Dexamethasone exposure and memory function in adult survivors of childhood acute lymphoblastic leukemia: A report from the SJLIFE cohort

Characterization of brain development with neuroimaging in a female mouse model of chemotherapy treatment of acute lymphoblastic leukemia

Background

Survivors of pediatric acute lymphoblastic leukemia (ALL) exhibit abnormal neurocognitive outcomes that are possibly due to exposures to neurotoxic chemotherapy agents. This study aimed to determine the feasibility of characterizing long-term neuroanatomical changes with in vivo neuroimaging in a preclinical model of treatment for ALL.

Methods

Female mice (C57BL/6) were randomly assigned to a saline control group (n=10) or a treatment group (n=10) that received intrathecal methotrexate and oral dexamethasone (IT-MTX + DEX). Mice were subsequently scanned three times on a 7T MRI at ages 3, 6, and 12 months (T1, T2, and T3, respectively), which corresponds with human age-equivalents spanning early to late adulthood. Regional brain volumes were automatically segmented, and volume change between timepoints (i.e., T1 to T2; and T2 to T3) were compared between groups (i.e., saline vs. IT-MTX + DEX).

Results

Five mice in the IT-MTX + DEX group, and seven mice in the saline group completed all three scans. Between T1 and T2, volumetric change was significantly different between groups in total gray matter [estimate =2.06, 95% confidence interval (CI): 0.27-3.84], the cerebrum (estimate =1.62, 95% CI: 0.14-3.09), claustrum (estimate =0.06, 95% CI: 0.02-0.09), amygdala (estimate =0.16, 95% CI: 0.03-0.29), and striatum (estimate =0.18, 95% CI: 0.01-0.35), with the IT-MTX + DEX group exhibiting a more robust increase in volume than the saline-treated group. Between T2 and T3, group differences in structural brain development were evident for total white matter (estimate =-0.14, 95% CI: -0.27 to -0.01), and the corpus callosum (estimate =-0.09, 95% CI: -0.19 to 0.00) and amygdala (estimate =-0.05, 95% CI: -0.10 to 0.00). In contrast to the rapid brain growth observed earlier in development (i.e., T1 to T2), the IT-MTX + DEX group exhibited an attenuated increase in volume relative to the saline-treated group between T2 and T3.

Conclusions

The results demonstrate feasibility of modeling pediatric ALL treatment in a preclinical model and highlight the potential of using preclinical neuroimaging models to gain insight into brain development throughout survivorship.

Neurocognitive outcome and associated factors in long-term, adult survivors of childhood acute lymphoblastic leukemia, treated without cranial radiation therapy

OBJECTIVE

There is limited research on neurocognitive outcome and associated risk factors in long-term, adult survivors of childhood acute lymphoblastic leukemia (ALL), without treatment of cranial radiation therapy. Moreover, the impact of fatigue severity and pain interference on neurocognition has received little attention. In this cross-sectional study, we examined neurocognitive outcome and associated factors in this population.

METHOD

Intellectual abilities, verbal learning/memory, processing speed, attention, and executive functions were compared to normative means/medians with one sample t tests or Wilcoxon signed-rank tests. Associations with risk factors, fatigue severity, and pain interference were analyzed with linear regressions.

RESULTS

Long-term, adult survivors of childhood ALL (N = 53, 51% females, mean age = 24.4 years, SD = 4.4, mean = 14.7 years post-diagnosis, SD = 3.4) demonstrated above average intellectual abilities, but performed below average in attention, inhibition, processing speed, and shifting (p < 0.001). Executive functioning complaints were significantly higher than normative means, and positively associated with fatigue (p < 0.001). There was no interaction between sex and fatigue and no neurocognitive impairments were associated with pain interference, risk group, age at diagnosis, or sex.

CONCLUSIONS

Long-term, adult survivors of ALL treated without cranial radiation therapy, demonstrate domain-specific performance-based neurocognitive impairments. However, continued research on the neurocognitive outcome in this population as they age will be important in the coming years. Executive functioning complaints were frequently in the clinical range, and often accompanied by fatigue. This suggests a need for cognitive rehabilitation programs.

Long-term neurotoxicity among childhood acute lymphoblastic leukaemia survivors enrolled between 1971 and 1998 in EORTC Children Leukemia Group studies

Survival after childhood acute lymphoblastic leukemia (ALL) has increased over the last 40 years with an overall survival above 90%. Survivors may experience neurological late effects secondary to chemotherapy and radiotherapy. This observational retrospective study evaluated the cumulative incidence of neurological late effects among 890 childhood ALL survivors treated in EORTC CLG trials (58741, 58831/2 and 58881) between 1971 and 1998. Median follow-up was 19 years and interquartile range of the follow-up was 15-22 years. At 20 years from the end of treatment, approximately 66% of patients from the 58741 trial (accrual time: 1971-1978) and approximately 15% from the more recent trials had cognitive disturbance grade 1 or higher. Cumulative incidences at 20 years from treatment end of seizures, stroke and leukoencephalopathy were respectively 45%, 16% and 62% in study 58741, 13%, 2% and 5% in study 58831/2, and 8%, 2% and 3% in study 58881. Patients who were 10-17 years of age at diagnosis had a higher incidence of stroke and leukoencephalopathy as compared to those less than 6 years of age. Noteworthy, all neurological late effects continued to occur beyond 5 years after end of treatment. This retrospective study highlights the frequency of neurological late effects in survivors of childhood ALL. With the increase of the overall survival of ALL patients, the role and potential benefit of longitudinal neurological screening should be evaluated in further studies as these neurological late effects become an important public health challenge. This study is part of the larger EORTC CLG 58 Late Adverse Effects (LAE) study (ClinicalTrials.gov Identifier NCT01298388, date of registration February 16, 2011).

Understanding the impact of pediatric kidney transplantation on cognition: A review of the literature

BACKGROUND

Chronic kidney disease (CKD) is a relatively rare childhood disease that is associated with a wide array of medical comorbidities. Roughly half of all pediatric patients acquire CKD due to congenital anomalies of the kidneys and urinary tract, and of those with congenital disease, 50% will progress to end-stage kidney disease (ESKD) necessitating a kidney transplantation. The medical sequelae of advanced CKD/ESKD improve dramatically following successful kidney transplantation; however, the impact of kidney transplantation on neurocognition in children is less clear. It is generally thought that cognition improves following kidney transplantation; however, our knowledge on this topic is limited by the sparsity of high-quality data in the context of the relative rarity of pediatric CKD/ESKD.

