Infectious Complications in Children With Acute Myeloid Leukemia and Down Syndrome: Analysis of the Prospective Multicenter Trial AML-BFM 2004

Occurrence and Case Fatality Rate of Invasive Aspergillosis in Children With Acute Leukemia: A Systematic Review and Meta-analysis

Invasive aspergillosis (IA) is a potentially life-threatening complication of childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). We conducted a systematic review and meta-analyses of studies on acute leukemia in children aged 0-17 years since 2000. Findings were reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We included 24 studies with 3661 ALL patients and 1728 AML patients. IA cumulative incidence varied (0%-10% for ALL and 0%-18% for AML) across the studies. Pooled cumulative IA incidences were estimated at 3.2% (95% CI: 1.8%-5.8%) in ALL and 5.2% (95% CI: 3.1%-8.6%) in AML, with corresponding case fatality rates of 13.3% (95% CI: 6.3%-25.9%), and 7.8% (95% CI: 0.7%-51.2%), respectively. Our analysis highlights the impact of IA in childhood leukemia, underscoring the need to address strategies for prevention, early detection, and treatment of IA in pediatric leukemia.

Down syndrome-associated leukaemias: current evidence and challenges

Children with Down syndrome (DS) are at increased risk of developing haematological malignancies, in particular acute megakaryoblastic leukaemia and acute lymphoblastic leukaemia. The microenvironment established by abnormal haematopoiesis driven by trisomy 21 is compounded by additional genetic and epigenetic changes that can drive leukaemogenesis in patients with DS. GATA-binding protein 1 (GATA1) somatic mutations are implicated in the development of transient abnormal myelopoiesis and the progression to myeloid leukaemia of DS (ML-DS) and provide a model of the multi-step process of leukaemogenesis in DS. This review summarises key genetic drivers for the development of leukaemia in patients with DS, the biology and treatment of ML-DS and DS-associated acute lymphoblastic leukaemia, late effects of treatments for DS-leukaemias and the focus for future targeted therapy.

Down syndrome and leukemia: An insight into the disease biology and current treatment options

Children with Down syndrome (DS) have a 10- to 20-fold greater predisposition to develop acute leukemia compared to the general population, with a skew towards myeloid leukemia (ML-DS). While ML-DS is known to be a subtype with good outcome, patients who relapse face a dismal prognosis. Acute lymphocytic leukemia in DS (DS-ALL) is considered to have poor prognosis. The relapse rate is high in DS-ALL compared to their non-DS counterparts. We have a better understanding about the mutational spectrum of DS leukemia. Studies using animal, embryonic stem cell- and induced pluripotent stem cell-based models have shed light on the mechanism by which these mutations contribute to disease initiation and progression. In this review, we list the currently available treatment strategies for DS-leukemias along with their outcome with emphasis on challenges with chemotherapy-related toxicities in children with DS. We focus on the mechanisms of initiation and progression of leukemia in children with DS and highlight the novel molecular targets with greater success in preclinical trials that have the potential to progress to the clinic.

Myeloid Leukemia of Down Syndrome

Myeloid leukemia of Down syndrome (ML-DS) is characterized by a distinct natural history and is classified by the World Health Organization (WHO) as an independent entity, occurring with unique clinical and molecular features. The presence of a long preleukemic, myelodysplastic phase, called transient abnormal myelopoiesis (TAM), precedes the initiation of ML-DS and is defined by unusual chromosomal findings. Individuals with constitutional trisomy 21 have a profound dosage imbalance in the hematopoiesis-governing genes located on chromosome 21 and thus are subject to impaired fetal as well as to neonatal erythro-megakaryopoiesis. Almost all neonates with DS develop quantitative and morphological hematological abnormalities, yet still only 5-10% of them present with one of the preleukemic or leukemic conditions of DS. The acquired mutations in the key hematopoietic transcription factor gene GATA1, found solely in cells trisomic for chromosome 21, are considered to be the essential step for the selective growth advantage of leukemic cells. While the majority of cases of TAM remain clinically 'silent' or undergo spontaneous remission, the remaining 20% to 30% of them progress into ML-DS until the age of 4 years. The hypersensitivity of ML-DS blasts to chemotherapeutic agents, including but not limited to cytarabine, and drugs' increased infectious and cardiac toxicity have necessitated the development of risk-adapted treatment protocols for children with ML-DS. Recent advances in cytogenetics and specific molecular mechanisms involved in the evolution of TAM and ML-DS are reviewed here, as well as their integration in the improvement of risk stratification and targeted management of ML-DS.

