PAX5 Alterations in a Consecutive Childhood B-Cell Acute Lymphoblastic Leukemia Cohort Treated Using the ALL IC-BFM 2009 Protocol.

In this study, we aimed to identify patients within our B-ALL cohort with altered PAX5. Our objective was to use a comprehensive analysis approach to characterize the types of genetic changes, determine their origin (somatic/germline), and analyze the clinical outcomes associated with them. A consecutive cohort of 99 patients with B-ALL treated at the Children's Hospital of the UMC Ljubljana according to the ALL IC-BFM 2009 protocol was included in our study. We used RNA sequencing data for gene expression analysis, fusion gene detection and single nucleotide variant identification, multiplex-ligation dependent probe amplification for copy number variation assessment, and Sanger sequencing for germline variant detection. PAX5 was impacted in 33.3% of our patients, with the genetic alterations ranging from CNVs and rearrangements to SNVs. The most common were CNVs, which were found in more than a third of patients, followed by point mutations in 5.2%, and gene rearrangements in 4.1%. We identified eight patients with a PAX5-associated genetic subtype that were previously classified as "B-other", and they showed intermediate outcomes. We showed higher minimal residual disease values at the end of induction and poorer event-free survival in hyperdiploid cases carrying duplications in PAX5 compared to other hyperdiploid cases. We also report an interesting case of a patient with PAX5::FKBP15 and a pathogenic variant in PTPN11 who underwent an early relapse with a monocytic switch. In conclusion, this study provides valuable insights into the presence, frequency, and prognostic significance of diverse PAX5 alterations in B-ALL patients, highlighting the complexity of genetic factors and their impact on patient outcomes.

The influence of cytotoxic drugs on the immunophenotype of blast cells in paediatric B precursor acute lymphoblastic leukaemia.

BACKGROUND: Flow cytometry plays is important in the diagnosis of acute lymphoblastic leukaemia (ALL) and when antigen-specific immunotherapy is indicated. We have investigated the effects of prednisolone, vincristine, daunorubicin, asparaginase and methotrexate on the antigen expression on blast cells that could influence the planning of antigen-specific therapy as well as risk-based treatment assignment. PATIENTS AND METHODS: Patients aged ≤ 17 years with de novo B-cell ALL (B-ALL) were enrolled in the study. Blast cells were isolated and exposed in vitro to 5 individual cytotoxic drugs in logarithmically increasing concentrations. Then, the expression of CD10, CD19, CD20, CD27, CD34, CD45, CD58, CD66c and CD137 antigens was determined by quantitative flow cytometry. RESULTS: Cytotoxic drugs caused dose-dependent or dose-independent modulation of antigen expression. Daunorubicin caused a dose-dependent down-modulation of CD10, CD19, CD34, CD45 and CD58 and an up-modulation of CD137. Vincristine caused a dose-dependent down-modulation of CD19 and CD58 and an up-modulation of CD45. Daunorubicin also caused dose-independent down-modulation of CD27 and prednisolone down-modulation of CD10, CD19, CD27, CD34 and CD58. Down-modulation of CD20 was detected only in relation to the specific dose of daunorubicin. CONCLUSIONS: The results of the study have shown that cytotoxic drugs can alter the expression of antigens that are important for immunotherapy. Importantly, daunorubicin, prednisolone and vincristine caused down-modulation of CD19 and CD58, suggesting that these drugs are better avoided during bridging therapy prior to bispecific antibodies or CAR-T cell therapy. In addition, immunophenotypic changes on blast cells induced by different drugs could also influence risk-based treatment assignment.

Paediatric Medical Traumatic Stress in Children with Cancer and their Parents: Difference in Stress Levels Due to Illness and Treatment Factors.

