Prospective External Validation of the Esbenshade Vanderbilt Models Accurately Predicts Bloodstream Infection Risk in Febrile Non-Neutropenic Children With Cancer

PURPOSE

The optimal management of fever without severe neutropenia (absolute neutrophil count [ANC] ≥500/µL) in pediatric patients with cancer is undefined. The previously proposed Esbenshade Vanderbilt (EsVan) models accurately predict bacterial bloodstream infections (BSIs) in this population and provide risk stratification to aid management, but have lacked prospective external validation.

MATERIALS AND METHODS

Episodes of fever with a central venous catheter and ANC ≥500/µL occurring in pediatric patients with cancer were prospectively collected from 18 academic medical centers. Variables included in the EsVan models and 7-day clinical outcomes were collected. Five versions of the EsVan models were applied to the data with calculation of C-statistics for both overall BSI rate and high-risk organism BSI (gram-negative and Staphylococcus aureus BSI), as well as model calibration.

RESULTS

In 2,565 evaluable episodes, the BSI rate was 4.7% (N = 120). Complications for the whole cohort were rare, with 1.1% (N = 27) needing intensive care unit (ICU) care by 7 days, and the all-cause mortality rate was 0.2% (N = 5), with only one potential infection-related death. C-statistics ranged from 0.775 to 0.789 for predicting overall BSI, with improved accuracy in predicting high-risk organism BSI (C-statistic 0.800-0.819). Initial empiric antibiotics were withheld in 14.9% of episodes, with no deaths or ICU admissions attributable to not receiving empiric antibiotics.

CONCLUSION

The EsVan models, especially EsVan2b, perform very well prospectively across multiple academic medical centers and accurately stratify risk of BSI in episodes of non-neutropenic fever in pediatric patients with cancer. Implementation of routine screening with risk-stratified management for non-neutropenic fever in pediatric patients with cancer could safely reduce unnecessary antibiotic use.

An Exome Capture-Based RNA-Sequencing Assay for Genome-Wide Identification and Prioritization of Clinically Important Fusions in Pediatric Tumors

This study reports the development of an exome capture-based RNA-sequencing assay to detect recurring and novel fusions in hematologic, solid, and central nervous system tumors. The assay used Twist Comprehensive Exome capture with either fresh or formalin-fixed samples and a bioinformatic platform that provides fusion detection, prioritization, and downstream curation. A minimum of 50 million uniquely mapped reads, a consensus read alignment/fusion calling approach using four callers (Arriba, FusionCatcher, STAR-Fusion, and Dragen), and custom software were used to integrate, annotate, and rank the candidate fusion calls. In an evaluation of 50 samples, the number of calls varied substantially by caller, from a mean of 24.8 with STAR-Fusion to 259.6 with FusionCatcher; only 1.1% of calls were made by all four callers. Therefore a filtering and ranking algorithm was developed based on multiple criteria, including number of supporting reads, calling consensus, genes involved, and cross-reference against databases of known cancer-associated or likely false-positive fusions. This approach was highly effective in pinpointing known clinically relevant fusions, ranking them first in 47 of 50 samples (94%). Detection of pathogenic gene fusions in three diagnostically challenging cases highlights the importance of a genome-wide and nontargeted method for fusion detection in pediatric cancer.

Lack of benefit from premedication for pegylated asparaginase during pediatric acute lymphoblastic leukemia/lymphoma therapy: A side-by-side comparison

BACKGROUND

Pegylated l-asparaginase (PEG) is integral to treatment regimens for acute lymphoblastic leukemia (ALL) and lymphoma. Hypersensitivity reactions (HSRs) to PEG are common and can preclude continued administration. Data supporting recommendations for universal premedication (UPM) prior to PEG infusion to reduce incidence of HSRs are limited; UPM has become common practice.

PROCEDURES

Two free-standing children's hospitals independently implemented UPM prior to PEG infusions in 2016 and 2019, respectively. In a side-by-side retrospective analysis, incidence and severity of HSRs were analyzed pre- and postimplementation of UPM in youth ≥1 years old treated with frontline PEG-containing ALL regimens (2015-2018, 2016-2020). All HSRs were centrally reviewed within each institution to confirm and grade the HSR (Common Terminology Criteria for Adverse Events, v5). Planned analyses of subsets at potentially greater risk for HSRs included intensive PEG regimens (≥5 doses), adolescent and young adults (AYA), Hispanic/Latinx ethnicity, and obesity.

RESULTS

In 410 patients (by institution, n = 282 and n = 128), the overall incidence of Grade ≥ 3 HSRs was 20% (56 out of 282) and 18% (23 out of 128), respectively. No difference in incidence of Grade ≥ 3 HSRs in patients with versus without UPM was found at either institution (23 vs. 19%, p = .487 and 19 vs. 17%, p = .845). UPM also did not reduce the severity of HSRs, nor influence HSR risk within any patient subset.

CONCLUSIONS

UPM prior to PEG infusion did not alter incidence or severity of HSRs at either institution. HSR remains a common complication of PEG therapy, impacting the patient experience. Alternative strategies to reduce HSRs are urgently required.

Apixaban versus no anticoagulation for the prevention of venous thromboembolism in children with newly diagnosed acute lymphoblastic leukaemia or lymphoma (PREVAPIX-ALL): a phase 3, open-label, randomised, controlled trial

BACKGROUND

Paediatric patients with acute lymphoblastic leukaemia or lymphoma are at increased risk of venous thromboembolism resulting in increased mortality and morbidity. We hypothesised that apixaban, a direct oral anticoagulant, would safely reduce venous thromboembolism in this patient population.

METHODS

PREVAPIX-ALL was a phase 3, open-label, randomised, controlled trial conducted in 74 paediatric hospitals in 9 countries. Participants aged 1 year or older to younger than 18 years with newly diagnosed acute lymphoblastic leukaemia (pre-B cell or T cell) or lymphoblastic lymphoma (B cell or T cell immunophenotype) and a central venous line in place throughout induction were randomly assigned 1:1 to standard of care (SOC, ie, no systemic anticoagulation) or weight-adjusted twice-daily apixaban during induction. Randomisation was performed centrally and stratified by age (those <10 years or those ≥10 years). Participants weighing 35 kg or less were administered 2·5 mg twice daily of apixaban as a 2·5 mg tablet, 0·5 mg tablets, or 0·4 mg/mL oral solution, while those weighing more than 35 kg were administered weight-adjusted prophylactic doses using 0·5 mg tablets or the 0·4 mg/mL oral solution twice daily. Primary outcomes were assessed by a blinded central adjudication committee. The primary efficacy outcome for the intention to treat population was the composite of symptomatic or clinically unsuspected venous thromboembolism, the primary safety outcome was major bleeding, and secondary safety outcomes included clinically relevant non-major (CRNM) bleeding. Patients were screened for venous thromboembolism by ultrasound and echocardiogram at the end of induction. The trial was registered with ClinicalTrials.gov (NCT02369653) and is now complete.

FINDINGS

Between Oct 22, 2015, and June 4, 2021, 512 participants were randomly assigned and included in analyses (222 [43%] female and 290 [57%] male; 388 [76%] White, 52 [10%] Asian, 24 [5%] Black or African American, and 48 [9%] other races; and 122 [24%] Hispanic or Latino ethnicity). During a median follow-up period of 27 days (IQR 26-28), 31 (12%) of 256 patients on apixaban had a composite venous thromboembolism compared with 45 (18%) of 256 participants receiving SOC (relative risk [RR] 0·69, 95% CI 0·45-1·05; p=0·080). Two major bleeding events occurred in each group (RR 1·0, 95% CI 0·14-7·01; p=1·0). A higher incidence of CRNM bleeding, primarily grade 1 or 2 epistaxis, occurred in the apixaban group (11 [4%] of 256 participants) compared with the SOC group (3 [1%] of 256; RR 3·67, 95% CI 1·04-12·97, p=0·030). The most frequent grade 3-5 adverse events in both groups were thrombocytopenia (n=28 for the apixaban group and n=20 for the SOC group) or platelet count decreased (n=49 and n=45), anaemia (n=77 and n=74), febrile neutropenia (n=27 and n=20), and neutropenia (n=16 and n=17) or neutrophil count decreased (n=22 and n=25). Five deaths occurred, which were due to infection (n=3 in the SOC group), cardiac arrest (n=1 in apixaban group), and haemorrhagic cerebral sinus vein thrombosis (n=1 in the SOC group). There was one apixaban-related death (coagulopathy and haemorrhage after cardiac arrest of unknown cause).

INTERPRETATION

PREVAPIX-ALL is, to our knowledge, the first trial assessing primary thromboprophylaxis using a direct oral anticoagulant in paediatric patients with acute lymphoblastic leukaemia or lymphoma. No statistically significant treatment benefit was identified in participants receiving apixaban. Major and CRNM bleeding were infrequent overall, but a higher incidence of CRNM bleeding (primarily epistaxis in younger children) occurred in participants receiving apixaban. For patients deemed to be at particularly high risk of thrombosis, PREVAPIX-ALL provides encouraging safety data for the use of apixaban in clinical settings in which the potential benefits are thought to outweigh the risk of bleeding.

FUNDING

Bristol Myers Squibb-Pfizer Alliance.

Dose-limiting mucositis: friend or foe?

Dose-limiting toxicities are ubiquitous to cancer-directed therapy, presenting with severity to a degree that necessitates therapy de-escalation, pause, or discontinuation. To date, there is incredible limited understanding if these therapy de-escalations present risk for survival by limiting delivery of intensive therapy, or if they indicate physiologic susceptibility and are a favorable prognostic indicator. Mucositis is an excellent illustration of the current paradox of dose-limiting toxicities-it has existed alongside therapy for eight decades, but despite its presence, there is an incomplete understanding of how it develops, why it varies between oncologic populations, and if it relates to cancer survival. Rigorous methodologic approaches in symptom science holds potential to better understand mucositis, to determine if it is a marker of response or threat, and evaluate if it holds potential to guide therapy delivery.