Multi-institutional analysis of central nervous system germ cell tumors in patients with Down syndrome

PURPOSE

Primary germ cell tumors (GCTs) are the most common central nervous system (CNS) neoplasm in patients with Down syndrome (DS). However, a standard of care has not been established due to paucity of data.

METHODS

A retrospective multi-institutional analysis was conducted, in addition to a comprehensive review of the literature.

RESULTS

Ten patients from six institutions (five USA, one Brazil) were identified, in addition to 31 patients in the literature from 1975 to 2021. Of the 41 total patients (mean age 9.9 years; 61% male), 16 (39%) had non-germinomatous germ cell tumors (NGGCTs), 16 (39%) had pure germinomas, and eight (19.5%) had teratomas. Basal ganglia was the most common tumor location (n = 13; 31.7%), followed by posterior fossa (n = 7; 17%). Nine patients (22%) experienced disease relapse or progression, of which four died from tumor progression (one germinoma, three teratomas). Sixteen patients (39%) experienced treatment-related complications, of which eight (50%) died (five germinomas, three NGGCTs). Of the germinoma patients, two died from chemotherapy-related sepsis, one from postsurgery cardiopulmonary failure, one from pneumonia, and one from moyamoya following radiation therapy (RT). Of the NGGCT patients, one died from chemotherapy-related sepsis, one from postsurgical infection, and one from pneumonia following surgery/chemotherapy/RT. Three-year overall survival was 66% for all histological types: 62% germinomas, 79% for NGGCTs, and 53% for teratomas.

CONCLUSION

Patients with DS treated for CNS GCTs are at an increased risk of treatment-related adverse events. A different therapeutic approach may need to be considered to mitigate treatment-related complications and long-term neurocognitive sequelae.

Neutropenia and Infection Prophylaxis in Childhood Cancer

PURPOSE OF REVIEW

Pediatric oncology patients frequently experience episodes of prolonged neutropenia which puts them at high risk for infection with significant morbidity and mortality. Here, we review the data on infection prophylaxis with a focus on both pharmacologic and ancillary interventions. This review does not include patients receiving hematopoietic stem cell transplantation.

RECENT FINDINGS

Patients with hematologic malignancies are at highest risk for infection. Bacterial and fungal prophylaxis decrease the risk of infection in certain high-risk groups. Ancillary measures such as ethanol locks, chlorhexidine gluconate baths, GCSF, IVIG, and mandatory hospitalization do not have enough data to support routine use. There is limited data on risk of infection and role of prophylaxis in patients receiving immunotherapy and patients with solid tumors. Patients with Down syndrome and adolescent and young adult patients may benefit from additional supportive care measures and protocol modifications. Consider utilizing bacterial and fungal prophylaxis in patients with acute myeloid leukemia or relapsed acute lymphoblastic leukemia. More research is needed to evaluate other supportive care measures and the role of prophylaxis in patients receiving immunotherapy.

High-dose AraC is essential for the treatment of ML-DS independent of postinduction MRD: results of the COG AAML1531 trial

Myeloid leukemia in children with Down syndrome (ML-DS) is associated with young age and somatic GATA1 mutations. Because of high event-free survival (EFS) and hypersensitivity of the leukemic blasts to chemotherapy, the prior Children's Oncology Group protocol ML-DS protocol (AAML0431) reduced overall treatment intensity but lacking risk stratification, retained the high-dose cytarabine course (HD-AraC), which was highly associated with infectious morbidity. Despite high EFS of ML-DS, survival for those who relapse is rare. AAML1531 introduced therapeutic risk stratification based on the previously identified prognostic factor, measurable residual disease (MRD) at the end of the first induction course. Standard risk (SR) patients were identified by negative MRD using flow cytometry (<0.05%) and did not receive the historically administered HD-AraC course. Interim analysis of 114 SR patients revealed a 2-year EFS of 85.6% (95% confidence interval [CI], 75.7-95.5), which was significantly lower than for MRD- patients treated with HD-AraC on AAML0431 (P = .0002). Overall survival at 2 years was 91.0% (95% CI, 83.8-95.0). Twelve SR patients relapsed, mostly within 1 year from study entry and had a 1-year OS of 16.7% (95% CI, 2.7-41.3). Complex karyotypes were more frequent in SR patients who relapsed compared with those who did not (36% vs 9%; P = .0248). MRD by error-corrected sequencing of GATA1 mutations was piloted in 18 SR patients and detectable in 60% who relapsed vs 23% who did not (P = .2682). Patients with SR ML-DS had worse outcomes without HD-AraC after risk classification based on flow cytometric MRD.