Pediatric medical traumatic stress (PMTS) is a set of children's and their parents' psychological and physiological responses to pain, injuries, serious illnesses, and other experiences with the medical environment. Pediatric cancer patients have the highest prevalence of PMTS as the illness its treatment involve a set of stressors that trigger many negative psychological reactions. The current study examined the difference in levels of traumatic stress in children with cancer and their parents due to medical factors (type of cancer, outcome, duration, and intensity of treatment, time since diagnosis, relapse, and hospitalization in ICU). The study involved 183 parents of 133 children and 62 children and adolescents who were treated between 2009 and 2019 at the Clinical Department of Pediatric Hematology and Oncology of University Children's Hospital in Ljubljana. We collected the data using The Intensity of Treatment Rating Scale 2.0 [IRT-2], PTSD Checklist for Children/Parent [PCL-C/PR], The PTSD Checklist for DSM-5 [PCL-5] and The Child PTSD Symptoms Scale for DSM-5 [CPSS-5]. Traumatic stress symptoms are frequently present in both children and their parents, regardless of the cancer type, treatment duration, and treatment outcome. Children with relapse, children with more intensive treatment, and parents of the latter are at higher risk for PMTS occurrence. Additionally, we found a decreasing trend of traumatic responses after five or more years post-cancer diagnosis. [Table: see text].

Photobiomodulation for Chemotherapy-Induced Oral Mucositis in Pediatric Patients.

Oral mucositis (OM) is a common side effect in patients undergoing chemotherapy (CT), especially in children due to their rapid epithelial mitotic rate. It has been associated with a significant reduction in life quality since it leads to pain, an inadequate intake of nutrients, an increased risk of opportunistic infections, and interruptions of CT. Photobiomodulation (PMB) with low-level laser therapy (LLLT) has shown faster healing, reduction in pain, and the reduced use of analgesic compared to placebo groups. The purpose of this review is to analyze and compare the existing clinical trials and identify their shortcomings in hope to make future research easier. Using MeSH terms and keywords, the Embase, Medline, and PubMed databases we searched for the period of the last 5 years. We identified a total of 15 clinical trials, with a total of 929 pediatric patients analyzed in this review. We compared different light sources and other laser technique characteristics used in clinical trials such as wavelength, energy and power density, spot size, irradiation time, PBM protocol, and OM evaluation. The main findings show inconsistent laser parameter quotations, differences in the PBM protocol along with a laser application technique, and a lack of clinical trials. Based on that, more studies with a high methodological quality should be conducted in order to provide a unified PBM protocol suitable for the pediatric population.

Clinical impacts of copy number variations in B-cell differentiation and cell cycle control genes in pediatric B-cell acute lymphoblastic leukemia: a single centre experience.

BACKGROUND: IKZF1 gene deletions have been identified as a poor prognostic factor in pediatric B-cell acute lymphoblastic leukemia (B-ALL), especially in the presence of co-occurring deletions (IKZF1plus profile). This study aimed to determine the frequency of IKZF1 deletions and deletions in other B-cell differentiation and cell cycle control genes, and their prognostic impact in Slovenian pediatric B-ALL patients. PATIENTS AND METHODS: We studied a cohort of 99 patients diagnosed with B-ALL from January 2012 to December 2020 and treated according to the ALL IC-BFM 2009 protocol. Eighty-eight bone marrow or peripheral blood samples were analysed for copy number variations (CNVs) using the SALSA MLPA P335 ALL-IKZF1 probemix. RESULTS: At least one CNV was detected in more than 65% of analysed samples. The most frequently altered genes were PAX5 and CDKN2A/B (30.7%, 26.1%, and 25.0%, respectively). Deletions in IKZF1 were present in 18.2% of analysed samples and were associated with an inferior 5-year event-free survival (EFS; 54.8% vs. 85.9%, p = 0.016). The IKZF1plus profile was identified in 12.5% of the analysed samples, and these patients had an inferior 5-year EFS than those with deletions in IKZF1 only and those without deletions (50.8% vs. 75.0% vs. 85.9%, respectively, p = 0.049). Overall survival (OS) was also worse in patients with the IKZF1plus profile than those with deletions in IKZF1 only and those without deletions (5-year OS 76.2% vs. 100% vs. 93.0%, respectively). However, the difference between the groups was not statistically significant. CONCLUSIONS: Our results are in concordance with the results obtained in larger cooperative clinical trials. Copy number variations analysis using the SALSA MLPA kit is a reliable tool for initial diagnostic approach in children with B-ALL, even in smaller institutions in low- and middle-income countries.

Micronized, Microencapsulated Ferric Iron Supplementation in the Form of >Your< Iron Syrup Improves Hemoglobin and Ferritin Levels in Iron-Deficient Children: Double-Blind, Randomized Clinical Study of Efficacy and Safety.

