The impact of therapy for childhood acute lymphoblastic leukaemia on intelligence quotients; results of the risk-stratified randomized central nervous system treatment trial MRC UKALL XI

No clear benefit of preventive cranial radiotherapy in childhood Philadelphia-positive acute lymphoblastic leukemia: a retrospective analysis of the EsPhALL2010 study

Not available.

A brain organoid/ALL coculture model reveals the AP-1 pathway as critically associated with CNS involvement of BCP-ALL

ABSTRACT

Central nervous system (CNS) involvement remains a clinical hurdle in treating childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The disease mechanisms of CNS leukemia are primarily investigated using 2-dimensional cell culture and mouse models. Given the variations in cellular identity and architecture between the human and murine CNS, it becomes imperative to seek complementary models to study CNS leukemia. Here, we present a first-of-its-kind 3-dimensional coculture model combining human brain organoids and BCP-ALL cells. We noticed significantly higher engraftment of BCP-ALL cell lines and patient-derived xenograft (PDX) cells in cerebral organoids than non-ALL cells. To validate translatability between organoid coculture and in vivo murine models, we confirmed that targeting CNS leukemia-relevant pathways such as CD79a/Igα or C-X-C motif chemokine receptor 4-stromal cell-derived factor 1 reduced the invasion of BCP-ALL cells into organoids. RNA sequencing and functional validations of organoid-invading leukemia cells compared with the noninvaded fraction revealed significant upregulation of activator protein 1 (AP-1) transcription factor-complex members in organoid-invading cells. Moreover, we detected a significant enrichment of AP-1 pathway genes in PDX ALL cells recovered from the CNS compared with spleen blasts of mice that had received transplantation with TCF3::PBX1+ PDX cells, substantiating the role of AP-1 signaling in CNS disease. Accordingly, we found significantly higher levels of the AP-1 gene, jun proto-oncogene, in patients initially diagnosed as CNS-positive BCP-ALL compared with CNS-negative cases as well as CNS-relapse vs non-CNS-relapse cases in a cohort of 100 patients with BCP-ALL. Our results suggest CNS organoids as a novel model to investigate CNS involvement and identify the AP-1 pathway as a critical driver of CNS disease in BCP-ALL.

Impact of Propofol Exposure on Neurocognitive Outcomes in Children With High-Risk B ALL: A Children's Oncology Group Study

PURPOSE

Many children treated for ALL develop long-term neurocognitive impairments. Increased risk of these impairments is associated with treatment and demographic factors. Exposure to anesthesia is an additional possible risk factor. This study evaluated the impact of cumulative exposure to anesthesia on neurocognitive outcomes among a multicenter cohort of children with ALL.

METHODS

This study was embedded in AALL1131, a Children's Oncology Group phase III trial for patients with high-risk B-ALL. In consenting patients age 6-12 years, prospective uniform assessments of neurocognitive function were performed during and at 1 year after completion of therapy. Exposure to all episodes of anesthetic agents was abstracted. Multivariable linear regression models determined associations of cumulative anesthetic agents with the primary neurocognitive outcome reaction time/processing speed (age-normed) at 1 year off therapy, adjusting for baseline neurocognitive score, age, sex, race/ethnicity, insurance status (as a proxy for socioeconomic status), and leukemia risk group.

RESULTS

One hundred and forty-four children, 76 (52.8%) males, mean age of 9.1 (min-max, 6.0-12.0) years at diagnosis, underwent a median of 27 anesthetic episodes (min-max, 1-37). Almost all patients were exposed to propofol (140/144, 97.2%), with a mean cumulative dose of 112.3 mg/kg. One year after therapy, the proportion of children with impairment (Z-score ≤-1.5) was significantly higher compared with a normative sample. In covariate-adjusted multivariable analysis, cumulative exposure to propofol was associated with a 0.05 Z-score decrease in reaction time/processing speed per each 10 mg/kg propofol exposure (P = .03).

CONCLUSION

In a multicenter and uniformly treated cohort of children with B-ALL, cumulative exposure to propofol was an independent risk factor for impairment in reaction time/processing speed 1 year after therapy. Anesthesia exposure is a modifiable risk, and opportunities to minimize propofol use should be considered.

Detecting High-Dose Methotrexate-Induced Brain Changes in Pediatric and Young Adult Cancer Survivors Using [18F]FDG PET/MRI: A Pilot Study

