Less toxicity by optimizing chemotherapy, but not by addition of granulocyte colony-stimulating factor in children and adolescents with acute myeloid leukemia: results of AML-BFM 98

Long-term survival outcome of childhood acute myeloid leukemia: a 43-year experience in Thailand, a resource-limited country

Although there have been advances in treating pediatric patients with acute myeloid leukemia (AML) in developed countries, outcomes in low- to middle-income countries remain poor. The goal of this study was to investigate the outcomes in children with AML who were treated at a tertiary care center in Thailand. We divided the study into 4 research periods based on the chemotherapy protocols employed. The 5-year probabilities of event-free survival (pEFS) rates for periods 1-4 were 19.0%, 20.6%, 17.4%, and 37.3% (p value = 0.32), while the 5-year probabilities of overall survival (pOS) rates were 19.0%, 24.7%, 18.7%, and 42.5% (p value = 0.18), respectively. The multivariable model indicated an improvement in 5-year pOS between periods 1 and 4 (p value = 0.04). Age, white blood cell count, and study period were significant predictors of survival outcomes. The pOS of AML patients improved over time, increasing from 19.0% to 42.5%.

Risk factors and development of a predictive score model for tumor lysis syndrome in childhood leukemia: a 10-year experience from a single tertiary hospital in Thailand

Tumor lysis syndrome (TLS) in childhood leukemia was assessed retrospectively in 252 patients in a single tertiary center in Thailand during 2009-2019. Fifty-one (20.2%) developed TLS during their induction chemotherapy; 60.7% (31/51) were spontaneous TLS and 47% (24/51) developed clinical TLS. The predictive score model consisted of white blood cell (WBC) count more than 50,000 cells/mm3, glomerular filtration rate less than 90, and aspartate transaminase more than 44 units/L. The TLS development rates were 11.1%, 46.2%, and 78.5% in the low, intermediate, and high-risk groups, respectively. Death during the first induction phase in patients with TLS was significantly higher than in the patients without TLS. However, the 5-year overall survival rates for the children with and without TLS were not significantly different.

The Impact of Prophylactic Post-Chemotherapy G-CSF on the Relapse Rates in Patients with Acute Myeloid Leukemia: A Meta-Analysis

This meta-analysis evaluated the impact of prophylactic post-chemotherapy granulocyte colony-stimulating factor (G-CSF) in patients with acute myeloid leukemia (AML). Overall, the relapse rate, overall survival, event-free survival, and mortality rate were similar in G-CSF (+) compared to G-CSF (-) patients. However, the relative risk (RR) of relapse was higher in children and in secondary AML patients who were treated with G-CSF compared to the G-CSF (-) group [RR, 95% confidence interval: 1.26, 1.04-1.52, and 1.12 (1.02-1.24)]. Treatment with post-chemotherapy G-CSF should be prescribed with caution in pediatric patients with AML and secondary AML as possibly increasing the relapse risk.

Optimized cytogenetic risk-group stratification of KMT2A-rearranged pediatric acute myeloid leukemia

ABSTRACT

A comprehensive international consensus on the cytogenetic risk-group stratification of KMT2A-rearranged (KMT2A-r) pediatric acute myeloid leukemia (AML) is lacking. This retrospective (2005-2016) International Berlin-Frankfurt-Münster Study Group study on 1256 children with KMT2A-r AML aims to validate the prognostic value of established recurring KMT2A fusions and additional cytogenetic aberrations (ACAs) and to define additional, recurring KMT2A fusions and ACAs, evaluating their prognostic relevance. Compared with our previous study, 3 additional, recurring KMT2A-r groups were defined: Xq24/KMT2A::SEPT6, 1p32/KMT2A::EPS15, and 17q12/t(11;17)(q23;q12). Across 13 KMT2A-r groups, 5-year event-free survival probabilities varied significantly (21.8%-76.2%; P < .01). ACAs occurred in 46.8% of 1200 patients with complete karyotypes, correlating with inferior overall survival (56.8% vs 67.9%; P < .01). Multivariable analyses confirmed independent associations of 4q21/KMT2A::AFF1, 6q27/KMT2A::AFDN, 10p12/KMT2A::MLLT10, 10p11.2/KMT2A::ABI1, and 19p13.3/KMT2A::MLLT1 with adverse outcomes, but not those of 1q21/KMT2A::MLLT11 and trisomy 19 with favorable and adverse outcomes, respectively. Newly identified ACAs with independent adverse prognoses were monosomy 10, trisomies 1, 6, 16, and X, add(12p), and del(9q). Among patients with 9p22/KMT2A::MLLT3, the independent association of French-American-British-type M5 with favorable outcomes was confirmed, and those of trisomy 6 and measurable residual disease at end of induction with adverse outcomes were identified. We provide evidence to incorporate 5 adverse-risk KMT2A fusions into the cytogenetic risk-group stratification of KMT2A-r pediatric AML, to revise the favorable-risk classification of 1q21/KMT2A::MLLT11 to intermediate risk, and to refine the risk-stratification of 9p22/KMT2A::MLLT3 AML. Future studies should validate the associations between the newly identified ACAs and outcomes and unravel the underlying biological pathogenesis of KMT2A fusions and ACAs.