Clinical and biological aspects of myeloid leukemia in Down syndrome

Children with Down syndrome are at an elevated risk of leukemia, especially myeloid leukemia (ML-DS). This malignancy is frequently preceded by transient abnormal myelopoiesis (TAM), which is self-limited expansion of fetal liver-derived megakaryocyte progenitors. An array of international studies has led to consensus in treating ML-DS with reduced-intensity chemotherapy, leading to excellent outcomes. In addition, studies performed in the past 20 years have revealed many of the genetic and epigenetic features of the tumors, including GATA1 mutations that are arguably associated with all cases of both TAM and ML-DS. Despite these advances in understanding the clinical and biological aspects of ML-DS, little is known about the mechanisms of relapse. Upon relapse, patients face a poor outcome, and there is no consensus on treatment. Future studies need to be focused on this challenging aspect of leukemia in children with DS.

Presentation acuity, induction mortality, and resource utilization in infants with acute leukemia

BACKGROUND

Treatment of infants with acute leukemia remains challenging, especially for acute lymphocytic leukemia (ALL). Infants have shown markedly higher rates of induction mortality compared with noninfants. There are limited data on presentation acuity and supportive care utilization in this age group.

METHODS

In retrospective analyses of patients treated for new onset ALL or acute myeloid leukemia (AML) at pediatric hospitals contributing to the Pediatric Health Information System, we compared presentation acuity, induction mortality, and resource utilization in infants relative to noninfants less than 10 years at diagnosis.

RESULTS

Analyses included 10 359 children with ALL (405 infants, 9954 noninfants) and 871 AML (189 infants, 682 noninfants). Infants were more likely to present with multisystem organ failure compared to noninfants for both ALL (12% and 1%, PR = 10.8, 95% CI: 7.4, 15.7) and AML (6% vs. 3%; PR = 2.0, 95% CI: 1.0, 3.7). Infants with ALL had higher induction mortality compared to noninfants, even after accounting for differences in anthracycline exposure and presentation acuity (2.7% vs. 0.5%, HR = 2.1, 95% CI: 1.0, 4.8). Conversely, infants and noninfants with AML had similar rates of induction mortality (3.2% vs. 2.1%, HR = 1.2, 95% CI: 0.3, 3.9), which were comparable to rates among infants with ALL. Infants with ALL and AML had greater requirements for blood products, diuretics, supplemental oxygen, and ventilation during induction relative to noninfants.

CONCLUSIONS

Infants with leukemia present with higher acuity compared with noninfants. Induction mortality and supportive care requirements for infants with ALL were similar to all children with AML, and significantly higher than those for noninfants with ALL.

8th European Conference on Infections in Leukaemia: 2020 guidelines for the use of antibiotics in paediatric patients with cancer or post-haematopoietic cell transplantation

Paediatric patients with cancer and those undergoing haematopoietic cell transplantation are at high risk of bacterial infections. The 8th European Conference on Infections in Leukaemia (ECIL-8) convened a Paediatric Group to review the literature and to formulate recommendations for the use of antibiotics according to the European Society of Clinical Microbiology and Infectious Diseases grading system. The evaluation of antibacterial prophylaxis included mortality, bloodstream infection, febrile neutropenia, emergence of resistance, and adverse effects as endpoints. Initial antibacterial therapy and antibiotic de-escalation or discontinuation focused on patients with a clinically stable condition and without previous infection or colonisation by resistant bacteria, and on patients with a clinically unstable condition or with previous infection or colonisation by resistant bacteria. The final considerations and recommendations of the ECIL-8 Paediatric Group on antibacterial prophylaxis, initial therapy, and de-escalation strategies are summarised in this Policy Review.