A major problem of oral iron supplementation efficacy in children is its tolerability and compliance. We aimed to determine the safety and efficacy of a novel food supplement >Your< Iron Syrup in the replenishment of iron stores and improvement of hematological parameters in iron-deficient children aged nine months to six years. We randomized 94 healthy children with iron deficiency in a ratio of 3:1 to either receive >Your< Iron Syrup or placebo. A 12-week supplementation with >Your< Iron Syrup resulted in a significant increase in ferritin and hemoglobin levels as compared to placebo (p = 0.04 and p = 0.02). Adverse events were reported with similar frequencies across both study arms. >Your< Iron Syrup represents an effective, well-tolerated, and safe option for the management of nutritional iron deficiency in children.

Association of CEP72 rs924607 TT Genotype with Vincristine-induced Peripheral Neuropathy Measured by Motor Nerve Conduction Studies.

Vincristine is at the core of many treatment protocols for childhood malignancies. The major dose-limiting side effect is vincristine-induced peripheral neuropathy (VIPN) which may cause morbidity and disrupt curative treatment. Several studies have tried to identify pharmacogenetic biomarkers for susceptibility to vincristine-induced toxicity (Egbelakin A et al., Pediatr Blood Cancer 2011; 56: 361-367. Aplenc R et al., Br J Haematol 2003; 122: 240-244. Diouf B et al., JAMA 2015; 313: 815-823. Zgheib NK et al., Pharmacogenet Genomics, 2018; 28: 189-195. Gutierrez-Camino A et al., Pharmacogenet Genomics 2016; 26: 100-102. Wright GE et al., Clin Pharmacol Ther 2019; 105: 402-410. Kayilioglu H et al., J Pediatr Hematol Oncol 2017; 39(6): 458-462). A major limitation of these studies is that VIPN is difficult to measure objectively using only clinical examination and clinical scales. This is especially true for children, who are often unable to report or grade symptoms such as paresthesia, numbness, and pain. Furthermore, some studies are questioning the validity of currently available neuropathy grading scales (Postma TJ et al., Ann Oncol 1998; 9: 739-744). Our group recently showed that electrophysiological studies can be used with great accuracy for early detection of VIPN (Kavcic M et al., J Pediatr Hematol Oncol 2017; 39: 266-271). In the previous study, we found that VIPN presents with primary axonal involvement and is more pronounced on motor neurons (Kavcic M et al., J Pediatr Hematol Oncol 2017; 39: 266-271).

Centrosomal protein72 rs924607 and vincristine-induced neuropathy in pediatric acute lymphocytic leukemia: meta-analysis.

AIM: We examined the utility of the rs924607 TT genotype of the centrosomal protein 72 (CEP72) as a potential biomarker for predilection toward vincristine-induced peripheral neuropathy in children treated for acute lymphoblastic leukemia. MATERIALS & METHODS: We conducted a random-effects meta-analysis of data from four studies comprising 817 patients. We tested for an association using a recessive model where a one-sided p-value < 0.05 was considered statistically significant. RESULTS & CONCLUSION: We were unable to confirm the association between the rs924607 TT genotype and neurotoxicity (odds ratio: 1.99; p = 0.16; 95% CI: 0.76-5.25) in our global meta-analysis. Analysis of the continuation phase (following induction) studies showed significantly higher odds for neuropathy in CEP72 rs924607 TT homozygotes (odds ratio: 2.28; p = 0.02; 95% CI: 1.16-6.87).

Parvovirus B19-associated Hemophagocytic Lymphohistiocytosis in a Patient With Glucose-6-phosphate Dehydrogenase Deficiency.

We report a case of a 12-year-old male with glucose-6-phosphate dehydrogenase deficiency presenting with clinical signs of sepsis and pancytopenia. Investigations revealed parvovirus B19 (PVB19)-associated hemophagocytic lymphohistiocytosis (HLH). The patient recovered fully and quickly with symptomatic treatment. Current evidence suggests that PVB19-associated HLH has a favorable prognosis. Mild undiagnosed cases of HLH may be the cause of pancytopenia in PVB19 infections.

Electrophysiological Studies to Detect Peripheral Neuropathy in Children Treated With Vincristine.