Reevaluation of sodium thiosulfate otoprotection using the consensus International Society of Paediatric Oncology Ototoxicity Scale: A report from the Children's Oncology Group study ACCL0431

In two randomized trials (Children's Oncology Group ACCL0431 and International Childhood Liver Tumour Strategy Group SIOPEL-6), sodium thiosulfate (STS) demonstrated efficacy in preventing cisplatin-induced hearing loss (CIHL). However, the measures used in those trials have been superseded by the consensus International Society of Paediatric Oncology (SIOP) Ototoxicity Scale. To provide benchmark data for STS efficacy when using this contemporary scale, we reanalyzed ACCL0431 hearing outcomes with the SIOP scale and using multiple timepoints. Compared to the control arm, STS significantly reduced CIHL when assessed by the SIOP scale across these different approaches. These results provide critical data to inform treatment discussions and support future potential trial designs comparing otoprotectants.

Intravenous N-Acetylcysteine to Prevent Cisplatin-Induced Hearing Loss in Children: A Nonrandomized Controlled Phase I Trial

PURPOSE

Cisplatin-induced hearing loss (CIHL) is common and permanent. As compared with earlier otoprotectants, we hypothesized N-acetylcysteine (NAC) offers potential for stronger otoprotection through stimulation of glutathione (GSH) production. This study tested the optimal dose, safety, and efficacy of NAC to prevent CIHL.

PATIENTS AND METHODS

In this nonrandomized, controlled phase Ia/Ib trial, children and adolescents newly diagnosed with nonmetastatic, cisplatin-treated tumors received NAC intravenously 4 hours post-cisplatin. The trial performed dose-escalation across three dose levels to establish a safe dose that exceeded the targeted peak serum NAC concentration of 1.5 mmol/L (as identified from preclinical models). Patients with metastatic disease or who were otherwise ineligible were enrolled in an observation-only/control arm. To evaluate efficacy, serial age-appropriate audiology assessments were performed. Integrated biology examined genes involved in GSH metabolism and post-NAC GSH concentrations.

RESULTS

Of 52 patients enrolled, 24 received NAC and 28 were in the control arm. The maximum tolerated dose was not reached; analysis of peak NAC concentration identified 450 mg/kg as the recommended phase II dose (RP2D). Infusion-related reactions were common. No severe adverse events occurred. Compared with the control arm, NAC decreased likelihood of CIHL at the end of cisplatin therapy [OR, 0.13; 95% confidence interval (CI), 0.021-0.847; P = 0.033] and recommendations for hearing intervention at end of study (OR, 0.082; 95% CI, 0.011-0.60; P = 0.014). NAC increased GSH; GSTP1 influenced risk for CIHL and NAC otoprotection.

CONCLUSIONS

NAC was safe at the RP2D, with strong evidence for efficacy to prevent CIHL, warranting further development as a next-generation otoprotectant.

Symptom management care pathway adaptation process and specific adaptation decisions

BACKGROUND

There is substantial heterogeneity in symptom management provided to pediatric patients with cancer. The primary objective was to describe the adaptation process and specific adaptation decisions related to symptom management care pathways based on clinical practice guidelines. The secondary objective evaluated if institutional factors were associated with adaptation decisions.

METHODS

Fourteen previously developed symptom management care pathway templates were reviewed by an institutional adaptation team composed of two clinicians at each of 10 institutions. They worked through each statement for all care pathway templates sequentially. The institutional adaptation team made the decision to adopt, adapt or reject each statement, resulting in institution-specific symptom management care pathway drafts. Institutional adaption teams distributed the 14 care pathway drafts to their respective teams; their feedback led to care pathway modifications.

RESULTS

Initial care pathway adaptation decision making was completed over a median of 4.2 (interquartile range 2.0-5.3) weeks per institution. Across all institutions and among 1350 statements, 551 (40.8%) were adopted, 657 (48.7%) were adapted, 86 (6.4%) were rejected and 56 (4.1%) were no longer applicable because of a previous decision. Most commonly, the reason for rejection was not agreeing with the statement (70/86, 81.4%). Institutional-level factors were not significantly associated with statement rejection.

CONCLUSIONS

Acceptability of the 14 care pathways was evident by most statements being adopted or adapted. The adaptation process was accomplished over a relatively short timeframe. Future work should focus on evaluation of care pathway compliance and determination of the impact of care pathway-consistent care on patient outcomes.

TRIAL REGISTRATION

clinicaltrials.gov, NCT04614662. Registered 04/11/2020, https://clinicaltrials.gov/ct2/show/NCT04614662?term=NCT04614662&draw=2&rank=1 .

Special considerations in the design and implementation of pediatric otoprotection trials

PURPOSE

Cisplatin-induced hearing loss (CIHL) is a common late effect after childhood cancer treatment having profound, lifelong consequences that lower quality of life. The recent identification of intravenous sodium thiosulfate (STS) as an effective agent for preventing pediatric CIHL represents a paradigm shift that has created new opportunities for expanding STS usage and developing additional otoprotectants. The purpose of this paper is to discuss key considerations and recommendations for the design and implementation of future pediatric otoprotection trials.

METHODS

An approach synthesizing published data and collective experience was used.

RESULTS

Key issues were identified in the categories of translational research, trial designs for systemic and intratympanic agents, measurement of ototoxicity, and biostatistical challenges.

CONCLUSIONS

Future pediatric otoprotection trials should emphasize (1) deep integration of preclinical and early-phase studies; (2) an embedded or free-standing design for systemic agents based on mechanistic considerations; (3) use of suitable audiologic testing batteries for children, SIOP grading criteria, and submission of raw audiologic data for central review; and (4) novel endpoints and innovative study designs that maximize trial efficiency for limited sample sizes. Additional recommendations include routine collection of DNA specimens for assessing modifying effects of genetic susceptibility and meaningful inclusion of patient/family advocates for informing trial development.

IMPLICATIONS FOR CANCER SURVIVORS

Changing the historical paradigm from acceptance to prevention of pediatric CIHL through expanded research with existing and emerging otoprotectants will dramatically improve quality of life for future childhood cancer survivors exposed to cisplatin.

Asparaginase toxicity in Hispanic adult and pediatric patients with acute lymphoblastic leukemia: current understanding

INTRODUCTION

Asparaginase is essential to chemotherapy regimens for acute lymphoblastic leukemia (ALL). Survival of patients with ALL has improved since incorporating asparaginase into chemotherapy backbones. Hispanic patients have a higher incidence of ALL than other ethnicities and suffer inferior outcomes. The inferior outcome of Hispanics is due to several factors, including the increased incidence of high-risk genetic subtypes and susceptibility to treatment-related toxicity.

AREAS COVERED

We summarize the current knowledge of asparaginase-related toxicity by comparing their incidence between Hispanic and non-Hispanic patients. These toxicities include hypersensitivity, hepatotoxicity, pancreatitis, thrombosis, and hypertriglyceridemia. The PubMed database and Google Scholar were used to search for this review from October 2022 to June 2023.

EXPERT OPINION

Except for hepatotoxicity and hypertriglyceridemia secondary to asparaginase-based treatments, which may develop more frequently among Hispanic patients with ALL, other toxicities were comparable between Hispanic and non-Hispanic patients. Nevertheless, studies with larger cohorts and more accurate capturing of Hispanic ethnicity should be conducted to fill the gaps in the current knowledge.

QOL-13. Impact of hearing loss on neuropsychological functioning in children treated for medulloblastoma: A report from the Children’s Oncology Group (COG)

BACKGROUND/OBJECTIVE: We prospectively examined neuropsychological outcomes and ototoxicity in children with average-risk medulloblastoma. METHODS: Eligible patients included those treated on COG protocol ACNS0331 who completed audiograms at end of therapy or one-year off-therapy, and neuropsychological assessments between 2- and 5-years post-diagnosis. Conventional pure-tone audiometric evaluations (0.25-8kHz) were assigned an ototoxicity grade based on the International Society of Pediatric Oncology (SIOP) grading scale. Grade for the better hearing ear was used for analyses. Participants were divided into two groups: SIOP grade≥3 hearing loss (HL) versus SIOP grade<3. Cutoff score of 60 on BASC-2 was used to dichotomize parent-reported anxiety and depression scores as ‘low’ or ‘high’. RESULTS: Data were available for 113 children (66% male; 86% white), aged 3.0-18.5 at diagnosis (Mean=9.1). One-quarter (24.8%, n=28) had at least moderate HL (≥ SIOP grade 2), and 12.3% (n=14) had severe HL (≥ SIOP grade 3). After controlling for radiation exposure and age, children with severe HL showed significantly higher levels of anxiety (OR=5.9, 95%CI 1.3-26.0, p=0.0195) and borderline differences in depression (OR=4.0, 95%CI 1.0-16.5, p=0.0563), but no differences in cognitive functioning when compared to other participants. When moderate and severe HL were combined in exploratory analyses, significantly greater anxiety (OR=9.0, 95%CI 2.1-37.4, p=.0027) and depression (OR=4.6, 95%CI 1.3-15.7, p=.0165) were observed. CONCLUSIONS: Survivors of pediatric medulloblastoma with moderate to severe HL evidenced greater psychosocial, but not neurocognitive, difficulties compared to those with no or mild HL. It may be that modern treatment protocols generally preserve cognitive functioning such that associations between HL and cognitive impairment are no longer significant. It is also possible that neurocognitive risk associated with HL may not manifest until survivors are further from diagnosis. In contrast, survivors with HL may be at greater risk for negative psychosocial adjustment, suggesting that increased monitoring of mental health outcomes is warranted.