Significant improvements in treatments for children with cancer have resulted in a growing population of childhood cancer survivors who may face long-term adverse outcomes. Here, we aimed to diagnose high-dose methotrexate-induced brain injury on [18F]FDG PET/MRI and correlate the results with cognitive impairment identified by neurocognitive testing in pediatric cancer survivors. Methods: In this prospective, single-center pilot study, 10 children and young adults with sarcoma (n = 5), lymphoma (n = 4), or leukemia (n = 1) underwent dedicated brain [18F]FDG PET/MRI and a 2-h expert neuropsychologic evaluation on the same day, including the Wechsler Abbreviated Scale of Intelligence, second edition, for intellectual functioning; Delis-Kaplan Executive Function System (DKEFS) for executive functioning; and Wide Range Assessment of Memory and Learning, second edition (WRAML), for verbal and visual memory. Using PMOD software, we measured the SUVmean, cortical thickness, mean cerebral blood flow (CBFmean), and mean apparent diffusion coefficient of 3 different cortical regions (prefrontal cortex, cingulate gyrus, and hippocampus) that are routinely involved during the above-specified neurocognitive testing. Standardized scores of different measures were converted to z scores. Pairs of multivariable regression models (one for z scores < 0 and one for z scores > 0) were fitted for each brain region, imaging measure, and test score. Heteroscedasticity regression models were used to account for heterogeneity in variances between brain regions and to adjust for clustering within patients. Results: The regression analysis showed a significant correlation between the SUVmean of the prefrontal cortex and cingulum and DKEFS-sequential tracking (DKEFS-TM4) z scores (P = 0.003 and P = 0.012, respectively). The SUVmean of the hippocampus did not correlate with DKEFS-TM4 z scores (P = 0.111). The SUVmean for any evaluated brain regions did not correlate significantly with WRAML-visual memory (WRAML-VIS) z scores. CBFmean showed a positive correlation with SUVmean (r = 0.56, P = 0.01). The CBFmean of the cingulum, hippocampus, and prefrontal cortex correlated significantly with DKEFS-TM4 (all P < 0.001). In addition, the hippocampal CBFmean correlated significantly with negative WRAML-VIS z scores (P = 0.003). Conclusion: High-dose methotrexate-induced brain injury can manifest as a reduction in glucose metabolism and blood flow in specific brain areas, which can be detected with [18F]FDG PET/MRI. The SUVmean and CBFmean of the prefrontal cortex and cingulum can serve as quantitative measures for detecting executive functioning problems. Hippocampal CBFmean could also be useful for monitoring memory problems.

Nuanced Management of a Skull Base Tumor in the Setting of Relapsed Acute Lymphoblastic Leukemia

Introduction  Relapsed acute lymphoblastic leukemia (ALL) involving the central nervous system (CNS) is a significant issue that contributes to both morbidity and mortality. Given the poor outcomes in patients with CNS relapse, understanding how ALL involving intracranial relapse presents and is treated is critical. Here, we present a complex case of relapsed recurrent ALL in a pediatric patient. Case Report  An 11-year-old patient presented with double relapse of ALL in the form of an extensive skull base lesion and again with leptomeningeal disease. For the skull base lesion, she was treated nonsurgically with chemotherapy and radiation, which led to a remarkable reduction in the size of the lesion. However, she was found to have early recurrence with leptomeningeal enhancement resulting in hydrocephalus 5 months after completing therapy. A shunt was placed successfully. Currently, she is being managed with monthly intrathecal chemotherapy with cerebrospinal fluid sampling and bone marrow biopsies every 2 months. Discussion  We report the significant effect of chemotherapy and radiotherapy in reducing the size of the extensive skull base lesion, saving the patient from the risks associated with surgery. This patient's initial relapse, with a large skull base lesion that had intracranial involvement, is an unusual presentation of relapsed ALL. The additional early recurrence of leptomeningeal disease further makes this case unique and the management even more nuanced. Here, we demonstrate a multidisciplinary approach for the successful treatment of our patient, which can help guide the management of similar patients in the future.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Central nervous system involvement in childhood acute lymphoblastic leukemia: challenges and solutions

Delivery of effective anti-leukemic agents to the central nervous system (CNS) is considered essential for cure of childhood acute lymphoblastic leukemia. Current CNS-directed therapy comprises systemic therapy with good CNS-penetration accompanied by repeated intrathecal treatments up to 26 times over 2-3 years. This approach prevents most CNS relapses, but is associated with significant short and long term neurotoxicity. Despite this burdensome therapy, there have been no new drugs licensed for CNS-leukemia since the 1960s, when very limited anti-leukemic agents were available and there was no mechanistic understanding of leukemia survival in the CNS. Another major barrier to improved treatment is that we cannot accurately identify children at risk of CNS relapse, or monitor response to treatment, due to a lack of sensitive biomarkers. A paradigm shift in treating the CNS is needed. The challenges are clear - we cannot measure CNS leukemic load, trials have been unable to establish the most effective CNS treatment regimens, and non-toxic approaches for relapsed, refractory, or intolerant patients are lacking. In this review we discuss these challenges and highlight research advances aiming to provide solutions. Unlocking the potential of risk-adapted non-toxic CNS-directed therapy requires; (1) discovery of robust diagnostic, prognostic and response biomarkers for CNS-leukemia, (2) identification of novel therapeutic targets combined with associated investment in drug development and early-phase trials and (3) engineering of immunotherapies to overcome the unique challenges of the CNS microenvironment. Fortunately, research into CNS-ALL is now making progress in addressing these unmet needs: biomarkers, such as CSF-flow cytometry, are now being tested in prospective trials, novel drugs are being tested in Phase I/II trials, and immunotherapies are increasingly available to patients with CNS relapses. The future is hopeful for improved management of the CNS over the next decade.