METHOD

We conducted a narrative review to gauge the scope of the literature, using the PubMed database and the following keywords: cognition, kidney, brain, pediatric, neurocognition, intelligence, executive function, transplant, immunosuppression, and neuroimaging.

RESULTS

There are few published longitudinal studies, and existing work often includes wide heterogeneity in age at transplant, variable dialysis exposure/duration prior to transplant, and unaccounted cofounders which persist following transplantation, including socio-economic status. Furthermore, the impact of long-term maintenance immunosuppression on the brain and cognitive function of pediatric kidney transplant (KT) recipients remains unknown.

CONCLUSION

In this educational review, we highlight what is known on the topic of neurocognition and neuroimaging in the pediatric KT population.

Supplementation with Vitamin D3 Protects against Mitochondrial Dysfunction and Loss of BDNF-Mediated Akt Activity in the Hippocampus during Long-Term Dexamethasone Treatment in Rats

Dexamethasone (DEXA) is a commonly used steroid drug with immunosuppressive and analgesic properties. Unfortunately, long-term exposure to DEXA severely impairs brain function. This study aimed to investigate the effects of vitamin D3 supplementation during chronic DEXA treatment on neurogenesis, mitochondrial energy metabolism, protein levels involved in the BDNF-mediated Akt activity, and specific receptors in the hippocampus. We found reduced serum concentrations of 25-hydroxyvitamin D3 (25(OH)D3), downregulated proBDNF and pAkt, dysregulated glucocorticosteroid and mineralocorticoid receptors, impaired mitochondrial biogenesis, and dysfunctional mitochondria energy metabolism in the DEXA-treated group. In contrast, supplementation with vitamin D3 restored the 25(OH)D3 concentration to a value close to that of the control group. There was an elevation in neurotrophic factor protein level, along with augmented activity of pAkt and increased citrate synthase activity in the hippocampus after vitamin D3 administration in long-term DEXA-treated rats. Our findings demonstrate that vitamin D3 supplementation plays a protective role in the hippocampus and partially mitigates the deleterious effects of long-term DEXA administration. The association between serum 25(OH)D3 concentration and BDNF level in the hippocampus indicates the importance of applying vitamin D3 supplementation to prevent and treat pathological conditions.

Contribution of Fatigue to Cognitive Dysfunction in Childhood Acute Lymphoblastic Leukemia Survivors

Late effects such as neurocognitive issues and fatigue have been reported in childhood acute lymphoblastic leukemia (cALL) survivors. Yet, their association is often poorly understood. In this study, we wished to (1) describe neurocognitive difficulties and fatigue in a well-characterized cohort of long-term cALL survivors and (2) explore the risk of having neurocognitive deficits as a function of fatigue. Childhood ALL survivors (N = 285) from three Canadian treatment centers completed the DIVERGT battery of cognitive tests and the PedsQL Multidimensional Fatigue Scale. We performed logistic regressions to assess the risk of a survivor to show cognitive deficits (<2.0 SD) depending on their fatigue levels. At least one cognitive deficit on the DIVERGT was present in 31% of participants. Domains primarily affected were working memory, fine motor skills, and verbal fluency. Sleep/rest fatigue in youths was higher than norms (d = 0.35). The risk for cognitive deficits increased independently with levels of fatigue in the domains of cognitive speed and flexibility, working memory, and verbal fluency. For every 10-point increase on general or sleep/rest fatigue on the 0-100 scale, there was a median +23-35% risk of showing a deficit among the 7 tasks significantly associated with fatigue. Fatigue may constitute a complementary target when searching to mitigate cognitive issues in this population.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Association between fatigue and sleep disturbances during treatment for pediatric acute lymphoblastic leukemia and posttreatment neurocognitive performance

BACKGROUND

Survivors of pediatric acute lymphoblastic leukemia (ALL) are at increased risk of neurocognitive weakness in the areas of attention, executive function, and processing speed. Although fatigue and sleep disturbances are frequent complications of ALL therapy and associated with cognitive functions, the impact of fatigue and sleep profiles during active ALL treatment on posttreatment neurocognitive performance has received limited attention.

METHODS

Pediatric patients (n = 120) with ALL (diagnosed 2011-2016) who completed fatigue and sleep questionnaires at four time points during active treatment were enrolled in a study of neurocognitive performance. Latent class growth analysis identified subgroups of patients with similar sleep and fatigue profiles during treatment. Neurocognitive performance collected >6 months post treatment on 40 participants was compared between latent classes using multivariable linear regression models.

RESULTS

Participants (57.5% male and 79.1% Hispanic or non-Hispanic White) were classified into one of two fatigue and sleep profiles: Class 1 characterized by mild fatigue and sleep disturbances during treatment (50.8%), and Class 2 characterized by higher levels of fatigue and sleep disturbances (49.2%). Posttreatment cognitive performance was in the normal range for most measures, but significantly below normative means for executive function, verbal short-term memory, attention, and distractability measures. Compared to Class 1, Class 2 demonstrated significantly (p < .05) poorer posttreatment neurocognitive performance, particularly in measures of attention.

CONCLUSIONS

Our findings indicate that fatigue and sleep disturbances during the first year of pediatric ALL therapy may impact long-term neurocognitive performance. Sleep and fatigue may be targets for intervention to preserve cognitive functioning in survivors.

Characterizing academic performance in pediatric acute lymphoblastic leukemia with population-based achievement tests

BACKGROUND

Recent shifts from radiation to chemotherapy-based treatment for acute lymphoblastic leukemia (ALL) have contributed to reduced long-term morbidity. Despite this, ALL survivors remain at increased risk for long-term cognitive impairments.

AIM

To identify demographic and treatment factors associated with school performance in pediatric survivors of ALL.

METHODS

We collected standardized test scores for reading, math, and science obtained in a school setting from grades 3-11 in 63 ALL survivors (46.0% boys). Most participants were assessed across multiple grades (median number of grades n = 5, range 1-7), and 269 observations were considered in the analyses. Treatment exposures were extracted from medical records. Socio-economic status was estimated using participation in free/reduced lunch programs at school. Mixed effects linear regression models were conducted to determine factors associated with school performance.