Effects of age, obesity, and body surface area on asparaginase-associated toxicities during acute lymphoblastic leukemia induction therapy: A report from the Children’s Oncology Group

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Background: Asparaginase is integral to pediatric-inspired regimens (PIR) to treat acute lymphoblastic leukemia (ALL) in adolescents and young adults (AYA). However, asparaginase-associated toxicities (AAT) often preclude delivery of planned therapy. Older age, obesity and/or large body surface area (BSA) have been associated with higher risk of AAT in PIR, but data are conflicting, and the impact of dose modification based on these factors is unknown. Methods: We examined induction toxicity data from patients ages 1-30 years enrolled in the frontline Children’s Oncology Group (COG) trials for high-risk B-ALL (AALL0232, 2004-2011) and T-ALL (AALL0434, 2007-2014). During Induction, patients received pegaspargase (2,500 IU/m2 without prescribed dose-capping) plus daunorubicin, vincristine, and prednisone or dexamethasone. AAT were defined as CTCAE v4 hyperbilirubinemia (Grade ≥3), elevated alanine aminotransferase (ALT) (Grade ≥4), thrombosis (any), or pancreatitis (any, included consolidation phase). Obesity was classified using population norms as body mass index (BMI) ≥30 (or ≥95th percentile for age/sex). BSA was analyzed continuously and dichotomized at 1.5 m2 (equivalent to pegaspargase 3,750 IU, the threshold for permissible dose-capping in PIR). The association of AAT with end-Induction minimal residual disease (MRD) ≥0.01% was assessed. Results: Among 4,925 patients, 25% were ≥15 years, 39% had BSA >1.5m2, and 18% had obesity. Multivariable logistic analyses inclusive of BMI and BSA together found increased risk for any AAT in age groups ≥10 years (10-15y, odds ratio (OR) 2.0, 15-20y OR 2.2, ≥21 OR 3.3, p=0.002). Only patients with both obesity and high BSA (>1.5m2) were at additional risk (OR 3.3, p<0.0001). Similarly, risks for hyperbilirubinemia, ALT elevations, and thrombosis were increased in patients with both high BSA and obesity (OR 3.5, 95% confidence interval [CI] 2.2-5.7), OR 3.3, 95%CI 1.7-6.6, and OR 3.1 95%CI 1.5-6.5, respectively), but not in those with high BSA without obesity. The risk of hyperbilirubinemia was greater with increasing obesity (p<0.0001) and was also higher in all age groups ≥10 years (OR 6.3-7.9, p<0.0001). Age was not associated with thrombosis or ALT elevation; risk for pancreatitis was associated with Hispanic ethnicity, but not with age, BMI, or BSA. AAT were not associated with pooled trial MRD ≥0.01%. Conclusions: We report here the largest dataset of AAT in children and AYAs receiving ALL Induction therapy without routinely prescribed dose-capping of pegaspargase. Risk for AAT was increased in patients >10 years and in those with obesity, but not high BSA alone. Dose capping may not be necessary for children and AYAs with high BSA without obesity. Prospective studies of AAT pharmacogenomics and modifiable risk factors will support safer dosing in PIR. Clinical trial information: NCT00075725, NCT00408005.

Temsirolimus combined with cyclophosphamide and etoposide for pediatric patients with relapsed/refractory acute lymphoblastic leukemia: a Therapeutic Advances in Childhood Leukemia Consortium trial (TACL 2014-001)

Phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling is commonly dysregulated in acute lymphoblastic leukemia (ALL). The TACL2014-001 phase I trial of the mTOR inhibitor temsirolimus in combination with cyclophosphamide and etoposide was performed in children and adolescents with relapsed/refractory ALL. Temsirolimus was administered intravenously (IV) on days 1 and 8 with cyclophosphamide 440 mg/m2 and etoposide 100 mg/m2 IV daily on days 1-5. The starting dose of temsirolimus was 7.5 mg/m2 (DL1) with escalation to 10 mg/m2 (DL2), 15 mg/m2 (DL3), and 25 mg/m2 (DL4). PI3K/mTOR pathway inhibition was measured by phosphoflow cytometry analysis of peripheral blood specimens from treated patients. Sixteen heavily-pretreated patients were enrolled with 15 evaluable for toxicity. One dose-limiting toxicity of grade 4 pleural and pericardial effusions occurred in a patient treated at DL3. Additional dose-limiting toxicities were not seen in the DL3 expansion or DL4 cohort. Grade 3/4 non-hematologic toxicities occurring in three or more patients included febrile neutropenia, elevated alanine aminotransferase, hypokalemia, mucositis, and tumor lysis syndrome and occurred across all doses. Response and complete were observed at all dose levels with a 47% overall response rate and 27% complete response rate. Pharmacodynamic correlative studies demonstrated dose-dependent inhibition of PI3K/mTOR pathway phosphoproteins in all studied patients. Temsirolimus at doses up to 25 mg/m2 with cyclophosphamide and etoposide had an acceptable safety profile in children with relapsed/refractory ALL. Pharmacodynamic mTOR target inhibition was achieved and appeared to correlate with temsirolimus dose. Future testing of next-generation PI3K/mTOR pathway inhibitors with chemotherapy may be warranted to increase response rates in children with relapsed/refractory ALL.

Levocarnitine for pegaspargase-induced hepatotoxicity in older children and young adults with acute lymphoblastic leukemia

Background

Pegaspargase (PEG‐ASP) is an integral component of therapy for acute lymphoblastic leukemia (ALL) but is associated with hepatotoxicity that may delay or limit future therapy. Obese and adolescent and young adult (AYA) patients are at high risk. Levocarnitine has been described as potentially beneficial for the treatment or prevention of PEG‐ASP‐associated hepatotoxicity.

Methods

We collected data for patients age ≥10 years who received levocarnitine during induction therapy for ALL, compared to a similar patient cohort who did not receive levocarnitine. The primary endpoint was conjugated bilirubin (c.bili) >3 mg/dl. Secondary endpoints were transaminases >10× the upper limit of normal and any Grade ≥3 hepatotoxicity.

Results

Fifty‐two patients received levocarnitine for prophylaxis (n = 29) or rescue (n = 32) of hepatotoxicity. Compared to 109 patients without levocarnitine, more patients receiving levocarnitine were obese and/or older and had significantly higher values for some hepatotoxicity markers at diagnosis and after PEG‐ASP. Levocarnitine regimens varied widely; no adverse effects of levocarnitine were identified. Obesity and AYA status were associated with an increased risk of conjugated hyperbilirubinemia and severe transaminitis. Multivariable analysis identified a protective effect of levocarnitine on the development of c.bili >3 mg/dl (OR 0.12, p = 0.029). There was no difference between groups in CTCAE Grade ≥3 hepatotoxicity. C.bili >3 mg/dl during induction was associated with lower event‐free survival.

Conclusions

This real‐world data on levocarnitine supplementation during ALL induction highlights the risk of PEG‐ASP‐associated hepatotoxicity in obese and AYA patients, and hepatotoxicity's potential impact on survival. Levocarnitine supplementation may be protective, but prospective studies are needed to confirm these findings.

A Meta-analysis of the Utility of Red Cell Distribution Width as a Biomarker to Predict Outcomes in Pediatric Illness (PROSPERO CRD42020208777)

Red cell distribution width (RDW) is an average of the variation in red blood cell (RBC) sizes reported on a complete blood count. An elevated RDW indicates a pathological process that is affecting erythropoiesis. Studies showed that as the severity of disease process increases, the RDW often increases as well. Particularly in resource-limited countries, RDW has been studied as an outcome predictor for conditions in a variety of disciplines and is offered as an adjunct monitoring tool that is cost effective, readily available, and indicative of pathological processes amenable to intervention. Particularly in pediatric critical care settings, RDW has been shown to be a reliable tool for surveillance of disease states such as sepsis. Despite the increased attention of RDW as a marker for disease outcome, collective evaluation on the utility of RDW as a marker for outcome in pediatric critical care settings is lacking. We offer a systematic review and meta-analysis of published studies to assess the ability of RDW to predict illness severity and mortality among pediatric critical care patients. Among eight studies of over 4,800 patients, we found over a two-fold increase in odds for mortality in critically ill children whose RDW was above 15.7%. This is the first systematic review of RDW being used to predict mortality in critically ill children and findings of this study may prompt early intervention in the pediatric critical care setting.

