Children's Oncology Group's 2013 blueprint for research: acute myeloid leukemia

Inv(3) Acute Myeloid Leukemia in a Young Adult and Review of the Literature

Acute myeloid leukemia (AML) with the high-risk variant inv(3)/t(3;3) or t(3;3)(q21;26.2) is rarely seen in the pediatric and young adult population. It is associated with poor outcomes with ineffective therapeutic options. Here, we present a case of an 18-year-old female with treatment refractory inv(3) AML in whom remission was unable to be obtained. Better treatment options are needed given the increased resistance to traditional therapy this subtype portrays. Here, we review the literature on pediatric and young adult inv(3) AML along with newer therapeutic options.

Homoharringtonine-Based Induction Regimen Improved the Remission Rate and Survival Rate in Chinese Childhood AML: A Report From the CCLG-AML 2015 Protocol Study

PURPOSE

Homoharringtonine (HHT) is commonly used for the treatment of Chinese adult AML, and all-trans retinoic acid (ATRA) has been verified in acute promyelocytic leukemia (APL). However, the efficacy and safety of HHT-based induction therapy have not been confirmed for childhood AML, and ATRA-based treatment has not been evaluated among patients with non-APL AML.

PATIENTS AND METHODS

This open-label, multicenter, randomized Chinese Children's Leukemia Group-AML 2015 study was performed across 35 centers in China. Patients with newly diagnosed childhood AML were first randomly assigned to receive an HHT-based (H arm) or etoposide-based (E arm) induction regimen and then randomly allocated to receive cytarabine-based (AC arm) or ATRA-based (AT arm) maintenance therapy. The primary end points were the complete remission (CR) rate after induction therapy, and the secondary end points were the overall survival (OS) and event-free survival (EFS) at 3 years.

RESULTS

We enrolled 1,258 patients, of whom 1,253 were included in the intent-to-treat analysis. The overall CR rate was significantly higher in the H arm than in the E arm (79.9% v 73.9%, P = .014). According to the intention-to-treat analysis, the 3-year OS was 69.2% (95% CI, 65.1 to 72.9) in the H arm and 62.8% (95% CI, 58.7 to 66.6) in the E arm (P = .025); the 3-year EFS was 61.1% (95% CI, 56.8 to 65.0) in the H arm and 53.4% (95% CI, 49.2 to 57.3) in the E arm (P = .022). Among the per-protocol population, who received maintenance therapy, the 3-year EFS did not differ significantly across the four arms (H + AT arm: 70.7%, 95% CI, 61.1 to 78.3; H + AC arm: 74.8%, 95% CI, 67.0 to 81.0, P = .933; E + AC arm: 72.9%, 95% CI, 65.1 to 79.2, P = .789; E + AT arm: 66.2%, 95% CI, 56.8 to 74.0, P = .336).

CONCLUSION

HHT is an alternative combination regimen for childhood AML. The effects of ATRA-based maintenance are comparable with those of cytarabine-based maintenance therapy.

Children's Oncology Group's 2023 blueprint for research: Myeloid neoplasms

During the past decade, the outcomes of pediatric patients with acute myeloid leukemia (AML) have plateaued with 5-year event-free survival (EFS) and overall survival (OS) of approximately 46 and 64%, respectively. Outcomes are particularly poor for those children with high-risk disease, who have 5-year OS of 46%. Substantial survival improvements have been observed for a subset of patients treated with targeted therapies. Specifically, children with KMT2A-rearranged AML and/or FLT3 internal tandem duplication (FLT3-ITD) mutations benefitted from the addition of gemtuzumab ozogamicin, an anti-CD33 antibody-drug conjugate, in the AAML0531 clinical trial (NCT00372593). Sorafenib also improved response and survival in children with FLT3-ITD AML in the AAML1031 clinical trial (NCT01371981). Advances in characterization of prognostic cytomolecular events have helped to identify patients at highest risk of relapse and facilitated allocation to consolidative hematopoietic stem cell transplant (HSCT) in first remission. Some patients clearly have improved survival with HSCT, although the benefit is largely unknown for most patients. Finally, data-driven refinements in supportive care recommendations continue to evolve with meaningful and measurable reductions in toxicity and improvements in EFS and OS. As advances in application of targeted therapies, risk stratification, and improved supportive care measures are incorporated into current trials and become standard-of-care, there is every expectation that we will see improved survival with a reduction in toxic morbidity and mortality. The research agenda of the Children's Oncology Group's Myeloid Diseases Committee continues to build upon experience and outcomes with an overarching goal of curing more children with AML.

Clinical and Cytogenetic Characteristics of Children With Leukemia 20-Year Retrospective Study

Acute leukemias are the most common malignant diseases in childhood. The aims of this retrospective cohort study were to investigate the frequency of cytogenetic abnormalities in acute pediatric leukemia; the correlation between cytogenetic abnormalities and 5-year survival; and the correlation between cytogenetic abnormalities and clinical and laboratory features. We included 105 patients; acute lymphoblastic leukemia (ALL) had 80.9% patients, B-cell lineage ALL (B-ALL) 84.7% of them, and T-cell lineage (T-ALL) 15.3%. The overall 5-year survival for B-ALL was 85.9% and for T-ALL was 84.6%. The most common cytogenetic abnormalities in patients with B-ALL were t(12;21)(p13.2;q22.1); ETV6-RUNX1 with 22.2% and hyperdiploidy with 19.4%. Our survival analysis showed that t(12;21)(p13.2;q22.1); ETV6-RUNX1 and t(1;19)(q23;p13.3); TCF3-PBX1 had the best 5-year survival with 100% of patients surviving, whereas t(v;11q23.3); KMT2A rearranged had the worst 5-year survival of just 33.3% of patients surviving after 5 years. We found no difference in 5-year survival in B-ALL when comparing clinical features. Acute myelogenous leukemia had 20 patients with 70.6% 5-year survival. The most common cytogenetic abnormality in acute myelogenous leukemia was t(8;21)(q21;q22.1); RUNX1-RUNX1T1 (20%). In conclusion, this study showed the correlation of different cytogenetic abnormalities with 5-year survival in B-ALL patients. Such correlation was not found when comparing clinical features and 5-year survival of patients with B-ALL. This emphasized the significance of cytogenetic analysis in pediatric leukemia.

High expression level of the FTH1 gene is associated with poor prognosis in children with non-M3 acute myeloid leukemia

Acute myelogenous leukemia (AML) is a disease that severely affects the physical health of children. Thus, we aimed to identify biomarkers associated with AML prognosis in children. Using transcriptomics on an mRNA dataset from 27 children with non-M3 AML, we selected genes from among those with the top 5000 median absolute deviation (MAD) values for subsequent analysis which showed that two modules were associated with AML risk groups. Thus, enrichment analysis was performed using genes from these modules. A one-way Cox analysis was performed on a dataset of 149 non-M3 AML patients downloaded from the TCGA. This identified four genes as significant: FTH1, RCC2, ABHD17B, and IRAK1. Through survival analysis, FTH1 was identified as a key gene associated with AML prognosis. We verified the proliferative and regulatory effects of ferroptosis on MOLM-13 and THP-1 cells using Liproxstatin-1 and Erastin respectively by CCK-8 and flow cytometry assays. Furthermore, we assayed expression levels of FTH1 in MOLM-13 and THP-1 cells after induction and inhibition of ferroptosis by real-time quantitative PCR, which showed that upregulated FTH1 expression promoted proliferation and inhibited apoptosis in leukemia cells. In conclusion, high expression of FTH1 promoted proliferation and inhibited apoptosis of leukemic cells through the ferroptosis pathway and is thus a potential risk factor that affects the prognosis of non-M3 AML in children.