Genomic breakpoint-specific monitoring of measurable residual disease in pediatric non-standard-risk acute myeloid leukemia

Pediatric acute myeloid leukemia (AML) is a highly heterogeneous disease making standardized measurable residual disease (MRD) assessment challenging. Currently, patient-specific DNA-based assays are only rarely applied for MRD assessment in pediatric AML. We tested whether quantification of genomic breakpoint-specific sequences via quantitative polymerase chain reaction (gDNA-PCR) provides a reliable means of MRD quantification in children with non-standardrisk AML and compared its results to those obtained with state-of-the-art ten-color flow cytometry (FCM). Breakpointspecific gDNA-PCR assays were established according to Euro-MRD consortium guidelines. FCM-MRD assessment was performed according to the European Leukemia Network guidelines with adaptations for pediatric AML. Of 77 consecutively recruited non-standard-risk pediatric AML cases, 49 (64%) carried a chromosomal translocation potentially suitable for MRD quantification. Genomic breakpoint analysis returned a specific DNA sequence in 100% (41/41) of the cases submitted for investigation. MRD levels were evaluated using gDNA-PCR in 243 follow-up samples from 36 patients, achieving a quantitative range of at least 10-4 in 231/243 (95%) of samples. Comparing gDNA-PCR with FCM-MRD data for 183 bone marrow follow-up samples at various therapy timepoints showed a high concordance of 90.2%, considering a cut-off of ≥0.1%. Both methodologies outperformed morphological assessment. We conclude that MRD monitoring by gDNA-PCR is feasible in pediatric AML with traceable genetic rearrangements and correlates well with FCM-MRD in the currently applied clinically relevant range, while being more sensitive below that. The methodology should be evaluated in larger cohorts to pave the way for clinical application.

Survival outcomes of myeloid leukemia associated with Down syndrome and de novo acute myeloid leukemia in children: Experience from a single tertiary center in Thailand

Few studies have reported the survival outcomes of myeloid leukemia associated with Down syndrome (DS) in resource-limited countries. This study aimed to compare characteristics and survival outcomes of children with acute myeloid leukemia (AML) between those with and without DS in Thailand. The medical records of AML patients aged 0-15 years treated in a major tertiary center in Southern Thailand between October 1978 and December 2019 were reviewed retrospectively. The overall (OS) and event-free survivals (EFS) rates were calculated using the Kaplan-Meier method. A total of 362 AML patients were included, of which 41 (11.3%) had DS. The mean age at diagnosis of the DS patients was 2.5 ± 1.9 years and most of them (90.2%) were under the age of five. The DS patients had lower initial white blood cell counts and peripheral blasts compared to the non-DS patients. The AML-M7 subtype was more common in the DS than in the non-DS patients (80.5% vs. 9.1%, p < 0.01, respectively). The 5-year OS and EFS rates of the DS patients were lower compared to the non-DS patients (12.9% vs. 20.5%, p = 0.05 and 13.7% vs. 18.4%, p = 0.03, respectively). DS patients had a significantly higher rate of early and treatment-related deaths compared to non-DS patients (30.3% vs. 13.5%, p < 0.01 and 39.4% vs. 19.5%, p = 0.02, respectively). Over the study period, there were a decrease in early death rate and an increase in survival rates of DS patients, which suggests that chemotherapy regimens and supportive care have improved over time.

Measurable Residual Disease and Fusion Partner Independently Predict Survival and Relapse Risk in Childhood KMT2A-Rearranged Acute Myeloid Leukemia: A Study by the International Berlin-Frankfurt-Münster Study Group

PURPOSE

A previous study by the International Berlin-Frankfurt-Münster Study Group (I-BFM-SG) on childhood KMT2A-rearranged (KMT2A-r) AML demonstrated the prognostic value of the fusion partner. This I-BFM-SG study investigated the value of flow cytometry-based measurable residual disease (flow-MRD) and evaluated the benefit of allogeneic stem-cell transplantation (allo-SCT) in first complete remission (CR1) in this disease.

METHODS

A total of 1,130 children with KMT2A-r AML, diagnosed between January 2005 and December 2016, were assigned to high-risk (n = 402; 35.6%) or non-high-risk (n = 728; 64.4%) fusion partner-based groups. Flow-MRD levels at both end of induction 1 (EOI1) and 2 (EOI2) were available for 456 patients and were considered negative (<0.1%) or positive (≥0.1%). End points were 5-year event-free survival (EFS), cumulative incidence of relapse (CIR), and overall survival (OS).

RESULTS

The high-risk group had inferior EFS (30.3% high risk v 54.0% non-high risk; P < .0001), CIR (59.7% v 35.2%; P < .0001), and OS (49.2% v 70.5%; P < .0001). EOI2 MRD negativity was associated with superior EFS (n = 413; 47.6% MRD negativity v n = 43; 16.3% MRD positivity; P < .0001) and OS (n = 413; 66.0% v n = 43; 27.9%; P < .0001), and showed a trend toward lower CIR (n = 392; 46.1% v n = 26; 65.4%; P = .016). Similar results were obtained for patients with EOI2 MRD negativity within both risk groups, except that within the non-high-risk group, CIR was comparable with that of patients with EOI2 MRD positivity. Allo-SCT in CR1 only reduced CIR (hazard ratio, 0.5 [95% CI, 0.4 to 0.8]; P = .00096) within the high-risk group but did not improve OS. In multivariable analyses, EOI2 MRD positivity and high-risk group were independently associated with inferior EFS, CIR, and OS.