RESULTS

ALL survivors' scores were comparable to state norms on reading, math, and science performances. On multivariable analysis, participation in free/reduced lunch programs was significantly associated with lower reading scores (β = -12.52; 95% CI -22.26:-2.77, p = .01). Exposure to radiation during treatment was also associated with lower reading test scores (β = -30.81, 95% CI -52.00:-9.62, p = .01). No significant associations between demographics and treatment parameters were observed for math and science test scores.

CONCLUSIONS

We utilized population-based achievement tests conducted from grades 3-11 to characterize school performance in ALL survivors. Our results imply that survivors with low socio-economic status and those exposed to radiation during treatment could benefit from early monitoring and intervention to maximize academic success.

Structural and Functional Brain Imaging in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia Treated With Chemotherapy: A Systematic Review

Background

The effect of chemotherapy on brain development in long-term survivors of pediatric acute lymphoblastic leukemia (ALL) was systematically reviewed.

Methods

A systematic search of Pubmed, Scopus, and PsycINFO databases was conducted to identify articles published between January 2000 and February 2020 that implemented magnetic resonance imaging to assess brain structure and function in pediatric ALL survivors (diagnosed younger than 21 years of age). The review included articles that were published on children diagnosed with ALL between 0 and 21 years of age and treated with chemotherapy-only protocols. Articles meeting the inclusion criteria described survivors on average of 5 years or more from diagnosis and were peer-reviewed articles and original studies.

Results

The search yielded 1975 articles with 23 articles meeting inclusion criteria. The review revealed that survivors had statistically significant alterations in brain anatomy, most commonly a smaller hippocampus and impaired microstructural white matter integrity in frontal brain regions. Survivors also had impaired brain function including lower brain network efficiency and altered resting state connectivity. Survivors also displayed widespread reductions in brain activation (ie, frontal, temporal, parietal brain regions) during cognitive tasks.

Conclusion

Although the neurotoxic effects of cancer treatment are reduced in the absence of cranial radiation, survivors treated on chemotherapy-only protocols still display long-term alterations in brain structure and function, which contribute to lifelong neurocognitive late effects.

Effects of chemotherapy for acute lymphoblastic leukemia on cognitive function in animal models of contemporary protocols: A systematic literature review

Survival rates of childhood acute lymphoblastic leukemia (ALL) have improved greatly due to advanced therapies and supportive care. Intrathecal chemotherapy replaced cranial radiation due to radiation-induced neurotoxicity and late-effects. Survivors treated with chemotherapy-only experience neurologic and cognitive problems following cessation of treatment. Very long-term cognitive outcomes remain unclear. Animal models are being generated to assess late-effects of chemotherapy on cognitive function. Although, few address juvenile models of chemotherapy-induced cognitive impairment (CICI) and developing brain, results of this review outline neurocognitive effects of chemotherapy consistent with childhood ALL therapy. Studies demonstrate deficits across cognitive domains including spatial memory, executive function, short-term memory, anxiety and depression. Inflammation, oxidative stress, excitotoxity, and other metabolic disruptions may lead to neurodegeneration associated with cognitive impairment observed in ALL survivors. Interventions directly targeting these mechanisms may prevent and/or promote recovery of cognitive function and improve long-term outcomes. Evidence suggests success of anti-inflammatory and antioxidant treatments in reducing cognitive decline. Animal models provide basis for assessing effects of chemotherapy on neurologic processes to guide future clinical investigations.

The Working Memory Network and Its Association with Working Memory Performance in Survivors of non-CNS Childhood Cancer

Childhood cancer and its treatment puts survivors at risk of low working memory capacity. Working memory represents a core cognitive function, which is crucial in daily life and academic tasks. The aim of this functional MRI (fMRI) study was to examine the working memory network of survivors of childhood cancer without central nervous system (CNS) involvement and its relation to cognitive performance. Thirty survivors (aged 7-16 years, ≥ 1 year after cancer treatment) and 30 healthy controls performed a visuospatial working memory task during MRI, including a low- and a high-demand condition. Working memory performance was assessed using standardized tests outside the scanner. When cognitive demands increased, survivors performed worse than controls and showed evidence for slightly atypical working memory-related activation. The survivor group exhibited hyperactivation in the right-hemispheric superior parietal lobe (SPL) in the high- compared to the low-demand working memory condition, while maintaining their performance levels. Hyperactivation in the right SPL coincided with poorer working memory performance outside the scanner in survivors. Even in survivors of childhood cancer without CNS involvement, we find neural markers pointing toward late effects in the cerebral working memory network.AbbreviationsfMRI: Functional magnetic resonance imaging; CNS: Central nervous system; MNI: Montreal Neurological Institute; SES: Socioeconomic status; SPL: Superior parietal lobe.

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.

Sex-Specific Associations Between Chemotherapy, Chronic Conditions, and Neurocognitive Impairment in Acute Lymphoblastic Leukemia Survivors: A Report From the Childhood Cancer Survivor Study

BACKGROUND

The purpose was to examine associations between treatment and chronic health conditions with neurocognitive impairment survivors of acute lymphoblastic leukemia (ALL) treated with chemotherapy only.

METHODS

This cross-sectional study included 1207 ALL survivors (54.0% female; mean age 30.6 years) and 2273 siblings (56.9% female; mean age 47.6 years), who completed the Childhood Cancer Survivor Study Neurocognitive Questionnaire. Multivariable logistic regression compared prevalence of neurocognitive impairment between survivors and siblings by sex. Associations between neurocognitive impairment with treatment exposures and chronic conditions (graded according to Common Terminology Criteria for Adverse Events) were also examined. Statistical tests were 2-sided.