Supportive methods for childhood acute lymphoblastic leukemia then and now: A compilation for clinical practice

Survival of childhood acute lymphoblastic leukemia has significantly improved over the past decades. In the early years of chemotherapeutic development, improvement in survival rates could be attained only by increasing the cytostatic dose, also by modulation of the frequency and combination of chemotherapeutic agents associated with severe short- and long-time side-effects and toxicity in a developing child's organism. Years later, new treatment options have yielded promising results through targeted immune and molecular drugs, especially in relapsed and refractory leukemia, and are continuously added to conventional therapy or even replace first-line treatment. Compared to conventional strategies, these new therapies have different side-effects, requiring special supportive measures. Supportive treatment includes the prevention of serious acute and sometimes life-threatening events as well as managing therapy-related long-term side-effects and preemptive treatment of complications and is thus mandatory for successful oncological therapy. Inadequate supportive therapy is still one of the main causes of treatment failure, mortality, poor quality of life, and unsatisfactory long-term outcome in children with acute lymphoblastic leukemia. But nowadays it is a challenge to find a way through the flood of supportive recommendations and guidelines that are available in the literature. Furthermore, the development of new therapies for childhood leukemia has changed the range of supportive methods and must be observed in addition to conventional recommendations. This review aims to provide a clear and recent compilation of the most important supportive methods in the field of childhood leukemia, based on conventional regimes as well as the most promising new therapeutic approaches to date.

Neuropathic pain and neurocognitive functioning in children treated for acute lymphoblastic leukemia

ABSTRACT

Children with acute lymphoblastic leukemia (ALL) often experience treatment-related neurocognitive deficits and significant pain. Pain may exacerbate these cognitive impairments. This study examined neuropathic pain and neurocognitive outcomes in survivors of childhood ALL treated with contemporary therapy on a clinical trial (NCT00137111). There were 345 survivors (45% female, M = 6.9 years at diagnosis) who completed neurocognitive assessments including measures of sustained attention, learning and memory, and parent ratings of attention during at least one of 4 time points: on-therapy (Induction and Reinduction), end of therapy, and 2 years post-therapy. At-risk performance was defined as a score at least 1SD below the age-adjusted mean. Data on neuropathic pain (events, duration, and severity according NCI Common Toxicity Criteria) and pharmacologic pain management (opioids and gabapentin) were ascertained. Results showed that 135 survivors (39%) experienced neuropathic pain during treatment. Compared with those without pain, survivors with pain had greater memory impairments at end of therapy (California Verbal Learning Test [CVLT]-Total, 24% vs 12%, P = 0.046). Within the pain group, survivors who experienced a greater number of pain events (CVLT-Total = -0.88, P = 0.023) and those who were treated with opioids (versus gabapentin) had poorer learning and memory performance (CVLT-Total = -0.73, P = 0.011; Short Delay = -0.57, P = 0.024; Long Delay = -0.62, P = 0.012; and Learning Slope = -0.45, P = 0.042) across time points. These are considered medium-to-large effects (SD = 0.45-0.88). Neuropathic pain may be a risk factor for learning problems after therapy completion, and treatment for pain with opioids may also adversely affect neurocognitive performance. Therefore, patients who experience pain may require closer monitoring and additional intervention for neurocognitive impairment.

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.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Cognitive interference processing in adult survivors of childhood acute lymphoblastic leukemia using functional magnetic resonance imaging

BACKGROUND

Childhood acute lymphoblastic leukemia (ALL) is associated with cognitive impairment in adulthood. Cognitive interference processing and its correlated functional magnetic resonance imaging (fMRI) activity in the brain have not yet been studied in this patient group.

MATERIAL

Twenty-six adult childhood ALL survivors (median [interquartile range {IQR}] age, 40.0 [37.0-42.3] years) were investigated at median age (IQR), 35.0 (32.0-37.0) years after treatment with intrathecal and intravenous chemotherapy as well as cranial radiotherapy (24 Gy) and compared with 26 matched controls (median [IQR] age, 37.5 [33.0-41.5] years).

METHODS

Cognitive interference processing was investigated in terms of behavioral performance (response times [ms] and accuracy performance [%]) and fMRI activity in the cingulo-fronto-parietal (CFP) attention network as well as other parts of the brain using the multisource interference task (MSIT).

RESULTS

ALL survivors had longer response times and reduced accuracy performance during cognitive interference processing (median [IQR] interference effect, 371.9 [314.7-453.3] ms and 6.7 [4.2-14.7]%, respectively) comparedwith controls (303.7 [275.0-376.7] ms and 2.3 [1.6-4.3]%, respectively), but did not exhibit altered fMRI activity in the CFP attention network or elsewhere in the brain.

CONCLUSION

Adult childhood ALL survivors demonstrated impaired behavioral performance but no altered fMRI activity when performing cognitive interference processing when compared with controls. The results can be used to better characterize this patient group and to optimize follow-up care and support for these individuals.