Ultra-High Dose Vitamin D in Pediatric Hematopoietic Stem Cell Transplantation: A Nonrandomized Controlled Trial

Vitamin D is essential for bone health and has immunomodulatory properties. Most pediatric patients are vitamin D insufficient (<30 ng/mL) before hematopoietic stem cell transplantation (HSCT). Standard supplementation strategies fail to achieve vitamin D sufficiency in the acute post-transplantation period, and there are scarce data to support optimal vitamin D supplementation in this patient population. This study aimed to evaluate whether a single, oral, weight-based ultra-high dose of vitamin D (Stoss dosing) was more effective than standard supplementation to achieve pre-HSCT vitamin D sufficiency and reduce the incidence of HSCT-related complications (acute graft-versus-host disease, veno-occlusive disease, and/or transplant-associated thrombotic microangiopathy) that are associated with immune-mediated endothelial damage. Secondary endpoints examined the immunomodulatory properties of vitamin D. We conducted a nonrandomized controlled clinical trial of Stoss-dosed vitamin D in pediatric patients receiving HSCT. The study prospectively enrolled 33 patients, 29 of whom successfully received Stoss-dosed vitamin D and were compared to 136 patients in a historical control. Patient characteristics were compared using Fisher's exact test or t-test. The one-sided Fisher's exact test was used for cohort comparison of the primary endpoints. Logistic regression was used to examine the association between patient-specific factors and total 25-hydroxy vitamin D (25-OHD) levels and the compiled HSCT complications. In the Stoss cohort, 97% (n = 28/29) of patients achieved pre-HSCT vitamin D sufficiency compared to 67% (n = 10/15) of patients in the historical control who were on standard supplementation at the time the total 25-OHD level was assessed (P = .013). The mean total 25-OHD level in the Stoss cohort was significantly higher than patients in the historical control who received standard supplementation (72.2 ng/mL versus 35.8 ng/mL, P < .001). Nine patients in the Stoss cohort maintained vitamin D sufficiency throughout the first 100 days after HSCT, and the remaining 19 patients maintained sufficiency for a median of 63 days (range 6-105 days) from the Stoss dose. Patients receiving Stoss-dosed vitamin D developed a lower combined incidence of HSCT-related complications than the historical control (25% [n = 7/28] versus 42% [n = 57/136], P = .055). After Stoss dosing, immunophenotyping studies found a significant decrease in subsets of CD8+ T cells and mononuclear cells (P = .040 and.013, respectively), and, in a subset of cells, larger decreases in phosphoprotein expression were seen with greater increases in total 25-OHD levels. Inflammatory cytokines did not change significantly after Stoss dosing. Stoss dosing is therefore a safe and effective approach to maintain vitamin D sufficiency in the immediate post-HSCT period and may be associated with decreased HSCT-related complications. Randomized studies are warranted to further investigate the efficacy of Stoss-dosed vitamin D to improve bone health and reduce complications in pediatric patients receiving HSCT.

Adipocytes Provide Fatty Acids to Acute Lymphoblastic Leukemia Cells

Background

There is increasing evidence that adipocytes play an active role in the cancer microenvironment. We have previously reported that adipocytes interact with acute lymphoblastic leukemia (ALL) cells, contributing to chemotherapy resistance and treatment failure. In the present study, we investigated whether part of this resistance is due to adipocyte provision of lipids to ALL cells.

Methods

We cultured 3T3-L1 adipocytes, and tested whether ALL cells or ALL-released cytokines induced FFA release. We investigated whether ALL cells took up these FFA, and using fluorescent tagged BODIPY-FFA and lipidomics, evaluated which lipid moieties were being transferred from adipocytes to ALL. We evaluated the effects of adipocyte-derived lipids on ALL cell metabolism using a Seahorse XF analyzer and expression of enzymes important for lipid metabolism, and tested whether these lipids could protect ALL cells from chemotherapy. Finally, we evaluated a panel of lipid synthesis and metabolism inhibitors to determine which were affected by the presence of adipocytes.

Results

Adipocytes release free fatty acids (FFA) when in the presence of ALL cells. These FFA are taken up by the ALL cells and incorporated into triglycerides and phospholipids. Some of these lipids are stored in lipid droplets, which can be utilized in states of fuel deprivation. Adipocytes preferentially release monounsaturated FFA, and this can be attenuated by inhibiting the desaturating enzyme steroyl-CoA decarboxylase-1 (SCD1). Adipocyte-derived FFA can relieve ALL cell endogenous lipogenesis and reverse the cytotoxicity of pharmacological acetyl-CoA carboxylase (ACC) inhibition. Further, adipocytes alter ALL cell metabolism, shifting them from glucose to FFA oxidation. Interestingly, the unsaturated fatty acid, oleic acid, protects ALL cells from modest concentrations of chemotherapy, such as those that might be present in the ALL microenvironment. In addition, targeting lipid synthesis and metabolism can potentially reverse adipocyte protection of ALL cells.

Conclusion

These findings uncover a previously unidentified interaction between ALL cells and adipocytes, leading to transfer of FFA for use as a metabolic fuel and macromolecule building block. This interaction may contribute to ALL resistance to chemotherapy, and could potentially be targeted to improve ALL treatment outcome.

Association of body mass index with toxicity and survival in pediatric patients treated with cisplatin-containing regimens

Malnutrition is associated with treatment-related toxicities (TRT) in adults with solid tumors and in children with leukemia. Few studies have assessed whether malnutrition in pediatric patients treated for solid tumors impacts risk for TRT, relapse, and/or survival. To address this knowledge gap, this retrospective study evaluated the association between body mass index (BMI) at diagnosis, and imputed BMI during therapy, on the prevalence of TRT, specific toxicities, relapse, and survival in pediatric patients with solid tumors treated with cisplatin-containing regimens. Kaplan-Meier curves and regression models evaluated the association between patient-specific characteristics (including BMI) and TRT, relapse, and survival. The cohort included 221 patients, of whom 22% were malnourished at diagnosis (10% were underweight and 12% were obese). Most patients (60%) experienced at least one severe TRT, and 30% developed more than one severe TRT. Most patients with obesity at diagnosis remained obese during therapy (62%). In multivariable analysis, obesity at diagnosis was significantly associated with a more than threefold greater risk for developing severe TRT (p = 0.037), specifically for acute or chronic kidney injury (p = 0.014). Obesity at diagnosis and adolescent and young adult age (≥15 years at diagnosis) were associated with worse event-free survival (hazard ratio [HR] 2.32, p = 0.024 and HR 2.28, p = 0.010, respectively) and overall survival (HR 3.69, p = 0.006 and HR 2.6, p = 0.012, respectively). Obese and older patients therefore constitute populations at risk for poorer outcomes. Prospective studies are warranted to gain further insight into the mechanism and role of obesity and adolescence in developing TRT and/or treatment failure.

Hearing Loss Risk in Pediatric Patients Treated with Cranial Irradiation and Cisplatin-Based Chemotherapy

PURPOSE

Cranial radiation therapy (RT) and cisplatin-based chemotherapy are essential to treating many pediatric cancers but cause significant ototoxicity. The objective of this study is to determine the relationship between the RT dose and the risk of subsequent hearing loss in pediatric patients treated with cisplatin.

METHODS AND MATERIALS

This retrospective study of cisplatin-treated pediatric patients examined ototoxicity from cranial RT. Ototoxicity was graded for each ear according to the International Society of Pediatric Oncology (SIOP) consensus ototoxicity scale. The RT dose to the cochlea was calculated using the mean, median, maximum, and minimum dose received to determine the most predictive parameter for hearing loss. Multivariable logistic regression models then examined risk factors for hearing loss.

RESULTS

In 96 children (161 ears) treated with RT + cisplatin, the minimum cochlear RT dose was most predictive of hearing loss. A higher cochlear RT dose was associated with increased hearing loss (odds ratio per 10 Gy dose increase = 1.64; P = .043), with an added risk in those receiving an autologous bone marrow transplantation (hazard ratio = 10.47; P < .001).

CONCLUSIONS

This research supports further testing of the minimum cochlear RT dose as a more predictive dose parameter for risk of ototoxicity. The cochlear RT dose was additive to the risk of hearing loss from underlying cisplatin-based chemotherapy. Exposure to autologous bone marrow transplantation was the strongest predictor of developing hearing loss, placing these children at particularly high risk for hearing loss across all cochlear doses. Future prospective studies are crucial to further inform RT dose thresholds and minimize the risk of hearing loss in childhood cancer survivors.

Prevalence and risk factors for cisplatin-induced hearing loss in children, adolescents, and young adults: a multi-institutional North American cohort study

BACKGROUND

Cisplatin is used to treat a wide range of childhood cancers and cisplatin-induced hearing loss (CIHL) is a common and debilitating toxicity. We aimed to address persistent knowledge gaps in CIHL by establishing benchmarks for the prevalence of and risk factors for CIHL.

METHODS

In this multi-institutional cohort study, children (age 0-14 years), adolescents, and young adults (age 15-39 years) diagnosed with a cisplatin-treated tumour from paediatric cancer centres, who had available cisplatin dosing information, and primary audiology data for central review from consortia located in Canada and the USA were eligible for inclusion. Audiology was centrally reviewed and CIHL graded using the consensus International Society of Pediatric Oncology (SIOP) Boston Ototoxicity Scale. We assessed the prevalence of moderate or severe CIHL (SIOP grade ≥2) at latest follow-up and end of therapy, in each demographic, diagnosis, and treatment group and their relative contributions to risk for CIHL. Secondary endpoints explored associations of cisplatin dose reductions and CIHL with survival. We also examined whether cisplatin dose reductions and CIHL were associated with survival outcomes.

FINDINGS

We included 1481 patients who received cisplatin. Of the 1414 (95·5%) participants who had audiometry at latest follow-up (mean 3·9 years [SD 4·2] since diagnosis), 620 (43·8%) patients developed moderate or severe CIHL. The highest prevalence of CIHL was seen in the youngest patients (aged <5 years; 360 [59·4%] of 606 patients) and those with a CNS tumour (221 [50·9%] of 434 patients), hepatoblastoma (110 [65·9%] of 167 patients), or neuroblastoma (154 [62·1%] of 248 patients). After accounting for cumulative cisplatin dose, higher fractionated doses were associated with risk for CIHL (for each 10mg/m² increase per day, adjusted odds ratio [aOR] 1·15 [95% CI 1·07-1·25]; for each 50 mg/m² increase per cycle aOR 2·16 [1·37-3·51]). Vincristine exposure was newly identified as a risk factor for CIHL (aOR 3·55 [2·19-5·84]). Dose reductions and moderate or severe CIHL were not significantly associated with survival differences.

INTERPRETATION

Using this large, multicentre cohort, benchmarks were established for the prevalence of CIHL in patients treated with cisplatin. Variations in cisplatin dosing confer additive risk for developing CIHL and warrant investigation as a potential approach to decrease the burden of therapy.

