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.

Enhanced Risk Stratification for Children and Young Adults with B-Cell Acute Lymphoblastic Leukemia: A Children's Oncology Group Report

Current strategies to treat pediatric acute lymphoblastic leukemia rely on risk stratification algorithms using categorical data. We investigated whether using continuous variables assigned different weights would improve risk stratification. We developed and validated a multivariable Cox model for relapse-free survival (RFS) using information from 21199 patients. We constructed risk groups by identifying cutoffs of the COG Prognostic Index (PICOG) that maximized discrimination of the predictive model. Patients with higher PICOG have higher predicted relapse risk. The PICOG reliably discriminates patients with low vs. high relapse risk. For those with moderate relapse risk using current COG risk classification, the PICOG identifies subgroups with varying 5-year RFS. Among current COG standard-risk average patients, PICOG identifies low and intermediate risk groups with 96% and 90% RFS, respectively. Similarly, amongst current COG high-risk patients, PICOG identifies four groups ranging from 96% to 66% RFS, providing additional discrimination for future treatment stratification. When coupled with traditional algorithms, the novel PICOG can more accurately risk stratify patients, identifying groups with better outcomes who may benefit from less intensive therapy, and those who have high relapse risk needing innovative approaches for cure.

Comprehensive analysis of MYB/MYBL1-altered pediatric-type diffuse low-grade glioma

BACKGROUND

Pediatric-type diffuse low-grade gliomas (pLGG) harboring recurrent genetic alterations involving MYB or MYBL1 are closely related tumors. Detailed treatment and outcome data of large cohorts are still limited. This study aimed to comprehensively evaluate pLGG with these alterations to define optimal therapeutic strategies.

METHODS

We retrospectively reviewed details of pLGG with MYB or MYBL1 alterations from patients treated or referred for pathologic review at St. Jude Children's Research Hospital. Tumor specimens were centrally reviewed, and clinical data were collated.

RESULTS

Thirty-three patients (18 male; median age, 5 y) were identified. Two tumors had MYBL1 alterations; 31 had MYB alterations, MYB::QKI fusion being the most common (n=10, 30%). Most tumors were in the cerebral hemispheres (n=22, 67%). Two patients (6%) had metastasis at diagnosis. The median follow-up was 6.1 years. The 5-year event-free survival (EFS) rate was 81.3±8.3%; the 5-year overall survival (OS) rate was 96.4±4.1%. Patients receiving a near-total or gross-total resection had a 5-year EFS of 100%; those receiving a biopsy or subtotal resection had a 5-year EFS rate of 56.6±15.2% (p<0.01). No difference in EFS was observed based on location, histology, or molecular alterations. However, the tumors that progressed or metastasized may have distinct methylation profiles with evidence of activation of the MAPK and PI3K/AKT/mTOR pathways.

CONCLUSIONS

pLGG with MYB/MYBL1 alterations have good outcomes. Our findings suggest that surgical resectability is a crucial determinant of EFS. Further characterization is required to identify optimal treatment strategies for progressive tumors.

MRD at the End of Induction and EFS in T-cell Lymphoblastic Lymphoma: Children's Oncology Group Trial AALL1231

Defining prognostic variables in T-lymphoblastic lymphoma (T-LL) remains a challenge. AALL1231 was a COG phase 3 clinical trial for newly diagnosed with T Acute Lymphoblastic leukemia or T-LL patients randomizing children and young adults to a modified augmented BFM backbone to receive standard therapy (Arm A) or with addition of bortezomib (Arm B). Optional bone marrow (BM) samples to assess minimal residual disease (MRD) at the end of induction (EOI) were collected in T-LL analyzed to assess the correlation of MRD at the EOI to event-free survival (EFS). Eighty-six (41%) of the 209 T-LL patients accrued to this trial submitted samples for MRD assessment. Patients with MRD <0.1% (n= 75) at EOI had a superior 4-year EFS versus those with MRD >0.1% (n= 11), (89.0±4.4% versus 63.6±17.2%, p= 0.025). Overall survival did not significantly differ between the two groups. Cox regression for EFS using Arm A as a reference demonstrated that MRD EOI ≥0.1% was associated with a greater risk of inferior outcome (Hazard Ratio, HR= 3.73 (1.12-12.40, p= 0.032), which was independent of treatment arm assignment. Consideration to incorporate MRD at EOI into future trials will help establish its value in defining risk groups. CT# NCT02112916.

Germline Genetic NBN Variation and Predisposition to B-cell Acute Lymphoblastic Leukemia in Children

Biallelic mutation in the DNA-damage repair gene NBN is the genetic cause of Nijmegen Breakage Syndrome, which is associated with predisposition to lymphoid malignancies. Heterozygous carriers of germline NBN variants may also be at risk for leukemia development, although this is much less characterized. Sequencing 4,325 pediatric B-ALL patients, we systematically examined the frequency of germline NBN variants and identified 25 unique, putatively damaging NBN coding variants in 50 patients. Compared with the frequency of NBN variants in gnomAD non-cancer controls (189 unique, putatively damaging NBN coding variants in 472 of 118,479 individuals) we found significant overrepresentation in pediatric B-ALL (p=0.004, OR=1.8). Most B-ALL-risk variants were missense and cluster within the NBN N-terminal domains. Using two functional assays, we verified 14 of 25 variants with severe loss-of-function phenotypes and thus classified these as non-functional or partially functional. Finally, we found that germline NBN variant carriers, all of which were identified as heterozygous genotypes, showed similar survival outcomes relative to those with WT status. Taken together, our findings provide novel insights into the genetic predisposition to B-ALL, and the impact of NBN variants on protein function and suggest that heterozygous NBN variant carriers may safely receive B-ALL therapy.

Connecting Clinical Capacity and Intervention Sustainability in Resource-Variable Pediatric Oncology Centers in Latin America

Clinical capacity for sustainability, or the clinical resources needed to sustain an evidence-based practice, represent proximal determinants that contribute to intervention sustainment. We examine the relationship between clinical capacity for sustainability and sustainment of PEWS, an evidence-based intervention to improve outcomes for pediatric oncology patients in resource-variable hospitals. We conducted a cross-sectional survey among Latin American pediatric oncology centers participating in Proyecto Escala de Valoración de Alerta Temprana (EVAT), an improvement collaborative to implement Pediatric Early Warning Systems (PEWS). Hospitals were eligible if they had completed PEWS implementation. Clinicians were eligible to participate if they were involved in PEWS implementation or used PEWS in clinical work. The Spanish language survey consisted of 56 close and open-ended questions about the respondent, hospital, participants' assessment of clinical capacity to sustain PEWS using the clinical sustainability assessment tool (CSAT), and perceptions about PEWS and its use as an intervention. Results were analyzed using a multi-level modeling approach to examine the relationship between individual, hospital, intervention, and clinical capacity determinants to PEWS sustainment. A total of 797 responses from 37 centers in 13 countries were included in the analysis. Eighty-seven percent of participants reported PEWS sustainment. After controlling for individual, hospital, and intervention factors, clinical capacity was significantly associated with PEWS sustainment (OR 3.27, p < .01). Marginal effects from the final model indicate that an increasing capacity score has a positive influence (11% for every additional CSAT point) of predicting PEWS sustainment. PEWS is a sustainable intervention and clinical capacity to sustain PEWS contributes meaningfully to PEWS sustainment.

Development of osteonecrosis and improved survival in B-ALL: results of Children's Oncology Group Trial AALL0232

Osteonecrosis is a significant toxicity of acute lymphoblastic leukemia (ALL) therapy. In retrospective analyses, superior event-free survival was noted among affected adolescents in an earlier trial. We prospectively assessed osteonecrosis incidence, characteristics, and risk factors in patients 1-30 years with newly diagnosed high-risk B-ALL on COG AALL0232. Patients were randomized to induction dexamethasone vs prednisone, and interim maintenance high-dose methotrexate vs escalating-dose Capizzi methotrexate/pegaspargase. Event-free and overall survival were compared between patients with/without imaging-confirmed osteonecrosis. Osteonecrosis developed in 322/2730 eligible, evaluable patients. The 5-year cumulative incidence was 12.2%. Risk was greater in patients ≥10 years (hazard ratio [HR], 7.23; P < 0.0001), particularly females (HR, 1.37; P = 0.0057), but lower in those with asparaginase allergy (HR, 0.60; P = 0.0077). Among rapid early responders ≥10 years, risk was greater with dexamethasone (HR, 1.84; P = 0.0003) and with prednisone/Capizzi (HR, 1.45; P = 0.044), even though neither therapy was independently associated with improved survival. Patients with osteonecrosis had higher 5-year event-free (HR, 0.51; P < 0.0001) and overall survival (HR, 0.42; P < 0.0001), and this was directly attributable to reduced relapse rates (HR, 0.57; P = 0.0014). Osteonecrosis in high-risk B-ALL patients is associated with improved survival, suggesting an important role for host factors in mediating both toxicity and enhanced efficacy of specific therapies.

Treatment of high-risk Hodgkin lymphoma with a modified Stanford V regimen in the AHOPCA: Substituting chemotherapy agents and hampered outcomes

BACKGROUND/OBJECTIVES

High-risk Hodgkin lymphoma (HRHL) in children is curable with combined modality therapy. The Association of Pediatric Hematology-Oncology of Central America (AHOPCA) is a consortium of cancer centers from Central America. In 2004, AHOPCA implemented a guideline with a short course of chemotherapy (mStanfordV), strict diagnostics, and radiation guidelines, aimed at reducing abandonment and improving outcomes.

METHODS

Newly diagnosed children less than 18 years of age with high-risk HL (Ann Arbor stages: IIB, IIIB, IV) from AHOPCA centers were staged with chest radiography and ultrasound or computed tomography. Therapy was a modified Stanford V (mStanfordV), substituting cyclophosphamide for mechlorethamine and involved field radiation.

RESULTS

Of 219 patients with HRHL, 181 patients were eligible and evaluable; 146 (81%) were boys, 22% being less than 6 years; 43 were stage IIB, 84 IIIB, and 54 IV. Thirty-one (17%) abandoned therapy, 28 (15%) progressed, 30 (17%) relapsed, and eight (4%) died of toxicity. Radiation guidelines were not followed. Five-year abandonment-sensitive event-free survival and overall survival (AS-EFS, AS-OS ± SE) for the cohort were 46% ± 4% and 56% ± 4%; 5-year AS-OS for stages IIB, IIIB, and IV was 76% ± 7%, 59% ± 7%, and 35% ± 7% (p = .0006).