Toxicity and effectiveness of CD19 CAR T therapy in children with high-burden central nervous system refractory B-ALL

INTRODUCTION

Although recent clinical trials have demonstrated the efficacy of CD19-directed chimeric antigen receptor (CAR) T-cell therapy for refractory or relapsed B acute lymphoblastic leukemia (r/r B-ALL), most trials exclude patients with high-burden CNS leukemia (CNSL) to avoid the risk of severe neurotoxicity. There were only sparse cases describing the effect of CAR T cells on low-burden CNSL, and the safety and effectiveness of CAR T cells in high-burden CNSL remains unknown.

METHODS

Here, we retrospectively analyzed the results of CD19 CAR T-cell therapy in 12 pediatric patients that had low (Blasts < 20/μL in CSF) or high-burdens (Blasts or intracranial solid mass) of CNS B-ALL, that are enrolled in three clinical trials and one pilot study at Beijing Boren Hospital RESULTS: Eleven patients (91.7%) achieved complete remission (CR) on day 30, and one patient got CR on day 90 after infusion. Most patient experienced mild cytokine-release syndrome. However, of the five patients who retained > 5/μL blasts in CSF or a solid mass before CAR T-cell expansion, four developed severe (grade 3-4) neurotoxicity featured by persistent cerebral edema and seizure, and they fully recovered after intensive managements. Sustained remission was achieved in 9 of the 12 patients, resulted in a 6-month leukemia-free survival rate of 81.8% (95% CI 59.0-100). Only one patient has CNS relapse again.

CONCLUSION

Our study demonstrates that CAR T cells are effective in clearing both low- and high-burden CNSL, but a high CNSL burden before CAR T-cell expansion may cause severe neurotoxicity requiring intense intervention.

Longitudinal Trajectories of Neurocognitive Functioning in Childhood Acute Lymphoblastic Leukemia

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cognitive function of children and adolescent survivors of acute lymphoblastic leukemia: A meta-analysis

Pediatric cancer and its treatment may have an impact on the neurocognitive functions of childhood cancer survivors (CCS). The aim of the present meta-analysis was to compare the intelligence quotient (IQ) scores between CCS of acute lymphoblastic leukemia (ALL) and controls. A comprehensive electronic search identified original research articles that reported scores of the Wechsler Intelligence Scale (WISC; WISC-III, WISC-IV and WISC-R) for children and adolescents, aged 6-16 years at evaluation, survivors of ALL and healthy controls. The included CCS had completed anticancer treatment and were in remission at the time of assessment. A total of 16 studies were included in the meta-analysis, out of 128 extracted studies, and involved a total of 1,676 children and adolescents: 991 CCS (ALL) and 685 healthy controls. Among the studies, a random effects model revealed a moderate estimate of effect size [standardized mean difference (SMD), -0.78; 95% CI, -1.05 to -0.50], indicating that the WISC scores for total IQ were significantly lower in the CCS than in the controls. The mean total IQ range was 85.2-107.2 in the CCS and 88.4-114.1 in the controls. The difference in the mean total IQ between controls and CCS ranged from -13.8 to 20.6. As regards the WISC scores for verbal IQ, 11 studies were included. A random effects model revealed a moderate estimate of effect size (SMD, -0.71; 95% CI, -1.05 to -0.38), indicating that the WISC scores for verbal IQ were significantly lower in the CCS than in the controls. Among the 9 studies that had available data for performance IQ scores, a fixed effect model revealed a moderate estimate of effect size (SMD, -0.80; 95% CI, -1.09 to -0.52), indicating that the WISC scores for performance IQ were significantly lower in the CCS than in the controls. As the survival rates of children and adolescents with ALL are steadily increasing, regular, lifelong follow-up for neurocognitive late effects is imperative in order to improve their education and employment prospects and overall, their quality of life.

Folinic acid over rescue of high dose methotrexate: How problematic citations conserve discredited concepts

BACKGROUND

The outdated axiom that the dose of Folinic acid (FA) rescue used after high dose Methotrexate (HDMTX) should be kept to a minimum in order to prevent a reduction of prognosis ("over rescue") continues to be expressed even though the concept has been seriously challenged. Study aim The ways "problematic citations" are used to support an old theory, such as this, was examined.

RESULTS

Ten patterns of "problematic citation" use were identified. In 8 of these patterns the articles used were scientifically sound and the problem was with the articles citing them. However in 2 other pattens, the articles and their conclusions were flawed and citing them, apparently, resulted from accepting the presented data or conclusions as sound and valid. The patterns were 1. Claims based on data that are not present in the cited article. 2. Selective inclusion of data from cited articles. 3. Citation of misleading data presented only in the abstract. 4. Reporting trends as statistically significant. 5. Copying the citations used by others without checking the article. 6. Acceptance of illusionary truth in spite of knowledge to the contrary. 7. Citation of reports not relevant to the population under discussion 8. Presenting opinions as facts without any citation. 9. Selective presentation of data sets that support the thesis while ignoring the data sets that show the opposite results. 10. Use of a title expressing what the authors intended to show but not what was found.

