in ALL survivors beyond childhood is highlighted.

Assessment of neuropsychological late effects in survivors of childhood leukemia

The neurologic dysfunctions caused by treatment may affect health and quality of life in survivors of childhood leukemia. The objective of this study was to identify the neuropsychological late effects of leukemia treatment to provide an assessment about the degree and incidence of these late effects. Neurological and ophtalmological examination, cranial magnetic resonance imaging (MRI), auditory and neurocognitive tests, and questionnaires of quality of life were performed to 44 acute leukemia survivors at least 5 years after diagnosis. Median time since completion of chemotherapy was 7.5 years (2-18) and median age at the time of the study was 16.4 years (8-31). At least one or more late effects detected by physical examination (PE), neurological tests, or neurocognitive tests encountered in 80% of the patients, and 64% of the patients specified at least one complaint in the quality of life questionnaire. MRI revealed pathological findings in 18% and electroencephalogram (EEG) abnormalities were present in 9% of the patients. Evaluation of total intelligence scores revealed that 30% of patients' IQ scores were <80 and 70% of the patients' scores demonstrated neurocognitive dysfunctions. The patients >6 years at the time of diagnosis were found to have more psychological problems and higher rates of smoking and alcohol consumption. The most frequent complaint was headache and the most common problem in school was denoted as difficulty in concentration. Our study demonstrated that most of the survivors of childhood leukemia are at risk of developing neuropsycological 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.

Effects of chemotherapy on the brain in childhood: diffusion tensor imaging of subtle white matter damage

INTRODUCTION

With reducing mortality in children with hematological malignancies, the survivors' quality of life regarding development of chronic neurological disturbances is important. We aimed to determine whether chemotherapy affects white matter (WM).

METHODS

Using brain diffusion tensor imaging, we evaluated 17 patients (15 with acute lymphoblastic leukemia, 2 with non-Hodgkin's lymphoma; 9 male, 8 female; age, 1.6-13 years) before and after chemotherapy. We measured the quantitative values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) at the regions of interest (ROIs) such as periventricular WM, corona radiata, posterior limb of the internal capsule, and corpus callosum. We assessed sensorimotor and callosal tracts by tractography.

RESULTS

Reduction in FA and increase in ADC were significant at the ROIs of the left and right anterior periventricular WM and corona radiata and at the tract passing through the genu. A significant reduction in FA with a nonsignificant increase in ADC was seen at the ROI of the genu and at the tracts passing through the body and isthmus.

CONCLUSION

Chemotherapy in children with hematological malignancies predominantly affects the frontal WM. This finding might indicate a negative effect of chemotherapy on neurological development in children with hematological malignancies.

Evaluation of memory impairment in aging adult survivors of childhood acute lymphoblastic leukemia treated with cranial radiotherapy

BACKGROUND

Cranial radiotherapy (CRT) is a known risk factor for neurocognitive impairment in survivors of childhood cancer and may increase risk for mild cognitive impairment and dementia in adulthood.

METHODS

We performed a cross-sectional evaluation of survivors of childhood acute lymphoblastic leukemia (ALL) treated with 18 Gy (n = 127) or 24 Gy (n = 138) CRT. Impairment (age-adjusted score >1 standard deviation below expected mean, two-sided exact binomial test) on the Wechsler Memory Scale IV (WMS-IV) was measured. A subset of survivors (n = 85) completed structural and functional neuroimaging.

RESULTS

Survivors who received 24 Gy, but not 18 Gy, CRT had impairment in immediate (impairment rate = 33.8%, 95% confidence interval [CI] = 25.9% to 42.4%; P < .001) and delayed memory (impairment rate = 30.2%, 95% CI = 22.6% to 38.6%; P < .001). The mean score for long-term narrative memory among survivors who received 24 Gy CRT was equivalent to that for individuals older than 69 years. Impaired immediate memory was associated with smaller right (P = .02) and left (P = .008) temporal lobe volumes, and impaired delayed memory was associated with thinner parietal and frontal cortices. Lower hippocampal volumes and increased functional magnetic resonance imaging activation were observed with memory impairment. Reduced cognitive status (Brief Cognitive Status Exam from the WMS-IV) was identified after 24 Gy (18.5%, 95% CI = 12.4% to 26.1%; P < .001), but not 18 Gy (8.7%, 95% CI = 4.4% to 15.0%; P = .11), CRT, suggesting a dose-response effect. Employment rates were equivalent (63.8% for 24 Gy CRT and 63.0% for 18 Gy CRT).