CONCLUSION

Despite instituting a short treatment guideline, it did not improve the abandonment rate (17%) and did not achieve the reported outcomes of Stanford V. The cyclophosphamide dose used to replace merchlorethamine was inadequate. Despite strict guidelines, the radiation therapy application was inaccurate. Weekly chemotherapy may have adversely affected abandonment of therapy by increasing the burden of travel time. Based on these results, AHOPCA established a new abandonment strategy and a new guideline.

Outcomes in Children, Adolescents, and Young Adults With Down Syndrome and ALL: A Report From the Children's Oncology Group

PURPOSE

Patients with Down syndrome (DS) and B-ALL experience increased rates of relapse, toxicity, and death. We report results for patients with DS B-ALL enrolled on Children's Oncology Group trials between 2003 and 2019.

METHODS

We analyzed data for DS (n = 743) and non-DS (n = 20,067) patients age 1-30 years on four B-ALL standard-risk (SR) and high-risk trials.

RESULTS

Patients with DS exhibited more frequent minimal residual disease (MRD) ≥0.01% at end induction (30.8% v 21.5%; P < .001). This difference persisted at end consolidation only in National Cancer Institute (NCI) high-risk patients (34.0% v 11.7%; P < .0001). Five-year event-free survival (EFS) and overall survival (OS) were significantly poorer for DS versus non-DS patients overall (EFS, 79.2% ± 1.6% v 87.5% ± 0.3%; P < .0001; OS, 86.8% ± 1.4% v 93.6% ± 0.2%; P < .0001), and within NCI SR and high-risk subgroups. Multivariable Cox regression analysis of the DS cohort for risk factors associated with inferior EFS identified age >10 years, white blood count >50 × 103/μL, and end-induction MRD ≥0.01%, but not cytogenetics or CRLF2 overexpression. Patients with DS demonstrated higher 5-year cumulative incidence of relapse (11.5% ± 1.2% v 9.1% ± 0.2%; P = .0008), death in remission (4.9% ± 0.8% v 1.7% ± 0.1%; P < .0001), and induction death (3.4% v 0.8%; P < .0001). Mucositis, infections, and hyperglycemia were significantly more frequent in all patients with DS, while seizures were more frequent in patients with DS on high-risk trials (4.1% v 1.8%; P = .005).

CONCLUSION

Patients with DS-ALL exhibit an increased rate of relapse and particularly of treatment-related mortality. Novel, less-toxic therapeutic strategies are needed to improve outcomes.

Prognostic significance of ETP phenotype and minimal residual disease in T-ALL: a Children's Oncology Group study

The early thymic precursor (ETP) immunophenotype was previously reported to confer poor outcome in T-cell acute lymphoblastic leukemia (T-ALL). Between 2009 and 2014, 1256 newly diagnosed children and young adults enrolled in Children's Oncology Group (COG) AALL0434 were assessed for ETP status and minimal residual disease (MRD) using flow cytometry at a central reference laboratory. The subject phenotypes were categorized as ETP (n = 145; 11.5%), near-ETP (n = 209; 16.7%), or non-ETP (n = 902; 71.8%). Despite higher rates of induction failure for ETP (6.2%) and near-ETP (6.2%) than non-ETP (1.2%; P < .0001), all 3 groups showed excellent 5-year event-free survival (EFS) and overall survival (OS): ETP (80.4% ± 3.9% and 86.8 ± 3.4%, respectively), near-ETP (81.1% ± 3.3% and 89.6% ± 2.6%, respectively), and non-ETP (85.3% ± 1.4% and 90.0% ± 1.2%, respectively; P = .1679 and P = .3297, respectively). There was no difference in EFS or OS for subjects with a day-29 MRD <0.01% vs 0.01% to 0.1%. However, day-29 MRD ≥0.1% was associated with inferior EFS and OS for patients with near-ETP and non-ETP, but not for those with ETP. For subjects with day-29 MRD ≥1%, end-consolidation MRD ≥0.01% was a striking predictor of inferior EFS (80.9% ± 4.1% vs 52.4% ± 8.1%, respectively; P = .0001). When considered as a single variable, subjects with all 3 T-ALL phenotypes had similar outcomes and subjects with persistent postinduction disease had inferior outcomes, regardless of their ETP phenotype. This clinical trial was registered at AALL0434 as #NCT00408005.

Sustainability determinants of an intervention to identify clinical deterioration and improve childhood cancer survival in Latin American hospitals: the INSPIRE study protocol

BACKGROUND

More than 90% of children with cancer live in low-resourced settings, where survival is only 20%. Sustainable evidence-based (EB) interventions yielding ongoing beneficial patient outcomes are critical to improve childhood cancer survival. A better understanding of factors promoting intervention sustainability in these settings is urgently needed. The aim of this study is to provide an empirical understanding of how clinical capacity for sustainability, or the resources needed to sustain an intervention, impacts the sustainment of Pediatric Early Warning System (PEWS), an EB intervention that improves pediatric oncology outcomes in low-resource hospitals by detecting clinical deterioration and preventing the need for more intense treatment.

METHODS

We will conduct a prospective, longitudinal study of approximately 100 resource-variable hospitals implementing and sustaining PEWS participating in Proyecto EVAT, a quality improvement collaborative of Latin American pediatric oncology centers. Aim 1: We will evaluate how clinical capacity for sustainability changes over time through 5 to 9 prospective measurements of capacity via survey of clinical staff using PEWS (approximately n = 13 per center) during the phases of PEWS adoption, implementation, and sustainability using the Clinical Sustainability Assessment Tool (CSAT). Aim 2: We will determine the relationship between capacity and a) PEWS sustainment and b) clinical deterioration mortality among pediatric oncology patients at centers sustaining PEWS for 2 to 10 years using chart review and an existing patient outcomes registry. Aim 3: We will develop novel strategies to promote sustainability by gaining a deeper understanding of perceived challenges to building capacity and PEWS sustainment. In combination with quantitative outcomes, we will conduct 24 focus groups with staff (doctors, nurses, and administrators) from hospitals with both high (n = 4) and low capacity (n = 4). We will then use implementation mapping to generate theoretically driven, empirically-supported sustainability strategies.

DISCUSSION

This study will advance implementation science by providing a theoretically driven, foundational understanding of factors that predict sustainability among a large, diverse cohort of hospitals. We will then use this knowledge to develop sustainability evidence-informed strategies that optimize capacity and promote long-term sustainment of PEWS and improvements in patient outcomes, thus promoting equity in childhood cancer care globally.

Outcome for Children and Young Adults With T-Cell ALL and Induction Failure in Contemporary Trials

PURPOSE

Historically, patients with T-cell acute lymphoblastic leukemia (T-ALL) who fail to achieve remission at the end of induction (EOI) have had poor long-term survival. The goal of this study was to examine the efficacy of contemporary therapy, including allogeneic hematopoietic stem cell transplantation (HSCT) in first remission (CR1).

METHODS

Induction failure (IF) was defined as the persistence of at least 5% bone marrow (BM) lymphoblasts and/or extramedullary disease after 4-6 weeks of induction chemotherapy. Disease features and clinical outcomes were reported in 325 of 6,167 (5%) patients age 21 years and younger treated in 14 cooperative study groups between 2000 and 2018.

RESULTS

With a median follow-up period of 6.4 years (range, 0.3-17.9 years), the 10-year overall survival (OS) was 54.7% (SE = 2.9), which is significantly higher than the 27.6% (SE = 2.9) observed in the historical cohort from 1985 to 2000. There was no significant impact of sex, age, white blood cell count, central nervous system disease status, T-cell maturity, or BM disease burden at EOI on OS. Postinduction complete remission (CR) was achieved in 93% of patients with 10-year OS of 59.6% (SE = 3.1%) and disease-free survival (DFS) of 56.3% (SE = 3.1%). Among the patients who achieved CR, 72% underwent HSCT and their 10-year DFS (with a 190-day landmark) was significantly better than nontransplanted patients (63.8% [SE = 3.6] v 45.5% [SE = 7.1]; P = .005), with OS of 66.2% (SE = 3.6) versus 50.8% (SE = 6.8); P = .10, respectively.

CONCLUSION

Outcomes for patients age 21 years and younger with T-ALL and IF have improved in the contemporary treatment era with a DFS benefit among those undergoing HSCT in CR1. However, outcomes still lag considerably behind those who achieve remission at EOI, warranting investigation of new treatment approaches.

Assessment of proxy-reported responses as predictors of motor and sensory peripheral neuropathy in children with B-lymphoblastic leukemia

Chemotherapy-induced peripheral neuropathy (CIPN), a common condition in children with acute lymphoblastic leukemia, can be challenging to diagnose. Using data from Children's Oncology Group AALL0932 physical function study, we sought to determine if parent/guardian proxy-reported responses from the Pediatric Outcomes Data Collection Instrument could identify children with motor or sensory CIPN diagnosed by physical/occupational therapists (PT/OT). Four variables moderately discriminated between children with and without motor CIPN (c-index 0.76, 95% confidence interval [CI]: 0.64-0.84), but sensory and optimism-corrected models had weak discrimination (c-index sensory models 0.65, 95% CI: 0.54-0.74). New proxy-report measures are needed to identify children with PT/OT diagnosed CIPN.