CONCLUSION

EOI2 flow-MRD is an independent prognostic factor and should be included as risk stratification factor in childhood KMT2A-r AML. Treatment approaches other than allo-SCT in CR1 are needed to improve prognosis.

Transient abnormal myelopoiesis in Down syndrome: Experience of long term follow up from a single tertiary center in Thailand

Transient abnormal myelopoiesis (TAM) is a unique disease occurring in Down syndrome (DS) infants from which most patients have spontaneous remission. This study aimed to evaluate the incidence and outcomes of TAM in a tertiary center in Thailand. We reviewed the records of 997 DS patients diagnosed between June 1993 and October 2019. From the 997 DS patients, 32 had been diagnosed with TAM. The incidence of TAM was 3.2% and an overall survival rate of 87.5%. A total of 2/28 who survived (7.1%) subsequently developed AML-DS at the ages of 2.1 and 4.5 years, respectively. The risk factors related with death included maternal multiparity, sepsis, skin bleeding, subcutaneous nodules, high WBC count, low hemoglobin, and elevated AST level.Abbreviations.

Characteristics and outcome of primary resistant disease in paediatric acute myeloid leukaemia

A significant proportion of events in paediatric acute myeloid leukaemia (AML) are caused by resistant disease (RD). We investigated clinical and biological characteristics in 66 patients with RD from 1013 children with AML registered and treated according to the NOPHO-AML 93, NOPHO-AML 2004, DB AML-01 and NOPHO-DBH AML 2012 protocols. Risk factors for RD were age10 years or older and a white-blood-cell count (WBC) of 100 × 10⁹ /L or more at diagnosis. The five-year overall survival (OS) was 38% (95% confidence interval [CI]: 28%-52%). Of the 63 children that received salvage therapy with chemotherapy, 59% (N = 37) achieved complete remission (CR) with OS 57% (95% CI: 42%-75%) compared to 12% (95% CI: 4%-35%) for children that did not achieve CR. Giving more than two salvage chemotherapy courses did not increase CR rates. OS for all 43 patients receiving allogeneic haematopoietic stem cell transplantation (HSCT) was 49% (95% CI: 36%-66%). Those achieving CR and proceeding to HSCT had an OS of 56% (95% CI: 41%-77%, N = 30). This study showed that almost 40% of children with primary resistant AML can be cured with salvage therapy followed by HSCT. Children that did not achieve CR after two salvage courses with chemotherapy did not benefit from additional chemotherapy.

Supportive care in pediatric acute myeloid leukemia:Expert-based recommendations of the NOPHO-DB-SHIP consortium

INTRODUCTION

Pediatric acute myeloid leukemia (AML) is the second most common type of pediatric leukemia. Patients with AML are at high risk for several complications such as infections, typhlitis, and acute and long-term cardiotoxicity. Despite this knowledge, there are no definite supportive care guidelines as to what the best approach is to manage or prevent these complications.

AREA COVERED

The NOPHO-DB-SHIP (Nordic-Dutch-Belgian-Spain-Hong-Kong-Israel-Portugal) consortium, in preparation for a new trial in pediatric AML patients, had dedicated meetings for supportive care. In this review, the authors discuss the available data and outline recommendations for the management of children and adolescents with AML with an emphasis on hyperleukocytosis, tumor lysis syndrome, coagulation abnormalities and bleeding, infection, typhlitis, malnutrition, cardiotoxicity, and fertility preservation.

EXPERT OPINION

Improved supportive care has significantly contributed to increased cure rates. Recommendations on supportive care are an essential part of treatment for this highly susceptible population and will further improve their outcome.

Acute kidney injury and childhood acute myeloid leukemia

BACKGROUND

Acute kidney injury (AKI) appears to be particularly common in children with acute myeloid leukemia (AML), although the epidemiology data on this patient population is sparse. The objective of this study was to assess the prevalence and factors associated with AKI in childhood AML during chemotherapy treatment.

METHODS

The medical records of 112 children aged under 15 years diagnosed with AML who received chemotherapy in a major tertiary-care referral center in southern Thailand were reviewed. Logistic regression was used to identify factors associated with AKI.

RESULTS

Fifty-six (50%) children had AKI events. The median time from AML diagnosis to the first AKI was 29.5 days (interquartile range: 11.0-92.8) and the median follow-up time was 10.9 months (interquartile range: 3.6-31.1). Age at diagnosis ≥ 10 years (OR 2.75, 95% CI 1.09-6.93), glomerular filtration rate < 90 mL/min/1.73 m² at AML diagnosis (OR 7.58, 95% CI 1.89-30.5), and septic shock (OR 22.0, 95% CI 4.63-104.3) were independently associated with AKI.