FUNDING

US National Institutes of Health and National Institute on Deafness and Other Communication Disorders, US National Institutes of Health and National Cancer institute, St Baldrick's Foundation, Genome Canada, Genome British Columbia, Canadian Institutes of Health Research, the Canada Foundation for Innovation, University of British Columbia, British Columbia Children's Hospital Research Institute, British Columbia Provincial Health Services Authority, Health Canada, and C17 Research Network.

Mixed Phenotype Acute Leukemia: Current Approaches to Diagnosis and Treatment

PURPOSE OF REVIEW

Mixed phenotype acute leukemia (MPAL) is a rare subtype of acute leukemia with features of both acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). The review examines current definitions and controversies in classification of MPAL, new insights into genomic drivers and pathogenesis, recent evidence to support treatment recommendations, and opportunities for future research.

RECENT FINDINGS

Recent collaborative efforts have made progress in understanding the genomic landscape and optimal therapy for MPAL. The preponderance of retrospective data supports beginning therapy with ALL directed regimens. Differences in prognosis for adult and children with MPAL have led to divergent approaches for therapy intensity, including use of stem cell transplantation consolidation. MPAL remains a challenging leukemia to understand, research, and treat due to low incidence, shifting and subjective approaches to classification, and innate biological heterogeneity. Ongoing research hopes to surmount these obstacles through prospective studies within large cooperative groups to provide new insight into targetable biology and further refine optimal therapy.

Effect of Body Fat on Population Pharmacokinetics of High-Dose Methotrexate in Pediatric Patients With Acute Lymphoblastic Leukemia

Nearly all international regimens for pediatric acute lymphoblastic leukemia (ALL) incorporate intravenous "high-dose" methotrexate (HDMTX, ≥1 g/m² ) to penetrate the central nervous system. Dosing is routinely adjusted for body surface area (BSA), but limited data describe the pharmacokinetics of HDMTX, particularly in obese and/or large patients. To understand the impact of body size (BSA) and body fat percentage (BFP) on HDMTX pharmacokinetics, we performed a secondary analysis of 36 children and adolescents 10-21 years old treated for newly diagnosed ALL and who were enrolled in a prospective study examining body composition. All patients received 5 g/m² of HDMTX infused over 24 hours. Plasma methotrexate concentrations were measured at 24, 42, and 48 hours. At 48 hours, ≥0.4 μmol/L was defined as "delayed elimination," necessitating prolonged supportive care. BFP was measured using dual-energy x-ray absorptiometry. A nonparametric population pharmacokinetic model was constructed with subsequent simulations to explore effects of BSA and BFP extremes. Despite standard BSA-adjusted dosing, we found significant intrapatient variability in mean MTX concentration (38%; range, 1.2%-86%). BSA and BFP were not linearly associated with increased area under the curve (AUC, P = 0.74 and P = 0.12), but both larger size (BSA) and greater obesity (BFP) were associated with an approximately 2-fold higher risk for delayed elimination at 48 hours. HDMTX AUC was not associated with toxicity. MTX pharmacokinetics vary among and even within patients despite BSA-adjusted dosing. Obesity and large size are identified as new risk factors for delayed elimination, requiring further investigation.

Assessment of provider perspectives on otoprotection research for children and adolescents: A Children's Oncology Group Cancer Control and Supportive Care Committee survey

BACKGROUND

Cisplatin-induced hearing loss (CIHL) is a common and debilitating toxicity for childhood cancer survivors. Understanding provider perspectives is crucial to developing otoprotection studies that are both informative and feasible. Two international trials (ACCL0431 and SIOPEL6) investigated the drug sodium thiosulfate (STS) as an otoprotectant, but definitive interpretation of the findings of these trials has been challenging. Adoption of STS has therefore been uneven, and provider perspectives on its role are unknown.

PROCEDURE

The Children's Oncology Group (COG) Cancer Control and Supportive Care Neurotoxicity Subcommittee therefore conducted a survey of providers at COG institutions to determine perspectives on pediatric otoprotection practices and research surrounding three major themes: (1) prevalence of routine use of STS with cisplatin-based regimens, (2) application of audiometry to cisplatin therapy, and (3) preferred modalities for otoprotection research.

RESULTS

Survey respondents (45%, 44/98 surveyed institutions) were of diverse institutional sizes, practice settings, and geographical locations primarily in the United States and Canada. Overall, respondents considered CIHL an important toxicity and indicated strong enthusiasm for future studies (98%, 40/41). Results indicated that while STS was the current or planned standard of care in a minority of responding institutions (36%, 16/44), most sites were receptive to its inclusion in appropriate study designs. Application of audiometry for ototoxicity monitoring varied widely across sites. For otoprotection research, systemic agents were preferred (68%, 28/41) as compared with intratympanic approaches.

CONCLUSION

These results suggest that pediatric otoprotection trials remain of interest to providers; the emphasis of these trials should remain on systemic and not intratympanic therapy.

Abstract 6059: Targeting the anthracycline metabolizing enzyme AKR1C3 in adipocytes to improve cytotoxicity

Introduction: We have reported that mouse and human adipocytes take up and metabolize the anthracycline, daunorubicin (DNR), reducing its concentration in the adipocyte microenvironments. This may contribute to anthracycline resistance for cancers, which reside in adipocyte rich environments such as omentum and bone marrow. Adipocytes express several carbonyl- and aldo-keto reductases (CBRs and AKRs) which metabolize and inactivate anthracyclines, and it is unclear which of these might be important targets to improve treatment outcome.

Experimental Procedures: We knocked out AKR1C3 in the human preadipocyte cell line Chub S7 using CRISPR/Cas9 gene editing technology. We chose AKR1C3 first as it is one of the overexpressed enzymes in adipocytes with the highest anthracycline-metabolizing activity. We delivered ribonucleoprotein complexes of CRISPR-Cas9 enzyme plus guide RNAs by nucleofection. Then we established single-cell derived clones and tested for successful KO by Western blot. Finally, we quantified adipocyte lysate AKR activity using a colorimetric assay based on NADPH-dependent reduction of phenanthrenequinone.

Data Summary: We chose three Chub S7 preadipocyte clones that demonstrated successful AKR1C3 knockout based on almost undetectable protein expression by western blot. AKR activity was significantly reduced in all three clones; control preadipocytes had 44±4.7, while clones had activity of 28±7.3, 33±3.4, and 35±5.7 pmol/min/µg (p&lt;0.05 for all comparisons, n=3 for each assay).

Conclusions: These findings demonstrate that AKR1C3 knockout can be successfully done in human preadipocytes using a CRISPR-Cas9 system. Knockout of AKR1C3 significantly reduces overall aldoketoreductase activity in preadipocyte cells. This implies that a substantial portion of preadipocyte AKR activity is dependent on the isoenzyme, AKR1C3. Future testing is needed to determine whether AKR1C3 KO will reduce the clearance of anthracyclines from the cancer microenvironment, and may represent a treatment target to enhance anthracycline cytotoxicity.

Citation Format: Vladislava Paharkova, Etan Orgel, Michael Neely, Stan. Louie, Steven Mittelman. Targeting the anthracycline metabolizing enzyme AKR1C3 in adipocytes to improve cytotoxicity [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6059.

Mechanisms by Which Obesity Impacts Survival from Acute Lymphoblastic Leukemia

The prevalence of obesity has steadily risen over the past decades, even doubling in more than 70 countries. High levels of body fat (adiposity) and obesity are associated with endocrine and hormonal dysregulation, cardiovascular compromise, hepatic dysfunction, pancreatitis, changes in drug metabolism and clearance, inflammation, and metabolic stress. It is thus unsurprising that obesity can affect the development of and survival from a wide variety of malignancies. This review focuses on acute lymphoblastic leukemia, the most common malignancy in children, to explore the multiple mechanisms connecting acute lymphoblastic leukemia, obesity, and adipocytes, and the implications for leukemia therapy.

Myosteatosis in adolescents and young adults treated for acute lymphoblastic leukemia

Myosteatosis refers to fat deposition within muscle and is linked to risk of cardiovascular disease and metabolic disorders. Though these comorbidities are common during and after therapy for acute lymphoblastic leukemia (ALL), little is known about tissue distribution, including myosteatosis, in this population. Using quantitative computed tomography, we assessed the impact of ALL therapy on bone, muscle, subcutaneous, and muscle-associated (MA) fat in 12 adolescents and young adults (AYA) treated for ALL as compared to a healthy control group without ALL (n = 116). AYA had a marked loss of muscle with a gain in MA fat between ALL diagnosis and end of induction. These changes persisted throughout intensive therapy. Lower bone and muscle and higher MA fat were also observed during and after treatment in comparison to controls. Altered lower extremity tissue distribution, specifically myosteatosis and sarcopenia, may contribute to functional declines and increased risk of metabolic disorders and cardiovascular diseases.

Mixed-phenotype acute leukemia: A cohort and consensus research strategy from the Children's Oncology Group Acute Leukemia of Ambiguous Lineage Task Force

BACKGROUND

Optimal chemotherapy for treating mixed-phenotype acute leukemia (MPAL) and the role of hematopoietic stem cell transplantation (HSCT) remain uncertain. Major limitations in interpreting available data are MPAL's rarity and the use of definitions other than the currently widely accepted criteria: the World Health Organization 2016 (WHO2016) classification.

METHODS

To assess the relative efficacy of chemotherapy types for treating pediatric MPAL, the Children's Oncology Group (COG) Acute Leukemia of Ambiguous Lineage Task Force assembled a retrospective cohort of centrally reviewed WHO2016 MPAL cases selected from banking studies for acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Patients were not treated in COG trials; treatment and outcome data were captured separately. The findings were then integrated with the available, mixed literature to develop a prospective trial in pediatric MPAL.