Identification and targeting of treatment resistant progenitor populations in T-cell Acute Lymphoblastic Leukemia

Refractoriness to initial chemotherapy and relapse after remission are the main obstacles to cure in T-cell Acute Lymphoblastic Leukemia (T-ALL). Biomarker guided risk stratification and targeted therapy have the potential to improve outcomes in high-risk T-ALL; however, cellular and genetic factors contributing to treatment resistance remain unknown. Previous bulk genomic studies in T-ALL have implicated tumor heterogeneity as an unexplored mechanism for treatment failure. To link tumor subpopulations with clinical outcome, we created an atlas of healthy pediatric hematopoiesis and applied single-cell multiomic (CITE-seq/snATAC-seq) analysis to a cohort of 40 cases of T-ALL treated on the Children's Oncology Group AALL0434 clinical trial. The cohort was carefully selected to capture the immunophenotypic diversity of T-ALL, with early T-cell precursor (ETP) and Near/Non-ETP subtypes represented, as well as enriched with both relapsed and treatment refractory cases. Integrated analyses of T-ALL blasts and normal T-cell precursors identified a bone-marrow progenitor-like (BMP-like) leukemia sub-population associated with treatment failure and poor overall survival. The single-cell-derived molecular signature of BMP-like blasts predicted poor outcome across multiple subtypes of T-ALL within two independent patient cohorts using bulk RNA-sequencing data from over 1300 patients. We defined the mutational landscape of BMP-like T-ALL, finding that NOTCH1 mutations additively drive T-ALL blasts away from the BMP-like state. We transcriptionally matched BMP-like blasts to early thymic seeding progenitors that have low NR3C1 expression and high stem cell gene expression, corresponding to a corticosteroid and conventional cytotoxic resistant phenotype we observed in ex vivo drug screening. To identify novel targets for BMP-like blasts, we performed in silico and in vitro drug screening against the BMP-like signature and prioritized BMP-like overexpressed cell-surface (CD44, ITGA4, LGALS1) and intracellular proteins (BCL-2, MCL-1, BTK, NF-κB) as candidates for precision targeted therapy. We established patient derived xenograft models of BMP-high and BMP-low leukemias, which revealed vulnerability of BMP-like blasts to apoptosis-inducing agents, TEC-kinase inhibitors, and proteasome inhibitors. Our study establishes the first multi-omic signatures for rapid risk-stratification and targeted treatment of high-risk T-ALL.

Retrospective analysis of outcomes for pediatric acute lymphoblastic leukemia in South American centers

Introduction

Acute lymphoblastic Leukemia (ALL) is the most common pediatric malignancy. While the survival rate for childhood ALL exceeds 90% in high-income countries, the estimated survival in low-and middle-income countries ranges from 22-79%, depending on the region and local resources.

Methods

This study retrospectively reviewed demographic, biological, and clinical parameters of children under 18 years of age with newly diagnosed ALL presenting between 2013-2017 across five pediatric centers in 4 countries in South America. Survival analyses were estimated using the Kaplan-Meier method.

Results

Across the five centers, 752 patients were analyzed (Bolivia [N=9], Ecuador [N=221], Paraguay [N=197], Peru [N=325]) and 92.1% (n=690) patients were diagnosed with B-cell and 7.5% (n= 56) with T-cell ALL. The median age was 5.5 years old (IQR 7.29). At diagnosis, 47.8% of patients were categorized as standard and 51.9% as high risk per their institutional regimen. Advanced diagnostics availability varied between modalities. MRD was evaluated in 69.1% of patients; molecular testing was available for ETV6-RUNX, BCR-ABL1, TCF3-PBX1, and KMT2A-rearranged ALL in 75-81% of patients; however, karyotyping and evaluation for iAMP21 were only performed in 42-61% of patients. Central nervous system (CNS) involvement was evaluated at diagnosis in 57.3% (n=429) patients; of these, 93.7% (n=402) were CNS 1, 1.6% (n=7) were CNS 2, 0.7% (n=11) were CNS3, 1.9% (n=8) had cranial nerve palsy, and 2.1% (n=9) results unavailable. Chemotherapy delays >2 weeks were reported in 56.0% (n=421) patients during treatment. Delays were attributed to infection in 63.2% (n=265), drug-related toxicities in 47.3% (n=198), and resource constraints, including lack of bed availability in 23.2% (n=97) of patients. The 3-year Abandonment-sensitive EFS and OS were 61.0±1.9% and 67.2±1.8%, respectively. The 3-year EFS and OS were 71.0±1.8% and 79.6±1.7%, respectively.

Discussion

This work reveals opportunities to improve survival, including addressing severe infections, treatment interruptions, and modifications due to drug shortages. In 2018, healthcare professionals across South America established the Pediatric Oncology Latin America (POLA) group in collaboration with St. Jude Children's Research Hospital. POLA collaborators developed an evidence-based, consensus-derived, adapted treatment guideline, informed by preliminary results of this evaluation, to serve as the new standard of care for pediatric ALL in participating institutions.

Evaluation of factors leading to poor outcomes for pediatric acute lymphoblastic leukemia in Mexico: a multi-institutional report of 2,116 patients

Background and aims

Pediatric acute lymphoblastic leukemia (ALL) survival rates in low- and middle-income countries are lower due to deficiencies in multilevel factors, including access to timely diagnosis, risk-stratified therapy, and comprehensive supportive care. This retrospective study aimed to analyze outcomes for pediatric ALL at 16 centers in Mexico.

Methods

Patients <18 years of age with newly diagnosed B- and T-cell ALL treated between January 2011 and December 2019 were included. Clinical and biological characteristics and their association with outcomes were examined.

Results

Overall, 2,116 patients with a median age of 6.3 years were included. B-cell immunophenotype was identified in 1,889 (89.3%) patients. The median white blood cells at diagnosis were 11.2.5 × 103/mm3. CNS-1 status was reported in 1,810 (85.5%), CNS-2 in 67 (3.2%), and CNS-3 in 61 (2.9%). A total of 1,488 patients (70.4%) were classified as high-risk at diagnosis. However, in 52.5% (991/1,889) of patients with B-cell ALL, the reported risk group did not match the calculated risk group allocation based on National Cancer Institute (NCI) criteria. Fluorescence in situ hybridization (FISH) and PCR tests were performed for 407 (19.2%) and 736 (34.8%) patients, respectively. Minimal residual disease (MRD) during induction was performed in 1,158 patients (54.7%). The median follow-up was 3.7 years. During induction, 191 patients died (9.1%), and 45 patients (2.1%) experienced induction failure. A total of 365 deaths (17.3%) occurred, including 174 deaths after remission. Six percent (176) of patients abandoned treatment. The 5-year event-free survival (EFS) was 58.9% ± 1.7% for B-cell ALL and 47.4% ± 5.9% for T-cell ALL, while the 5-year overall survival (OS) was 67.5% ± 1.6% for B-cell ALL and 54.3% ± 0.6% for T-cell ALL. The 5-year cumulative incidence of central nervous system (CNS) relapse was 5.5% ± 0.6%. For the whole cohort, significantly higher outcomes were seen for patients aged 1-10 years, with DNA index >0.9, with hyperdiploid ALL, and without substantial treatment modifications. In multivariable analyses, age and Day 15 MRD continued to have a significant effect on EFS.

Conclusion

Outcomes in this multi-institutional cohort describe poor outcomes, influenced by incomplete and inconsistent risk stratification, early toxic death, high on-treatment mortality, and high CNS relapse rate. Adopting comprehensive risk-stratification strategies, evidence-informed de-intensification for favorable-risk patients and optimized supportive care could improve outcomes.

Treatment-related mortality in children with cancer in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Approximately 90% of children with cancer live in low-income and middle-income countries (LMICs), where 5-year survival is lower than 20%. Treatment-related mortality in high-income countries is approximately 3-5%; however, in LMICs, treatment-related mortality has been reported in up to 45% of children with cancer. This study aimed to systematically explore the burden of treatment-related mortality in children with cancer in LMICs and to explore the association between country income level and treatment-related mortality.

METHODS

For this systematic review and meta-analysis we identified articles published between Jan 1, 2010, and June 22, 2021, describing treatment-related mortality in paediatric patients (aged 0-21 years) with cancer in LMICs. We searched PubMed, Trip, Web of Science, Embase, and the WHO Global Metric Index databases. The search was limited to full-text articles and excluded case reports (<10 patients) and haematopoietic stem-cell transplantation recipients. Two reviewers independently screened studies for eligibility, extracted data from included publications, and evaluated data quality. Random and mixed-effects models were used to estimate treatment-related mortality burden and trends. The Cochran-Q statistic was used to assess heterogeneity between studies. This study is registered on PROSPERO (CRD42021264849).

FINDINGS

Of 13 269 identified abstracts, 501 studies representing 68 351 paediatric patients with cancer were included. The treatment-related mortality estimate was 6·82% (95% CI 5·99-7·64), accounting for 30·9% of overall mortality (4437 of 14 358 deaths). Treatment-related mortality was inversely related to country income. Treatment-related mortality was 14·19% (95% CI 9·65-18·73) in low-income countries, 9·21% (7·93-10·49) in lower-middle-income countries, and 4·47% (3·42-5·53) in upper-middle-income countries (Cochran-Q 42·39, p<0·0001). In upper-middle-income countries, the incidence of treatment-related mortality decreased over time (slope -0·002, p=0·0028); however, outcomes remained unchanged in low-income (p=0·21) and lower-middle-income countries (p=0·16).

INTERPRETATION

Approximately one in 15 children receiving cancer treatment in LMICs die from treatment-related complications. Although treatment-related mortality has decreased in upper-middle-income countries over time, it remains unchanged in LMICs. There is an urgent need for targeted supportive care interventions to reduce global disparities in childhood cancer survival.

FUNDING

American Lebanese Syrian Associated Charities and National Cancer Institute.

Children's Oncology Group AALL1331: Phase III Trial of Blinatumomab in Children, Adolescents, and Young Adults With Low-Risk B-Cell ALL in First Relapse

PURPOSE

Blinatumomab, a bispecific T-cell engager immunotherapy, is efficacious in relapsed/refractory B-cell ALL (B-ALL) and has a favorable toxicity profile. One aim of the Children's Oncology Group AALL1331 study was to compare survival of patients with low-risk (LR) first relapse of B-ALL treated with chemotherapy alone or chemotherapy plus blinatumomab.

PATIENTS AND METHODS

After block 1 reinduction, patients age 1-30 years with LR first relapse of B-ALL were randomly assigned to block 2/block 3/two continuation chemotherapy cycles/maintenance (arm C) or block 2/two cycles of continuation chemotherapy intercalated with three blinatumomab blocks/maintenance (arm D). Patients with CNS leukemia received 18 Gy cranial radiation during maintenance and intensified intrathecal chemotherapy. The primary and secondary end points were disease-free survival (DFS) and overall survival (OS).