RESULTS

Relative to same-sex siblings, male and female ALL survivors reported increased prevalence of impaired task efficiency (males: 11.7% vs 16.9%; adjusted odds ratio [OR] = 1.89, 95% confidence interval [CI] = 1.31 to 2.74; females: 12.5% vs 17.6%; OR = 1.50, 95% CI = 1.07 to 2.14), as well as impaired memory (males: 11.6% vs 19.9%, OR = 1.89, CI = 1.31 to 2.74; females: 14.78% vs 25.4%, OR = 1.96, 95% CI = 1.43 to 2.70, respectively). Among male survivors, impaired task efficiency was associated with 2-4 neurologic conditions (OR = 4.33, 95% CI = 1.76 to 10.68) and with pulmonary conditions (OR = 4.99, 95% CI = 1.51 to 16.50), and impaired memory was associated with increased cumulative dose of intrathecal methotrexate (OR = 1.68, 95% CI = 1.16 to 2.46) and with exposure to dexamethasone (OR = 2.44, 95% CI = 1.19 to 5.01). In female survivors, grade 2-4 endocrine conditions were associated with higher risk of impaired task efficiency (OR = 2.19, 95% CI = 1.20 to 3.97) and memory (OR = 2.26, 95% CI = 1.31 to 3.92).

CONCLUSION

Neurocognitive impairment is associated with methotrexate, dexamethasone, and chronic health conditions in a sex-specific manner, highlighting the need to investigate physiological mechanisms and monitor impact through survivorship.

Anatomical brain MRI study of pediatric cancer survivors treated with chemotherapy: Correlation with behavioral measures

The negative impacts of chemotherapy on pediatric patients treated with chemotherapy during the formative years of brain development are understudied compared to adult chemotherapy cancer patients. This work investigated the morphometry, cortical thickness, and subcortical volumes using MRI and their correlations with behavioral measures in pediatric oncology survivors treated with chemotherapy. Chemotherapy-treated childhood cancer survivors (N = 15, 15.12 ± 5.98 years old) diagnosed with a non-central nervous system malignancy and healthy age-matched controls (N = 15, 15.13 ± 4.21 years old) were studied. MRI was acquired at 3 Tesla. Behavioral Rating Inventory of Executive Functioning (BRIEF) Parental Rating, Purdue Pegboard manual dexterity and n-back working memory measures were administered. Structural MRI scans at 3 Tesla were acquired. Voxel-based morphometry, cortical thickness and subcortical volumes were analyzed and correlated with behavioral scores. Parametric statistics with a p < .05 and adjusted for multiple comparison corrections were performed. Patients exhibited significantly smaller gray-matter volumes in the left globus pallidum, bilateral thalami, left caudate and left nucleus accumbens (p < .05) and thinner cortex in the right parahippocampal gyrus (p < .05) compared to controls. BRIEF scores were similar to normative values. Purdue Pegboard revealed manual dexterity deficits compared to normative values, and the n-back task showed working-memory deficits in patients compared to controls. Left thalamus volume positively correlated with dexterity performance (p = .029). The number of correct answers positively correlated and the number of incorrect answers negatively correlated with total-brain and white-matter volume (p < .05), but not gray-matter volume (p > .05). Our results support the hypothesis that the neurotoxicity of systemic chemotherapy has widespread negative effects on brain development in pediatric oncology patients with relatively mild cognitive deficits. MRI identified neuroanatomical changes have the potential to provide neural correlates of the sequelae associated with pediatric chemotherapy.

Neural correlates of working memory function in pediatric cancer survivors treated with chemotherapy: an fMRI study

The goal of this study is to investigate the neural correlates of working memory function associated with chemotherapy in pediatric cancer survivors using event-related functional MRI (fMRI) analysis. Fifteen pediatric cancer survivors treated with chemotherapy and 15 healthy controls were studied. Blood oxygenation level dependent (BOLD) fMRI was acquired. A visual n-back task was used to test working memory function during the fMRI scan. Responses were recorded via an MRI compatible button box for analysis. fMRI scans were analyzed using statistical parametric mapping software. All statistics were corrected for multiple comparisons by false discovery rate, with p < 0.05 as significance. Patients however gave more incorrect responses (p < 0.05), more no responses (p < 0.05), and longer response times (p < 0.05) compared with healthy controls. Correct responses generated significantly lower BOLD responses in the posterior cingulate for pediatric cancer survivors compared with controls (p < 0.05). Incorrect responses generated significantly greater BOLD responses in the angular gyrus in survivors (p < 0.05), and no response trials generated greater BOLD responses within the superior parietal lobule (p < 0.05) compared with controls. Working memory impairment appears to be due to an inability to manipulate information and to retrieve information from memory. The ability to delineate the affected neural circuits associated with chemotherapy-induced cognitive impairment could inform treatment strategies, identify patients at high risk of developing cognitive deficits, and pre-emptively tailor behavioral enrichment to overcome specific cognitive deficits.

Neuroanatomical abnormalities related to dexamethasone exposure in survivors of childhood acute lymphoblastic leukemia

Survivors of childhood acute lymphoblastic leukemia (ALL) treated with chemotherapy only are at risk for neurocognitive impairment. Regions of interest were identified a priori based on glucocorticoid receptor distribution, and sex-stratified multivariable linear regression models were used to test associations between brain MRI morphology and total number of intrathecal injections, and serum concentration of dexamethasone and methotrexate. Compared with controls, ALL survivors have persistently smaller volumes in the bilateral cerebellum (P < 0.005), hippocampal subregions (P < 0.03), temporal lobe regions (P < 0.03), frontal lobe regions (P < 0.04), and parietal lobe regions (precuneus; P < 0.002). Long-term problems with learning may be related to residual posttreatment brain differences.

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

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

Influence of genetic factors on long-term treatment related neurocognitive complications, and on anxiety and depression in survivors of childhood acute lymphoblastic leukemia: The Petale study

BACKGROUND

A substantial number of survivors of childhood acute lymphoblastic leukemia suffer from treatment-related late adverse effects including neurocognitive impairment. While multiple studies have described neurocognitive outcomes in childhood acute lymphoblastic leukemia (ALL) survivors, relatively few have investigated their association with individual genetic constitution.

METHODS

To further address this issue, genetic variants located in 99 genes relevant to the effects of anticancer drugs and in 360 genes implicated in nervous system function and predicted to affect protein function, were pooled from whole exome sequencing data of childhood ALL survivors (PETALE cohort) and analyzed for an association with neurocognitive complications, as well as with anxiety and depression. Variants that sustained correction for multiple testing were genotyped in entire cohort (n = 236) and analyzed with same outcomes.