CONCLUSIONS

Childhood AML has a high rate of kidney injury with 50% having AKI. Age ≥ 10 years at diagnosis, impaired kidney function before treatment, and septic shock were strongly associated with AKI. A higher resolution version of the Graphical abstract is available as Supplementary information.

A novel event-free survival endpoint in locally advanced pancreatic cancer

The treatment paradigm for locally advanced pancreatic cancer (LAPC) is evolving rapidly. The development of neoadjuvant therapies composed of combination therapies and the evaluation of their impact on conversion to borderline resectable (BR) status, resection, and ultimately overall survival (OS) are presently being pursued. These efforts justify re-visiting study endpoints in order to better predict therapeutic effects on OS, by capturing not only the achievement of R0 resection at the end of induction therapy but also the long-term reductions in the rate of local and distal recurrence. The proposed herein event-free survival (EFS) endpoint, with its novel definition specific to LAPC, is formulated to achieve these objectives. It is an analog to disease-free survival (DFS) endpoint in the adjuvant setting applied to the neoadjuvant setting and may be a valuable surrogate endpoint for this patient population.

Late outcomes in survivors of childhood acute myeloid leukemia: a report from the St. Jude Lifetime Cohort Study

Cumulative burden of chronic health conditions and neurocognitive and physical function were examined among survivors of childhood acute myeloid leukemia (AML) treated with hematopoietic cell transplant (HCT; n = 66) or conventional therapy (CT; n = 67). Survivors and controls underwent a comprehensive clinical assessment, and health conditions were graded using a modified version of the Common Terminology Criteria for Adverse Events. By age 40 years, HCT and CT survivors had an average 17.4 (95% confidence interval [CI] 14.6-20.1) and 9.3 (7.7-11.1) grade 1-4 conditions versus 3.8 (3.3-4.2) in community controls. Compared to controls, HCT survivors had a higher prevalence of hypertriglyceridemia (45.5% vs. 18.3%), hypercholesterolemia (47.0% vs. 30.9%), hypothyroidism (27.3% vs. 4.0%), and primary hypogonadism (p < 0.001). CT survivors had a higher prevalence of cardiomyopathy (11.9% vs. 2.7%) and hypertension (53.7% vs. 44.3%). Neurocognitive impairment was elevated across all domains compared to controls but did not differ by treatment modality. Compared to controls, a higher proportion of HCT survivors had impairments in strength and endurance; whereas flexibility and mobility impairments were noted among CT survivors. Despite successful advances in childhood AML therapy, many therapeutic exposures remain unchanged. These findings support ongoing investigations of novel therapies and strategies to ameliorate the risk of late morbidities.

How I treat pediatric acute myeloid leukemia

Treatment outcomes for pediatric patients with acute myeloid leukemia (AML) have continued to lag behind outcomes reported for children with acute lymphoblastic leukemia (ALL), in part because of the heterogeneity of the disease, a paucity of targeted therapies, and the relatively slow development of immunotherapy compared to ALL. In addition, we have reached the limits of treatment intensity and, even with outstanding supportive care, it is highly unlikely that further intensification of conventional chemotherapy alone will impact relapse rates. However, comprehensive genomic analyses and a more thorough characterization of the leukemic stem cell have provided insights that should lead to tailored and more effective therapies in the near future. In addition, new therapies are finally emerging, including the BCL-2 inhibitor venetoclax, CD33 and CD123-directed chimeric antigen receptor T cell therapy, CD123-directed antibody therapy, and menin inhibitors. Here we present four cases to illustrate some of the controversies regarding the optimal treatment of children with newly diagnosed or relapsed AML.

Gemtuzumab Ozogamicin Improves Event-Free Survival and Reduces Relapse in Pediatric KMT2A-Rearranged AML: Results From the Phase III Children's Oncology Group Trial AAML0531

PURPOSE

We investigated the impact of the CD33-targeted agent gemtuzumab ozogamicin (GO) on survival in pediatric patients with KMT2A-rearranged (KMT2A-r) acute myeloid leukemia (AML) enrolled in the Children's Oncology Group trial AAML0531 (NCT01407757).

METHODS

Patients with KMT2A-r AML were identified and clinical characteristics described. Five-year overall survival (OS), event-free survival (EFS), disease-free survival (DFS), and relapse risk (RR) were determined overall and for higher-risk versus not high-risk translocation partners. GO's impact on response was determined and outcomes based on consolidation approach (hematopoietic stem cell transplant [HSCT] v chemotherapy) described.

RESULTS

Two hundred fifteen (21%) of 1,022 patients enrolled had KMT2A-r AML. Five-year EFS and OS from study entry were 38% and 58%, respectively. EFS was superior with GO treatment (EFS 48% with GO v 29% without, P = .003), although OS was comparable (63% v 53%, P = .054). For patients with KMT2A-r AML who achieved complete remission, GO was associated with lower RR (40% GO v 66% patients who did not receive GO [No-GO], P = .001) and improved 5-year DFS (GO 57% v No-GO 33%, P = .002). GO benefit was observed in both higher-risk and not high-risk KMT2A-r subsets. For patients who underwent HSCT, prior GO exposure was associated with decreased relapse (5-year RR: 28% GO and HSCT v 73% No-GO and HSCT, P = .006). In multivariable analysis, GO was independently associated with improved EFS, improved DFS, and reduced RR.