The survival of childhood leukemia: An 8-year single-center experience

BACKGROUND

The survival of childhood leukemia has improved. We aimed to report the survival rate and the associated factors in children with acute leukemia during an 8-year follow-up.

AIMS

This study investigates the 8-year survival rates of children with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) in Shiraz, the largest oncology center in Southern Iran. We also aimed to assess the independent factors associated with higher mortality in childhood leukemia.

METHODS

Children 0-18 years with acute leukemia were followed from 2013 to 2021 in Shiraz, Iran. The 8-year overall survival (OS) and event-free survival (EFS) rates were estimated by the Kaplan-Meier method. Independent factors associated with survival were assessed by the Cox regression hazard modeling.

RESULTS

We included 786 children, with 43.5% female, and a mean age of 6.32 ± 4.62 years. Patients with AML compared to ALL experienced more relapse (34.6% vs. 22.5%, p = .01) and death (31.7% vs. 11.3%, p < .001). The cumulative 8-year OS and EFS were 81% (95% confidence interval (CI), 74.3% to 86.1%) and 68.3% (95% CI, 63.5% to 72.7%) in ALL patients and 63.5% (95% CI, 52.1% to 72.9%) and 43% (95% CI, 33.1% to 52.6%) in AML patients. Multivariable analysis revealed that hepatomegaly (hazard ratio = 4, 95% CI, 1.0 to 22.3, p = .05) was the main independent risk factor of death in ALL patients. No definite risk factor was defined for AML patients.

CONCLUSION

The survival of childhood leukemia has recently increased dramatically in low-middle income countries. Hepatomegaly was introduced as a potential risk factor for lower survival in ALL patients. Further multicenter studies are needed to confirm the validity of this association.

Ultraviolet Radiation Promoted Hypoxia-Induced Apoptosis in HL-60 Human Promyelocytic Leukemia Cell Line

Minimal residual disease (MRD) is an important reason for the failure of autologous hematopoietic stem cell transplantation (auto-HSCT). Reducing MRD in grafts is particularly important to improve the efficacy of auto-HSCT. Previously, we reported that ultraviolet light-emitting diode (UV LED) suppressed the expression of Bcl-2 to induce apoptosis in HL-60 cells. Leukemia can lead to severe hypoxia of the bone marrow. Therefore, this study aimed to investigate the effect of UV LED on leukemia cells under hypoxia. HL-60 cells were irradiated with a UV LED (30 J/m²) and simulated under hypoxia with cobalt chloride. We found that UV LED irradiation or CoCl₂ inhibited proliferation, induced apoptosis, decreased the Bcl-2/Bax ratio, and increased the levels of caspase 3, cleaved-caspase 3, and caspase 9 in HL-60 cells. In particular, the combined application of UV and CoCl₂ significantly enhanced the apoptosis of HL-60 cells. In conclusion, UV LED in hypoxia exacerbated the inhibition of proliferation and induction of apoptosis and necrosis in HL-60 cells via the regulation of caspase 3/9 and the Bcl-2/Bax ratio-dependent pathway. The application of UV LEDs in hypoxia conditions may be a promising approach to kill residual drug-resistant leukemia cells in autologous grafts.

Outcomes of allogeneic haematopoietic stem cell transplantation for paediatric patients with MLL-rearranged acute myeloid leukaemia

Background

The presence of mixed-lineage leukaemia rearrangement (MLL-r) in paediatric patients with acute myeloid leukaemia (AML) is a poor prognostic predictor. Whether allogeneic haematopoietic stem cell transplantation (allo-HSCT) is beneficial in such cases remains unclear.

Methods

We evaluated the outcomes and prognostic factors of allo-HSCT in 44 paediatric patients with MLL-r AML in the first complete remission (CR1) between 2014 and 2019 at our institution.

Results

For all the 44 patients, the 3-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse (CIR) were 74.5%, 64.1%, and 29.1%, respectively. Among them, 37 (84.1%) patients received haploidentical (haplo)-HSCT, and the 3-year OS, EFS, and CIR were 73.0%, 65.6%, and 26.4%, respectively. The 100-day cumulative incidence of grade II–IV acute graft-versus-host disease (aGVHD) post-transplantation was 27.3%, and that of grade III–IV aGVHD was 15.9%. The overall 3-year cumulative incidence of chronic graft-versus-host disease (cGVHD) post-transplantation was 40.8%, and that of extensive cGVHD was 16.7%. Minimal residual disease (MRD)-positive (MRD +) status pre-HSCT was significantly associated with lower survival and higher risk of relapse. The 3-year OS, EFS, and CIR differed significantly between patients with MRD + pre-HSCT (n = 15; 48.5%, 34.3% and 59%) and those with MRD-pre-HSCT (n = 29; 89.7%, 81.4% and 11.7%). Pre-HSCT MRD + status was an independent risk factor in multivariate analysis.

Conclusions

Allo-HSCT (especially haplo-HSCT) can be a viable strategy in these patients, and pre-HSCT MRD status significantly affected the outcomes.

Pediatric acute myeloid leukemia patients with KMT2A rearrangements: a single-center retrospective study

PURPOSE

Pediatric acute myeloid leukemia (AML) with KMT2A rearrangements has a very different prognosis. Poor outcomes cannot be avoided even after hematopoietic stem cell transplantation. In order to investigate the prognosis and efficacy, we conducted a retrospective analysis.

PATIENTS AND METHODS

We retrospectively analyzed a total of 32 children with KMT2A rearrangements AML treated in our hospital between January 2015 and February 2021.

RESULTS

The proportion of patients with KMT2A-rearranged in the medium-risk group of overall survival (OS) and event-free survival (EFS) was 100%. No differences in OS, EFS and cumulative incidence of relapse (CIR) were detected between the haploidentical hematopoietic stem cell transplantation (haplo-HSCT) and full matched HSCT (P = 0.289, P = 0.303, P = 0.303). Acute graft-versus-host disease (aGVHD) was often detected in the haplo-HSCT cohort, while full matched HSCT had no obvious aGVHD, assessed as≤1 grade (P < 0.05). Patients in the medium-risk pediatric group could acquire 100% OS and EFS only after chemotherapy. There was no significant difference in OS, EFS and CIR between full matched HSCT and haploidentical transplantation in pediatric AML with KMT2A rearrangements, but full matched HSCT seemed to have a lower death rate. The severity of aGVHD in the full matched HSCT was less than that in the haploidentical transplantation group.

CONCLUSION

The primary choice of donor can be HLA-matched sibling donors or matched unrelated donors for children with AML with KMT2A rearrangements, and the secondary choice can be haploid donors.