IMPLICATIONS

The containing acceptance of this old insupportable conjecture, in part, because of "problematic citations" has resulted in unnecessary neurocognitive damage to patients and may have resulted in the misconception that it is the outcome of HDMTX that may have lead to its abandonment in favour of more toxic therapies. Realisation that this is a significant problem in data analysis should lead authors and reviewers to be even more carefully in checking all references. The importance of high-quality reviews is clearly evident. The effect of "Canonization of false facts" is a serious impairment to the acceptance of new hypotheses that better express reality and could lead to improved treatment results. Authors are advised only to cite articles they have read in entirety not relying on the title, abstract or previous use and to check the content of citations before submission.

Metabolic adaptation of acute lymphoblastic leukemia to the central nervous system microenvironment is dependent on Stearoyl CoA desaturase

Metabolic reprogramming is a key hallmark of cancer, but less is known about metabolic plasticity of the same tumor at different sites. Here, we investigated the metabolic adaptation of leukemia in two different microenvironments, the bone marrow and the central nervous system (CNS). We identified a metabolic signature of fatty-acid synthesis in CNS leukemia, highlighting Stearoyl-CoA desaturase (SCD1) as a key player. In vivo SCD1 overexpression increases CNS disease, whilst genetic or pharmacological inhibition of SCD1 decreases CNS load. Overall, we demonstrated that leukemic cells dynamically rewire metabolic pathways to suit local conditions and that targeting these adaptations can be exploited therapeutically.

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.

Auditory attention late effects in pediatric acute lymphoblastic leukemia

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

New attempts for central nervous infiltration of pediatric acute lymphoblastic leukemia

The cure rate of acute lymphoblastic leukemia (ALL), the commonest childhood cancer, has been sharply improved and reached almost 90% ever since the central nervous system (CNS)-directed therapy proposed in the 1960s. However, relapse, particularly in the central nervous system (CNS), is still a common cause of treatment failure. Up to now, the classic CNS-directed treatment for CNS leukemia (CNSL) has been aslant from cranial radiation to high-dose system chemotherapy plus intrathecal (IT) chemotherapy for the serious side effects of cranial radiation. The neurotoxic effects of chemotherapy and IT chemotherapy have been reported in recent years as well. For better prevention and treatment of CNSL, plenty of studies have tried to improve the detection sensitivity for CNSL and prevent CNSL from happening by targeting cytokines and chemokines which could be key factors for the traveling of ALL cells into the CNS. Other studies also have aimed to completely kill ALL cells (including dormant cells) in the CNS by promoting the entering of chemotherapy drugs into the CNS or targeting the components of the CNS niche which could be in favor of the survival of ALL cells in CNS. The aim of this review is to discuss the imperfection of current diagnostic methods and treatments for CNSL, as well as new attempts which could be significant for better elimination of CNSL.

Leptomeningeal malignancy of childhood: sharing learning between childhood leukaemia and brain tumour trials

Leptomeningeal malignancy complicates childhood cancers, including leukaemias, brain tumours, and solid tumours. In leukaemia, such malignancy is thought to invade leptomeninges via the vascular route. In brain tumours, dissemination from the primary tumour, before or after surgery, via CSF pathways is assumed; however, evidence exists to support the vascular route of dissemination. Success in treating leptomeningeal malignancy represents a rate-limiting step to cure, which has been successfully overcome in leukaemia with intensified systemic therapy combined with intra-CSF therapy, which replaced cranial radiotherapy for many patients. This de-escalated CNS-directed therapy is still associated with some neurotoxicity. The balanced benefit justifies exploration of ways to further de-escalate CNS-directed therapy. For primary brain tumours, standard therapy is craniospinal radiotherapy, but attendant risk of acute and delayed brain injury and endocrine deficiencies compounds post-radiation impairment of spinal growth. Alternative ways of treating leptomeninges by intensifying drug therapy delivered to CSF are being investigated-preliminary evidence suggests improved outcomes. This Review seeks to describe methods of intra-CSF drug delivery and drugs in use, and consider how the technique could be modified and additional drugs might be selected for this route of administration.

Should nitrous oxide ever be used in oncology patients receiving methotrexate therapy?

Nitrous oxide (N₂ O) is frequently used for short anesthesia/analgesia in children undergoing painful or repetitive procedures. Children with acute lymphoblastic leukemia (ALL) require repeated lumbar punctures with direct instillation of intrathecal chemotherapy, usually the anti-folate agent methotrexate, during their treatment. These procedures are frequently performed under anesthesia. Concerns have been intermittently raised about a drug interaction between methotrexate and N₂ O that may potentiate the undesirable side effects of methotrexate, including neurotoxicity. However, the clinical evidence consists mainly of isolated case reports leading to a lack of consensus among pediatric anesthetists about the relative risk benefits of using N₂ O in children with ALL. In this article, we review the biochemical basis and scientific observations that suggest a significant interaction between N₂ O and methotrexate due to their dual inhibition of the key enzyme methionine synthase. The possible role of this interaction in potentiating neurotoxicity in children with cancer is discussed, and arguments and counterarguments about the clinical significance of this largely theoretical relationship are explored. Following comprehensive review of all the available data, we make the case for the circumstantial evidence being sufficiently compelling to prompt a review of practice by pediatric anesthetists and call for a precautionary approach by avoiding the use of N₂ O in children receiving concurrent methotrexate.