CONCLUSION

GO added to conventional chemotherapy improved outcomes for KMT2A-r AML; consolidation with HSCT may further enhance outcomes. Future clinical trials should study CD33-targeted agents in combination with HSCT for pediatric KMT2A-r AML.

Investigating the Role of Indoleamine 2,3-Dioxygenase in Acute Myeloid Leukemia: A Systematic Review

Background: The immunomodulatory enzyme, indoleamine 2,3-dioxygenase (IDO) facilitates tryptophan catabolism at the rate-limiting step of the kynurenine (Kyn) pathway. IDO expression and elevations in Kyn metabolites are associated with immunosuppressive tumor microenvironment including T cell proliferative arrest and generation of regulatory T cells (Tregs) which can favor tumor progression. However, the extent of the role of IDO in acute myeloid leukemia (AML) is currently ill-defined. This study reviews the role of IDO-driven Treg function in AML and evaluates the current body of evidence implicating IDO in AML pathogenesis.

Method: Studies related to IDO in AML were identified through a systematic review of PubMed and Scopus. Data extracted described sample analysis, IDO expression, IDO in prognosis, techniques used in Treg phenotypic studies, and the effect of IDO inhibitors.

Results: Twenty studies were included in the systematic review. Expression of IDO was identified in a range of cells in AML, both inducible and constitutive. Seven studies indicated an association between elevated expression and poor clinical prognosis. Six studies suggested a positive correlation between IDO expression and Treg induction, with FoxP3 being the prominent Treg phenotypic marker. Of eight studies investigating IDO inhibition, some reported reductions in Treg frequency and enhanced effector T cell proliferation.

Conclusion: This review highlights that IDO expression in AML is associated with poor prognosis and measurement of IDO and its Kyn metabolites may offer utility as prospective prognostic markers. Pharmacological inhibition of IDO using novel drugs may hold promise for the treatment of AML.

Outcome and Prognostic Features in Pediatric Acute Megakaryoblastic Leukemia Without Down Syndrome: A Retrospective Study in China

BACKGROUND

Acute megakaryoblastic leukemia (AMKL) is a biologically heterogeneous subtype of acute myeloid leukemia that originates from megakaryocytes. Patients with AMKL with non-Down syndrome (DS) had a poorer prognosis. However, clear prognostic indicators and treatment recommendations for this subgroup remain controversial.

PATIENTS AND METHODS

Herein, we performed a retrospective study on 40 patients (age ≤ 18 years) with non-Down syndrome AMKL at our institution. We assessed the effect of different prognostic factors, such as their cytogenetic abnormalities, early treatment response, and the role of hematopoietic stem cell transplantation (HSCT) as post-remission treatment on the outcomes.

RESULTS

The complete remission (CR) rate of the patients was 57.9% and 81.1%, respectively, at the end of induction therapy 1 and 2. The overall survival (OS) and event-free survival rates at 2 years were 41% ± 13% and 41% ± 10%, respectively. An analysis of the cytogenetic features showed that patients with +21 or hyperdiploid (> 50 chromosomes) had significantly better OS than those in other cytogenetic subgroups (P_log-rank = .048 and P_log-rank = .040, respectively). Besides cytogenetics, an excellent early treatment response (CR and minimal residual disease < 1% after induction therapy 1) also provided a significant survival benefit in univariate analysis in our study. However, multivariate analysis indicated that allogeneic HSCT was the only independent prognostic marker (relative risk, 11.192; 95% confidence interval, 2.045-61.241; P = .005 for OS and relative risk, 5.400; 95% confidence interval, 1.635-17.832; P = .006 for event-free survival, respectively).

CONCLUSION

AMKL in patients with non-Down syndrome has a poor outcome. With poor OS but CR rates comparable with other acute myeloid leukemia subtypes, allogenic HSCT may be a better option for post-remission therapy than conventional chemotherapy, especially for those having a poor response to induction therapy.

Levofloxacin prophylaxis in hospitalized children with leukemia: A cost-utility analysis

BACKGROUND

Infections are common and are a major cause of morbidity and mortality during treatment of childhood leukemia. We evaluated the cost effectiveness of levofloxacin antibiotic prophylaxis, compared to no prophylaxis, in children receiving chemotherapy for acute myeloid leukemia (AML) or relapsed acute lymphoblastic leukemia (ALL).

PROCEDURES

A cost-utility analysis was conducted from the perspective of the single-payer health care system using a lifetime horizon. A comprehensive literature review identified available evidence for effectiveness, safety, costs of antibiotic prophylaxis in children with leukemia, and health utilities associated with the relevant health states. The effects of levofloxacin prophylaxis on health outcomes, quality-adjusted life-years (QALY), and direct health costs were derived from a combined decision tree and state-transition model. One-way deterministic and probabilistic sensitivity analyses were performed to test the sensitivity of results to parameter uncertainty.