RESULTS

Common variants in MTR, PPARA, ABCC3, CALML5, CACNB2 and PCDHB10 genes were associated with deficits in neurocognitive tests performance, whereas a variant in SLCO1B1 and EPHA5 genes was associated with anxiety and depression. Majority of associations were modulated by intensity of treatment. Associated variants were further analyzed in an independent SJLIFE cohort of 545 ALL survivors. Two variants, rs1805087 in methionine synthase, MTR and rs58225473 in voltage-dependent calcium channel protein encoding gene, CACNB2 are of particular interest, since associations of borderline significance were found in replication cohort and remain significant in combined discovery and replication groups (OR = 1.5, 95% CI, 1-2.3; p = 0.04 and; OR = 3.7, 95% CI, 1.25-11; p = 0.01, respectively). Variant rs4149056 in SLCO1B1 gene also deserves further attention since previously shown to affect methotrexate clearance and short-term toxicity in ALL patients.

CONCLUSIONS

Current findings can help understanding of the influence of genetic component on long-term neurocognitive impairment. Further studies are needed to confirm whether identified variants may be useful in identifying survivors at increased risk of these complications.

Brain Network Connectivity and Executive Function in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia

Chemotherapeutic agents used to treat acute lymphoblastic leukemia (ALL), the most common cancer affecting young children, have been associated with long-term cognitive impairments that reduce quality of life. Executive dysfunction is one of the most consistently observed deficits and can have substantial and pervasive effects on academic success, occupational achievement, psychosocial function, and psychiatric status. We examined the neural mechanisms of executive dysfunction by measuring structural and functional connectomes in 161 long-term survivors of pediatric ALL, age 8-21 years, who were treated on a single contemporary chemotherapy-only protocol for standard/high- or low-risk disease. Lower global efficiency, a measure of information exchange and network integration, of both structural and functional connectomes was found in survivors with executive dysfunction compared with those without dysfunction (p < 0.046). Patients with standard/high- versus low-risk disease and those who received greater number of intrathecal treatments containing methotrexate had the lowest network efficiencies. Patients with executive dysfunction also showed hyperconnectivity in sensorimotor, visual, and auditory-processing regions (p = 0.037) and poor separation between sensorimotor, executive/attention, salience, and default mode networks (p < 0.0001). Connectome disruption was consistent with a pattern of delayed neurodevelopment that may be associated with reduced resilience, adaptability, and flexibility of the brain network. These findings highlight the need for interventions that will prevent or manage cognitive impairment in survivors of pediatric acute lymphoblastic leukemia.

Neurocognitive Outcomes and Interventions in Long-Term Survivors of Childhood Cancer

Recent research has demonstrated that survivors of childhood cancer are at risk for a myriad of late effects that affect physical and mental quality of life. We discuss the patterns and prevalence of neurocognitive problems commonly experienced by survivors of CNS tumors and acute lymphoblastic leukemia, the two most commonly researched cancer diagnoses. Research documenting the direct effects of tumor location and treatment type and intensity is presented, and patient characteristics that moderate outcomes (eg, age at diagnosis and sex) are discussed. Potential biologic mechanisms of neurotoxic treatment exposures, such as cranial irradiation and intrathecal and high-dose antimetabolite chemotherapy, are reviewed. Genetic, brain imaging, and neurochemical biomarkers of neurocognitive impairment are discussed. Long-term survivors of childhood cancer are also at risk for physical morbidity (eg, cardiac, pulmonary, endocrine) and problems with health behaviors (eg, sleep); research is reviewed that demonstrates these health problems contribute to neurocognitive impairment in survivors with or without exposure to neurotoxic therapies. We conclude this review with a discussion of literature supporting specific interventions that may be beneficial in the treatment of survivors who already experience neurocognitive impairment, as well as in the prevention of impairment manifestation.

Neurodevelopmental consequences of pediatric cancer and its treatment: applying an early adversity framework to understanding cognitive, behavioral, and emotional outcomes

Today, children are surviving pediatric cancer at unprecedented rates, making it one of modern medicine's true success stories. However, we are increasingly becoming aware of several deleterious effects of cancer and the subsequent "cure" that extend beyond physical sequelae. Indeed, survivors of childhood cancer commonly report cognitive, emotional, and psychological difficulties, including attentional difficulties, anxiety, and posttraumatic stress symptoms (PTSS). Cognitive late- and long-term effects have been largely attributed to neurotoxic effects of cancer treatments (e.g., chemotherapy, cranial irradiation, surgery) on brain development. The role of childhood adversity in pediatric cancer - namely, the presence of a life-threatening disease and endurance of invasive medical procedures - has been largely ignored in the existing neuroscientific literature, despite compelling research by our group and others showing that exposure to more commonly studied adverse childhood experiences (i.e., domestic and community violence, physical, sexual, and emotional abuse) strongly imprints on neural development. While these adverse childhood experiences are different in many ways from the experience of childhood cancer (e.g., context, nature, source), they do share a common element of exposure to threat (i.e., threat to life or physical integrity). Therefore, we argue that the double hit of early threat and cancer treatments likely alters neural development, and ultimately, cognitive, behavioral, and emotional outcomes. In this paper, we (1) review the existing neuroimaging research on child, adolescent, and adult survivors of childhood cancer, (2) summarize gaps in our current understanding, (3) propose a novel neurobiological framework that characterizes childhood cancer as a type of childhood adversity, particularly a form of early threat, focusing on development of the hippocampus and the salience and emotion network (SEN), and (4) outline future directions for research.