CONCLUSIONS

Adult survivors who received 24 Gy CRT had reduced cognitive status and memory, with reduced integrity in neuroanatomical regions essential in memory formation, consistent with early onset mild cognitive impairment.

Effect of cancer therapy on neural stem cells: implications for cognitive function

PURPOSE OF REVIEW

Modern cancer therapies have allowed for a dramatic increase in the survival rates in both children and adults. However, a frequent and unfortunate side-effect of cancer therapy is a long-term decline in neurocognitive function. Specifically, cranial radiation therapy markedly alters memory processes, while chemotherapeutic agents are correlated with deficits in attention, concentration, and speed of information processing. Here, we describe the putative cellular etiologies of cancer treatment-induced cognitive decline, with an emphasis on the role of neural stem and precursor cell dysfunction.

RECENT FINDINGS

New studies highlight the lasting effects of chemotherapy on memory, executive function, attention, and speed of information processing up to 20 years following chemotherapy. Cognitive decrements are associated with decreased white-matter integrity as well as alterations in stem cell function in humans and rodent models of cancer therapy. Genetic polymorphisms may underlie differential sensitivity of certain individuals to the neurological consequences of chemotherapy. Increasing data support the concept that disruption of normal neural stem and precursor cell function is an important causative factor for the cognitive deficits that result from cancer therapy in both children and adults.

SUMMARY

Further studies are needed to elucidate the role of chemotherapy on cell-intrinsic processes and cellular microenvironments. Further, the effects of the new generation of targeted molecular therapies on neural stem and progenitor cell function remains largely untested. Understanding the mechanisms behind cancer therapy-induced damage to neural stem and precursor cell populations will elucidate neuroprotective and cell replacement strategies aimed at preserving cognition after cancer therapy.

Slower processing speed after treatment for pediatric brain tumor and acute lymphoblastic leukemia

BACKGROUND

Acute lymphoblastic leukemia (ALL) and brain tumor (BT) survivors are at risk for post-treatment IQ declines. The extent to which lower scores represent global cognitive decline versus domain-specific impairment remains unclear. This study examined discrepancies between processing speed and estimated IQ (EIQ) scores and identified clinical characteristics associated with score discrepancies in a sample of pediatric cancer survivors.

PROCEDURE

Survivors (50 ALL, 50 BT) ages 12-17 years completed cognitive testing. The Wechsler Abbreviated Scale of Intelligence provided an untimed measure of general reasoning ability (EIQ). The age-appropriate Wechsler Intelligence Scale provided a Processing Speed Index (PSI) score. Scores were examined and compared.

RESULTS

Survivors' PSI scores were lower than their EIQ scores (BT t(45) =6.3, p<0.001; ALL t(49) =6.9, p<0.001). For BT survivors, lower PSI scores were associated with history of craniospinal irradiation, t(44) =3.3, p<0.01. For ALL survivors, lower PSI scores were associated with male gender, grade retention, and time since diagnosis, F(3, 46) =10.1, p<0.001. Clinically significant EIQ-PSI score discrepancies were identified in 41.3% of BT and 14.0% of ALL survivors.

CONCLUSIONS

Many pediatric BT and ALL survivors exhibit slower processing speed than expected for age, whereas general reasoning ability remains largely intact. Risk factors associated with larger EIQ-PSI discrepancies include the following: BT diagnosis, craniospinal irradiation (BT only), male gender, and younger age at diagnosis (ALL only). Grade retention was frequent and associated with lower EIQ scores (both groups) and PSI scores (ALL only). Describing post-treatment cognitive declines using global measures of intellectual ability may underestimate dysfunction or fail to isolate specific underlying deficits contributing to impairment.