RESULTS

The literature review revealed one randomized controlled trial on levofloxacin prophylaxis in childhood AML and relapsed ALL, by Alexander et al, that showed a significant reduction in rates of fever and neutropenia (71.2% vs 82.1%) and bacteremia (21.9% vs 43.4%) with levofloxacin compared to no prophylaxis. In our cost-utility analysis, levofloxacin prophylaxis was dominant over no prophylaxis, resulting in cost savings of $542.44 and increased survival of 0.13 QALY. In probabilistic sensitivity analysis, levofloxacin prophylaxis was dominant in 98.8% of iterations.

CONCLUSIONS

The present analysis suggests that levofloxacin prophylaxis, compared to no prophylaxis, is cost saving in children receiving intensive chemotherapy for AML or relapsed ALL.

Predisposition to prolonged neutropenia after chemotherapy for paediatric acute myeloid leukaemia is associated with better prognosis in the Japanese Paediatric Leukaemia/Lymphoma Study Group AML-05 study

The variability in myelosuppression after chemotherapy for acute myeloid leukaemia (AML) can affect its prognosis; however, the underlying mechanism remains controversial. In the Japanese Paediatric Leukaemia/Lymphoma Study Group AML-05 study, we showed that prolonged neutropenia was associated with high overall survival (P = 0·011) and low frequency of relapse (P = 0·042) in patients without granulocyte-colony stimulating factor (G-CSF) who completed the indicated treatment protocol. Our data indicate that predisposition to prolonged neutropenia after chemotherapy is correlated with a better outcome of AML treatment. Our results promote the usage of individualised drug dosing strategies to improve the therapeutic outcome in AML patients.

Infections as a potential long-term risk following childhood leukemia

Leukemia is the most common childhood cancer. While infections are a frequent and potentially severe complication while on treatment, less is known about the risk for infections following therapy completion. In this article, we propose that leukemia survivors might be at increased risk of infections following therapy completion than the general population, independently of potential confounders such as age, sex and Down syndrome. This association is conceivably due to several factors. First, therapy-induced immune dysfunction of both the humoral and cellular compartments appears to last for several years following anti-cancer therapy and after hematopoietic stem cell transplantation. Second, clinical and epidemiological research has shown leukemia survivors are disproportionally affected by comorbidities related to leukemia treatment and its complications, such as diabetes and obesity, which may induce secondary immunodeficiency and infections. Last, differences in health-related behaviors between leukemia survivors and the general population (such as re-vaccination practices) may affect the baseline risk of infections. Although under-represented in the epidemiological literature as a possible late effect of childhood leukemia and its treatment, it is plausible that leukemia survivors are at increased risk of infections for several years when compared to the general population and their siblings. Further research is needed to empirically test these hypotheses.

Pharmacological prophylaxis of infection in pediatric acute myeloid leukemia patients

Introduction: Pediatric patients treated for acute myeloid leukemia (AML) are at high risk of developing severe infectious complications. The choice of an optimum supportive treatment should be based on local epidemiology, as well as intensity and toxicity of the anti-leukemic therapy applied.Areas covered: This review presents an overview of recently published studies focusing on the prevention of infection in pediatric AML patients. PubMed has been systematically searched for clinical trials, reviews, and meta-analyses published in the last 10 years. The focus of this article will be limited to primary prophylaxis only, while secondary prophylaxis is beyond the scope of the current review.Expert opinion: Although anti-bacterial agents may decrease the bacterial infection burden, there is no consensus regarding prophylactic use. To that end, there is a need for further randomized controlled trials to establish the precise role of anti-bacterial prophylaxis in pediatric AML patients. The prophylactic use of anti-fungal agents is strongly recommended for all AML patients. Since the contribution of hematopoietic growth factors to improved survival has not been demonstrated, they should not be routinely applied. Decisions regarding an appropriate prophylactic strategy should be taken in collaboration with the infectious disease experts and pharmacology team.

Retrospective analysis of children with high-risk acute myeloid leukemia who underwent allogeneic hematopoietic stem cell transplantation following complete remission with initial induction chemotherapy in the AML-05 clinical trial

In the AML-05 clinical trial conducted by the Japanese Pediatric Leukemia/Lymphoma Group from 2006 to 2010, children with high-risk acute myeloid leukemia (HR AML) received allogeneic hematopoietic stem cell transplantation (allo-HSCT) at first complete remission (CR1). The aim of this study was to investigate the impact of allo-HSCT on the outcome of HR AML. Patients with either monosomy 7, 5q-, t(16;21), Ph1, FLT3-ITD, or induction failure after the first course of chemotherapy were eligible for transplant. Of 53 children with HR AML, 51 received allo-HSCT-45 in CR1, five in CR2, and one with non-CR. t(8;21), t(9;11), and t(16;21) abnormalities were identified in eight, five, and four patients, respectively. The stem cell sources varied-bone marrow in 30 patients, peripheral blood in three, and cord blood in 18. The median follow-up was 62 months. The overall survival (OS) rates at 3 years were 73% and 25% for patients who received transplant at CR1 and ≥CR2, respectively. Multivariable analysis showed that patients with chronic graft-versus-host disease (cGVHD) had better OS. This study supports that allo-HSCT is a suitable treatment for HR AML in CR1. The favorable outcome associated with cGVHD indicates that a graft-versus-leukemia effect might be occurring.