RESULTS

The central review confirmed that 54 of 70 cases fulfilled WHO2016 criteria for MPAL. ALL induction regimens achieved remission in 72% of the cases (28 of 39), whereas AML regimens achieved remission in 69% (9 of 13). The 5-year event-free survival (EFS) and overall survival (OS) rates for the entire cohort were 72% ± 8% and 77% ± 7%, respectively. EFS and OS were 75% ± 13% and 84% ± 11%, respectively, for those receiving ALL chemotherapy alone without HSCT (n = 21).

CONCLUSIONS

The results of the COG MPAL cohort and a literature review suggest that ALL chemotherapy without HSCT may be the preferred initial therapy. A prospective trial within the COG is proposed to investigate this approach; AML chemotherapy and/or HSCT will be reserved for those with treatment failure as assessed by minimal residual disease. Embedded biology studies will provide further insight into MPAL genomics.

Improving the Timeliness of Chemotherapy Administration in the Bone Marrow Transplant Unit

Patients undergoing hematopoietic stem cell transplantation (HSCT) are often admitted to the hospital the day they are due to begin their conditioning regimen. Timely initiation of chemotherapy during regular work hours is important for patient safety, because during the night shift fewer physicians and pharmacists are available for urgent or unexpected matters. A review of the data at our institution from October 2017 to August 2018 showed that approximately one-third of our chemotherapy was started during the night shift (after 19:00), and the average time from admission to start of chemotherapy was over 8 hours. There are currently no well-defined benchmarks for timeliness of chemotherapy initiation. The aim of this quality improvement initiative was to increase the percentage of patients who start chemotherapy in the bone marrow transplant unit before 19:00 from 65% to >80% by March 31, 2019. We identified barriers to timely initiation of chemotherapy through process mapping and analysis of failures. The primary barriers were late admissions (after 12:00 pm) and time from admission to preparation of chemotherapy. We addressed mechanisms to mitigate these barriers through Plan-Do-Study-Act testing. Interventions included providing families specific admission times and their rationales and process for notifying pharmacy of admissions immediately on arrival. We used standardized control charts to measure the impact of the interventions on change. We also monitored medication errors before and during the intervention. From September 2018 to March 2019 the percentage of patients who started preparative chemotherapy before 19:00 increased from 65% to 85%, the percentage of patients who were admitted after 12:00 remained similar before (31%) and after the interventions (33%), and the average time from admission to start of chemotherapy decreased from 8.6 hours (513 minutes) to 6.4 hours (382 minutes). Medication errors were similar before (n = 50) and after the interventions (n = 43). Using standardized processes, we demonstrated a substantial decrease in the percentage of HSCT patients starting their preparative regimen after 19:00 without a concurrent increase in errors. We believe these interventions and measurements can be used in all transplant centers and have the potential to influence patient safety and outcomes.

Levocarnitine does not impair chemotherapy cytotoxicity against acute lymphoblastic leukemia

Asparaginase (ASNase) is an integral part of pediatric induction chemotherapy that has also been shown to improve adult survival rates; however, pegylated (PEG)-ASNase induces severe hepatotoxicity in this population. Recent case reports describe the incorporation of levocarnitine (LC) supplementation into PEG-ASNase-containing induction regimens to prevent or treat hepatotoxicity. Because LC facilitates the metabolism of free fatty acids (FFA), a primary fuel source for ALL cells, LC could potentially interfere with ALL chemotherapy efficacy. To test this, we employed in vitro and in vivo models of ALL. We show in vitro that LC supplementation does not impact cytotoxicity from vincristine, daunorubicin, dexamethasone, or ASNase on human ALL cells nor lead to an increase in ALL cell metabolic rate. In vivo, we demonstrate LC does not impair PEG-ASNase monotherapy in mice with syngeneic ALL. Together, our findings show that LC supplementation is a safe strategy to prevent/reverse ASNase-induced toxicities in preclinical models.

Recommendations for ototoxicity surveillance for childhood, adolescent, and young adult cancer survivors: a report from the International Late Effects of Childhood Cancer Guideline Harmonization Group in collaboration with the PanCare Consortium

Childhood, adolescent, and young adult (CAYA) cancer survivors treated with platinum-based drugs, head or brain radiotherapy, or both have an increased risk of ototoxicity (hearing loss, tinnitus, or both). To ensure optimal care and reduce consequent problems-such as speech and language, social-emotional development, and learning difficulties-for these CAYA cancer survivors, clinical practice guidelines for monitoring ototoxicity are essential. The implementation of surveillance across clinical settings is hindered by differences in definitions of hearing loss, recommendations for surveillance modalities, and remediation. To address these deficiencies, the International Guideline Harmonization Group organised an international multidisciplinary panel, including 32 experts from ten countries, to evaluate the quality of evidence for ototoxicity following platinum-based chemotherapy and head or brain radiotherapy, and formulate and harmonise ototoxicity surveillance recommendations for CAYA cancer survivors.

The genetic basis and cell of origin of mixed phenotype acute leukaemia

Mixed phenotype acute leukaemia (MPAL) is a high-risk subtype of leukaemia with myeloid and lymphoid features, limited genetic characterization, and a lack of consensus regarding appropriate therapy. Here we show that the two principal subtypes of MPAL, T/myeloid (T/M) and B/myeloid (B/M), are genetically distinct. Rearrangement of ZNF384 is common in B/M MPAL, and biallelic WT1 alterations are common in T/M MPAL, which shares genomic features with early T-cell precursor acute lymphoblastic leukaemia. We show that the intratumoral immunophenotypic heterogeneity characteristic of MPAL is independent of somatic genetic variation, that founding lesions arise in primitive haematopoietic progenitors, and that individual phenotypic subpopulations can reconstitute the immunophenotypic diversity in vivo. These findings indicate that the cell of origin and founding lesions, rather than an accumulation of distinct genomic alterations, prime tumour cells for lineage promiscuity. Moreover, these findings position MPAL in the spectrum of immature leukaemias and provide a genetically informed framework for future clinical trials of potential treatments for MPAL.

Obesity and risk for venous thromboembolism from contemporary therapy for pediatric acute lymphoblastic leukemia

INTRODUCTION

Acute lymphoblastic leukemia (ALL) therapy confers risk for venous thromboembolism (VTE) and associated acute and long-term morbidity. Obesity increases VTE risk in the general population but its impact on ALL therapy-associated VTE is unknown.

METHODS

In a retrospective cohort of children treated for ALL between 2008 and 2016 (n = 294), we analyzed obesity at diagnosis (body mass index [BMI] ≥95%) and subsequent development of VTE. A subset participated in two concurrent prospective ALL trials studying body composition via dual-energy X-ray absorptiometry (DXA) (n = 35) and hypercoagulability via thromboelastography (TEG) (n = 46). Secondary analyses explored whether precise measurement of body fat and/or global hemostasis ex vivo by TEG could further delineate VTE risk in the obese.

RESULTS

Overall, we found 27/294 (9.2%) patients developed symptomatic VTE during therapy, 19/27 (70%) occurred during Induction. Study-defined "serious" VTE developed in 4/294 (1.4%) of patients. Obesity but not overweight was strongly predictive of symptomatic VTE (obesity odds ratio = 3.8, 95% confidence interval 1.5-9.6, p = 0.008). In the DXA subset, only 2/35 patients developed symptomatic VTE. However, within those prospectively screened during Induction, 30% (14/46) developed VTE; eight (17%) of these were asymptomatic and found only via screening.

CONCLUSIONS

In this pediatric ALL cohort, obesity conferred more than a three-fold increased risk for symptomatic VTE. In a subgroup of patients who underwent active screening, up to a third were noted to have VTE (symptomatic and asymptomatic). TEG did not predict VTE. Additional studies are necessary to validate these findings and to further refine a risk-stratified approach to thrombo-prevention during ALL therapy.

Predictors of hepatotoxicity and pancreatitis in children and adolescents with acute lymphoblastic leukemia treated according to contemporary regimens

BACKGROUND

Hepatotoxicity and pancreatitis are common treatment-related toxicities (TRTs) during contemporary treatment regimens for acute lymphoblastic leukemia (ALL). Limited detailed data from Children's Oncology Group (COG) regimens has been previously reported to enable identification of patient and treatment risk factors for these toxicities and their impact on outcomes.

PROCEDURE

We analyzed a retrospective pediatric ALL cohort treated at a single institution according to COG regimens from 2008 to 2015. The primary endpoint was cumulative incidence of study-defined "severe" hepatotoxicity (Common Terminology Criteria for Adverse Events [CTCAE] Grade ≥ 4 transaminitis or Grade ≥ 3 hyperbilirubinemia) and clinically significant pancreatitis (any grade). Pancreatitis was additionally classified using the Ponte di Legno (PdL) toxicity criteria. Secondary endpoints were chemotherapy interruptions, early disease response (end of induction [EOI] minimal residual disease [MRD]), and event-free survival (EFS).

RESULTS

We identified 262 patients, of whom 71 (27%) and 28 (11%) developed hepatotoxicity and pancreatitis, respectively. Three cases of pancreatitis did not fulfill PdL criteria despite otherwise consistent presentations. Both TRTs occurred throughout therapy, but approximately 25% of hepatotoxicity (18/71) and pancreatitis (8/28) occurred during induction alone. Both obesity and age (≥10 years) were identified as predictors of hepatotoxicity (subdistribution hazard ratio [SHR] obesity = 1.75, 95% confidence interval [95% CI] 1.04-2.96; SHR age ≥10 = 1.9, 95% CI 1.19-3.10) and pancreatitis (SHR obesity = 2.18, 95% CI 1.01-4.67; SHR age ≥ 10 = 2.76, 95% CI 1.19-6.39, P = 0.018). Dose interruptions were common but neither toxicity influenced EOI MRD nor EFS.