Patients treated with vincristine predictably develop peripheral neuropathy. The aim of our study was to investigate the pattern of vincristine-induced neuropathy in children by nerve conduction studies and somatosensory-evoked potentials (SSEPs). We included data from 39 children who received vincristine for various pediatric malignancies, and we performed initial and follow-up (after a minimum of 4 doses of vincristine 1.5 mg/m) conduction studies in 27 patients and SSEPs studies in 34 patients. On follow-up the most prevalent symptoms were paresthesias (44%) and constipation (22%), and the most common neurological sign was impaired myotatic reflexes (89%). Performing nerve conduction studies we found that significant reductions were measured for distal amplitudes, distal latencies were prolonged, and conduction velocities were relatively preserved. The most pronounced differences in amplitudes and distal latencies were measured in the peroneal nerves. Changes of SSEPs studies were subtle. Vincristine-induced neuropathy presents with primary axonal involvement and is more pronounced on motor neurons. We found a trend between higher age and higher dose and the degree of neuropathy in our group of patients.

Genomic architecture and treatment outcome in pediatric acute myeloid leukemia: a Children's Oncology Group report.

Childhood acute myeloid leukemia (AML) is frequently characterized by chromosomal instability. Approximately 50% of patients have disease relapse, and novel prognostic markers are needed to improve risk stratification. We performed genome-wide genotyping in 446 pediatric patients with de novo AML enrolled in Children's Oncology Group (COG) studies AAML0531, AAML03P1, and CCG2961. Affymetrix and Illumina Omni 2.5 platforms were used to evaluate copy-number alterations (CNAs) and determine their associations with treatment outcome. Data from Affymetrix and Illumina studies were jointly analyzed with ASCAT and GISTIC software. An average of 1.14 somatically acquired CNAs per patient were observed. Novel reoccurring altered genomic regions were identified, and the presence of CNAs was found to be associated with decreased 3-year overall survival (OS), event-free survival (EFS), and relapse risk from the end of induction 1 (hazard ratio [HR], 1.7; 95% confidence interval [CI], 1.2-2.4; HR, 1.4; 95% CI, 1.0-1.8; and HR, 1.4; 95% CI, 1.0-2.0, respectively). Analyses by risk group demonstrated decreased OS and EFS in the standard-risk group only (HR, 1.9; 95% CI, 1.1-3.3 and HR, 1.7; 95% CI, 1.1-2.6, respectively). Additional studies are required to test the prognostic significance of CNA presence in disease relapse in patients with AML. COG studies AAML0531, AAML03P1, and CCG2961 were registered at www.clinicaltrials.gov as #NCT01407757, #NCT00070174, and #NCT00003790, respectively.

Accuracy of Adverse Event Ascertainment in Clinical Trials for Pediatric Acute Myeloid Leukemia.

PURPOSE: Reporting of adverse events (AEs) in clinical trials is critical to understanding treatment safety, but data on AE accuracy are limited. This study sought to determine the accuracy of AE reporting for pediatric acute myeloid leukemia clinical trials and to test whether an external electronic data source can improve reporting. METHODS: Reported AEs were evaluated on two trials, Children's Oncology Group AAML03P1 and AAML0531 arm B, with identical chemotherapy regimens but with different toxicity reporting requirements. Chart review for 12 AEs for patients enrolled in AAML0531 at 14 hospitals was the gold standard. The sensitivity and positive predictive values (PPV) of the AAML0531 AE report and AEs detected by review of Pediatric Health Information System (PHIS) billing and microbiology data were compared with chart data. RESULTS: Select AE rates from AAML03P1 and AAML0531 arm B differed significantly and correlated with the targeted toxicities of each trial. Chart abstraction was performed on 204 patients (758 courses) on AAML0531. AE report sensitivity was < 50% for eight AEs, but PPV was > 75% for six AEs. AE reports for viridans group streptococcal bacteremia, a targeted toxicity on AAML0531, had a sensitivity of 78.3% and PPV of 98.1%. PHIS billing data had higher sensitivity (> 50% for nine AEs), but lower PPV (< 75% for 10 AEs). Viridans group streptococcal detection using PHIS microbiology data had high sensitivity (92.3%) and PPV (97.3%). CONCLUSION: The current system of AE reporting for cooperative oncology group clinical trials in pediatric acute myeloid leukemia underestimates AE rates. The high sensitivity and PPV of PHIS microbiology data suggest that using external data sources may improve the accuracy of AE reporting.