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.

Radiation therapy in the prevention of brain metastases

Over 150,000 cancer patients will be diagnosed with brain metastases this year alone. Survival for those diagnosed with brain metastases remains poor despite multimodality management with surgery, chemotherapy, and radiation. Preventative strategies to mitigate brain metastases have met with mixed results. In leukemia and small cell lung cancer there are defined roles for preventative radiation to be delivered, which can result in improved local control and survival. There is a less defined role for preventative radiation in locally advanced non-small cell lung cancer and budding interest for radiation prevention in breast cancer. The potential impact preventative cranial irradiation may have on neurocognitive function and quality of life needs to be considered prior to its administration.

Long-term results of combined preradiation chemotherapy and age-tailored radiotherapy doses for childhood medulloblastoma

To reduce the sequelae of craniospinal irradiation (CSI) in children under 10 (≥3) years old and to improve the prognosis for high-risk medulloblastoma in adolescents, we adjusted postoperative chemotherapy and CSI doses to patients' stage and age. From 1986 to 1995, 73 patients entered the study. Children under 10 and adolescents with metastases, residual disease (RD) or stage >T3 received postoperative IV vincristine and high-dose (HD) ± intrathecal (IT) methotrexate, while standard-risk adolescents were given IV vincristine and IT methotrexate. Chemotherapy was followed by CSI (19.8 Gy for children <10; 36 Gy for adolescents), with a 54-Gy posterior fossa boost. Maintenance chemotherapy with lomustine and vincristine was administered for a year afterwards. A total of 39 children were under 10 of whom 20 had metastases. Response to chemotherapy was recorded in 70%, but 5-year EFS and OS were only 48 and 56%, respectively. Results were significantly worse for metastatic cases, patients under 10, those with RD, and those staged without MRI (unavailable early in the study). Efforts to preserve survivors' quality of life did not pay off, and most patients over 30 still depended on their parents' income and had severe cognitive/endocrine disabilities. In conclusion, despite a very high response rate with this preradiation HD methotrexate schedule, the outcome for high-risk medulloblastoma patients did not improve (especially when lower CSI doses were used) and patients still developed severe morbidities.

ICRP publication 118: ICRP statement on tissue reactions and early and late effects of radiation in normal tissues and organs--threshold doses for tissue reactions in a radiation protection context

This report provides a review of early and late effects of radiation in normal tissues and organs with respect to radiation protection. It was instigated following a recommendation in Publication 103 (ICRP, 2007), and it provides updated estimates of 'practical' threshold doses for tissue injury defined at the level of 1% incidence. Estimates are given for morbidity and mortality endpoints in all organ systems following acute, fractionated, or chronic exposure. The organ systems comprise the haematopoietic, immune, reproductive, circulatory, respiratory, musculoskeletal, endocrine, and nervous systems; the digestive and urinary tracts; the skin; and the eye. Particular attention is paid to circulatory disease and cataracts because of recent evidence of higher incidences of injury than expected after lower doses; hence, threshold doses appear to be lower than previously considered. This is largely because of the increasing incidences with increasing times after exposure. In the context of protection, it is the threshold doses for very long follow-up times that are the most relevant for workers and the public; for example, the atomic bomb survivors with 40-50years of follow-up. Radiotherapy data generally apply for shorter follow-up times because of competing causes of death in cancer patients, and hence the risks of radiation-induced circulatory disease at those earlier times are lower. A variety of biological response modifiers have been used to help reduce late reactions in many tissues. These include antioxidants, radical scavengers, inhibitors of apoptosis, anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, growth factors, and cytokines. In many cases, these give dose modification factors of 1.1-1.2, and in a few cases 1.5-2, indicating the potential for increasing threshold doses in known exposure cases. In contrast, there are agents that enhance radiation responses, notably other cytotoxic agents such as antimetabolites, alkylating agents, anti-angiogenic drugs, and antibiotics, as well as genetic and comorbidity factors. Most tissues show a sparing effect of dose fractionation, so that total doses for a given endpoint are higher if the dose is fractionated rather than when given as a single dose. However, for reactions manifesting very late after low total doses, particularly for cataracts and circulatory disease, it appears that the rate of dose delivery does not modify the low incidence. This implies that the injury in these cases and at these low dose levels is caused by single-hit irreparable-type events. For these two tissues, a threshold dose of 0.5Gy is proposed herein for practical purposes, irrespective of the rate of dose delivery, and future studies may elucidate this judgement further.