Long-Term Risk of Infections After Treatment of Childhood Leukemia: A Population-Based Cohort Study Using Administrative Health Data

PURPOSE

Infections are a frequent complication during childhood leukemia treatment. Little is known about the infectious risk in survivors. We compared the relative rate (RR) of infections after treatment completion between pediatric leukemia survivors and the general population.

METHODS

We performed a retrospective, population-based cohort study of children diagnosed with leukemia between 1992 and 2015 in Ontario, Canada, who were alive and relapse free 30 days after treatment completion (index date). Leukemia survivors were matched 5:1 with the general population by year of birth, sex, and rural status and stratified by initial treatment, including and excluding hematopoietic stem-cell transplantation (HSCT). The primary outcome was time to infections, as identified using validated diagnostic codes from administrative databases. Individuals were censored at the earliest of death, first relapse, loss to follow-up, or end of study.

RESULTS

A total of 2,204 leukemia survivors were included and matched with 11,020 controls. The rate of infections was elevated after treatment completion compared with controls (RR, 1.51; 95% CI, 1.45 to 1.57) and at less than 1 year (RR, 1.77; 95% CI, 1.69 to 1.86); 1 to 4.99 years (RR, 1.66; 95% CI, 1.62 to 1.71), and 5 or more years (RR, 1.29; 95% CI, 1.22 to 1.36) from the index date. Among those whose initial treatment excluded HSCT, the rate remained elevated more than 5 years from the index date (RR, 1.29; 95% CI, 1.23 to 1.35). Infection-related death was significantly increased in leukemia survivors both among the entire cohort (hazard ratio, 149.3; 95% CI, 20.4 to 1,091.9) and among those without HSCT (hazard ratio, 92.7; 95% CI, 12.4 to 690.7).

CONCLUSION

A significant association was found between a history of leukemia therapy and an increased risk of infections. Additional study is needed to establish which exposures in patients with leukemia lead to late infections.

Clofarabine Can Replace Anthracyclines and Etoposide in Remission Induction Therapy for Childhood Acute Myeloid Leukemia: The AML08 Multicenter, Randomized Phase III Trial

PURPOSE

To identify effective and less toxic therapy for children with acute myeloid leukemia, we introduced clofarabine into the first course of remission induction to reduce exposure to daunorubicin and etoposide.

PATIENTS AND METHODS

From 2008 through 2017, 285 patients were enrolled at eight centers; 262 were randomly assigned to receive clofarabine and cytarabine (Clo+AraC, n = 129) or high-dose cytarabine, daunorubicin, and etoposide (HD-ADE, n = 133) as induction I. Induction II consisted of low-dose ADE given alone or combined with sorafenib or vorinostat. Consolidation therapy comprised two or three additional courses of chemotherapy or hematopoietic cell transplantation. Genetic abnormalities and the level of minimal residual disease (MRD) at day 22 of initial remission induction determined final risk classification. The primary end point was MRD at day 22.

RESULTS

Complete remission was induced after two courses of therapy in 263 (92.3%) of the 285 patients; induction failures included four early deaths and 15 cases of resistant leukemia. Day 22 MRD was positive in 57 of 121 randomly assigned evaluable patients (47%) who received Clo+AraC and 42 of 121 patients (35%) who received HD-ADE (odds ratio, 1.86; 95% CI, 1.03 to 3.41; P = .04). Despite this result, the 3-year event-free survival rate (52.9% [44.6% to 62.8%] for Clo+AraC v 52.4% [44.0% to 62.4%] for HD-ADE, P = .94) and overall survival rate (74.8% [67.1% to 83.3%] for Clo+AraC v 64.6% [56.2% to 74.2%] for HD-ADE, P = .1) did not differ significantly across the two arms.

CONCLUSION

Our findings suggest that the use of clofarabine with cytarabine during remission induction might reduce the need for anthracycline and etoposide in pediatric patients with acute myeloid leukemia and may reduce rates of cardiomyopathy and treatment-related cancer.

Early Deaths in Pediatric Acute Leukemia: A Major Challenge in Developing Countries

Children with acute leukemia may experience high treatment-related mortality, which often occurs early in the induction phase. The aim of the study was to assess the incidence and risk factors related to increased mortality during induction therapy of pediatric patients with acute leukemia. This is a retrospective study that included pediatric acute leukemia patients who presented to the National Cancer Institute, Cairo University, between January 2011 and December 2013. The study included 370 patients, 253 with acute lymphoblastic leukemia, 100 with acute myeloid leukemia, and 17 with mixed phenotype acute leukemia. The total and induction death rates were 40.5% and 19.2%, respectively. Most of the early deaths were attributed to infections (64.7%) and cerebrovascular accidents (18.3%). Using enhanced supportive care measures during 2013 had significantly reduced the overall and induction mortality rates (29% and 13.6%, respectively, in 2013 vs. 46% and 20.3% in 2011). Induction deaths in pediatric acute leukemia remain a major challenge in developing countries, and using enhanced supportive care measures is effective to improve the survival outcome in this group of patients.