Immunophenotypically defined stem cell subsets in paediatric AML are highly heterogeneous and demonstrate differences in BCL-2 expression by cytogenetic subgroups

In adult acute myeloid leukaemia (AML), immunophenotypic differences enable discrimination of leukaemic stem cells (LSCs) from healthy haematopoietic stem cells (HSCs). However, immunophenotypic stem cell characteristics are less explored in paediatric AML. Employing a 15-colour flow cytometry assay, we analysed the expression of eight aberrant surface markers together with BCL-2 on CD34⁺ CD38^- bone marrow stem cells from 38 paediatric AML patients and seven non-leukaemic, age-matched controls. Furthermore, clonality was investigated by genetic analyses of sorted immunophenotypically abnormal stem cells from six patients. A total of 50 aberrant marker positive (non-HSC-like) subsets with 41 different immunophenotypic profiles were detected. CD123, CLEC12A, and IL1RAP were the most frequently expressed markers. IL1RAP, CD93, and CD25 expression were not restricted to stem cells harbouring leukaemia-associated mutations. Differential BCL-2 expression was found among defined cytogenetic subgroups. Interestingly, only immunophenotypically abnormal non-HSC-like subsets demonstrated BCL-2 overexpression. Collectively, we observed pronounced immunophenotypic heterogeneity within the stem cell compartment of paediatric AML patients. Additionally, certain aberrant markers used in adults seemed to be ineligible for detection of leukaemia-representing stem cells in paediatric patients implying that inference from adult studies must be done with caution.

HLA-haploidentical peripheral blood stem cell transplantation following reduced-intensity conditioning with very low-dose antithymocyte globulin for relapsed/refractory acute leukemia in pediatric patients: a single-institution retrospective analysis

The prognosis of relapsed/refractory (R/R) pediatric acute leukemia is extremely poor. We retrospectively reviewed 20 consecutive pediatric patients with R/R acute leukemia who underwent a first HLA-haploidentical peripheral blood stem cell transplantation following reduced-intensity conditioning (haplo-RIC-PBSCT) with very low-dose antithymocyte globulin (ATG) between 2012 and 2019. Of these 20 patients, 7 patients had acute lymphoblastic leukemia, and 13 had acute myeloid leukemia. At the time of haplo-RIC-PBSCT, 15 patients had active disease. The median follow-up duration for survivors was 56 months (range 22-108 months). Graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus, short-term methotrexate, methylprednisolone, and ATG 1.25 mg/kg on day-2. The 2-year cumulative incidence of transplant-related mortality and relapse were 5.0% [95% confidence interval (CI) 0.7-30.5%)] and 57.8% (95% CI 37.4-79.6%), respectively. Among the 20 patients, 16 (80.0%) developed grade III-IV acute GVHD, and 2 developed severe chronic GVHD. The 2-year event-free survival and overall survival rates were 40.0% (95% CI 19.3-60.0%) and 50.0% (95% CI 27.1-69.2%), respectively. Although the sample size is small, the survival outcomes of the present study are encouraging.

Unifying heterogeneous expression data to predict targets for CAR-T cell therapy

Chimeric antigen receptor (CAR) T-cell therapy combines antigen-specific properties of monoclonal antibodies with the lytic capacity of T cells. An effective and safe CAR-T cell therapy strategy relies on identifying an antigen that has high expression and is tumor specific. This strategy has been successfully used to treat patients with CD19+ B-cell acute lymphoblastic leukemia (B-ALL). Finding a suitable target antigen for other cancers such as acute myeloid leukemia (AML) has proven challenging, as the majority of currently targeted AML antigens are also expressed on hematopoietic progenitor cells (HPCs) or mature myeloid cells. Herein, we developed a computational method to perform a data transformation to enable the comparison of publicly available gene expression data across different datasets or assay platforms. The resulting transformed expression values (TEVs) were used in our antigen prediction algorithm to assess suitable tumor-associated antigens (TAAs) that could be targeted with CAR-T cells. We validated this method by identifying B-ALL antigens with known clinical effectiveness, such as CD19 and CD22. Our algorithm predicted TAAs being currently explored preclinically and in clinical CAR-T AML therapy trials, as well as novel TAAs in pediatric megakaryoblastic AML. Thus, this analytical approach presents a promising new strategy to mine diverse datasets for identifying TAAs suitable for immunotherapy.

Comparable Outcomes Between Adolescent/Young Adults and Children With Acute Myeloid Leukemia Following Allogeneic Hematopoietic Cell Transplantation: A Single-Center Experience

BACKGROUND

The cytogenetics of acute myeloid leukemia (AML) increases exponentially with age. Adolescent and young adult (AYA) patients have specific psychosocial and other challenges, influencing their ability to access appropriate treatment. Therefore, in allogeneic hematopoietic stem cell transplantation (allo-HSCT) for AML, inferior outcomes would be observed in AYA patients compared to children.

METHODS

We defined the age range of AYA patients as 15 to 29 years. Sixty-three patients who underwent allo-HSCT from 1998 to 2020 at Chang Gung Children Hospital were enrolled in this study. Overall survival was the time duration from HSCT to death from any cause. Disease-free survival was the time duration from HSCT to the last follow-up or first event (failure to achieve complete remission, relapse, secondary malignancy, or death from any cause).

RESULTS

Thirty-seven (59%) patients were <15 years of age during allo-HSCT, and 26 (41%) were 15 to 29 years of age. The median age during allo-HSCT was 6.3 years for those <15 years of age compared with 15.7 years for AYA patients. The median follow-up period was 2.2 years after hematopoietic stem cell transplantation for patients <15 years old and 3.8 years after hematopoietic stem cell transplantation for AYA patients. Univariate analysis revealed no significant difference in the 5-year overall survival or disease-free survival among all patients.

CONCLUSIONS

Several distinct AML subtypes could be amenable to treatment deintensification and targeted therapies. Furthermore, we found that children and AYA patients who underwent allo-HSCT for AML had similar survival.

Arsenic Combined With All-Trans Retinoic Acid for Pediatric Acute Promyelocytic Leukemia: Report From the CCLG-APL2016 Protocol Study

PURPOSE

Arsenic combined with all-trans retinoic acid (ATRA) is the standard of care for adult acute promyelocytic leukemia (APL). However, the safety and effectiveness of this treatment in pediatric patients with APL have not been reported on the basis of larger sample sizes.

METHODS

We conducted a multicenter trial at 38 hospitals in China. Patients with newly diagnosed APL were stratified into two risk groups according to baseline WBC count and FLT3-ITD mutation. ATRA plus arsenic trioxide or oral arsenic without chemotherapy were administered to the standard-risk group, whereas ATRA, arsenic trioxide, or oral arsenic plus reduced-dose anthracycline were administered to the high-risk group. Primary end points were event-free survival and overall survival at 2 years.

RESULTS

We enrolled 193 patients with APL. After a median follow-up of 28.9 months, the 2-year overall survival rate was 99% (95% CI, 97 to 100) in the standard-risk group and 95% (95% CI, 90 to 100) in the high-risk group (P = .088). The 2-year event-free survival was 97% (95% CI, 93 to 100) in the standard-risk group and 90% (95% CI, 83 to 96) in the high-risk group (P = .252). The plasma levels of arsenic were significantly elevated after treatment, with a stable effective level ranging from 42.9 to 63.2 ng/mL during treatment. In addition, plasma, urine, hair, and nail arsenic levels rapidly decreased to normal 6 months after the end of treatment.

CONCLUSION

Arsenic combined with ATRA is effective and safe in pediatric patients with APL, although long-term follow-up is still needed.

Targeted Next-Generation Sequencing of Circulating Tumor DNA, Bone Marrow, and Peripheral Blood Mononuclear Cells in Pediatric AML

Background

The aim of the study was to validate the diagnostic role of circulating tumor DNA (ctDNA) in genetics aberration on the basis of next-generation sequencing (NGS) in pediatric acute myeloid leukemia (AML).