Characterizing neurocognitive late effects in childhood leukemia survivors using a combination of neuropsychological and cognitive neuroscience measures

Knowledge about cognitive late effects in survivors of childhood acute lymphoblastic leukemia (ALL) is largely based on standardized neuropsychological measures and parent reports. To examine whether cognitive neuroscience paradigms provided additional insights into neurocognitive and behavioral late effects in ALL survivors, we assessed cognition and behavior using a selection of cognitive neuroscience tasks and standardized measures probing domains previously demonstrated to be affected by chemotherapy. 130 ALL survivors and 158 control subjects, between 8 and 18 years old at time of testing, completed the n-back (working memory) and stop-signal (response inhibition) tasks. ALL survivors also completed standardized measures of intelligence (Wechsler Intelligence Scales [WISC-IV]), motor skills (Grooved Pegboard), math abilities (WIAT-III), and executive functions (Delis-Kaplan Executive Function System). Parents completed behavioral measures of executive functions (Behavior Rating Inventory of Executive Function [BRIEF]) and attention (Conners-3). ALL survivors exhibited deficiencies in working memory and response inhibition compared with controls. ALL survivors also exhibited deficits on WISC-IV working memory and processing speed, Grooved Pegboard, WIAT-III addition and subtraction fluency, and numerical operations, as well as DKEFS number-letter switching. Parent reports suggested more attention deficits (Conners-3) and behavioral difficulties (BRIEF) in ALL survivors compared with referenced norms. Low correspondence between standardized and experimental measures of working memory and response inhibition was noted. The use of cognitive neuroscience paradigms complements our understanding of the cognitive deficits evident after treatment of ALL. These measures could further delineate cognitive processes involved in neurocognitive late effects, providing opportunities to explore their underlying mechanisms.

Microstructure alterations in the hypothalamus in cranially radiated childhood leukaemia survivors but not in craniopharyngioma patients unaffected by hypothalamic damage

OBJECTIVE

Metabolic complications are frequent in childhood leukaemia (ALL) survivors treated with cranial radiotherapy (CRT). These complications are potentially mediated by damage to the hypothalamus (HT), as childhood onset (CO) craniopharyngioma (CP) survivors without HT involvement are spared overt obesity. Diffusion tensor imaging (DTI) shows brain tissue microstructure alterations, by fractional anisotrophy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). We used DTI to determine the integrity of the microstructure of the HT in ALL survivors.

DESIGN

Case-control study.

PATIENTS

Three groups were included: (i) 27 CRT treated ALL survivors on hormone supplementation, (ii) 17 CO-CP survivors on hormone supplementation but without HT involvement and (iii) 27 matched controls.

MEASUREMENTS

DTI parameters of the HT were measured and body composition.

RESULTS

Microstructural alterations in the HT were more severe in ALL survivors with a BMI ≥25 than with BMI <25. Compared to controls, ALL survivors had reduced FA (P=.04), increased MD (P<.001), AD (P<.001) and RD (P<.001) in the right and left HT. In the right HT, ALL survivors with a BMI ≥25 showed elevated MD (P=.03) and AD (P=.02) compared to ALL survivors with BMI <25. In contrast, DTI parameters did not differ between CP survivors and controls.

CONCLUSIONS

Long-term follow-up after CRT for ALL DTI measures were affected in the HT despite complete hormone replacement. The present data suggest that ALL survivors have demyelination and axonal loss in the HT.

Family estimates of risk for neurocognitive late effects following pediatric cancer: From diagnosis through the first three years of survivorship

BACKGROUND

Families often express a need for additional information about neurocognitive late effects (NCLE) after a pediatric cancer diagnosis. Therefore, we examined: (i) differences in parent, child, and oncologist estimates of risk for NCLE; (ii) whether the estimates of parents and/or children change over time; and (iii) whether estimates are different for children treated with central nervous system (CNS) directed therapies.

PROCEDURE

Mothers, fathers, and children (initial age: 5-17, self-report: >10) from 258 families reported their perceived likelihood of the child developing "thinking/learning problems" on a visual analog scale (0-100%) at 2 months (T1), 1 year (T2), and 3 years (T3) following cancer diagnosis/relapse. Oncologists estimated the likelihood of NCLE at T1. Children were separated into groups based on CNS-directed treatment (n = 137; neurosurgery, intrathecal chemotherapy, and/or craniospinal radiation) or no CNS treatment.

RESULTS

Mother, father, and child estimates of risk for NCLE were similar to oncologists and to one another around diagnosis (T1). Although there were no significant mean differences, a considerable subset of family members either underestimated their child's risk for NCLE (>40%) or overestimated the risk for NCLE (20%) in comparison to oncologists. At T2 and T3, the estimates of mothers were significantly higher than children. Linear growth curves indicated that mothers' estimates for children with CNS-directed treatment significantly increased throughout the first 3 years of survivorship.

CONCLUSIONS

Considering that accurate understanding of NCLE is essential to seeking appropriate assessment and intervention, healthcare providers should focus on implementing family-based education early in treatment and throughout survivorship care.

Abnormal topological organization in white matter structural networks in survivors of acute lymphoblastic leukaemia with chemotherapy treatment

Previous diffusion tensor imaging (DTI) studies have detected white matter (WM) integrity abnormalities in some specific fibre bundles in acute lymphoblastic leukaemia (ALL) patients with chemotherapy. However, little is known about the changes in the topological organization of the WM structural network in ALL patients with chemotherapy. In the present study, we acquired DTI datasets from 28 ALL patients (mean age: 40.71 ± 8.58 years, years since diagnosis: 7–38) with chemotherapy and 20 matched healthy controls (mean age: 42.95 ± 6.39 years) and performed WM network analysis using a deterministic fibre-tracking approach. Graph theoretical analysis was used to compare the topological parameters of the WM networks between the two groups. Both ALL patients with chemotherapy and healthy controls had small-worldness in their WM networks. ALL patients showed significantly reduced global network efficiency, as indicated by the abnormally decreased clustering coefficient Cp and the normalized clustering coefficient γ and increased shortest path length Lp compared with healthy controls. Moreover, hubs were located more in parietal regions of healthy controls and in temporal regions in the ALL patients. We revealed the abnormal topological organization of the WM networks of ALL patients with chemotherapy, which may improve our understanding of the neural mechanism of chemotherapy in ALL from a WM topological organization level.

The relationship between cognitive and neuroimaging outcomes in children treated for acute lymphoblastic leukemia with chemotherapy only: A systematic review

Cognitive late-effects have been identified in patients treated with chemotherapy-only protocols for childhood acute lymphoblastic leukemia (ALL), yet the underlying neuropathology is not well understood. This review synthesized recent findings from eight articles investigating the relationship between neurocognitive and neuroimaging outcomes for patients treated for ALL with chemotherapy-only protocols. Reported cognitive domains, imaging methods, and neuroanatomy examined were variable. Despite this, 62.5% (n = 5) of the reviewed studies found a significant relationship between cognitive and imaging outcomes. Greater understanding of the effects of treatment on neuroanatomy and cognitive outcomes is critical for proactively managing ALL cognitive late-effects. Research directions are suggested.