RESULTS

The 4-year DFS/OS for the 255 LR patients accrued between December 2014 and September 2019 were 61.2% ± 5.0%/90.4% ± 3.0% for blinatumomab versus 49.5% ± 5.2%/79.6% ± 4.3% for chemotherapy (P = .089/P = .11). For bone marrow (BM) ± extramedullary (EM) (BM ± EM; n = 174) relapses, 4-year DFS/OS were 72.7% ± 5.8%/97.1% ± 2.1% for blinatumomab versus 53.7% ± 6.7%/84.8% ± 4.8% for chemotherapy (P = .015/P = .020). For isolated EM (IEM; n = 81) relapses, 4-year DFS/OS were 36.6% ± 8.2%/76.5% ± 7.5% for blinatumomab versus 38.8% ± 8.0%/68.8% ± 8.6% for chemotherapy (P = .62/P = .53). Blinatumomab was well tolerated and patients had low adverse event rates.

CONCLUSION

For children, adolescents, and young adults with B-ALL in LR first relapse, there was no statistically significant difference in DFS or OS between the blinatumomab and standard chemotherapy arms overall. However, blinatumomab significantly improved DFS and OS for the two thirds of patients with BM ± EM relapse, establishing a new standard of care for this population. By contrast, similar outcomes and poor DFS for both arms were observed in the one third of patients with IEM; new treatment approaches are needed for these patients (ClinicalTrials.gov identifier: NCT02101853).

Children's Oncology Group blueprint for research: Acute lymphoblastic leukemia

Cure rates for acute lymphoblastic leukemia (ALL), the most common childhood cancer have steadily improved over the past five decades. This is due to intensifying systemic therapy, recognizing and treating the central nervous system as a sanctuary site, and implementing modern risk stratification to deliver varying intensities of therapy based on age, presenting white blood count, sentinel somatic genetics, and therapy response. Recently, numerous Children's Oncology Group trials have demonstrated the lack of benefit of intensifying traditional chemotherapy, providing evidence that new approaches are needed to cure the patients for whom cure has been elusive. Distinguishing those who require intensive or novel therapeutic approaches from others who will be cured with minimal therapy is key for future trials. Incorporating new genomic biomarkers and more sensitive measures of minimal/measurable residual disease provide opportunities to achieve these goals.

Effect of paediatric early warning systems (PEWS) implementation on clinical deterioration event mortality among children with cancer in resource-limited hospitals in Latin America: a prospective, multicentre cohort study

BACKGROUND

Paediatric early warning systems (PEWS) aid in the early identification of clinical deterioration events in children admitted to hospital. We aimed to investigate the effect of PEWS implementation on mortality due to clinical deterioration in children with cancer in 32 resource-limited hospitals across Latin America.

METHODS

Proyecto Escala de Valoración de Alerta Temprana (Proyecto EVAT) is a quality improvement collaborative to implement PEWS in hospitals providing childhood cancer care. In this prospective, multicentre cohort study, centres joining Proyecto EVAT and completing PEWS implementation between April 1, 2017, and May 31, 2021, prospectively tracked clinical deterioration events and monthly inpatient-days in children admitted to hospital with cancer. De-identified registry data reported between April 17, 2017, and Nov 30, 2021, from all hospitals were included in analyses; children with limitations on escalation of care were excluded. The primary outcome was clinical deterioration event mortality. Incidence rate ratios (IRRs) were used to compare clinical deterioration event mortality before and after PEWS implementation; multivariable analyses assessed the correlation between clinical deterioration event mortality and centre characteristics.

FINDINGS

Between April 1, 2017, and May 31, 2021, 32 paediatric oncology centres from 11 countries in Latin America successfully implemented PEWS through Proyecto EVAT; these centres documented 2020 clinical deterioration events in 1651 patients over 556 400 inpatient-days. Overall clinical deterioration event mortality was 32·9% (664 of 2020 events). The median age of patients with clinical deterioration events was 8·5 years (IQR 3·9-13·2), and 1095 (54·2%) of 2020 clinical deterioration events were reported in male patients; data on race or ethnicity were not collected. Data were reported per centre for a median of 12 months (IQR 10-13) before PEWS implementation and 18 months (16-18) after PEWS implementation. The mortality rate due to a clinical deterioration event was 1·33 events per 1000 patient-days before PEWS implementation and 1·09 events per 1000 patient-days after PEWS implementation (IRR 0·82 [95% CI 0·69-0·97]; p=0·021). In the multivariable analysis of centre characteristics, higher clinical deterioration event mortality rates before PEWS implementation (IRR 1·32 [95% CI 1·22-1·43]; p<0·0001), being a teaching hospital (1·18 [1·09-1·27]; p<0·0001), not having a separate paediatric haematology-oncology unit (1·38 [1·21-1·57]; p<0·0001), and having fewer PEWS omissions (0·95 [0·92-0·99]; p=0·0091) were associated with a greater reduction in clinical deterioration event mortality after PEWS implementation; no association was found with country income level (IRR 0·86 [95% CI 0·68-1·09]; p=0·22) or clinical deterioration event rates before PEWS implementation (1·04 [0·97-1·12]; p=0·29).

INTERPRETATION

PEWS implementation was associated with reduced clinical deterioration event mortality in paediatric patients with cancer across 32 resource-limited hospitals in Latin America. These data support the use of PEWS as an effective evidence-based intervention to reduce disparities in global survival for children with cancer.

FUNDING

American Lebanese Syrian Associated Charities, US National Institutes of Health, and Conquer Cancer Foundation.

TRANSLATIONS

For the Spanish and Portuguese translations of the abstract see Supplementary Materials section.

The genomic landscape of acute lymphoblastic leukemia with intrachromosomal amplification of chromosome 21

Intrachromosomal amplification of chromosome 21 defines a subtype of high-risk childhood acute lymphoblastic leukemia (iAMP21-ALL) characterized by copy number changes and complex rearrangements of chromosome 21. The genomic basis of iAMP21-ALL and the pathogenic role of the region of amplification of chromosome 21 to leukemogenesis remains incompletely understood. In this study, using integrated whole genome and transcriptome sequencing of 124 patients with iAMP21-ALL, including rare cases arising in the context of constitutional chromosomal aberrations, we identified subgroups of iAMP21-ALL based on the patterns of copy number alteration and structural variation. This large data set enabled formal delineation of a 7.8 Mb common region of amplification harboring 71 genes, 43 of which were differentially expressed compared with non-iAMP21-ALL ones, including multiple genes implicated in the pathogenesis of acute leukemia (CHAF1B, DYRK1A, ERG, HMGN1, and RUNX1). Using multimodal single-cell genomic profiling, including single-cell whole genome sequencing of 2 cases, we documented clonal heterogeneity and genomic evolution, demonstrating that the acquisition of the iAMP21 chromosome is an early event that may undergo progressive amplification during disease ontogeny. We show that UV-mutational signatures and high mutation load are characteristic secondary genetic features. Although the genomic alterations of chromosome 21 are variable, these integrated genomic analyses and demonstration of an extended common minimal region of amplification broaden the definition of iAMP21-ALL for more precise diagnosis using cytogenetic or genomic methods to inform clinical management.

Physician Perceptions of and Barriers to Pediatric Palliative Care for Children With Cancer in Brazil

PURPOSE

Early integration of pediatric palliative care (PPC) for children with cancer is critical to improving the quality of life of both the patient and family. Understanding physician perceptions of palliative care and perceived barriers to early integration is necessary to develop PPC in Brazil.

METHODS

The Assessing Doctors' Attitudes on Palliative Treatment survey was modified for use in Brazil. The survey was open from January 2022 to June 2022 and distributed to physicians of all specialties from participating institutions who treat children with cancer. Statistical analysis was complemented by qualitative analysis of open-ended responses.

RESULTS

A total of 272 respondents participated. Most respondents reported access to PPC experts for consultation (77.2%) and 34.5% indicated previous palliative care training. Physician knowledge of PPC was generally aligned with WHO guidance (median alignment, 93.0%; range, 80.5%-98.2%). However, about half (53.3%) felt comfortable addressing physical needs of patients receiving PPC, 35.3% addressing emotional needs, 25.8% addressing spiritual needs, and 33.5% addressing grief and bereavement needs. Most respondents (65.4%) felt palliative care should be involved from diagnosis, but only 10.3% stated that this occurred in their setting. The most important barriers identified were physician discomfort (89.0%), limited physician knowledge (88.6%), and lack of home-based services (83.8%).

CONCLUSION

Despite a strong understanding of the role of palliative care, physicians in Brazil reported low confidence delivering PPC to children with cancer. Additionally, physicians generally believed that PPC should be integrated earlier in the disease trajectory of children with cancer. This work will direct educational and capacity building initiatives to ensure greater access to high-quality PPC for children with cancer in Brazil to address patient and family suffering.

Germline Genetic NBN Variation and Predisposition to B-cell Acute Lymphoblastic Leukemia in Children

Biallelic mutation in the DNA-damage repair gene NBN is the genetic cause of Nijmegen Breakage Syndrome, which is associated with predisposition to lymphoid malignancies. Heterozygous carriers of germline NBN variants may also be at risk for leukemia development, although this is much less characterized. We systematically examined the frequency of germline NBN variants in pediatric B-ALL and identified 25 putatively damaging NBN coding variants in 50 of 4,183 B-ALL patients. Compared with the frequency of NBN variants in 118,479 gnomAD non-cancer controls we found significant overrepresentation in pediatric B-ALL (p=0.004, OR=1.77). Most B-ALL-risk variants were missense and cluster within the NBN N-terminal domains. Using two functional assays, we verified 14 of 25 variants with severe loss-of-function phenotypes and thus classified these as pathogenic or likely pathogenic. Finally, we found that heterozygous germline NBN variant carriers showed similar survival outcomes relative to those with WT status. Taken together, our findings provide novel insights into the genetic predisposition to B-ALL, the impact of NBN variants on protein function and suggest that heterozygous NBN variant carriers may safely receive B-ALL therapy.