Methods

Bone marrow (BM) and peripheral blood (PB) were collected from 20 AML children at the time of initial diagnosis, and a ctDNA sample was isolated from PB. Detection of mutation was performed on ctDNA, BM, and peripheral blood mononuclear cell (PBMC) by NGS based on a 185-gene panel.

Results

Among 185 genes sequenced by the NGS platform, a total of 82 abnormal genes were identified in 20 patients. Among them, 61 genes (74.39%) were detected in ctDNA, PBMC, and BM samples, while 11 (13.41%) genes were found only in ctDNA and 4 (4.88%) were detected only in the BM sample, and 2 (2.44%) were detected only in PBMC. A total of 239 mutations were detected in three samples, while 209 in ctDNA, 180 in bone marrow, and 184 in PBMC. One hundred sixty-four mutations in ctDNA were shared by matched BM samples, and the median variant allelic frequency (VAF) of these mutations was 41.34% (range, 0.55% to 99.96%) and 44.36% (range, 0.56% to 99.98%) in bone marrow and ctDNA. It was found that 65.79% (75/114) of mutations with clinical significance were detected in three samples, with 9 mutations detected both in ctDNA and BM, and 2 mutations detected both in PBMC and BM. The consistency of mutations with clinical significance between ctDNA and BM was 77.06% (84/109). Among the 84 mutations with clinical significance detected in both sources, the concordance of VAF assessment by both methods was high (R² = 0.895).

Conclusion

This study demonstrates that ctDNA was a reliable sample in pediatric AML and can be used for mutation detection. Consistency analysis showed that ctDNA can mirror the genomic information from BM. In addition, a subset of mutations was exclusively detected in ctDNA. These data support the fact that monitoring ctDNA with next-generation sequencing-based assays can provide more information about gene mutations to guide precision treatment in pediatric AML.

Very Late Relapse in Pediatric Acute Myeloid Leukemia: A Case Report and Brief Literature Review

Acute myeloid leukemia (AML) is a heterogenous group of diseases affecting ~500 children in the United States annually. With current therapy, 90% of these children will obtain complete remission. However, 30% to 40% of these patients will relapse, most commonly within the first 3 years. Very late relapses, defined as relapse occurring >5 years after complete remission, are rare, accounting for 1% to 3% of relapses. We describe a patient with AML harboring an AFDN/KMT2A translocation who relapsed 12 years after matched sibling stem cell transplant, provide a brief review of the relevant literature, and describe proposed mechanisms to explain very late relapse AML.

Sudden Unexpected Death in a Child From Acute Myeloid Leukemia

ABSTRACT

Acute myeloid leukemia can rarely cause sudden, unexpected death in children. Presentation may be non-specific and death may occur in children with no prior medical history. Herein we present the case of a previously healthy 2-year and 2 month-old White girl, who on autopsy, was found to have acute myeloid leukemia with KMT2A rearrangement extensively involving all major thoracic and abdominal organs. This case is presented to the forensic community to discuss the presentation and findings in sudden death caused by acute leukemia. The case highlights when acute leukemia should enter the differential as a potential cause of death, as well as potential resources available in the postmortem workup of acute leukemias.

Improved outcome of children with relapsed/refractory acute myeloid leukemia by addition of cladribine to re-induction chemotherapy

Background

The preferred salvage treatment for children with relapsed/refractory acute myeloid leukemia (R/R‐AML) remains unclear. The combination of cladribine/Ara‐C/granulocyte‐colony stimulating factor and mitoxantrone (CLAG‐M) shown promising results in adult R/R‐AML. We aim to investigate the efficacy and safety of CLAG‐M versus mitoxantrone/etoposide/cytarabine (MEC) or idarubicin/etoposide/cytarabine (IEC) in R/R‐AML children.

Methods

Fifty‐five R/R‐AML children were analyzed. The overall response rate (ORR), overall survival (OS), and progression‐free survival (PFS) at 3‐year were documented. Karyotype or mutations status were summarized as different risk groups.

Results

The ORR was achieved in 80% (16/20) and 51% (18/35) of patients after one‐cycle of CLAG‐M and MEC/IEC treatment (p < 0.001). The CLAG‐M group's OS (66.8% ± 16.2% vs. 40.4% ± 10.9%, p = 0.019) and PFS (52.6% ± 13.7% vs. 34.9% ± 9.1%, p = 0.036) at 3‐year was significantly higher than the MEC/IEC group. In high‐risk patients, 33.3% experienced progression of disease (PD) and 22.2% dead in CLAG‐M group, while 50% experienced PD and 43.8% dead in MEC/IEC. When it comes to low‐risk group, none of them in CLAG‐M experienced PD or death, while up to 50% of patients received MEC/IEC suffered PD, and all of them died eventually. Similar results were also found in the intermediate‐risk group. Surprisingly, the presence of FLT3‐ITD was associated with poor outcome in both groups. The most common adverse events were hematologic toxicities, and the incidence was similar in both group.

Conclusions

CLAG‐M group demonstrated effective palliation along with acceptable toxicity in R/R‐AML patients. However, patients with FLT3‐ITD may benefit less from CLAG‐M, owing to higher PD rate and all‐cause mortality than other patients.

Expanded activated autologous lymphocyte infusions improve outcomes of low- and intermediate-risk childhood acute myeloid leukemia with low level of minimal residual disease

The presence of minimal residual disease (MRD) is a risk factor for relapse among children with acute myeloid leukemia (AML), and eliminating MRD can usually improve survival rates. To investigate the effect of expanded activated autologous lymphocytes (EAALs) combined with chemotherapy on eliminating MRD and improving survival rates of children with AML, we retrospectively analyzed the results of 115 children with low- or intermediate-risk AML with MRD treated at the Pediatric Hematological Center, Peking University People's Hospital, between January 2010 and January 2016. The patients were assigned to the chemotherapy plus EAAL (combined therapy) group (n = 61) and chemotherapy group (n = 54). The MRD-negativity rates were 95.1% (58/61) in the combined therapy group and 63.0% (34/54) in the chemotherapy group (P < 0.0001) during consolidation treatment. The 5-year event-free survival rate was higher in the combined therapy group than in the chemotherapy group (86.3 ± 4.6% vs. 72.1 ± 6.1%, P = 0.025). No severe adverse event was observed after EAAL infusion. The present study showed that EAAL combined with chemotherapy could improve the MRD-negativity rate and event-free survival rate among children with AML with low level MRD-positive status.

Advances in the Diagnosis and Treatment of Large Granular Lymphocytic Leukemia

PURPOSE OF REVIEW

The past decade in LGL leukemia research has seen increased pairing of clinical data with molecular markers, shedding new insights on LGL leukemia pathogenesis and heterogeneity. This review summarizes the current standard of care of LGL leukemia, updates from clinical trials, and our congruent improved understanding of LGL pathogenesis.

RECENT FINDINGS

Various clinical reports have identified associations between stem, bone marrow, and solid organ transplants and incidence of LGL leukemia. There is also a potential for underdiagnosis of LGL leukemia within the rheumatoid arthritis patient population, emphasizing our need for continued study. Preliminary results from the BNZ-1 clinical trial, which targets IL-15 along with IL-2 and IL-9 signaling pathways, show some evidence of clinical response. With advances in our understanding of LGL pathogenesis from both the bench and the clinic, exciting avenues for investigations lie ahead for LGL leukemia.