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.

Dexamethasone-(C21-phosphoramide)-[anti-EGFR]: molecular design, synthetic organic chemistry reactions, and antineoplastic cytotoxic potency against pulmonary adenocarcinoma (A549)

PURPOSE

Corticosteroids are effective in the management of a variety of disease states, such as several forms of neoplasia (leukemia and lymphoma), autoimmune conditions, and severe inflammatory responses. Molecular strategies that selectively "target" delivery of corticosteroids minimize or prevents large amounts of the pharmaceutical moiety from passively diffusing into normal healthy cell populations residing within tissues and organ systems.

MATERIALS AND METHODS

The covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide)-[anti-EGFR] was synthesized by reacting dexamethasone-21-monophosphate with a carbodiimide reagent to form a dexamethasone phosphate carbodiimide ester that was subsequently reacted with imidazole to create an amine-reactive dexamethasone-(C21-phosphorylimidazolide) intermediate. Monoclonal anti-EGFR immunoglobulin was combined with the amine-reactive dexamethasone-(C21-phosphorylimidazolide) intermediate, resulting in the synthesis of the covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide)-[anti-EGFR]. Following spectrophotometric analysis and validation of retained epidermal growth factor receptor type 1 (EGFR)-binding avidity by cell-ELISA, the selective anti-neoplasic cytotoxic potency of dexamethasone-(C21-phosphoramide)-[anti-EGFR] was established by MTT-based vitality stain methodology using adherent monolayer populations of human pulmonary adenocarcinoma (A549) known to overexpress the tropic membrane receptors EGFR and insulin-like growth factor receptor type 1.

RESULTS

The dexamethasone:IgG molar-incorporation-index for dexamethasone-(C21-phosphoramide)-[anti-EGFR] was 6.95:1 following exhaustive serial microfiltration. Cytotoxicity analysis: covalent bonding of dexamethasone to monoclonal anti-EGFR immunoglobulin did not significantly modify the ex vivo antineoplastic cytotoxicity of dexamethasone against pulmonary adenocarcinoma at and between the standardized dexamethasone equivalent concentrations of 10(-9) M and 10(-5) M. Rapid increases in antineoplastic cytotoxicity were observed at and between the dexamethasone equivalent concentrations of 10(-9) M and 10(-7) M where cancer cell death increased from 7.7% to a maximum of 64.9% (92.3%-35.1% residual survival), respectively, which closely paralleled values for "free" noncovalently bound dexamethasone.

DISCUSSION

Organic chemistry reaction regimens were optimized to develop a multiphase synthesis regimen for dexamethasone-(C21-phosphoramide)-[anti-EGFR]. Attributes of dexamethasone-(C21-phosphoramide)-[anti-EGFR] include a high dexamethasone molar incorporation-index, lack of extraneous chemical group introduction, retained EGFR-binding avidity ("targeted" delivery properties), and potential to enhance long-term pharmaceutical moiety effectiveness.

Chemotherapy Pharmacodynamics and Neuroimaging and Neurocognitive Outcomes in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia

PURPOSE

To examine associations among methotrexate pharmacodynamics, neuroimaging, and neurocognitive outcomes in long-term survivors of childhood acute lymphoblastic leukemia treated on a contemporary chemotherapy-only protocol.

PATIENTS AND METHODS

This longitudinal study linked pharmacokinetic assays collected during therapy to neurocognitive and brain imaging outcomes during long-term follow-up. A total of 218 (72.2%) of 302 eligible long-term survivors were recruited for outcome studies when they were more than 5 years post-diagnosis and older than 8 years of age. At long-term follow-up, survivors were an average of 13.8 years old and 7.7 years from diagnosis, and 51% were male. Neurocognitive testing, functional magnetic resonance imaging (MRI) during an executive function task, and structural MRI with diffusion tensor imaging were conducted. Generalized linear models were developed to identify predictors, and models were adjusted for age at diagnosis, sex, and parent education.

RESULTS

Intelligence was within normal limits (mean, 98; standard deviation, 14) compared with population expectations (mean, 100; standard deviation, 15), though measures of executive function, processing speed, and memory were less than population means (all P < .02 after correction for false discovery rates). Higher plasma concentration of methotrexate was associated with a poorer executive function score (P < .02). Higher plasma methotrexate was also associated with higher functional MRI activity, with thicker cortices in dorsolateral prefrontal brain regions, and with white matter microstructure in the frontostriatal tact. Neurocognitive impairment was associated with these imaging findings as well. Associations did not change after adjustment for age or dose of leucovorin rescue.

CONCLUSION

Survivors of childhood acute lymphoblastic leukemia treated on contemporary chemotherapy-only protocols demonstrate executive dysfunction. A higher plasma concentration of methotrexate was associated with executive dysfunction as well as with a thicker cortex and higher activity in frontal brain regions, regions often associated with executive function.

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.

Steroid-induced ocular hypertensive response in children and adolescents with acute lymphoblastic leukemia and non-Hodgkin lymphoma

The aim of this study was to evaluate intraocular pressure (IOP) associated with use of glucocorticoids in children and adolescents treated for acute lymphoblastic leukemia and non-Hodgkin lymphoma. We carried out a prospective descriptive study with measurement of IOP before treatment (D0), 8th (D8), 14th (D14), and 28 h days (D28) of treatment. We examined 12 patients, with two cases of ocular hypertension, and it was found a statistically significant difference between the means of IOP between D0 versus D8 and D0 versus D14 (P = 0.013). The possibility of silent ocular hypertension with irreversible blindness indicates the need of IOP verification.

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.

Risk of late effects of treatment in children newly diagnosed with standard-risk acute lymphoblastic leukaemia: a report from the Childhood Cancer Survivor Study cohort

BACKGROUND

Treatment of patients with paediatric acute lymphoblastic leukaemia has evolved such that the risk of late effects in survivors treated in accordance with contemporary protocols could be different from that noted in those treated decades ago. We aimed to estimate the risk of late effects in children with standard-risk acute lymphoblastic leukaemia treated with contemporary protocols.