Are the psychological needs of adolescent survivors of pediatric cancer adequately identified and treated?

OBJECTIVES

To describe the psychological needs of adolescent survivors of acute lymphoblastic leukemia (ALL) or brain tumor (BT), we examined the following: (i) the occurrence of cognitive, behavioral, and emotional concerns identified during a comprehensive psychological evaluation and (ii) the frequency of referrals for psychological follow-up services to address identified concerns.

METHODS

Psychological concerns were identified on measures according to predetermined criteria for 100 adolescent survivors. Referrals for psychological follow-up services were made for concerns previously unidentified in formal assessment or not adequately addressed by current services.

RESULTS

Most survivors (82%) exhibited at least one concern across domains: behavioral (76%), cognitive (47%), and emotional (19%). Behavioral concerns emerged most often on scales associated with executive dysfunction, inattention, learning, and peer difficulties. Cranial radiation therapy was associated with cognitive concerns, χ(2) (1, N = 100) = 5.63, p < 0.05. Lower income was associated with more cognitive concerns for ALL survivors, t(47) = 3.28, p < 0.01, and more behavioral concerns for BT survivors, t(48) = 2.93, p < 0.01. Of the survivors with concerns, 38% were referred for psychological follow-up services. Lower-income ALL survivors received more referrals for follow-up, χ(2) (1, N = 41) = 8.05, p < 0.01. Referred survivors had more concerns across domains than non-referred survivors, ALL: t(39) = 2.96, p < 0.01; BT: t(39) = 3.52, p < 0.01. Trends suggest ALL survivors may be at risk for experiencing unaddressed cognitive needs.

CONCLUSIONS

Many adolescent survivors of cancer experience psychological difficulties that are not adequately managed by current services, underscoring the need for long-term surveillance. In addition to prescribing regular psychological evaluations, clinicians should closely monitor whether current support services appropriately meet survivors' needs, particularly for lower-income survivors and those treated with cranial radiation therapy.

Childhood exposure to ionizing radiation to the head and risk of schizophrenia

While the association between exposure to ionizing radiation and cancer is well established, its association with schizophrenia is unclear. The aim of our study was to assess risk of schizophrenia after childhood exposure to ionizing radiation to the head (mean dose: 1.5 Gy). The study population included an exposed group of 10,834 individuals irradiated during childhood for treatment of tinea capitis in the 1950s and two unexposed comparison groups of 5392 siblings and 10,834 subjects derived from the National Population Registry individually matched to the exposed group by age, sex (when possible), country of birth, and year of immigration to Israel. These groups were followed for a median 46 years for diagnosis of schizophrenia updated to December 2002. The Cox proportional hazards model stratified by matched sets was used to compare the risk of schizophrenia between the groups. Based on 1,217,531 person-years of follow-up, 451 cases were identified. No statistically significant association was found between radiation exposure and schizophrenia for the total group (hazard ratio per 1 Gy to the brain: 1.05, 95% confidence interval: 0.93-1.18) or within subgroups of sex, dose categories or latent period. When comparing a subgroup of subjects irradiated under 5 years of age with the matched unexposed group, the estimated hazard ratio reached 1.18 (95% confidence interval: 0.96-1.44; P = 0.1). The results of our analysis do not support an association between exposure to ionizing radiation and risk of schizophrenia. More research on possible effects of early exposure to ionizing radiation on schizophrenia specifically and brain tissue in general is needed.