CONCLUSIONS

Obese and/or older children are particularly at risk for hepatotoxicity and pancreatitis, and may benefit from toxicity surveillance and chemoprotective strategies to prevent or mitigate associated morbidity.

Therapy for children and adults with mixed phenotype acute leukemia: a systematic review and meta-analysis

The rarity of mixed-phenotype acute leukemia (MPAL) has resulted in diffuse literature consisting of small case series, thus precluding a consensus treatment approach. We conducted a meta-analysis and systematic review to investigate the association of treatment type (acute lymphoblastic leukemia [ALL], acute myeloid leukemia [AML], or "hybrid" regimens), disease response, and survival. We searched seven databases from inception through June 2017 without age or language restriction. Included studies reported sufficient treatment detail for de novo MPAL classified according to the well-established European Group for Immunological Characterization of Acute Leukemias (EGIL) or World Health Organization (WHO2008) criteria. Meta-analyses and multivariable analyses of a patient-level compiled case series were performed for the endpoints of complete remission (CR) and overall survival (OS). We identified 97 reports from 33 countries meeting criteria, resulting in 1,499 unique patients with data, of whom 1,351 had sufficient detail for quantitative analysis of the study endpoints. Using either definition of MPAL, meta-analyses revealed that AML induction was less likely to achieve a CR as compared to ALL regimens, (WHO2008 odds ratio [OR] = 0.33, 95% confidence interval [95% CI] 0.18-0.58; EGIL, OR = 0.18, 95% CI 0.08-0.40). Multivariable analysis of the patient-level data supported poorer efficacy for AML induction (versus ALL: OR = 0.45 95% CI 0.27-0.77). Meta-analyses similarly found better OS for those beginning with ALL versus AML therapy (WHO2008 OR = 0.45, 95% CI 0.26-0.77; EGIL, OR = 0.43, 95% CI 0.24-0.78), but multivariable analysis of patient-level data showed only those starting with hybrid therapy fared worse (hazard ratio [HR] = 2.11, 95% CI 1.30-3.43). MPAL definition did not impact trends within each endpoint and were similarly predictive of outcome. Using either definition of MPAL, ALL-therapy is associated with higher initial remission rates for MPAL and is at least equivalent to more intensive AML therapy for long-term survival. Prospective trials are needed to establish a uniform approach to this heterogeneous disease.

Association of clinical trial enrollment and survival using contemporary therapy for pediatric acute lymphoblastic leukemia

While early studies reported superior survival for cancer patients enrolled on clinical trials, recent findings are inconclusive. We investigated the association between enrollment on contemporary trials and event-free survival (EFS) in pediatric B-cell acute lymphoblastic leukemia (B-ALL). In a retrospective cohort of 274 children (1-21 years) treated for B-ALL from 2008 to 2015, 55.5% enrolled with no disparity in enrollment by age, sex, or ethnicity. Three-year EFS was similar for enrolled and not enrolled patients (90.1% [95% CI, 82.5-94.5] versus 86.5% [95% CI, 77.7-92.0]). Clinical trial enrollment did not affect pediatric B-ALL survival, albeit in a limited-size cohort treated at a single academic institution.

Adipocytes Sequester and Metabolize the Chemotherapeutic Daunorubicin

Obesity is associated with poorer outcome for many cancers. Previously, we observed that adipocytes protect acute lymphoblastic leukemia (ALL) cells from the anthracycline, daunorubicin. In this study, it is determined whether adipocytes clear daunorubicin from the tumor microenvironment (TME). Intracellular daunorubicin concentrations were evaluated using fluorescence. Daunorubicin and its largely inactive metabolite, daunorubicinol, were analytically measured in media, cells, and tissues using liquid chromatography/mass spectrometry (LC/MS). Expression of daunorubicin-metabolizing enzymes, aldo-keto reductases (AKR1A1, AKR1B1, AKR1C1, AKR1C2, AKR1C3, and AKR7A2) and carbonyl reductases (CBR1, CBR3), in human adipose tissue, were queried using public databases and directly measured by quantitative PCR (qPCR) and immunoblot. Adipose tissue AKR activity was measured by colorimetric assay. Adipocytes absorbed and efficiently metabolized daunorubicin to daunorubicinol, reducing its antileukemia effect in the local microenvironment. Murine studies confirmed adipose tissue conversion of daunorubicin to daunorubicinol in vivo Adipocytes expressed high levels of AKR and CBR isoenzymes that deactivate anthracyclines. Indeed, adipocyte protein levels of AKR1C1, AKR1C2, and AKR1C3 are higher than all other human noncancerous cell types. To our knowledge, this is the first demonstration that adipocytes metabolize and inactivate a therapeutic drug. Adipocyte-mediated daunorubicin metabolism reduces active drug concentration in the TME. These results could be clinically important for adipocyte-rich cancer microenvironments such as omentum, breast, and marrow. As AKR and CBR enzymes metabolize several drugs, and can be expressed at higher levels in obese individuals, this proof-of-principle finding has important implications across many diseases.Implications: Adipocyte absorption and metabolism of chemotherapies can reduce cytotoxicity in cancer microenvironments, potentially contributing to poorer survival outcomes. Mol Cancer Res; 15(12); 1704-13. ©2017 AACR.

A randomized controlled trial testing an adherence-optimized Vitamin D regimen to mitigate bone change in adolescents being treated for acute lymphoblastic leukemia

Adolescents with acute lymphoblastic leukemia (ALL) develop osteopenia early in therapy, potentially exacerbated by high rates of concurrent Vitamin D deficiency. We conducted a randomized clinical trial testing a Vitamin D-based intervention to improve Vitamin D status and reduce bone density decline. Poor adherence to home supplementation necessitated a change to directly observed therapy (DOT) with intermittent, high-dose Vitamin D3 randomized versus standard of care (SOC). Compared to SOC, DOT Vitamin D3 successfully increased trough Vitamin 25(OH)D levels (p = .026) with no residual Vitamin D deficiency, 100% adherence to DOT Vitamin D3, and without associated toxicity. However, neither Vitamin D status nor supplementation impacted bone density. Thus, this adherence-optimized intervention is feasible and effective to correct Vitamin D deficiency in adolescents during ALL therapy. Repletion of Vitamin D and calcium alone did not mitigate osteopenia, however, and new, comprehensive approaches are needed to address treatment-associated osteopenia during ALL therapy.

Abstract 2960: Adipocytes sequester and metabolize daunorubicin

Obesity is associated with poorer outcome from many cancers, including childhood acute lymphoblastic leukemia (ALL). We have previously shown that adipocytes protect ALL cells from the anthracycline, daunorubicin (DNR). We therefore investigated whether adipocytes sequester and/or metabolize DNR in the ALL microenvironment. Using fluorescence and LC/MS measures, we demonstrated that adipocytes absorb DNR, reducing the intracellular DNR concentration in co-cultured BV173 ALL cells (after 48 hours, median fluorescent intensity of ALL cultured with adipocytes was 1.7±1.0 vs. 5.0±1.7 of those cultured alone, p&lt;0.01). Mouse adipocytes convert DNR to the less active metabolite, daunorubicinol (DNR-ol); over 48 hours, media DNR decreased to 0.1±0.2 (vs. 24.8±8.76 ng/mL in control wells). At the same time, DNR-ol increased to 15.0±1.9 (vs. 0.7±0.6 in control wells; both p&lt;0.05). Similar conversion of DNR to DNR-ol was observed in both mouse adipose explants and human adipose tissue biopsy samples ex vivo. qPCR confirmed human subcutaneous adipose tissue expresses several enzymes capable of metabolizing DNR, including AKR1A1, 1B1, 1C1, 1C2, 1C3, 7A2, and CBR1 and 3 (expression ranged between 20 and 195% β-actin). Using immunohistochemistry, we confirmed expression of AKR1C1, 1C2, and 1C3 in bone marrow adipocytes of children during the first month of treatment for ALL. Finally, two hours after an intravenous dose of DNR in mice, we found that the DNR-ol to DNR ratio was higher in subcutaneous (0.60±0.26) and omental (0.55±0.21) adipose than in white blood cells (0.16±0.11), bone marrow (undetectable DNR-ol), and spleen (undetectable DNR-ol). Together, these data demonstrate that adipocytes sequester and inactivate DNR, likely due to their expression of AKR and CBR enzymes. These findings uncover a novel and important mechanism which could promote local anthracycline resistance by cancer cells in microenvironment rich in adipocytes, such as bone marrow, omentum, and breast.

Citation Format: Xia Sheng, Jean-Hugues Parmentier, Jonathan Tucci, Hua Pei, Omar Cortez-Toledo, Christina Dieli-Conwright, Matthew Oberley, Michael Neely, Etan Orgel, Stan Louie, Steven D. Mittelman. Adipocytes sequester and metabolize daunorubicin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2960. doi:10.1158/1538-7445.AM2017-2960

Clinical Significance of Isolated Myeloperoxidase Expression in Pediatric B-Lymphoblastic Leukemia

Objectives

Diagnosis of B-cell acute lymphoblastic leukemia (B-ALL) requires immunophenotypic evidence of B-lineage and absence of specific myeloid or T-lineage markers. Rare cases of otherwise typical B-ALL express myeloperoxidase (MPO) detectable by flow cytometry with an absence of other myeloid markers, but the clinical significance of this finding is not well studied.

Methods

A retrospective cohort analysis of flow cytometry and clinical data was performed to investigate the clinical outcome of this specific group of patients.