The Impact of Low-Dose Cranial Boost on the Long-Term Outcomes of Adult Patients with High-Risk Acute Lymphoblastic Leukemia Undergoing Total Body Irradiation and Allogeneic Hematopoietic Stem Cell Transplantation

PURPOSE

Total body irradiation (TBI) is an integral part of the conditioning regimen for patients with acute lymphoblastic leukemia (ALL) undergoing allogeneic, hematopoietic, cell transplantation (allo-HCT). There are conflicting data in the literature regarding the utility of a cranial irradiation boost in high-risk adult ALL without evidence of preexisting central nervous system (CNS) involvement. This study investigates the posttransplant clinical outcomes of patients with high-risk adult ALL undergoing TBI conditioning for allo-HCT with or without a whole-brain boost, without overt CNS involvement at the time of diagnosis.

METHODS AND MATERIALS

A retrospective cohort study was conducted using a medical record analysis. We identified 58 patients who were treated between January 1998 and December 2016, and met our preset inclusion criteria of adults (age >18 years old) who carried a pathologically confirmed diagnosis of CNS-negative, high-risk ALL, who underwent hematopoietic stem cell transplantation with TBI conditioning. A multivariate analysis of correlation between patient outcomes and collected categorical variables was assessed with stepwise Cox logistic regression. Survival analyses were assessed using the Kaplan-Meier technique with a log-rank test.

RESULTS

With a median follow-up time of 5.3 years, there was a statistically significant improvement in actuarial 7-year CNS relapse-free survival (100% vs 76.4%; P = .043) in favor of patients undergoing a cranial boost. There was no statistically significant improvement in 7-year progression-free survival (78.3% vs 62.5%; P = .076) or overall survival (49.4% vs 43.5%; P = .921) with versus without a cranial boost. On multivariate analysis, the presence of a cranial boost was the only identified variable with an independent relationship to CNS relapse-free survival.

CONCLUSIONS

Adult patients with high-risk, CNS-negative ALL were found to have a statistically significant improvement in CNS relapse-free survival and a trend toward improved progression-free survival with the inclusion of a cranial boost with TBI pretransplant conditioning. Our data indicate that further investigation into the use of cranial boost in this patient population is warranted.

The Use of Ommaya Reservoirs to Deliver Central Nervous System-Directed Chemotherapy in Childhood Acute Lymphoblastic Leukaemia

Prophylactic eradication of central nervous system (CNS) leukaemia is the current standard of care in treating childhood acute lymphoblastic leukaemia (ALL). This is conventionally achieved through regular lumbar punctures with intrathecal injections of methotrexate into the cerebrospinal fluid (CSF). Ommaya reservoirs are subcutaneous implantable devices that provide a secure route of drug delivery into the CSF via an intraventricular catheter. They are an important alternative in cases where intrathecal injection via lumbar puncture is difficult. Among UK Paediatric Principal Treatment Centres for ALL we found considerable variation in methotrexate dosing when using an Ommaya reservoir. We review the current safety and theoretical considerations when using Ommaya reservoirs and evidence for methotrexate dose adjustments via this route. We conclude by summarising the pragmatic consensus decision to use 50% of the conventional intrathecal dose of methotrexate when it is administered via Ommaya reservoir in front-line ALL therapy.

Neurocognitive Functioning of Children Treated for High-Risk B-Acute Lymphoblastic Leukemia Randomly Assigned to Different Methotrexate and Corticosteroid Treatment Strategies: A Report From the Children's Oncology Group

Purpose Survivors of childhood acute lymphoblastic leukemia (ALL) are at risk for neurocognitive deficits that are associated with treatment, individual, and environmental factors. This study examined the impact of different methotrexate (MTX) and corticosteroid treatment strategies on neurocognitive functioning in children with high-risk B-lineage ALL. Methods Participants were randomly assigned to receive high-dose MTX with leucovorin rescue or escalating dose MTX with PEG asparaginase without leucovorin rescue. Patients were also randomly assigned to corticosteroid therapy that included either dexamethasone or prednisone. A neurocognitive evaluation of intellectual functioning (IQ), working memory, and processing speed (PS) was conducted 8 to 24 months after treatment completion (n = 192). Results The method of MTX delivery and corticosteroid assignment were unrelated to differences in neurocognitive outcomes after controlling for ethnicity, race, age, gender, insurance status, and time off treatment; however, survivors who were age < 10 years at diagnosis (n = 89) had significantly lower estimated IQ ( P < .001) and PS scores ( P = .02) compared with participants age ≥ 10 years. In addition, participants who were covered by US public health insurance had estimated IQs that were significantly lower ( P < .001) than those with US private or military insurance. Conclusion Children with high-risk B-lineage ALL who were age < 10 years at diagnosis are at risk for deficits in IQ and PS in the absence of cranial radiation, regardless of MTX delivery or corticosteroid type. These data may serve as a basis for developing screening protocols to identify children who are at high risk for deficits so that early intervention can be initiated to mitigate the impact of therapy on neurocognitive outcomes.