Long-term outcome of childhood acute myeloid leukemia: A 10-year retrospective cohort study

Acute Myeloid Leukemia (AML) in children is a serious disease. With a proper treatment, a long-term survival rate above 50% is typical. Before 2010, all the AML patients died in our hospital, and abandonment rate was more than 50%. The aims of this study are to explore the long-term outcome of newly childhood acute myeloid patients treated at Hue Central Hospital from 2010 to 2019.A retrospective study was conducted on 98 children with AML who admitted Hue Central Hospital from January 2010 to December 2019. The diagnosis was confirmed by morphological FAB criteria, cytochemistry and immunophenotype. Patients were treated with using modified AML 7-3 Regimen. Social supports were provided to patients/families. A total of 98 children with AML were analyzed with mean age of 5.6 years ranging from 3 months to 15 years. The male to female ratio was 1.8:1. The overall complete remission rate after induction were 82.6%). Patients accounted for 46 (46.9%) had relapses which occurred in during chemotherapy n=27 (27,6%), after finishing chemotherapy n=19(19,4%). Overall survival at 3 years were 23.2%. The event-free survival at 3 years were 20.2%o. Abandonment cases were 4 (4.1%). During the period study, abandonment has been reduced successfully with holistic strategies such as financial support, managing family group, providing education, early follow-up of patients who missed appointments and free accommodation near hospital for patients/families. However, with a high rate patient achieved complete remission after induction phase (82.6%), but the overal survival and event-free survival at 3 years were still low in my hospital (23.2 % and 20.2% respectively). It reflected that it was very difficult to treat successfully AML in lowand middle-income countries. We are considering the way how to improve the quality treatment for childhood acute myeloid leukemia in my hospital.

New and Emerging Targeted Therapies for Pediatric Acute Myeloid Leukemia (AML)

The relapse rate for children with acute myeloid leukemia (AML) remains high despite advancements in risk classification, multi-agent chemotherapy intensification, stem cell transplantation, and supportive care guidelines. Prognosis for this subgroup of children with relapsed/refractory AML remains poor. It is well known that the ceiling of chemotherapy intensification has been reached, limited by acute and chronic toxicity, necessitating alternative treatment approaches. In the last several years, our improved understanding of disease biology and critical molecular pathways in AML has yielded a variety of new drugs to target these specific pathways. This review provides a summary of antibody drug conjugates (ADCs), small molecule inhibitors, and tyrosine kinase inhibitors with an emphasis on those that are currently under clinical evaluation or soon to open in early phase trials for children with relapsed/refractory AML.

Bortezomib with standard chemotherapy for children with acute myeloid leukemia does not improve treatment outcomes: a report from the Children's Oncology Group

New therapeutic strategies are needed for pediatric acute myeloid leukemia (AML) to reduce disease recurrence and treatment-related morbidity. The Children's Oncology Group Phase III AAML1031 trial tested whether the addition of bortezomib to standard chemotherapy improves survival in pediatric patients with newly diagnosed AML. AAML1031 randomized patients younger than 30 years of age with de novo AML to standard treatment with or without bortezomib. All patients received the identical chemotherapy backbone with either four intensive chemotherapy courses or three courses followed by allogeneic hematopoietic stem cell transplantation for high-risk patients. For those randomized to the intervention arm, bortezomib 1.3 mg/m² was given on days 1, 4 and 8 of each chemotherapy course. For those randomized to the control arm, bortezomib was not administered. In total, 1,097 patients were randomized to standard chemotherapy (n=542) or standard chemotherapy with bortezomib (n=555). There was no difference in remission induction rate between the bortezomib and control treatment arms (89% vs 91%, P=0.531). Bortezomib failed to improve 3-year event-free survival (44.8±4.5% vs 47.0±4.5%, P=0.236) or overall survival (63.6±4.5 vs 67.2±4.3, P=0.356) compared with the control arm. However, bortezomib was associated with significantly more peripheral neuropathy (P=0.006) and intensive care unit admissions (P=0.025) during the first course. The addition of bortezomib to standard chemotherapy increased toxicity but did not improve survival. These data do not support the addition of bortezomib to standard chemotherapy in children with de novo AML. (Trial registered at clinicaltrials.gov NCT01371981; https://www.cancer.gov/clinicaltrials/ NCT01371981).

Atovaquone is active against AML by upregulating the integrated stress pathway and suppressing oxidative phosphorylation

Atovaquone, a US Food and Drug Administration-approved antiparasitic drug previously shown to reduce interleukin-6/STAT3 signaling in myeloma cells, is well tolerated, and plasma concentrations of 40 to 80 µM have been achieved with pediatric and adult dosing. We conducted preclinical testing of atovaquone with acute myeloid leukemia (AML) cell lines and pediatric patient samples. Atovaquone induced apoptosis with an EC50 <30 µM for most AML lines and primary pediatric AML specimens. In NSG mice xenografted with luciferase-expressing THP-1 cells and in those receiving a patient-derived xenograft, atovaquone-treated mice demonstrated decreased disease burden and prolonged survival. To gain a better understanding of the mechanism of atovaquone, we performed an integrated analysis of gene expression changes occurring in cancer cell lines after atovaquone exposure. Atovaquone promoted phosphorylation of eIF2α, a key component of the integrated stress response and master regulator of protein translation. Increased levels of phosphorylated eIF2α led to greater abundance of the transcription factor ATF4 and its target genes, including proapoptotic CHOP and CHAC1. Furthermore, atovaquone upregulated REDD1, an ATF4 target gene and negative regulator of the mechanistic target of rapamycin (mTOR), and caused REDD1-mediated inhibition of mTOR activity with similar efficacy as rapamycin. Additionally, atovaquone suppressed the oxygen consumption rate of AML cells, which has specific implications for chemotherapy-resistant AML blasts that rely on oxidative phosphorylation for survival. Our results provide insight into the complex biological effects of atovaquone, highlighting its potential as an anticancer therapy with novel and diverse mechanisms of action, and support further clinical evaluation of atovaquone for pediatric and adult AML.

Upfront Therapies and Downstream Effects: Navigating Late Effects in Childhood Cancer Survivors in the Current Era

PURPOSE OF REVIEW

As survival rates of those diagnosed with childhood cancer improve over time, the number of long-term survivors continues to grow. Advances have not only been made in the upfront treatment of childhood cancer, but also in the identification and treatment of late complications that may arise as a result of the chemotherapy, radiotherapy, or surgical interventions required to provide a cure.

RECENT FINDINGS

As new therapies emerge that are often more targeted to cancerous cells while sparing healthy tissues, the hope is that cure can be achieved without the same long-term side effects for survivors. However, much is unknown regarding how these novel interventions will impact patients in the years to come. It is critical that we continue to follow patients treated with new modalities in order to identify and treat the long-term complications that may arise in future childhood cancer survivors.