METHODS

We used data from similarly treated members of the Childhood Cancer Survivor Study cohort. The Childhood Cancer Survivor Study is a multicentre, North American study of 5-year survivors of childhood cancer diagnosed between 1970 and 1986. We included cohort members if they were aged 1·0-9·9 years at the time of diagnosis of acute lymphoblastic leukaemia and had received treatment consistent with contemporary standard-risk protocols for acute lymphoblastic leukaemia. We calculated mortality rates and standardised mortality ratios, stratified by sex and survival time, after diagnosis of acute lymphoblastic leukaemia. We calculated standardised incidence ratios and absolute excess risk for subsequent neoplasms with age-specific, sex-specific, and calendar-year-specific rates from the Surveillance, Epidemiology and End Results Program. Outcomes were compared with a sibling cohort and the general US population.

FINDINGS

We included 556 (13%) of 4329 cohort members treated for acute lymphoblastic leukaemia. Median follow-up of the survivors from 5 years after diagnosis was 18·4 years (range 0·0-33·0). 28 (5%) of 556 participants had died (standardised mortality ratio 3·5, 95% CI 2·3-5·0). 16 (57%) deaths were due to causes other than recurrence of acute lymphoblastic leukaemia. Six (1%) survivors developed a subsequent malignant neoplasm (standardised incidence ratio 2·6, 95% CI 1·0-5·7). 107 participants (95% CI 81-193) in each group would need to be followed-up for 1 year to observe one extra chronic health disorder in the survivor group compared with the sibling group. 415 participants (376-939) in each group would need to be followed-up for 1 year to observe one extra severe, life-threatening, or fatal disorder in the group of survivors. Survivors did not differ from siblings in their educational attainment, rate of marriage, or independent living.

INTERPRETATION

The prevalence of adverse long-term outcomes in children treated for standard risk acute lymphoblastic leukaemia according to contemporary protocols is low, but regular care from a knowledgeable primary-care practitioner is warranted.

FUNDING

National Cancer Institute, American Lebanese-Syrian Associated Charities, Swiss Cancer Research.

Evaluation of spatial memory and locomotor activity during hypercortisolism induced by the administration of dexamethasone in adult male rats

In neurosurgery practice glucocorticoids are commonly used. Steroids may have central nervous system side effects affecting whole body, including steroid-induced mental agitation and psychosis. In experimental and clinical studies conducted by using dexamethasone (DEX), it has been reported that DEX adversely affects learning and memory skills. Unfortunately, there are yet no clinically accepted clinical approaches to prevent DEX-induced cognitive dysfunction. In this experimental study it was aimed to investigate the effect of chronic DEX administration on learning-memory and locomotor behaviors in adult male Sprague Dawley rats. In addition, it was also aimed to explore the potential favorable contribution of melatonin (MEL) and vitamin C (Vit C) having antioxidant and neuroprotective properties to the effects of DEX on learning-memory and locomotor behaviors. For this purpose, rats were injected 10mg/kg DEX intraperitoneally, both alone and in combination with MEL (40 mg/kg) and Vit C (100mg/kg), for 9 days, and the animals were tested using the radial arm maze and open field apparatus. The test results revealed that DEX caused a significant decrease in spatial memory and locomotor activities and MEL and Vit C failed to reverse losses in these activities. Furthermore, DEX led to a gradual weight loss that reached 30% of the initial weight at 9th day of the injection. DEX administration causes a generalized loss of behavioral activity of rats. Experimental studies devised to investigate effects of DEX should take into account this DEX-induced generalized behavioral loss when assessing the effects of DEX on learning and memory skills. This article is part of a Special Issue entitled SI: Brain and Memory.

Neurocognitive outcomes decades after treatment for childhood acute lymphoblastic leukemia: a report from the St Jude lifetime cohort study

PURPOSE

To determine rates, patterns, and predictors of neurocognitive impairment in adults decades after treatment for childhood acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

Survivors of childhood ALL treated at St Jude Children's Research Hospital who were still alive at 10 or more years after diagnosis and were age ≥ 18 years were recruited for neurocognitive testing. In all, 1,014 survivors were eligible, 738 (72.8%) agreed to participate, and 567 (76.8%) of these were evaluated. Mean age was 33 years; mean time since diagnosis was 26 years. Medical record abstraction was performed for data on doses of cranial radiation therapy (CRT) and cumulative chemotherapy. Multivariable modeling was conducted and glmulti package was used to select the best model with minimum Akaike information criterion.

RESULTS

Impairment rates across neurocognitive domains ranged from 28.6% to 58.9%, and those treated with chemotherapy only demonstrated increased impairment in all domains (all P values < .006). In survivors who received no CRT, dexamethasone was associated with impaired attention (relative risk [RR], 2.12; 95% CI, 1.11 to 4.03) and executive function (RR, 2.42; 95% CI, 1.20 to 4.91). The impact of CRT was dependent on young age at diagnosis for intelligence, academic, and memory functions. Risk for executive function problems increased with survival time in a CRT dose-dependent fashion. In all survivors, self-reported behavior problems increased by 5% (RR, 1.05; 95% CI, 1.01 to 1.09) with each year from diagnosis. Impairment was associated with reduced educational attainment and unemployment.

CONCLUSION

This study demonstrates persistent and significant neurocognitive impairment in adult survivors of childhood ALL and warrants ongoing monitoring of brain health to facilitate successful adult development and to detect early onset of decline as survivors mature.

Brain volume and cognitive function in adult survivors of childhood acute lymphoblastic leukemia

The survival rate for childhood acute lymphoblastic leukemia (ALL) is greater than 80%. However, many of these survivors develop long-term chronic health conditions, with a relatively common late effect being neurocognitive dysfunction. Although neurocognitive impairments have decreased in frequency and severity as treatment has evolved, there is a subset of survivors in the current treatment era that are especially vulnerable to the neurotoxic effects of ALL and its treatment. Additionally, little is known about long-term brain development as survivors mature into adulthood. A recent study by Zeller et al. compared neurocognitive function and brain volume in 130 adult survivors of childhood ALL to 130 healthy adults matched on age and sex. They identified the caudate as particularly sensitive to the neurotoxic effects of chemotherapy. We discuss the implications and limitations of this study, including how their findings support the concept of individual vulnerability to ALL and its treatment.