A comparison of discharge strategies after chemotherapy completion in pediatric patients with acute myeloid leukemia: a report from the Children's Oncology Group.

While most children receive acute myeloid leukemia (AML) chemotherapy as inpatients, there is variability in timing of discharge after chemotherapy completion. This study compared treatment-related morbidity, mortality and cumulative hospitalization in children with AML who were discharged after chemotherapy completion (early discharge) and those who remained hospitalized. Chart abstraction data for 153 early discharge-eligible patients enrolled on a Children's Oncology Group trial were compared by discharge strategy. Targeted toxicities included viridans group streptococcal (VGS) bacteremia, hypoxia and hypotension. Early discharge occurred in 11% of courses post-Induction I. Re-admission occurred in 80-100%, but median hospital stay was 7 days shorter. Patients discharged early had higher rates of VGS (adjusted risk ratio (aRR) = 1.67, 95% CI = 1.11-2.51), hypoxia (aRR = 1.92, 95% CI = 1.06-3.48) and hypotension (aRR = 4.36, 95% CI = 2.01-9.46), but there was no difference in mortality. As pressure increases to shorten hospitalizations, these results have important implications for determining discharge practices in pediatric AML.

Concordance of copy number alterations using a common analytic pipeline for genome-wide analysis of Illumina and Affymetrix genotyping data: a report from the Children's Oncology Group.

Copy number alterations (CNAs) are a hallmark of pediatric cancer genomes. An increasing number of research groups use multiple platforms and software packages to detect and analyze CNAs. However, different platforms have experimental and analysis-specific biases that may yield different results. We sought to estimate the concordance of CNAs in children with de novo acute myeloid leukemia between two experimental platforms: Affymetrix SNP 6.0 array and Illumina OmniQuad 2.5 BeadChip. Forty-five paired tumor-remission samples were genotyped on both platforms, and CNAs were estimated from total signal intensity and allelic contrast values using the allele-specific copy number analysis of tumors (ASCAT) algorithm. The two platforms were comparable in detection of CNAs, each missing only two segments from a total of 42 CNAs (4.6%). Overall, there was an interplatform agreement of 96% for allele-specific tumor profiles. However, poor quality samples with low signal/noise ratios showed a high rate of false-positive segments independent of the genotyping platform. These results demonstrate that a common analytic pipeline can be utilized for SNP array data from these two platforms. The customized programming template for the preprocessing, data integration, and analysis is publicly available at https://github.com/AplenCHOP/affyLumCNA.

Dexrazoxane exposure and risk of secondary acute myeloid leukemia in pediatric oncology patients.

BACKGROUND: Dexrazoxane may reduce anthracycline-associated cardiotoxicity in pediatric cancer patients. However, concerns of secondary acute myeloid leukemia (AML) have led to restrictions on pediatric dexrazoxane use in Europe. Published data about dexrazoxane-associated secondary AML are limited and conflicting. We sought to estimate the secondary AML risk in children receiving dexrazoxane after anthracycline exposure. PROCEDURE: A retrospective cohort of children with newly identified malignancies (excluding AML) receiving anthracyclines between January 1, 1999 and March 31, 2011 was established using the Pediatric Health Information System (PHIS). Patients were followed for all subsequent admissions to identify dexrazoxane exposures and secondary AML, defined by AML ICD-9 codes and AML induction chemotherapy. Logistic regression was used to model the association of dexrazoxane and secondary AML risk. A propensity score was used to adjust for measurable confounding. RESULTS: Of 15,532 patients in the cohort exposed to anthracyclines, 1,406 received dexrazoxane. The secondary AML rate was 0.21% (3 of 1,046) in dexrazoxane-exposed and 0.55% (77 of 14,126) in unexposed patients. In a propensity score-adjusted multivariate analysis, dexrazoxane exposure was not associated with an increased risk of secondary AML, OR = 0.38, 95% CI 0.11-1.26. CONCLUSIONS: Dexrazoxane was not associated with an increased risk of secondary AML in a large cohort of pediatric cancer patients receiving anthracyclines in US hospitals. While these data support dexrazoxane's safety in the general pediatric oncology population, additional studies are needed to confirm these findings and to quantify dexrazoxane's long-term cardioprotective effects.