Uncovering the Genomic Landscape in Newly Diagnosed and Relapsed Pediatric Cytogenetically Normal FLT3-ITD AML

Fms-like tyrosine kinase 3 (FLT3) internal tandem duplication (ITD) mutations, common in pediatric acute myeloid leukemia (AML), associate with early relapse and poor prognosis. Past studies have suggested additional cooperative mutations are required for leukemogenesis in FLT3-ITD+ AML. Using RNA sequencing and a next-generation targeted gene panel, we broadly characterize the co-occurring genomic alterations in pediatric cytogenetically normal (CN) FLT3-ITD+ AML to gain a deeper understanding of the clonal patterns and heterogeneity at diagnosis and relapse. We show that chimeric transcripts were present in 21 of 34 (62%) of de novo samples, 2 (6%) of these samples included a rare reoccurring fusion partner BCL11B. At diagnosis, the median number of mutations other than FLT3 per patient was 1 (range 0-3), which involved 8 gene pathways; WT1 and NPM1 mutations were frequently observed (35% and 24%, respectively). Fusion transcripts and high variant allele frequency (VAF) mutants, which included WT1, NPM1, SMARCA2, RAD21, and TYK2, were retained from diagnosis to relapse. We did observe reduction in VAF of simple or single mutation clones, but VAFs were preserved or expanded in more complex clones with multiple mutations. Our data provide the first insight into the genomic complexity of pediatric CN FLT3-ITD+ AML and could help stratify future targeted treatment strategies.

The prognostic significance of the long non-coding RNAs "CCAT1, PVT1" in t(8;21) associated Acute Myeloid Leukemia

Long non-coding RNA (LncRNA) is recently linked to various types of cancers, CCAT and PVT1 are two LncRNAs linked to t(8;21) associated Acute Myeloid Leukemia, the interplay between CCAT, PVT1 and the MYC proto-oncogene implicated in t(8;21) could present an opportunity for using LncRNA as prognostic biomarker or a target for therapy, We investigated the expression levels of LncRNAs in 70 patients; 30 with t(8;21) positive AML and 40 with t(8;21) negative AML, We found that CCAT1 and PVT1 are expressed in higher levels in t(8;21) positive -AML by 5.3 folds compared to t(8;21) negative group; the expression values were significantly associated with high-risk clinical criteria; moreover, they are associated with lower overall survival (OS) rate and leukemia-free survival (LFS), however we didn't find a statistically significant cut-off value of LncRNAs using the Cox regression analysis for Lnc_PVT1 except with LFS, we conclude that high expression levels of CCAT1 and PVT1 are associated with poor prognosis while being poor prognostic biomarkers in t(8;21) associated AML.

Flow-Cytometric Monitoring of Minimal Residual Disease in Pediatric Patients With Acute Myeloid Leukemia: Recent Advances and Future Strategies

Minimal residual disease (MRD) by multiparametric flow cytometry (MFC) has been recently shown as a strong and independent prognostic marker of relapse in pediatric AML (pedAML) when measured at specific time points during Induction and/or Consolidation therapy. Hence, MFC-MRD has the potential to refine the current strategies of pedAML risk stratification, traditionally based on the cytogenetic and molecular genetic aberrations at diagnosis. Consequently, it may guide the modulation of therapy intensity and clinical decision making. However, the use of non-standardized protocols, including different staining panels, analysis, and gating strategies, may hamper a broad implementation of MFC-MRD monitoring in clinical routine. Besides, the thresholds of MRD positivity still need to be validated in large, prospective and multi-center clinical studies, as well as optimal time points of MRD assessment during therapy, to better discriminate patients with different prognosis. In the present review, we summarize the most relevant findings on MFC-MRD testing in pedAML. We examine the clinical significance of MFC-MRD and the recent advances in its standardization, including innovative approaches with an automated analysis of MFC-MRD data. We also touch upon other technologies for MRD assessment in AML, such as quantitative genomic breakpoint PCR, current challenges and future strategies to enable full incorporation of MFC-MRD into clinical practice.

The Children's Oncology Group: Organizational Structure, Membership, and Institutional Characteristics

BACKGROUND

The Children's Oncology Group (COG) is the only organization within the National Cancer Institute's National Clinical Trials Network dedicated exclusively to pediatric cancer research. The purpose of this article is to provide an overview of COG's organizational structure, to characterize its institutional and individual membership, and to summarize enrollments onto COG clinical trials.

METHOD

Data from 2013 to 2015 were compiled from sources internal (Network Operations, Statistics and Data Center, Chair's Office) and external (American Hospital Association, American Nurses Credentialing Center) to COG, to present a comprehensive overview of COG's structure, individual and institutional membership, and group operations.

RESULTS

In 2016, COG comprised 8,785 individuals from 223 member institutions, across seven countries. An average of 9,661 new patients were registered with COG per year over the most recent (2013-2015) 3-year period. Over the same 3-year time frame, there were an average of 16,836 enrollments onto therapeutic (i.e., treatment) and nontherapeutic (e.g., epidemiology, survivorship, biology) trials per year.

CONCLUSIONS

COG institutions have diverse characteristics related to size, geographical location, and infrastructure. Individual membership also reflects diversity with representation from over 28 disciplines and groups. The diversity of COG institutions and individual members allows for unique perspectives and contributions to science unified under a common goal to enroll children/adolescents onto clinical trials. COG's collaborative, multidisciplinary approach to science functions to support the development of research that seeks to continually improve outcomes for children and adolescents with cancer.

Complete Remission of a Refractory Acute Myeloid Leukemia with Myelodysplastic- and Monosomy 7-Related Changes after a Combined Conditioning Regimen of Plerixafor, Cytarabine and Melphalan in a 4-Year-Old Boy: A Case Report and Review of Literature

Acute myeloid leukemia with myelodysplastic changes and monosomy 7 is a rare form of pediatric leukemia associated with very poor disease-free survival. The refractoriness of the disease is due to the protection offered by the bone marrow niche, making leukemic stem cells impervious to whatever chemotherapy or myeloablative regimen is chosen. Using a mobilizing agent for haematopoietic stem cells, Plerixafor, could sensitise leukemic cells to the myeloablative therapy. This approach was not previously used in a pediatric population, and in adult populations, was used in combination with busulphan with no difference in overall survival. We describe the case of a 4-year-old boy affected by refractory acute myeloid leukemia with myelodysplastic changes and monosomy 7. The child had never achieved a remission. We proposed a combined time-scheduled scheme of therapy with plerixafor and melphalan. Combining pharmacokinetics of plerixafor with pharmacokinetics and rapid and elevated myeloablative potential of melphalan in high dosage (200 mg/m²), we succeeded in mobilizing more than 85% of stem blasts immediately before infusion of Melphalan. The count of residual blasts after 8 h from melphalan infusion was only 1.3 cells/μL. The child achieved an engraftment at day +32 with full donor chimerism. Sixteen months after haematopoietic stem cell transplantation (HSCT), he is well and in complete remission. Our case suggests that the use of plerixafor before a conditioning therapy with melphalan could induce remission in acute myeloid leukemia refractory to the usual conditioning therapy in pediatric patients. This work adds strength to the body of knowledge regarding the “personalized” conditioning regimen for high-risk leukemic patients.