Genomic landscape of Down syndrome-associated acute lymphoblastic leukemia

Trisomy 21, the genetic cause of Down syndrome (DS), is the most common congenital chromosomal anomaly. It is associated with a 20-fold increased risk of acute lymphoblastic leukemia (ALL) during childhood and results in distinctive leukemia biology. To comprehensively define the genomic landscape of DS-ALL, we performed whole-genome sequencing and whole-transcriptome sequencing (RNA-Seq) on 295 cases. Our integrated genomic analyses identified 15 molecular subtypes of DS-ALL, with marked enrichment of CRLF2-r, IGH::IGF2BP1, and C/EBP altered (C/EBPalt) subtypes compared with 2257 non-DS-ALL cases. We observed abnormal activation of the CEBPD, CEBPA, and CEBPE genes in 10.5% of DS-ALL cases via a variety of genomic mechanisms, including chromosomal rearrangements and noncoding mutations leading to enhancer hijacking. A total of 42.3% of C/EBP-activated DS-ALL also have concomitant FLT3 point mutations or insertions/deletions, compared with 4.1% in other subtypes. CEBPD overexpression enhanced the differentiation of mouse hematopoietic progenitor cells into pro-B cells in vitro, particularly in a DS genetic background. Notably, recombination-activating gene-mediated somatic genomic abnormalities were common in DS-ALL, accounting for a median of 27.5% of structural alterations, compared with 7.7% in non-DS-ALL. Unsupervised hierarchical clustering analyses of CRLF2-rearranged DS-ALL identified substantial heterogeneity within this group, with the BCR::ABL1-like subset linked to an inferior event-free survival, even after adjusting for known clinical risk factors. These results provide important insights into the biology of DS-ALL and point to opportunities for targeted therapy and treatment individualization.

Dasatinib with intensive chemotherapy in de novo paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia (CA180-372/COG AALL1122): a single-arm, multicentre, phase 2 trial

BACKGROUND

The outcome of children with Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukaemia significantly improved with the combination of imatinib and intensive chemotherapy. We aimed to investigate the efficacy of dasatinib, a second-generation ABL-class inhibitor, with intensive chemotherapy in children with newly diagnosed Ph-positive acute lymphoblastic leukaemia.

METHODS

CA180-372/COG AALL1122 was a joint Children's Oncology Group (COG) and European intergroup study of post-induction treatment of Ph-positive acute lymphoblastic leukaemia (EsPhALL) open-label, single-arm, phase 2 study. Eligible patients (aged >1 year to <18 years) with newly diagnosed Ph-positive acute lymphoblastic leukaemia and performance status of at least 60% received EsPhALL chemotherapy plus dasatinib 60 mg/m² orally once daily from day 15 of induction. Patients with minimal residual disease of at least 0·05% after induction 1B or who were positive for minimal residual disease after the three consolidation blocks were classified as high risk and allocated to receive haematopoietic stem-cell transplantation (HSCT) in first complete remission. The remaining patients were considered standard risk and received chemotherapy plus dasatinib for 2 years. The primary endpoint was the 3-year event-free survival of dasatinib plus chemotherapy compared with external historical controls. The trial was considered positive if one of the following conditions was met: superiority over chemotherapy alone in the AIEOP-BFM 2000 high-risk group; or non-inferiority (with a margin of -5%) or superiority to imatinib plus chemotherapy in the EsPhALL 2010 cohort. All participants who received at least one dose of dasatinib were included in the safety and efficacy analyses. This trial was registered with ClinicalTrials.gov, NCT01460160, and recruitment is closed.

FINDINGS

Between March 13, 2012, and May 27, 2014, 109 patients were enrolled at 69 sites (including 51 COG sites in the USA, Canada, and Australia, and 18 EsPhALL sites in Italy and the UK). Three patients were ineligible and did not receive dasatinib. 106 patients were treated and included in analyses (49 [46%] female and 57 [54%] male; 85 [80%] White, 13 [12%] Black or African American, five [5%] Asian, and three [3%] other races; 24 [23%] Hispanic or Latino ethnicity). All 106 treated patients reached complete remission; 87 (82%) were classified as standard risk and 19 (18%) met HSCT criteria and were classified as high risk, but only 15 (14%) received HSCT in first complete remission. The 3-year event-free survival of dasatinib plus chemotherapy was superior to chemotherapy alone (65·5% [90% Clopper-Pearson CI 57·7 to 73·7] vs 49·2% [38·0 to 60·4]; p=0·032), and was non-inferior to imatinib plus chemotherapy (59·1% [51·8 to 66·2], 90% CI of the treatment difference: -3·3 to 17·2), but not superior to imatinib plus chemotherapy (65·5% vs 59·1%; p=0·27). The most frequent grade 3-5 adverse events were febrile neutropenia (n=93) and bacteraemia (n=21). Nine remission deaths occurred, which were due to infections (n=5), transplantation-related (n=2), due to cardiac arrest (n=1), or had an unknown cause (n=1). No dasatinib-related deaths occurred.

INTERPRETATION

Dasatinib plus EsPhALL chemotherapy is safe and active in paediatric Ph-positive acute lymphoblastic leukaemia. 3-year event-free survival was similar to that of previous Ph-positive acute lymphoblastic leukaemia trials despite the limited use of HSCT in first complete remission.

FUNDING

Bristol Myers Squibb.

Minimal residual disease predicts outcomes in KMT2A-rearranged but not KMT2A-germline infant acute lymphoblastic leukemia: Report from Children's Oncology Group study AALL0631

We measured minimal residual disease (MRD) by multiparameter flow cytometry at three time points (TP) in 117 infants with KMT2A (lysine [K]-specific methyltransferase 2A)-rearranged and 58 with KMT2A-germline acute lymphoblastic leukemia (ALL) on Children's Oncology Group AALL0631 study. For KMT2A-rearranged patients, 3-year event-free survival (EFS) by MRD-positive (≥0.01%) versus MRD-negative (<0.01%) was: TP1: 25% (±6%) versus 49% (±7%; p = .0009); TP2: 21% (±8%) versus 47% (±7%; p < .0001); and TP3: 22% (±14%) versus 51% (±6%; p = .0178). For KMT2A-germline patients, 3-year EFS was: TP1: 88% (±12%) versus 87% (±5%; p = .73); TP2: 100% versus 88% (±5%; p = .24); and TP3: 100% versus 87% (±5%; p = .53). MRD was a strong independent outcome predictor in KMT2A-rearranged, but not KMT2A-germline infant ALL.

Outcomes of SARS-CoV-2 infection in 126 children and adolescents with central nervous system tumors

BACKGROUND

The Global Registry of COVID-19 in Childhood Cancer (GRCCC) seeks to describe the natural history of SARS-CoV-2 in children with cancer across the world. Here, we report the disease course and management of coronavirus disease 2019 (COVID-19) infection in the subset of children and adolescents with central nervous system (CNS) tumors who were included in the GRCCC until February 2021, the first data freeze.

PROCEDURE

The GRCCC is a deidentified web-based registry of patients less than 19 years of age with cancer or recipients of a hematopoietic stem cell transplant and laboratory-confirmed SARS-CoV-2 infection. Demographic data, cancer diagnosis, cancer-directed therapy, and clinical characteristics of SARS-CoV-2 infection were collected. Outcomes were collected at 30 and 60 days post infection.

RESULTS

The GRCCC included 1500 cases from 45 countries, including 126 children with CNS tumors (8.4%). Sixty percent of the cases were from middle-income countries, while no cases were reported from low-income countries. Low-grade gliomas, high-grade gliomas, and CNS embryonal tumors were the most common CNS cancer diagnoses (67%, 84/126). Follow-up at 30 days was available for 107 (85%) patients. Based on the composite measure of severity, 53.3% (57/107) of reported SARS-CoV-2 infections were asymptomatic, 39.3% (42/107) were mild/moderate, and 6.5% (7/107) were severe or critical. One patient died from SARS-CoV-2 infection. There was a significant association between infection severity and absolute neutrophil count less than 500 (p = .04). Of 107 patients with follow-up available, 40 patients (37.4%) were not receiving cancer-directed therapy. Thirty-four patients (50.7%) had a modification to their treatment due to withholding of chemotherapy or delays in radiotherapy or surgery.

CONCLUSION

In this cohort of patients with CNS tumors and COVID-19, the frequency of severe infection appears to be low, although severe disease and death do occur. We found that greater severity was seen in patients with severe neutropenia, although treatment modifications were not associated with infection severity or cytopenias. Additional analyses are needed to further describe this unique group of patients.

Interdisciplinary care of pediatric oncology patients: A survey of clinicians in Central America and the Caribbean

BACKGROUND

Quality cancer care depends on interdisciplinary communication. This study explored the communication practices of interdisciplinary clinicians, the types of healthcare services for which they engage in interdisciplinary collaboration, and the association between interdisciplinary care and perceived quality of care, as well as job satisfaction.

METHODS

We conducted a survey of interdisciplinary clinicians from cancer centers in Guatemala, Honduras, Panama, El Salvador, and Haiti. The survey included 68 items including previously validated tools and novel questions.

RESULTS

Total 174 interdisciplinary clinicians completed the survey: nurses (n = 60), medical subspecialists (n = 35), oncologists (n = 22), psychosocial providers (n = 20), surgeons (n = 12), pathologists (n = 9), radiologists (n = 9), and radiation oncologists (n = 5). Oncologists reported daily communication with nurses (95%) and other oncologists (91%). While 90% of nurses reported daily communication with other nurses, only 66% reported daily communication with oncologists, and more than 50% of nurses reported never talking to pathologists, radiologists, radiation oncologists, or surgeons. Most clinicians described interdisciplinary establishment of cancer treatment goals and prognosis (84%), patient preferences (81%), and determination of first treatment modality (80%). Clinicians who described more interdisciplinary collaboration had higher job satisfaction (p = .04) and perceived a higher level of overall quality of care (p = .004).

CONCLUSIONS

Clinicians in these limited resource settings describe strong interdisciplinary collaboration contributing to higher job satisfaction and perceived quality of care. However, nurses in these settings reported more limited interdisciplinary communication and care. Additional studies are necessary to further define clinical roles on interdisciplinary care teams and their associations with patient outcomes.