Pneumonia and respiratory infections in Down syndrome: A scoping review of the literature

Pneumonia and respiratory infections impact infants and children with Down syndrome; pneumonia is a leading cause of mortality in adults with Down syndrome. We aimed to review the literature to evaluate gaps and address key questions. A series of key questions were formulated a priori to inform the search strategy and review process; addressed prevalence, severity, etiology, risk factors, preventive methods, screening, and financial costs, potential benefits or harms of screening. Using the National Library of Medicine database, PubMed, detailed literature searches on pneumonia and respiratory infections in Down syndrome were performed. Previously identified review articles were also assessed. The quality of available evidence was then evaluated and knowledge gaps were identified. Forty-two relevant original articles were identified which addressed at least one key question. Study details including research design, internal validity, external validity, and relevant results are presented. Pneumonia and respiratory infections are more prevalent and more severe in individuals with Down syndrome compared to healthy controls through literature review, yet there are gaps in the literature regarding the etiology of pneumonia, the infectious organism, risk factors for infection, and to guide options for prevention and screening. There is urgent need for additional research studies in Down syndrome, especially in the time of the current COVID-19 pandemic.

Gain of chromosome 21 in hematological malignancies: lessons from studying leukemia in children with Down syndrome

Structural and numerical alterations of chromosome 21 are extremely common in hematological malignancies. While the functional impact of chimeric transcripts from fused chromosome 21 genes such as TEL-AML1, AML1-ETO, or FUS-ERG have been extensively studied, the role of gain of chromosome 21 remains largely unknown. Gain of chromosome 21 is a frequently occurring aberration in several types of acute leukemia and can be found in up to 35% of cases. Children with Down syndrome (DS), who harbor constitutive trisomy 21, highlight the link between gain of chromosome 21 and leukemogenesis, with an increased risk of developing acute leukemia compared with other children. Clinical outcomes for DS-associated leukemia have improved over the years through the development of uniform treatment protocols facilitated by international cooperative groups. The genetic landscape has also recently been characterized, providing an insight into the molecular pathogenesis underlying DS-associated leukemia. These studies emphasize the key role of trisomy 21 in priming a developmental stage and cellular context susceptible to transformation, and have unveiled its cooperative function with additional genetic events that occur during leukemia progression. Here, using DS-leukemia as a paradigm, we aim to integrate our current understanding of the role of trisomy 21, of critical dosage-sensitive chromosome 21 genes, and of associated mechanisms underlying the development of hematological malignancies. This review will pave the way for future investigations on the broad impact of gain of chromosome 21 in hematological cancer, with a view to discovering new vulnerabilities and develop novel targeted therapies to improve long term outcomes for DS and non-DS patients.

Retrospective Analysis of the Treatment Outcome in Myeloid Leukemia of Down Syndrome in Polish Pediatric Leukemia and Lymphoma Study Group From 2005 to 2019

Background: Children with Down syndrome (DS) have increased risk of myeloid leukemia (ML), but specific treatment protocols ensure excellent outcome. This study was a retrospective analysis of the treatment results and genetic characteristics of ML of DS (ML-DS) in Poland from 2005 to 2019. Methods: All 54 patients with ML-DS registered in the Polish Pediatric Leukemia and Lymphoma Study Group in analyzed period were enrolled to the study. There were 34 children treated with Acute Myeloid Leukemia-Berlin-Frankfurt-Munster 2004 Interim Protocol (group I) and 20 patients treated with ML-DS 2006 Protocol (group II). In the first protocol, there was reduction of the antracyclines doses and intrathecal treatment for ML-DS compared to non-DS patients. In the second protocol, further reduction of the treatment was introduced (omission of etoposide in the last cycle, no maintenance therapy). Results: Probabilities of 5-year overall survival (OS), event-free survival (EFS), and relapse-free survival in the whole analyzed group were 0.85 ± 0.05, 0.83 ± 0.05, and 0.97 ± 0.03, respectively. No significant differences were found between two protocols in the terms of OS and EFS (0.79 ± 0.07 vs. 0.95 ± 0.05, p = 0.14, and 0.76 ± 0.07 vs. 0.95 ± 0.05, p = 0.12, respectively). All deaths were caused by the treatment-related toxicities. Reduction of the treatment-related mortality was noticed (20% in group I and 5% in group II). The only one relapse in the whole cohort occurred in the patient from group I, older than 4 years, without GATA1 gene mutation. He was treated successfully with IdaFLA cycle followed by hematopoietic stem cell transplantation from matched sibling donor. No significant prognostic factor was found in the study group probably due to low number of patients in the subgroups. Conclusions: The study confirms that the reduced intensity protocols are very effective in ML-DS patients. The only cause of deaths was toxicities; however, systematic decrease of the treatment-related mortality was noticed.