Shining a light on cell signaling in leukemia through proteomics: relevance for the clinic

INTRODUCTION

Although cure rates for acute leukemia have steadily improved over the past decades, leukemia remains a deadly disease. Enhanced risk stratification and new therapies are needed to improve outcome. Extensive genetic analyses have identified many mutations that contribute to the development of leukemia. However, most mutations occur infrequently and most gene alterations have been difficult to target. Most patients have more than one driver mutation in combination with secondary mutations, that result in a leukemic transformation via the alteration of proteins. The proteomics of acute leukemia could more directly identify proteins to facilitate risk stratification, predict chemoresistance and aid selection of therapy. Areas covered: This review discusses aberrantly expressed proteins identified by mass spectrometry and reverse phase protein arrays and their relationship to survival. In addition, we will discuss proteins in the context of functionally related protein groups. Expert commentary: Proteomics is a powerful tool to analyze protein abundance and functional alterations simultaneously for large numbers of patients. In the forthcoming years, validation of tools to quickly assess protein levels to enable routine rapid profiling of proteins with differential abundance and functional activation may be used as adjuncts to aid in therapy selection and to provide additional prognostic insights.

Recognition of Recurrent Protein Expression Patterns in Pediatric Acute Myeloid Leukemia Identified New Therapeutic Targets

Heterogeneity in the genetic landscape of pediatric acute myeloid leukemia (AML) makes personalized medicine challenging. As genetic events are mediated by the expression and function of proteins, recognition of recurrent protein patterns could enable classification of pediatric AML patients and could reveal crucial protein dependencies. This could help to rationally select combinations of therapeutic targets. To determine whether protein expression levels could be clustered into functionally relevant groups, custom reverse-phase protein arrays were performed on pediatric AML (n = 95) and CD34⁺ normal bone marrow (n = 10) clinical specimens using 194 validated antibodies. To analyze proteins in the context of other proteins, all proteins were assembled into 31 protein functional groups (PFG). For each PFG, an optimal number of protein clusters was defined that represented distinct transition states. Block clustering analysis revealed strong correlations between various protein clusters and identified the existence of 12 protein constellations stratifying patients into 8 protein signatures. Signatures were correlated with therapeutic outcome, as well as certain laboratory and demographic characteristics. Comparison of acute lymphoblastic leukemia specimens from the same array and AML pediatric patient specimens demonstrated disease-specific signatures, but also identified the existence of shared constellations, suggesting joint protein deregulation between the diseases.Implication: Recognition of altered proteins in particular signatures suggests rational combinations of targets that could facilitate stratified targeted therapy. Mol Cancer Res; 16(8); 1275-86. ©2018 AACRSee related article by Hoff et al., p. 1263.

Improvement of treatment outcome over 2 decades in children with acute myeloid leukemia

Background

The prognosis of pediatric acute myeloid leukemia (AML) has recently improved. This study aimed to describe the epidemiology, changes in treatment strategies, and improvement of outcomes in Gwangju-Chonnam children with AML over 2 decades.

Methods

Medical records of 116 children with newly diagnosed AML were retrospectively reviewed for demographic characteristics, prognostic groups including cytogenetic risks, treatment protocols, and survival rates over the periods between 1996 and 2005 (Period I, N=53), and 2006 and 2015 (Period II, N=38).

Results

The annual incidence of AML has decreased with reduced pediatric population. The 5-year Kaplan-Meier (K-M) estimated overall survival (OS) and event-free survival (EFS) rates in 110 AML patients were 53.2±5.1% and 43.8±5.1%, respectively. The 5-year OS rate significantly improved during period II (70.3±7.0%) as compared to that during period I (40.0±6.8%) (P =0.001). The 5-year OS was not significantly different among cytogenetic risk groups (P =0.11). Fifty-eight patients underwent hematopoietic stem cell transplantation (HSCT). The K-M 5-year estimated survival for transplanted patients was 53.7±7.0%, while that for chemotherapy-only patients was 30.1±9.1% (P =0.014). Among the prognostic factors, treatment modality was the only independent factor. The chemotherapy-only group had a relative risk of 2.06 for death compared with the transplantation group (P=0.015).

Conclusion

The survival of Korean children with AML has improved to a level comparable with that of developed countries over 2 decades, owing to a change in induction strategy, better supportive care with economic growth, refinement of HSCT techniques including a better selection of patients based on prognostic groups, and stem cell donor selection.

Signs and symptoms of rheumatic diseases as first manifestation of pediatric cancer: diagnosis and prognosis implications

OBJECTIVE

To assess the prevalence and describe the clinical, laboratory and radiological findings, treatment and outcome of children with cancer initially referred to a tertiary outpatient pediatric rheumatology clinic.

METHODS

Retrospective analysis of medical records from patients identified in a list of 250 new patients attending the tertiary Pediatric Rheumatology Clinic, Ribeirão Preto Medical School hospital, University of São Paulo, from July 2013 to July 2015, whose final diagnosis was cancer.

RESULTS

Of 250 patients seen during the study period, 5 (2%) had a cancer diagnosis. Among them, 80% had constitutional symptoms, especially weight loss and asthenia, and 60% had arthritis. Initially, all patients had at least one alteration in their blood count, lactate dehydrogenase was increased in 80% and a bone marrow smear was conclusive in 60% of patients. Bone and intestine biopsies were necessary for the diagnosis in 2 patients. JIA was the most common initial diagnosis. The definitive diagnosis was acute lymphoblastic leukemia (2 patients), M3 acute myeloid leukemia, lymphoma, and neuroblastoma (one case each). Of 5 patients studied, 3 (60%) are in remission and 2 (40%) died, one of them with prior use of steroids.

CONCLUSION

The constitutional and musculoskeletal symptoms common to rheumatic and neoplastic diseases can delay the diagnosis and consequently worsen the prognosis of neoplasms. Initial blood count and bone marrow smear may be normal in the initial framework of neoplasms. Thus, the clinical follow-up of these cases becomes imperative and the treatment, mainly with corticosteroids, should be delayed until diagnostic definition.

Interleukin-6 levels predict event-free survival in pediatric AML and suggest a mechanism of chemotherapy resistance

The tumor microenvironment can protect cancer cells from conventional anticancer therapies. Thus, targeting these protective mechanisms could eradicate therapy-resistant cancer cells and improve outcomes. Interleukin-6 (IL-6) provides extrinsic protection for several solid tumors and multiple myeloma. In pediatric acute myeloid leukemia (AML), IL-6-induced STAT3 signaling frequently becomes stronger at relapse, and increases in IL-6-induced STAT3 activity are associated with inferior survival after relapse. These findings suggested that the IL-6-induced STAT3 pathway may promote chemotherapy resistance and disease progression. Thus, we investigated the dysregulation of IL-6 levels in the bone marrow niche in pediatric patients with AML and the association between IL-6 levels and outcome. We measured levels of over 40 cytokines and growth factors in plasma from diagnostic bone marrow aspirates of 45 pediatric AML patients and 7 healthy sibling controls. Of the measured cytokines, only IL-6 levels were associated with event-free survival. Importantly, the effect of elevated IL-6 was most striking among children classified as having a low risk of relapse. In these patients, 5-year event-free survival was 82.5% ± 11% for patients with low IL-6 levels at diagnosis (n = 14) compared with 17.3% ± 11% for patients with elevated IL-6 (n = 13, log-rank P = .0003). In vitro, exogenous IL-6 reduced mitoxantrone-induced apoptosis in cell lines and primary pediatric AML samples. These results suggest that IL-6 levels at diagnosis could be used to help identify children at high risk of relapse, particularly those who are otherwise classified as low risk by current algorithms. Moreover, the IL-6 pathway could represent a target for overcoming environment-mediated chemotherapy resistance.