Non-infectious chemotherapy-associated acute toxicities during childhood acute lymphoblastic leukemia therapy

During chemotherapy for childhood acute lymphoblastic leukemia, all organs can be affected by severe acute side effects, the most common being opportunistic infections, mucositis, central or peripheral neuropathy (or both), bone toxicities (including osteonecrosis), thromboembolism, sinusoidal obstruction syndrome, endocrinopathies (especially steroid-induced adrenal insufficiency and hyperglycemia), high-dose methotrexate-induced nephrotoxicity, asparaginase-associated hypersensitivity, pancreatitis, and hyperlipidemia. Few of the non-infectious acute toxicities are associated with clinically useful risk factors, and across study groups there has been wide diversity in toxicity definitions, capture strategies, and reporting, thus hampering meaningful comparisons of toxicity incidences for different leukemia protocols. Since treatment of acute lymphoblastic leukemia now yields 5-year overall survival rates above 90%, there is a need for strategies for assessing the burden of toxicities in the overall evaluation of anti-leukemic therapy programs.

How PET/MR Can Add Value For Children With Cancer

PURPOSE

To review how PET/MR technology could add value for pediatric cancer patients.

RECENT FINDINGS

Since many primary tumors in children are evaluated with MRI and metastases are detected with PET/CT, integrated PET/MR can be a time-efficient and convenient solution for pediatric cancer staging. 18F-FDG PET/MR can assess primary tumors and the whole body in one imaging session, avoid repetitive anesthesia and reduce radiation exposure compared to 18F-FDG PET/CT. This article lists 10 action points, which might improve the clinical value of PET/MR for children with cancer. However, even if PET/MR proves valuable, it cannot enter mainstream applications if it is not accessible to the majority of pediatric cancer patients. Therefore, innovations are needed to make PET/MR scanners affordable and increase patient throughput.

SUMMARY

PET/MR offers opportunities for more efficient, accurate and safe diagnoses of pediatric cancer patients. The impact on patient management and outcomes has to be substantiated by large-scale prospective clinical trials.

Ninth grade school performance in Danish childhood cancer survivors

Background:

Childhood cancer survivors can experience learning problems resulting in lower-than-expected attained education as adults. It is unclear whether learning problems manifest already during adolescence.

Methods:

We analysed nationwide Danish registries on school grades for Danish children during 2001–2014. Applying a matched design we compared grades of childhood cancer survivors to children without cancer at ninth grade. We estimated grade differences by subject and its correlation to cancer site and age at diagnosis. The available statistical precision allowed for an analysis of more rare cancer sites.

Results:

The total study population was 793 332 children (mean age 15.24 years and 49.7% girls), of whom 1320 were childhood cancer survivors. Lower rank grades were seen in children with cancer in all school subjects but differed substantially according to cancer site. Most affected were survivors of central nervous system (CNS) tumours, neuroblastoma, lymphoma, leukaemia, other malignant neoplasm and germ-cell tumours. Survivors from other cancer types did not obtain lower grades. Lower rank grades were associated with young age at diagnosis.

Conclusions:

The effect of childhood cancer differed substantially between cancer sites. The largest effect was among survivors of CNS tumours and leukaemia diagnosed at a young age, suggesting an association with radiation therapy. However, the majority of cancer survivors fare well. Increasing awareness on children affected by cancer and special accommodations may help maximise the learning potential of those most affected.

A meta-analysis of the neuropsychological effects of chemotherapy in the treatment of childhood cancer

BACKGROUND

Long-term neuropsychological deficits associated with pediatric cancers and the related treatments have been consistently reported. Whole brain cranial radiation therapy (CRT) is associated with neurocognitive impairment. As a result, physicians are reticent to use CRT in favor of systemic or intrathecal chemotherapy, which have a less clear impact on cognition.

PROCEDURE

The current meta-analysis examined post-treatment neuropsychological performance of children diagnosed with cancer and treated with chemotherapy to better understand the impact of chemotherapy upon cognition. Relevant test scores from 18 empirical studies were utilized and analyzed in comparison to normative data yielding 199 unique effect sizes across nine neurocognitive domains.

RESULTS

Children diagnosed with cancer, who received chemotherapy, demonstrated deficits in attentional capacity (g = -0.277). These deficits are noted in the context of relatively unaffected performance in other domains. When examining potential moderators, those tested more than 5 years after completion of treatment demonstrated better attentional performance than those tested within 5 years of treatment completion.

CONCLUSIONS

These deficits in attentional capacity have implications related to the academic success of these children. Given the potential for remediation strategies within this domain, neuropsychological assessment can be an integral aspect of long-term care plans of survivors of childhood cancer.