Results

Twenty-nine cases of otherwise typical B-ALL that expressed MPO by flow cytometry (B-ALL-isoMPO) without expression of other myeloid markers were identified. The B-ALL-isoMPO group had a significantly increased incidence of relapse (univariate log rank P  = .0083; multivariate hazard ratio, 2.50; 95% confidence interval, 1.07-5.85; P  = .034) and significantly worse event-free survival by univariate analysis (log rank P  = .0066) compared with a reference group of patients with B-ALL from the same time period (n = 264).

Conclusions

To our knowledge, this is the first report to document the clinical outcomes in a group of pediatric patients with B-ALL that expresses MPO in the absence of other myeloid markers. This group had an increased rate of relapse and a worse event-free survival than the patients with B-ALL who did not express MPO.

TACL'ing supportive care needs in pediatric early phase clinical trials for acute leukemia: A report from the therapeutic advances in childhood leukemia & lymphoma (TACL) consortium supportive care committee

A Supportive Care Committee was recently developed within the Therapeutic Advances in Childhood Leukemia & Lymphoma (TACL) Consortium. This was substantiated by the significantly high rate of serious adverse events (SAE) (CTCAE Grade ≥3 toxicity) experienced by patients with relapse/refractory acute leukemia enrolled on our phase I trials. Such treatment-related toxicity has resulted in patients being removed from study and thus potentially not receiving clinical benefit from the novel therapy. In addition, increased treatment-related toxicity may compromise new agents from moving forward in their clinical development. To address these challenges, TACL initiated a Supportive Care Committee to help mitigate the treatment-related toxicity risk that exists in heavily pre-treated patients with relapse/refractory leukemia. This manuscript reviews the mission of the TACL Supportive Care Committee presented at the 2016 TACL Investigators' Meeting (Los Angeles, CA) and the future direction in providing enhanced supportive care guidelines for all TACL studies.

Treatment-related adverse events associated with a modified UK ALLR3 induction chemotherapy backbone for childhood relapsed/refractory acute lymphoblastic leukemia

BACKGROUND

The UK ALLR3 (R3) regimen has been adopted to treat pediatric relapsed acute lymphoblastic leukemia (ALL) by many centers in the United States and has become a preferred therapeutic backbone for testing novel agents in clinical trials. A detailed toxicity profile of this platform has not previously been reported. The toxicity and response rates for its use beyond first relapse are unknown.

PROCEDURES

We performed a multi-institutional, retrospective study including children with relapsed ALL treated with the R3 reinduction chemotherapy backbone block 1 across five pediatric centers. Data were extracted from medical records and analyzed.

RESULTS

Fifty-nine patients were included in the study, including 16 patients with ≥2nd relapse. Ninety-seven percent of patients experienced at least one Grade ≥3 nonhematologic adverse event (AE). Grade 3 or higher infection was reported in 90% of patients. Other nonhematologic Grade ≥3 AEs included electrolyte abnormalities, elevation in hepatic enzymes, and pain. Eighty-five percent of patients achieved a complete remission (CR). There were no significant differences in the incidence of AEs, CR rate, and rate of minimal residual disease negativity between patients with 1st or ≥2nd relapse.

CONCLUSION

Our study confirmed that R3 block 1 is a highly active reinduction regimen in childhood relapsed ALL. However, it was associated with a high incidence of severe toxicities, particularly infection. The toxicity profiled in our report should be used to inform optimal supportive care and future clinical trial design with the R3 backbone, particularly when new agents are combined with this regimen.

Early injury to cortical and cancellous bone from induction chemotherapy for adolescents and young adults treated for acute lymphoblastic leukemia

Diminished bone density and skeletal fractures are common morbidities during and following therapy for acute lymphoblastic leukemia (ALL). While cumulative doses of osteotoxic chemotherapy for ALL have been reported to adversely impact bone density, the timing of onset of this effect as well as other changes to bone structure is not well characterized. We therefore conducted a prospective cohort study in pre-adolescent and adolescent patients (10-21years) newly diagnosed with ALL (n=38) to explore leukemia-related changes to bone at diagnosis and the subsequent impact of the first phase of chemotherapy ("Induction"). Using quantitative computerized tomography (QCT), we found that pre-chemotherapy bone properties were similar to age- and sex-matched controls. Subsequently over the one month Induction period, however, cancellous volumetric bone mineral density (vBMD) decreased markedly (-26.8%, p<0.001) with sparing of cortical vBMD (tibia -0.0%, p=0.860, femur -0.7%, p=0.290). The tibia underwent significant cortical thinning (average cortical thickness-1.2%, p<0.001; cortical area-0.4%, p=0.014), while the femur was less affected. Areal BMD (aBMD) concurrently measured by dual-energy X-ray absorptiometry (DXA) underestimated changes from baseline as compared to vBMD. Biochemical evidence revealed prevalent Vitamin D insufficiency and a net resorptive state at start and end of Induction. Our findings demonstrate for the first time that significant alterations to cancellous and cortical bone develop during the first month of treatment, far earlier during ALL therapy than previously considered. Given that osteotoxic chemotherapy is integral to curative regimens for ALL, these results provide reason to re-evaluate traditional approaches toward chemotherapy-associated bone toxicity and highlight the urgent need for investigation into interventions to mitigate this common adverse effect.

Association of body mass index and survival in pediatric leukemia: a meta-analysis

BACKGROUND

Obesity is a worldwide epidemic in children and adolescents. Adult cohort studies have reported an association between higher body mass index (BMI) and increased leukemia-related mortality; whether a similar effect exists in childhood leukemia remains controversial.

OBJECTIVE

We conducted a meta-analysis to determine whether a higher BMI at diagnosis of pediatric acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML) is associated with worse event-free survival (EFS), overall survival (OS), and cumulative incidence of relapse (CIR).

DESIGN

We searched 4 electronic databases from inception through March 2015 without language restriction and included studies in pediatric ALL or AML (0-21 y of age) reporting BMI as a predictor of survival or relapse. Higher BMI, defined as obese (≥95%) or overweight/obese (≥85%), was compared with lower BMI [nonoverweight/obese (<85%)]. Summary risk estimates for EFS, OS, and CIR (ALL only) were calculated with random- or fixed-effects models according to tests for between-study heterogeneity.

RESULTS

Of 4690 reports identified, 107 full-text articles were evaluated, with 2 additional articles identified via review of citations; 11 articles were eligible for inclusion in this meta-analysis. In ALL, we observed poorer EFS in children with a higher BMI (RR: 1.35; 95% CI: 1.20, 1.51) than in those at a lower BMI. A higher BMI was associated with significantly increased mortality (RR: 1.31; 95% CI: 1.09, 1.58) and a statistically nonsignificant trend toward greater risk of relapse (RR: 1.17; 95% CI: 0.99, 1.38) compared with a lower BMI. In AML, a higher BMI was significantly associated with poorer EFS and OS (RR: 1.36; 95% CI: 1.16, 1.60 and RR: 1.56; 95% CI: 1.32, 1.86, respectively) than was a lower BMI.

CONCLUSION

Higher BMI at diagnosis is associated with poorer survival in children with pediatric ALL or AML.

Effect of Sensorineural Hearing Loss on Neurocognitive Functioning in Pediatric Brain Tumor Survivors

BACKGROUND

Intensified therapy with platinum-based regimens for pediatric brain tumors has dramatically increased the number of pediatric brain tumor survivors (PBTS) but frequently causes permanent sensorineural hearing loss (SNHL). Although neurocognitive decline in PBTS is known to be associated with radiation therapy (RT), SNHL represents a potential additional contributor whose long-term impact has yet to be fully determined.

METHODS

The neurocognitive impact of significant SNHL (Chang scale ≥ 2b) in PBTS was assessed through a retrospective cohort study of audiograms and neurocognitive testing. Scores for neurocognitive domains and subtest task performance were analyzed to identify specific strengths and weakness for PBTS with SNHL.

RESULTS

In a cohort of PBTS (n = 58) treated with platinum therapy, significant SNHL was identified in more than half (55%, n = 32/58), of which the majority required hearing aids (72%, 23/32). RT exposure was approximately evenly divided between those with and without SNHL. PBTS were 6.7 ± 0.6 and 11.3 ± 0.7 years old at diagnosis and neurocognitive testing, respectively. In multivariate analyses adjusted for RT dose, SNHL was independently associated with deficits in intelligence, executive function, and verbal reasoning skills. Subtests revealed PBTS with SNHL to have poor learning efficiency but intact memory and information acquisition.

CONCLUSIONS

SNHL in PBTS increases the risk for severe therapy-related intellectual and neurocognitive deficits. Additional prospective investigation in malignant brain tumors is necessary to validate these findings through integration of audiology and neurocognitive assessments and to identify appropriate strategies for neurocognitive screening and rehabilitation specific to PBTS with and without SNHL.

Limitations of body mass index to assess body composition due to sarcopenic obesity during leukemia therapy

Obesity as defined by body mass index percentile (BMI%) is strongly associated with relapse and poorer survival in childhood ALL. Whether BMI% accurately reflects body fat percentage (BF%) in this population is unknown. We conducted a prospective study assessing body composition during frontline ALL therapy. Dual-energy X-ray absorptiometry measured BF% and lean muscle mass (LMM) at diagnosis, end of Induction, and end of Delayed Intensification. Sarcopenic obesity (gain in BF% with loss of LMM) was surprisingly common during ALL treatment, resulting in poor correlation between changes in BMI% (expressed as Z-score) and BF% overall (r = -0.05) and within patients (r = -0.09). BMI Z-score and BF% changed in opposite directions in >50% of interval assessments. While BMI% at diagnosis is a suitable predictor of obesity/BF% for epidemiological studies, change in BMI% (as expressed as Z-score) does not reflect body composition. Studies evaluating obesity in leukemia should consider using direct measures of body composition.