Central nervous system status is prognostic in T-cell acute lymphoblastic leukemia: a Children's Oncology Group report

To determine the prognostic significance of central nervous system (CNS) leukemic involvement in newly diagnosed T-cell acute lymphoblastic leukemia (T-ALL), outcomes on consecutive, phase 3 Children's Oncology Group clinical trials were examined. AALL0434 and AALL1231 tested efficacy of novel agents within augmented-Berlin-Frankfurt-Münster (aBFM) therapy. In addition to testing study-specific chemotherapy through randomization, the AALL0434 regimen delivered cranial radiation therapy (CRT) to most participants (90.8%), whereas AALL1231 intensified chemotherapy to eliminate CRT in 88.2% of participants. In an analysis of 2164 patients with T-ALL (AALL0434, 1550; AALL1231, 614), 1564 had CNS-1 (72.3%), 441 CNS-2 (20.4%), and 159 CNS-3 (7.3%). The 4-year event-free-survival (EFS) was similar for CNS-1 (85.1% ± 1.0%) and CNS-2 (83.2% ± 2.0%), but lower for CNS-3 (71.8% ± 4.0%; P = .0004). Patients with CNS-1 and CNS-2 had similar 4-year overall survival (OS) (90.1% ± 0.8% and 90.5% ± 1.5%, respectively), with OS for CNS-3 being 82.7% ± 3.4% (P = .005). Despite therapeutic differences, outcomes for CNS-1 and CNS-2 were similar regardless of CRT, intensified corticosteroids, or novel agents. Except for significantly superior outcomes with nelarabine on AALL0434 (4-year disease-free survival, 93.1% ± 5.2%), EFS/OS was inferior with CNS-3 status, all of whom received CRT. Combined analyses of >2000 patients with T-ALL identified that CNS-1 and CNS-2 status at diagnosis had similar outcomes. Unlike B-ALL, CNS-2 status in T-ALL does not impact outcome with aBFM therapy, without additional intrathecal therapy, with or without CRT. Although nelarabine improved outcomes for those with CNS-3 status, novel approaches are needed. These trials were registered at www.clinicaltrials.gov as #NCT00408005 (AALL0434) and #NCT02112916 (AALL1231).

Outcomes of Childhood Noninfant Acute Lymphoblastic Leukemia With 11q23/KMT2A Rearrangements in a Modern Therapy Era: A Retrospective International Study

PURPOSE

We aimed to study prognostic factors and efficacy of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) in first remission of patients with noninfant childhood acute lymphoblastic leukemia (ALL) with 11q23/KMT2A rearrangements treated with chemotherapy regimens between 1995 and 2010.

PATIENTS AND METHODS

Data were retrospectively retrieved from 629 patients with 11q23/KMT2A-rearranged ALL from 17 members of the Ponte-di-Legno Childhood ALL Working Group. Clinical and biologic characteristics, early response assessed by minimal residual disease at the end of induction (EOI) therapy, and allo-HSCT were analyzed for their impact on outcomes.

RESULTS

A specific 11q23/KMT2A translocation partner gene was identified in 84.3% of patients, with the most frequent translocations being t(4;11)(q21;q23) (n = 273; 51.5%), t(11;19)(q23;p13.3) (n = 106; 20.0%), t(9;11)(p21_22;q23) (n = 76; 14.3%), t(6;11)(q27;q23) (n = 20; 3.8%), and t(10;11)(p12;q23) (n = 14; 2.6%); 41 patients (7.7%) had less frequently identified translocation partner genes. Patient characteristics and early response varied among subgroups, indicating large biologic heterogeneity and diversity in therapy sensitivity among 11q23/KMT2A-rearranged ALL. The EOI remission rate was 93.2%, and the 5-year event-free survival (EFS) for the entire cohort was 69.1% ± 1.9%, with a range from 41.7% ± 17.3% for patients with t(9;11)-positive T-ALL (n = 9) and 64.8% ± 3.0% for patients with t(4;11)-positive B-ALL (n = 266) to 91.2% ± 4.9% for patients with t(11;19)-positive T-ALL (n = 34). Low EOI minimal residual disease was associated with favorable EFS, and induction failure was particularly predictive of nonresponse to further therapy and relapse and poor EFS. In addition, EFS was not improved by allo-HSCT compared with chemotherapy only in patients with both t(4;11)-positive B-ALL (n = 64 v 51; P = .10) and 11q23/KMT2A-rearranged T-ALL (n = 16 v 10; P = .69).

CONCLUSION

Compared with historical data, prognosis of patients with noninfant 11q23/KMT2A-rearranged ALL has improved, but allo-HSCT failed to affect outcome. Targeted therapies are needed to reduce relapse and treatment-related mortality rates.

Racial and ethnic disparities in childhood and young adult acute lymphocytic leukaemia: secondary analyses of eight Children's Oncology Group cohort trials

BACKGROUND

Previous studies have identified racial and ethnic disparities in childhood acute lymphocytic leukaemia survival. We aimed to establish whether disparities persist in contemporaneous cohorts and, if present, are attributable to differences in leukaemia biology or insurance status.

METHODS

Patients with newly diagnosed acute lymphocytic leukaemia in inpatient and outpatient centres in the USA, Canada, Australia, and New Zealand, aged 0-30 years, who had race or ethnicity data available, enrolled on eight completed Children's Oncology Group trials (NCT00103285, NCT00075725, NCT00408005, NCT01190930, NCT02883049, NCT02112916, NCT02828358, and NCT00557193) were included in this secondary analysis. Race and ethnicity were categorised as non-Hispanic White, Hispanic, non-Hispanic Black, non-Hispanic Asian, and non-Hispanic other. Event-free survival and overall survival were compared across race and ethnicity groups. The relative contribution of clinical and biological disease prognosticators and insurance status was examined through multivariable regression models, both among the entire cohort and among those with B-cell lineage versus T-cell lineage disease.

FINDINGS

Between Jan 1, 2004, and Dec 31, 2019, 24 979 eligible children, adolescents, and young adults with acute lymphocytic leukaemia were enrolled, of which 21 152 had race or ethnicity data available. 11 849 (56·0%) were male and 9303 (44·0%) were female. Non-Hispanic White patients comprised the largest racial or ethnic group (13 872 [65·6%]), followed by Hispanic patients (4354 [20·6%]), non-Hispanic Black patients (1517 [7·2%]), non-Hispanic Asian (n=1071 [5·1%]), and non-Hispanic other (n=338 [1·6%]). 5-year event-free survival was 87·4% (95% CI 86·7-88·0%) among non-Hispanic White patients compared with 82·8% (81·4-84·1%; hazard ratio [HR] 1·37, 95% CI 1·26-1·49; p<0·0001) among Hispanic patients and 81·8% (79·3-84·0; HR 1·45, 1·28-1·65; p<0·0001) among non-Hispanic Black patients. Non-hispanic Asian patients had a 5-year event-free survival of 88·1% (95% CI 85·5-90·3%) and non-Hispanic other patients had a survival of 82·8% (76·4-87·6%). Inferior event-free survival among Hispanic patients was substantially attenuated by disease prognosticators and insurance status (HR decreased from 1·37 [1·26-1·49; p<0·0001] to 1·11 [1·00-1·22; p=0·045]). The increased risk among non-Hispanic Black patients was minimally attenuated (HR 1·45 [1·28-1·65; p<0·0001] to 1·32 [1·14-1·52; p<0·0001]). 5-year overall survival was 93·6% (91·5-95·1%) in non-Hispanic Asian patients, 93·3% (92·8-93·7%) in non-Hispanic White patients, 89·9% (88·7-90·9%) in Hispanic, 89·7% (87·6-91·4%) in non-Hispanic Black patients, 88·9% (83·2-92·7%) in non-Hispanic other patients. Disparities in overall survival were wider than event-free survival (eg, among non-Hispanic other patients, the HR for event-free survival was 1·43 [1·10-1·85] compared with 1·74 [1·27-2·40] for overall survival). Disparities were restricted to patients with B-cell acute lymphocytic leukaemia, no differences in event-free survival or overall survival were seen in the T-cell acute lymphocytic leukaemia group.

INTERPRETATION

Substantial disparities in outcome for B-cell acute lymphocytic leukaemia persist by race and ethnicity, but are not observed in T-cell acute lymphocytic leukaemia. Future studies of relapsed patients, access to and quality of care, and other potential aspects of structural racism are warranted to inform interventions aimed at dismantling racial and ethnic disparities.

FUNDING

National Cancer Institute and St Baldrick's Foundation.

An international multicenter survey reveals health care providers' knowledge gap in childhood central nervous system tumors

Childhood central nervous system (CNS) tumors have longer delays in diagnosis than do other pediatric malignancies because health care providers (HCPs) lack awareness about clinical presentation of these tumors. To evaluate the knowledge gap among HCPs, we conducted a global cross-sectional survey. The survey consisted of a set of CNS tumor knowledge questions focused on symptoms, signs, and imaging indications. The survey was disseminated to HCPs via email (November 2018-March 2020). Participants had to complete a pre-test survey, attend an education seminar on CNS tumors, and complete a post-test survey. The knowledge gap was evaluated using pre-test and post-test scores. We received 889 pre-test and 392 post-test responses. Most respondents were from Asia (73.1% of pre-test responses; 87.5% of post-test responses). The median pre-test score was 40.0% (range: 13.1-92.9%). A high percentage of correct answers were given in post-test responses (median score: 77.1%, range: 14.9-98.2%). In the pre-test, 18.7% of participants accurately responded that Cushing's triad was a less common symptom, and 15.0% recognized that children aged > 10 years are at risk of late diagnosis. Surprisingly, 21.9% falsely reported that patients with malignancy experienced the longest pre-diagnostic symptom interval, and 54.5% of respondents wrongly selected medulloblastoma as the most common CNS tumor. Overall, pediatricians demonstrated a greater knowledge gap on both surveys than did other specialties.  Conclusion: Pre- and post-test surveys revealed significant knowledge gaps in childhood CNS tumors among HCPs. Thus, raising professional awareness on clinical presentations of CNS tumors through educational strategies is important to address this knowledge deficit. What is Known: • Diagnostic delay in childhood central nervous system (CNS) tumors continues to be a significant problem that negatively impacts the quality of life and treatment sequelae. • Lack of medical education on CNS tumors is a contributing factor to this problem. What is New: • Most health care providers do not realize that low-grade tumors are the most common neoplasm in children. • Health care providers fail to recognize that teenagers and adolescents are a vulnerable age group for diagnostic delays, with the longest pre-diagnostic symptom interval.