Intellectual development of childhood ALL patients: a multicenter longitudinal study

BACKGROUND

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

PROCEDURE

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

RESULTS

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

CONCLUSION

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

The ability to cross the blood-cerebrospinal fluid barrier is a generic property of acute lymphoblastic leukemia blasts

Prevention of central nervous system (CNS) relapse is critical for cure of childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Despite this, mechanisms of CNS infiltration are poorly understood, and the timing, frequency, and properties of BCP-ALL blasts entering the CNS compartment are unknown. We investigated the CNS-engrafting potential of BCP-ALL cells xenotransplanted into immunodeficient NOD.Cg- ITALIC! Prkdc (ITALIC! scid) ITALIC! Il2rg (ITALIC! tm1Wjl)/SzJ mice. CNS engraftment was seen in 23 of 29 diagnostic samples (79%): 2 of 2 from patients with overt CNS disease and 21 of 27 from patients thought to be CNS negative by diagnostic lumbar puncture. Histologic findings mimic human pathology and demonstrate that leukemic cells transit the blood-cerebrospinal fluid barrier situated close to the dural sinuses, the site of recently discovered CNS lymphatics. Retrieval of blasts from the CNS showed no evidence for chemokine receptor-mediated selective trafficking. The high frequency of infiltration and lack of selective trafficking led us to postulate that CNS tropism is a generic property of leukemic cells. To test this, we performed serial dilution experiments which showed CNS engraftment in 5 of 6 mice after transplant of as few as 10 leukemic cells. Clonal tracking techniques confirmed the polyclonal nature of CNS-infiltrating cells, with multiple clones engrafting in both the CNS and periphery. Overall, these findings suggest that subclinical seeding of the CNS is likely to be present in most BCP-ALL patients at original diagnosis, and efforts to prevent CNS relapse should concentrate on effective eradication of disease from this site rather than targeting entry mechanisms.

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.

Influence of Cranial Radiotherapy on Outcome in Children With Acute Lymphoblastic Leukemia Treated With Contemporary Therapy

PURPOSE

We sought to determine whether cranial radiotherapy (CRT) is necessary to prevent relapse in any subgroup of children with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

We obtained aggregate data on relapse and survival outcomes for 16,623 patients age 1 to 18 years old with newly diagnosed ALL treated between 1996 and 2007 by 10 cooperative study groups from around the world. The proportion of patients eligible for prophylactic CRT varied from 0% to 33% by trial and was not related to the proportion eligible for allogeneic stem-cell transplantation in first complete remission. Using a random effects model, with CRT as a dichotomous covariate, we performed a single-arm meta-analysis to compare event-free survival and cumulative incidence of isolated or any CNS relapse and isolated bone marrow relapse in high-risk subgroups of patients who either did or did not receive CRT.

RESULTS

Although there was significant heterogeneity in all outcome end points according to trial, CRT was associated with a reduced risk of relapse only in the small subgroup of patients with overt CNS disease at diagnosis, who had a significantly lower risk of isolated CNS relapse (4% with CRT v 17% without CRT; P = .02) and a trend toward lower risk of any CNS relapse (7% with CRT v 17% without CRT; P = .09). However, this group had a relatively high rate of events regardless of whether or not they received CRT (32% [95% CI, 26% to 39%] v 34% [95% CI, 19% to 54%]; P = .8).

CONCLUSION

CRT does not have an impact on the risk of relapse in children with ALL treated on contemporary protocols.

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

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

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.

Balancing cure and long-term risks in acute lymphoblastic leukemia

Cure rates for children and adolescents with acute lymphoblastic leukemia (ALL) have improved dramatically over the last few decades. With this success has come increasing recognition of the adverse late effects of treatment. The significant long-term sequelae in the earliest cohort of long-term survivors treated in the 1970s and 1980s are well documented. To reduce the incidence of these late effects, the majority of pediatric patients treated on more contemporary regimens receive less intensive treatment than did those treated 30-40 years ago. However, current therapies are not risk free; children treated with contemporary regimens remain at risk for developing long-term toxicities, including cardiac dysfunction, osteonecrosis, neurocognitive impairment, and second malignant neoplasms. One of the great challenges facing clinical investigators today is to identify interventions that will reduce the frequency and severity of long-term toxicities without adversely affecting cure rates. The use of dexrazoxane as a cardioprotectant (to prevent anthracycline-associated cardiotoxicity) and alternate-week dosing of dexamethasone (to reduce the risk of osteonecrosis) are examples of 2 such successful strategies. This article provides an overview of the long-term toxicities associated with current therapies and reviews results of clinical trials designed to minimize the burden of cure in long-term survivors.

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

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

Rhabdoid tumors: clinical approaches and molecular targets for innovative therapy

Rhabdoid tumors are rare but highly aggressive tumors with a predilection for infants and young children. The majority of these tumors harbor biallelic mutations in SMARCB1/INI1/hSNF5. Rather rare cases with mutations in other SWI/SNF core members such as BRG1 are on record. Rhabdoid tumors have only recently been registered and treated according to specifically designed treatment recommendations and in the framework of clinical trials. Within the last decade, prognosis has improved significantly but at least 50% of patients still relapse and subsequently almost inevitably succumb to their disease. This review summarizes past and current clinical approaches and presents an overview of the rationales for targeted therapy with potential for future clinical treatment trials for rhabdoid tumors.

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.