Infections in children with acute myeloid leukemia: increased mortality in relapsed/refractory patients

The aim of this nationwide study was to describe the epidemiology and profile of bacterial infections (BI), invasive fungal disease (IFD) and viral infections (VI) in patients with de novo and relapsed/refractory (rel/ref) acute myeloid leukemia (AML). Within the studied group of 250 children with primary AML, at least one infectious complication (IC) was diagnosed in 76.0% (n = 190) children including 85.1% (n = 504) episodes of BI, 8.3% (n = 49) - IFD and 6.6% (n = 39) - VI. Among 61 patients with rel/ref AML, at least one IC was found in 67.2% (n = 41) of children including 78.8% (n = 78) of BI, 14.1% (n = 14) of IFD and 7.1% (n = 7) of VI. In all AML patients, within BI Gram-negative strains were predominant. Half of these strains were multi-drug resistant. Characteristics of IFD and VI were comparable for de novo and rel/ref AML. The infection-related mortality was significantly higher, while survival from infection was significantly lower in patients with rel/ref disease.

Therapy reduction in patients with Down syndrome and myeloid leukemia: the international ML-DS 2006 trial

Reducing therapy intensity in the ML-DS 2006 trial did not impair the excellent prognosis in ML-DS compared with the historical control. Early treatment response and gain of chromosome 8 are independent prognostic factors.

Looking up for AML in Down syndrome

In this issue of Blood, Taub et al report improved survival with reduced-intensity therapy and the prognostic significance of end-induction residual disease from the largest prospective trial to date in children with myeloid leukemia of Down syndrome (ML-DS): the Children’s Oncology Group AAML0431 study.1

Improved outcomes for myeloid leukemia of Down syndrome: a report from the Children's Oncology Group AAML0431 trial

Patients with myeloid leukemia of Down syndrome (ML-DS) have favorable event-free survival (EFS), but experience significant treatment-related morbidity and mortality. ML-DS blast cells ex vivo have increased sensitivity to cytarabine (araC) and daunorubicin, suggesting that optimizing drug dosing may improve outcomes while reducing toxicity. The Children's Oncology Group (COG) AAML0431 trial consisted of 4 cycles of induction and 2 cycles of intensification therapy based on the treatment schema of the previous COG A2971 trial with several modifications. High-dose araC (HD-araC) was used in the second induction cycle instead of the intensification cycle, and 1 of 4 daunorubicin-containing induction cycles was eliminated. For 204 eligible patients, 5-year EFS was 89.9% and overall survival (OS) was 93.0%. The 5-year OS for 17 patients with refractory/relapsed leukemia was 34.3%. We determined the clinical significance of minimal residual disease (MRD) levels as measured by flow cytometry on day 28 of induction I. MRD measurements, available for 146 of the 204 patients, were highly predictive of treatment outcome; 5-year disease-free survival for MRD-negative patients (n = 125) was 92.7% vs 76.2% for MRD-positive patients (n = 21) (log-rank P = .011). Our results indicated that earlier use of HD-araC led to better EFS and OS in AAML0431 than in past COG studies. A 25% reduction in the cumulative daunorubicin dose did not impact outcome. MRD, identified as a new prognostic factor for ML-DS patients, can be used for risk stratification in future clinical trials. This trial was registered at www.clinicaltrials.gov as #NCT00369317.

Health-related Quality of Life (HR-QOL) and Chronic Health Conditions in Survivors of Childhood Acute Myeloid Leukemia (AML) with Down Syndrome (DS): A Report From the Children's Oncology Group

Survival rates for children with Down syndrome (DS) and acute myeloid leukemia (AML) are high; however, little is known regarding the health-related quality of life (HR-QOL) of these survivors. Individuals who survived ≥5 years following diagnosis of childhood AML were invited to complete parent or patient-report surveys measuring HR-QOL and chronic health conditions. In total, 26 individuals with DS had a median age at diagnosis of 1.8 years (range, 0.77 to 10.9 y) and median age at interview of 15 years (range, 8.3 to 27.6 y). Participants with DS and AML were compared with AML survivors without DS whose caregiver completed a HR-QOL survey (CHQ-PF50). In total, 77% of survivors with DS reported ≥1 chronic health condition compared with 50% of AML survivors without DS (P=0.07). Mean physical and psychosocial QOL scores for children with DS and AML were statistically lower than the population mean, though not discrepant from AML survivors without DS. Although the overall prevalence of chronic health conditions in survivors with DS is higher than in survivors without DS, prior studies of children with DS have reported similarly high rates of chronic health conditions, suggesting that AML therapy may not substantially increase this risk.