Administration of Dexrazoxane Improves Cardiac Indices in Children and Young Adults With Acute Myeloid Leukemia (AML) While Maintaining Survival Outcomes

Anthracycline-induced cardiotoxicity remains a significant contributor to late morbidity/mortality in children and young adults with acute myeloid leukemia (AML). The cardioprotectant dexrazoxane can be used as prophylaxis to diminish risk for cardiomyopathy but whether it affects risk of relapse in pediatric AML is unclear. Our institution adopted the use of dexrazoxane before anthracyclines administration for all oncology patients in 2011. We compared patients with AML (ages, 0 to 21 y) who received or did not receive dexrazoxane during the years 2008 to 2013. In total, 44 patients with AML (ages, 4.5 mo to 21.7 y) were included. We identified no statistical difference in 2-year event rate (62% vs. 50%, P=0.41) or 2-year overall survival (69% vs. 69%, P=0.53) between patients receiving (n=28) or not receiving (n=16) dexrazoxane. Ejection fraction (P=0.0262) and shortening fraction (P=0.0381) trended significantly higher in patients that received dexrazoxane compared with those that did not receive dexrazoxane. Utilization of the cardioprotectant dexrazoxane before anthracycline chemotherapy in pediatric patients with AML demonstrated no significant difference in either event rate or overall survival relative to institutional controls and seems to improve cardiac function indices. Further studies in this patient population are needed to confirm these findings.

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

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

Antibiotic prophylaxis with teicoplanin on alternate days reduces rate of viridans sepsis and febrile neutropenia in pediatric patients with acute myeloid leukemia

Intensive chemotherapy directed against acute myeloid leukemia of childhood is followed by profound neutropenia and high risk for bacterial and fungal infections, including viridans group streptococci as a common cause for gram-positive septicemia. Few retrospective studies have shown the efficacy of various antibiotic prophylactic regimens in children. We retrospectively studied 50 pediatric patients treated on the AML-BFM 2004 protocol between 2005 and 2015 at St. Anna Children's Hospital and assessed the effect of antibiotic prophylaxis on the frequency of febrile neutropenia and bacterial sepsis. Fifty pediatric patients underwent 199 evaluable chemotherapy cycles. Viridans sepsis occurred after none of 98 cycles with prophylactic administration of teicoplanin/vancomycin in comparison to 12 cases of viridans sepsis among 79 cycles without systemic antibacterial prophylaxis (0 vs. 15 %, p < 0.0001). In addition, there were significantly fewer episodes of febrile neutropenia in the teicoplanin/vancomycin group (44 % vs. no prophylaxis 82 %, p < 0.0001). Severity of infection seemed to be worse when no antibiotic prophylaxis had been administered with a higher rate of intensive care unit treatment (0/98, 0 %, vs. 4/79, 5 %, p = 0.038). So far, no increase of vancomycin-resistant enterococcus isolates in surveillance cultures was noticed. Antibiotic prophylaxis with teicoplanin (or vancomycin) appears safe and feasible and resulted in eradication of viridans sepsis and decreased incidence of febrile neutropenia in pediatric AML patients. The possibility to administer teicoplanin on alternate days on an outpatient basis or at home could contribute to patient's quality of life and decrease health care costs.

Progress and Prospects in Pediatric Leukemia

Pediatric leukemia is the single most common malignancy affecting children, representing up to 30% of all pediatric cancers. Dramatic improvements in survival for acute lymphoblastic leukemia (ALL) have taken place over the past 4 decades with outcomes approaching 90% in the latest studies. However, progress has been slower for myeloid leukemia and certain subgroups like infant ALL, adolescent/young adult ALL, and relapsed ALL. Recent advances include recognition of molecularly defined subgroups, which has ushered in precision medicine approaches. We discuss the current understanding of the biology of the various childhood leukemias, recent advances in research, and future challenges in this field.

Minimal Residual Disease and Childhood Leukemia: Standard of Care Recommendations From the Pediatric Oncology Group of Ontario MRD Working Group

Minimal residual disease (MRD) is an independent predictor of relapse risk in children with leukemia and is widely used for risk-adapted treatment. This article summarizes current evidence supporting the use of MRD, including clinical significance, current international clinical practice, impact statement, and recommended indications. The proposed MRD recommendations have been endorsed by the MRD Working Group of the Pediatric Oncology Group of Ontario and provide the foundation for a strategy that aims at equitable access to MRD evaluation for children with leukemia.

Acute Myeloid Leukemia: analysis of epidemiological profile and survival rate

OBJECTIVE

To describe the epidemiological profile and the survival rate of patients with acute myeloid leukemia (AML) in a state reference pediatric hospital.

METHOD

Clinical-epidemiological, observational, retrospective, descriptive study. The study included new cases of patients with AML, diagnosed between 2004 and 2012, younger than 15 years.

RESULTS

Of the 51 patients studied, 84% were white; 45% were females and 55%, males. Regarding age, 8% were younger than 1 year, 47% were aged between 1 and 10 years, and 45% were older than 10 years. The main signs/symptoms were fever (41.1%), asthenia/lack of appetite (35.2%), and hemorrhagic manifestations (27.4%). The most affected extra-medullary site was the central nervous system (14%). In 47% of patients, the white blood cell (WBC) count was below 10,000/mm(3) at diagnosis. The minimal residual disease (MRD) was less than 0.1%, on the 15th day of treatment in 16% of the sample. Medullary relapse occurred in 14% of cases. When comparing the bone marrow MRD with the vital status, it was observed that 71.42% of the patients with type M3 AML were alive, as were 54.05% of those with non-M3 AML. The death rate was 43% and the main proximate cause was septic shock (63.6%).

CONCLUSIONS

In this study, the majority of patients were male, white, and older than 1 year. Most patients with WBC count <10,000/mm(3) at diagnosis lived. Overall survival was higher in patients with MRD <0.1%. The prognosis was better in patients with AML-M3.

How Well Do All Patient Refined-Diagnosis-Related Groups Explain Costs of Pediatric Cancer Chemotherapy Admissions in the United States?

PURPOSE

State-based Medicaid programs have begun using All Patient Refined-Diagnosis-Related Groups (APR-DRGs) to determine hospital reimbursement rates. Medicaid provides coverage for 45% of childhood cancer admissions. This study aimed to examine how well APR-DRGs reflect admission costs for childhood cancer chemotherapy to inform clinicians, hospitals, and policymakers in the wake of policy changes.

METHODS

We identified 25,613 chemotherapy admissions in the 2009 Kids' Inpatient Database. To determine how well APR-DRGs explain costs, we applied a hierarchic linear regression model of hospital costs, allowing for a variety of patient, hospital, and geographic confounders.

RESULTS

APR-DRGs proved to be the most important predictors of admission costs (P < .001), with costs increasing by DRG severity code. Diagnosis, age, and hospital characteristics also predicted costs above and beyond those explained by APR-DRGs. Compared with admissions for patients with acute lymphoblastic leukemia, costs of admissions for patients with acute myelomonocytic leukemia were 82% higher; non-Hodgkin lymphoma, 20% higher; Hodgkin lymphoma, 25% lower; and CNS tumors, 27% lower. Admissions for children who were 10 years of age or older cost 26% to 35% more than admissions for infants. Admissions to children's hospitals cost 46% more than admissions to other hospital types.

CONCLUSION

APR-DRGs developed for adults are applicable to childhood cancer chemotherapy but should be refined to account for cancer diagnosis and patient age. Possible policy and clinical management changes merit further study to address factors not captured by APR-DRGs.