Addressing the Gap in Research Methodologies Education in Pediatric Oncology in the Eastern Mediterranean Region

PURPOSE

Formal training in clinical research methodologies is limited in limited-resource countries. Through collaboration among high- and middle-resource settings and in response to an identified need verbalized by regional pediatric oncology practitioners, Pediatric Oncology East & Mediterranean Group and St Jude Global developed a workshop focused on capacity building in research skills. Here, we describe its structure, implementation, and early results.

METHODS

Leveraging virtual capabilities, the format included lectures and small group breakout exercise sessions, for 3 hours per day on 2 consecutive days per week for 2 consecutive weeks. Topics included basics of study design, introduction to health care statistics, research ethics, data registries, and scientific writing. Applicants were required to submit an abstract for a potential research project. Each breakout group selected one abstract for further development and presented the final version in a groupwide session. The participants' experience was evaluated through an online survey.

RESULTS

Attendance included 29 registrants from 12 countries and six disciplines. Each breakout group was assigned a themed category: cohort studies, clinical trials, or registries. Critical feedback from the breakout sessions helped strengthen the selected projects, which included a retrospective study, a prospective observational study, a prospective interventional study, and a registry proposal. After the workshop, participants were invited to further develop their original abstracts, and three proposals received additional mentoring, one of which was a multi-institutional prospective study that was subsequently submitted through the Pediatric Oncology East & Mediterranean Group network for implementation. The postworkshop survey revealed an overall highly positive experience, and feedback provided potential themes for future workshops.

CONCLUSION

This workshop demonstrated the potential for collaborative network partnerships in targeting research training gaps in pediatric oncology. Lessons learned will be applied to future workshops to strengthen research in limited-resource settings.

Ideal vs Actual Timing of Palliative Care Integration for Children With Cancer in Latin America

IMPORTANCE

Early integration of pediatric palliative care (PPC) for children with cancer is critical for the quality of life of both patient and family. To improve access to PPC in resource-limited settings, barriers to early integration must be understood.

OBJECTIVES

To evaluate the ideal vs actual timing of PPC integration for children with cancer and to uncover barriers to early integration identified by physicians in Latin America.

DESIGN, SETTING, AND PARTICIPANTS

The Assessing Doctors' Attitudes on Palliative Treatment (ADAPT) survey was distributed electronically from August 1, 2020, to January 31, 2021, to physicians who treat children with cancer in 17 countries in Latin America.

MAIN OUTCOMES AND MEASURES

The ADAPT survey queried for understanding of ideal vs actual timing of PPC for children with cancer and for identification of barriers to PPC integration. Descriptive statistics were used to summarize the data. For secondary analyses, a comparison of the associations of previous palliative care training with physician specialty was performed using the Pearson χ2 test or the Fisher exact test. The McNemar test was used to assess responses regarding the actual vs ideal timing of PPC consultation. Analysis of variance was used to compare mean values for perceived barriers by country income level. Answers to open-ended questions were analyzed qualitatively.

RESULTS

A total of 831 physicians (578 women [69.6%]; 275 physicians [33.1%] aged <35 years and 556 physicians [66.9%] aged ≥35 years) from 17 countries participated, with an overall response rate of 37.9% (831 of 2193) and a median country response rate of 51.4% (range, 22.2%-88.9%). Most respondents (572 [68.8%]) said that PPC should be involved from diagnosis, but only 117 (14.1%) stated that this occurred at their institution (P < .001). The most significantly ranked barriers to PPC were lack of home-based services (713 [85.8%]), personnel (654 [78.7%]), and knowledge about PPC (693 [83.4%]), along with physician (676 [81.3%]) and family (603 [72.6%]) discomfort about PPC involvement. In addition, these barriers were rated as more important in lower-middle income countries compared with upper-middle income countries and high-income countries.

CONCLUSIONS AND RELEVANCE

This study highlights the discrepancy between ideal and actual timing of PPC for children with cancer and barriers to early PPC integration in Latin America. Interventions addressing access to PPC resources, didactic training, and clinical education (with a particular focus on equitable access to basic resources and support) are critical to improve the timing and quality of PPC in the region.

Impact of hospital characteristics on implementation of a Pediatric Early Warning System in resource-limited cancer hospitals

Background

Pediatric Early Warning Systems (PEWS) aid in identification of deterioration in hospitalized children with cancer but are underutilized in resource-limited settings. Proyecto EVAT is a multicenter quality improvement (QI) collaborative in Latin America to implement PEWS. This study investigates the relationship between hospital characteristics and time required for PEWS implementation.

Methods

This convergent mixed-methods study included 23 Proyecto EVAT childhood cancer centers; 5 hospitals representing quick and slow implementers were selected for qualitative analysis. Semi-structured interviews were conducted with 71 stakeholders involved in PEWS implementation. Interviews were recorded, transcribed and translated to English, then coded using a priori and novel codes. Thematic content analysis explored the impact of hospital characteristics and QI experience on time required for PEWS implementation and was supplemented by quantitative analysis exploring the relationship between hospital characteristics and implementation time.

Results

In both quantitative and qualitative analysis, material and human resources to support PEWS significantly impacted time to implementation. Lack of resources produced various obstacles that extended time necessary for centers to achieve successful implementation. Hospital characteristics, such as funding structure and type, influenced PEWS implementation time by determining their resource-availability. Prior hospital or implementation leader experience with QI, however, helped facilitate implementation by assisting implementers predict and overcome resource-related challenges.

Conclusions

Hospital characteristics impact time required to implement PEWS in resource-limited childhood cancer centers; however, prior QI experience helps anticipate and adapt to resource challenges and more quickly implement PEWS. QI training should be a component of strategies to scale-up use of evidence-based interventions like PEWS in resource-limited settings.

Association of Inherited Genetic Factors With Drug-Induced Hepatic Damage Among Children With Acute Lymphoblastic Leukemia

Importance

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Hepatotoxic effects, including hyperbilirubinemia and elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, are common during all phases of therapy and are linked to several chemotherapeutic agents, including asparaginase, mercaptopurine, and methotrexate.

Objective

To determine which genetic variants were associated with hyperbilirubinemia and elevated ALT and AST levels in children, adolescents, and young adults treated for ALL.

Design, Setting, and Participants

This retrospective analysis of a multiethnic genome-wide association study was conducted between January 1, 2019, and April 15, 2022, including patients treated as part of Children's Oncology Group (COG) trials with centers in the United States, Canada, and Australia, which accrued data from December 29, 2003, to January 21, 2011 (AALL0232), and from January 22, 2007, to July 24, 2014 (AALL0434). Germline genotypes were interrogated using genome-wide arrays and imputed using a National Institutes of Health TOPMed Imputation server. Mixed-effects logistic regressions were used to account for multiple episodes for an individual patient. Genotype × treatment phase interaction was tested to uncover phase-specific genetic risk factors.

Exposures

Total duration of multiagent protocol chemotherapy ranging from 2.5 to 3.5 years.

Main Outcomes and Measures

The primary outcomes were National Cancer Institute Common Terminology Criteria for Adverse Events (version 4) hyperbilirubinemia of grade 3 or higher and elevated liver ALT and AST levels.

Results

A total of 3557 participants were included in the analysis (2179 [61.3%] male; median age, 11.1 [range, 1-30] years). Among 576 known variants associated with these liver function test results in the general population, UGT1A1 variant rs887829 and PNPLA3 variant rs738409 were associated with increased risk of hyperbilirubinemia (odds ratio [OR], 2.18 [95% CI, 1.89-2.53]; P = 6.7 × 10-27) and ALT and AST levels (OR, 1.27 [95% CI, 1.15-1.40]; P = 3.7 × 10-7), respectively, during treatment for ALL. Corresponding polygenic risk scores were associated with hepatotoxic effects across all therapy phases and were largely driven by UGT1A1 and PNPLA3 variants. Genome-wide association analysis revealed an age-specific variant near the CPT1A gene that was only associated with elevated ALT and AST levels among patients younger than 10 years (OR, 1.28 [95% CI, 1.18-1.39]; P = 8.7 × 10-10).

Conclusions and Relevance

These results suggest a strong genetic basis for interpatient variability in hyperbilirubinemia and aminotransferase level elevations during leukemia chemotherapy.

Outcomes for critical illness in children with cancer: Analysis of risk factors for adverse outcome and resource utilization from a specialized center in Mexico

Introduction

Children with cancer have a higher risk of adverse outcomes during critical illness than general pediatric populations. In Low- and middle-income countries, lack of resources can further negatively impact outcomes in critically ill children with cancer.

Methods

In this study, we describe the outcomes of a large cohort of children with cancer including mortality and resource utilization. We performed a retrospective review of all patients admitted to our PICU between December 12th, 2013 and December 31st, 2019. Outcomes were defined as recovery or death and resource utilization was described via use of critical care interventions, Length of stay as well as PICU- and Mechanical Ventilation- free days.

Results

Overall mortality was 6.9% while mortality in the unplanned admissions was 9.1%. This remained lower than expected mortality based on PIM2 scoring. Type of PICU admission, Neurological Deterioration as a cause of PICU admission, and PIM2 were significant as risk factors in univariate analysis, but only PIM2 remained significant in the multivariate analysis.

Discussion

Our Study shows that high survival rates are achievable for children with cancer with critical illness in resource-limited settings with provision of high-quality critical care. Organizational and clinical practice facilitating quality improvement and early identification and management of critical illness may attenuate the impact of known risk factors for mortality in this population.

Improving infectious adverse event reporting for children and adolescents enrolled in clinical trials for acute lymphoblastic leukemia: A report from the Children's Oncology Group

Infections cause substantial morbidity for children with acute lymphoblastic leukemia (ALL). Therefore, accurate characterization of infectious adverse events (AEs) reported on clinical trials is imperative to defining, comparing, and managing safety and toxicity. Here, we describe key processes implemented to improve reporting of infectious AEs on two active phase III Children's Oncology Group (COG) ALL trials. Processes include: (a) identifying infections as a targeted toxicity, (b) incorporation of infection-specific case report form questions, and (c) physician review of AEs with real-time data cleaning. Preliminary assessment of these processes suggests improved reporting, as well as opportunities for further improvement.

Design and methods of a randomized web-based physical activity intervention among children with cancer: A report from the Children's Oncology Group

BACKGROUND

Promoting physical activity soon after treatment for childhood cancer may benefit health because sedentary lifestyle during curative therapy may perpetuate physical and emotional complications. The primary goals of this study are to evaluate the effects of a 6-month web-based, rewards-based physical activity intervention on fitness, biomarkers of cardiometabolic health, inflammation, adipokine status, quality of life and school attendance, and determine if effect of intervention on markers of cardiometabolic health is mediated by changes in fitness. The primary outcome of interest is fitness (physiological cost index, six-minute walk test) measured at end of intervention.

METHODS

This ongoing study is a two-arm, prospective, randomized design with accrual goals of 192 children for intervention and control groups. Children ≥8 years and < 16 years of age, not meeting recommended levels of physical activity, who completed therapy within the past 12 months are eligible. Both groups receive: 1) educational materials encouraging physical activity, 2) activity monitor, 3) access to web-based interface designed to motivate physical activity, 4) rewards based on physical activity levels, and 5) access to their activity data on the web-interface. Those randomized to intervention: 1) can view others' activity and interact with other participants, and 2) receive rewards based on physical activity levels throughout the intervention (vs. at the end of the intervention for control group).

CONCLUSION

Unique, scalable, and portable physical activity interventions that motivate young survivors are needed. This study will inform future web-based physical activity interventions for children with cancer by demonstrating effects of rewards and social interaction.

CLINICAL TRIALS

ClinicalTrials.gov Identifier: NCT03223753; COG Identifier: ALTE1631.

Molecular Mechanisms of ARID5B-Mediated Genetic Susceptibility to Acute Lymphoblastic Leukemia

BACKGROUND

There is growing evidence for the inherited basis of susceptibility to childhood acute lymphoblastic leukemia (ALL). Genome-wide association studies have identified non-coding ALL risk variants at the ARID5B gene locus, but their exact functional effects and the molecular mechanism linking ARID5B to B-cell ALL leukemogenesis remain largely unknown.

METHODS

We performed targeted sequencing of ARID5B in germline DNA of 5008 children with ALL. Variants were evaluated for association with ALL susceptibility using 3644 patients from the UK10K cohort as non-ALL controls, under an additive model. Cis-regulatory elements in ARID5B were systematically identified using dCas9-KRAB-mediated enhancer interference system enhancer screen in ALL cells. Disruption of transcription factor binding by ARID5B variant was predicted informatically and then confirmed using chromatin immunoprecipitation and coimmunoprecipitation. ARID5B variant association with hematological traits was examined using UK Biobank dataset. All statistical tests were 2-sided.

RESULTS

We identified 54 common variants in ARID5B statistically significantly associated with leukemia risk, all of which were noncoding. Six cis-regulatory elements at the ARID5B locus were discovered using CRISPR-based high-throughput enhancer screening. Strikingly, the top ALL risk variant (rs7090445, P = 5.57 × 10-45) is located precisely within the strongest enhancer element, which is also distally tethered to the ARID5B promoter. The variant allele disrupts the MEF2C binding motif sequence, resulting in reduced MEF2C affinity and decreased local chromosome accessibility. MEF2C influences ARID5B expression in ALL, likely via a transcription factor complex with RUNX1. Using the UK Biobank dataset (n = 349 861), we showed that rs7090445 was also associated with lymphocyte percentage and count in the general population (P = 8.6 × 10-22 and 2.1 × 10-18, respectively).

CONCLUSIONS

Our results indicate that ALL risk variants in ARID5B function by modulating cis-regulatory elements at this locus.

Regional adaptation of the education in palliative and end-of-life Care Pediatrics (EPEC-Pediatrics) curriculum in Eurasia

BACKGROUND

Pediatric palliative care (PPC) is a priority to improve pediatric hematology oncology (PHO) care in Eurasia. However, there are limited regional opportunities for PPC education. We describe the adaptation and implementation of a bilingual end-user Education in Palliative and End-of-Life Care (EPEC)-Pediatrics course for PHO clinicians in Eurasia.

METHODS

Due to COVID-19, this course was delivered virtually, consisting of prerecorded, asynchronous lectures, and a bilingual workshop with interactive lectures and small group sessions. A pre-postcourse design was used to evaluate the knowledge acquisition of the participants including their knowledge alignment with World Health Organization (WHO) guidance, ideal timing of palliative care, and comfort in providing palliative care to their patients. Questions were mostly quantitative with multiple choice or Likert scale options, supplemented by free-text responses.

RESULTS

A total of 44 (76%) participants from 14 countries completed all components of the course including pre- and postcourse assessments. Participant alignment with WHO guidance improved from 75% in the pre- to 90% in the postcourse assessments (p < 0.001). After participation, 93% felt more confident controlling the suffering of children at the end of life, 91% felt more confident in prescribing opioids and managing pain, and 98% better understood how to hold difficult conversations with patients and families. Most participants (98%) stated that they will change their clinical practice based on the skills and knowledge gained in this course.

CONCLUSIONS

We present a successful regional adaptation of the EPEC-Pediatrics curriculum, including novel delivery of course content via a virtual bilingual format. This course resulted in significant improvement in participant attitudes and knowledge of PPC along with an understanding of the ideal timing of palliative care consultation and comfort in providing PPC to children with cancer. We plan to incorporate participant feedback to improve the course and repeat it annually to improve access to high-quality palliative care education for PHO clinicians in Eurasia.

The genomic landscape of pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Here, using whole-genome, exome and transcriptome sequencing of 2,754 childhood patients with ALL, we find that, despite a generally low mutation burden, ALL cases harbor a median of four putative somatic driver alterations per sample, with 376 putative driver genes identified varying in prevalence across ALL subtypes. Most samples harbor at least one rare gene alteration, including 70 putative cancer driver genes associated with ubiquitination, SUMOylation, noncoding transcripts and other functions. In hyperdiploid B-ALL, chromosomal gains are acquired early and synchronously before ultraviolet-induced mutation. By contrast, ultraviolet-induced mutations precede chromosomal gains in B-ALL cases with intrachromosomal amplification of chromosome 21. We also demonstrate the prognostic significance of genetic alterations within subtypes. Intriguingly, DUX4- and KMT2A-rearranged subtypes separate into CEBPA/FLT3- or NFATC4-expressing subgroups with potential clinical implications. Together, these results deepen understanding of the ALL genomic landscape and associated outcomes.

Cancer treatment decision-making among parents of paediatric oncology patients in Guatemala: a mixed-methods study

OBJECTIVES

To examine treatment decision-making priorities and experiences among parents of children with cancer in Guatemala.

SETTING

This study was conducted at Guatemala's National Pediatric Cancer Center in Guatemala City.

PARTICIPANTS

Spanish-speaking parents of paediatric patients (≤18 years of age) diagnosed with any form of cancer within the 8 weeks prior to study enrolment. The quantitative portion of this study included 100 parent participants; the qualitative component included 20 parents. Most participants were Catholic or Evangelical Spanish-speaking mothers.

OUTCOMES

Priorities and experiences of cancer treatment decision-making including decision-making role and experienced regret.

RESULTS

A range of paediatric ages and cancer diagnoses were included. Most Guatemalan parents surveyed (70%) made decisions about their child's cancer together and almost all (94%) without input from their community. Surveyed parents predominately preferred shared decision-making with their child's oncologist (76%), however 69% agreed it was best not to be provided with many options. Two-thirds of surveyed parents (65%) held their preferred role in decision-making, with fathers more likely to hold their preferred role than mothers (p=0.02). A small number of parents (11%) experienced heightened decisional regret, which did not correlate with socio-demographic characteristics or preferred decision-making role. Qualitative results supported quantitative findings, demonstrating a decision-making process that emphasised trust and honesty.

CONCLUSIONS

Guatemalan parents preferred to make decisions with their medical team and appreciated providers who were honest and inclusive, but directive about decisions. This study reinforces the importance of the provider-parent relationship and encourages clinicians in all settings to ask about and honour each parent's desired role in decision-making.

Persistence of Chemotherapy-Induced Peripheral Neuropathy Despite Vincristine Reduction in Childhood B-Acute Lymphoblastic Leukemia

BACKGROUND

Children with B-acute lymphoblastic leukemia (B-ALL) are at risk for chemotherapy-induced peripheral neuropathy (CIPN). Children's Oncology Group AALL0932 randomized reduction in vincristine and dexamethasone (every 4 weeks vs 12 weeks during maintenance in the average-risk subset of National Cancer Institute standard-B-ALL (SR AR B-ALL). We longitudinally measured CIPN, overall and by treatment group.

METHODS

AALL0932 standard-B-ALL patients aged 3 years and older were evaluated at T1-T4 (end consolidation, maintenance month 1, maintenance month 18, 12 months posttherapy). Physical and occupational therapists (PT/OT) measured motor CIPN (hand and ankle strength, dorsiflexion and plantarflexion range of motion), sensory CIPN (finger and toe vibration and touch), function (dexterity [Purdue Pegboard], and walking efficiency [Six-Minute Walk]). Proxy-reported function (Pediatric Outcome Data Collection Instrument) and quality of life (Pediatric Quality of Life Inventory) were assessed. Age- and sex-matched z scores and proportion impaired were measured longitudinally and compared between groups.

RESULTS

Consent and data were obtained from 150 participants (mean age = 5.1 years [SD = 1.7], 48.7% female). Among participants with completed evaluations, 81.8% had CIPN at T1 (74.5% motor, 34.1% sensory). When examining severity of PT/OT outcomes, only handgrip strength (P < .001) and walking efficiency (P = .02) improved from T1-T4, and only dorsiflexion range of motion (46.7% vs 14.7%; P = .008) and handgrip strength (22.2% vs 37.1%; P = .03) differed in vincristine and dexamethasone every 4 weeks vs vincristine and dexamethasone 12 weeks at T4. Proxy-reported outcomes improved from T1 to T4 (P < .001), and most did not differ between groups.

CONCLUSIONS

CIPN is prevalent early in B-ALL therapy and persists at least 12 months posttherapy. Most outcomes did not differ between treatment groups despite reduction in vincristine frequency. Children with B-ALL should be monitored for CIPN, even with reduced vincristine frequency.