Incidence of infections after therapy completion in children with acute lymphoblastic leukemia or acute myeloid leukemia: a systematic review of the literature

Infections are a common complication of treatment for pediatric acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML). Less is known about infections occurring after treatment. We performed a systematic review of the literature to assess the incidence of infections after therapy completion in children and young adults with ALL or AML. Twenty-eight studies, with 4138 patients, were included. Four studies reported infections in patients who did not undergo hematopoietic stem cell transplant (HSCT). Respiratory tract and urinary tract infections affected 9.9-72.5% and 2.9-19.8% of patients, respectively. Twelve studies reported infections in patients treated with HSCT. Late bacterial, viral and fungal infections affected 3.9-38.5%, 16.1-66.7%, and 0.2-41.7% of patients, respectively. Viral hepatitis affected 0.8-75.4% of patients from 12 studies. Our review suggests that infections are a frequent complication after treatment for leukemia in children, especially after HSCT and identifies several knowledge gaps in the current literature.

[Mitoxantrone-cytarabine-etoposide induction therapy in children with acute myeloid leukemia: a single-center study of complications and clinical outcomes]

OBJECTIVE

To investigate the complications and clinical outcome of children with acute myeloid leukemia (AML) undergoing mitoxantrone-cytarabine-etoposide (MAE) induction therapy.

METHODS

A total of 170 children with AML were given MAE induction therapy, and the complications and remission rate were analyzed after treatment.

RESULTS

The male/female ratio was 1.33:1 and the mean age was 7.4 years (range 1-15 years). Leukocyte count at diagnosis was 29.52×10⁹/L [range (0.77-351)×10⁹/L]. Of all children, 2 had M0-AML, 24 had M2-AML, 2 had M4-AML, 48 had M5-AML, 3 had M6-AML, 7 had M7-AML, 69 had AML with t(8;21)(q22;q22), and 15 had AML with inv(16)(p13.1q22) or t(16;16)(p13.1;q22). The most common complication was infection (158/170, 92.9%). Among these 158 patients, 22 (13.9%) had agranulocytosis with pyrexia (with no definite focus of infection), and 136 (86.1%) had definite focus of infection (including bloodstream infection). Other complications included non-infectious diarrhea, bleeding, and drug-induced hepatitis. Treatment-related mortality was observed in 10 children, among whom 8 had severe infection, 1 had multiple organ failure, and 1 had respiratory failure. Remission rate was evaluated for 156 children and the results showed a complete remission rate of 85.3%, a partial remission rate of 4.5%, and a non-remission rate of 10.3%.

CONCLUSIONS

Induction therapy with the MAE regimen helps to achieve a good remission rate in children with AML after one course of treatment. Infection is the main complication and a major cause of treatment-related mortality.

Increased Survival for Children With Acute Myeloid Leukemia Results From Improved Postrelapse Treatment

BACKGROUND

The treatment for pediatric acute myeloid leukemia (AML) has not changed significantly over the past 3 decades, yet outcomes have improved with cure rates increasing from 30% to over 60% of all newly diagnosed children over this period. This improvement in survival has been attributed to both treatment intensification and improved supportive care over the decades, although the precise impact of each remains unknown.

PATIENTS AND METHODS

We retrospectively analyzed a unique cohort of 276 patients with de novo AML diagnosed in childhood, all treated with the same chemotherapy protocol over a 25-year period from 1986 to 2012.

RESULTS

The contemporary cohort (2000-2012), compared with the historical cohort (1986-1999) had significantly improved overall survival (75% vs. 50%; hazard ratio, 2.17; 95% confidence interval, 1.15-2.93), lower disease-related mortality (38% vs. 19%, P=0.02) and were significantly more likely to receive an allogeneic transplant after relapse (stem cell transplantation [SCT], 73% vs. 12%; P<0.0001). Allogeneic transplant postrelapse was associated with a significantly improved survival across the entire cohort (overall survival 50% for allogeneic SCT vs. 12% for autologous or none, P<0.0001). There was no significant difference between the contemporary and historical cohorts in treatment-related mortality (13% vs. 7%, P=0.42) or relapse rates after induction (50% in older cohort vs. 40% in recent era, P=0.25), suggesting consistency of induction treatment efficacy and toxicity across the 2 periods.

CONCLUSIONS

This data suggests improved survival in pediatric AML in the modern era has predominantly resulted from changes in treatment after relapse, including increased use of allogeneic SCT.

Outcome of Acute Myeloid Leukemia in Children Adolescents and Young Adults Treated with an Uniform Protocol in Casablanca, Morocco

Treatment of acute myeloblastic leukemia in children, adolescents and young adults (AYA) is a challenge in low-income countries. To evaluate treatment outcomes of children (≤ 15 years) and AYA (15-30 years) diagnosed with novo AML and treated in a single center according to the AML-MA 2011 protocol. From January 2011 to December 2015, eligible patients (age ≤ 30 years) with novo AML had been enrolled on a uniform treatment protocol. The diagnosis was confirmed according to the FAB classification using the WHO 2008 criteria. Patients with WBC ≥ 50 G/L had pretreated 4 days of hydroxyurea followed by two inductions and two consolidations. Supportive care consisted of transfusion of labile blood products, antibiotics and antifungals, and patient and family education by the hygiene team. 155 patients were recruited, 41 were < 15 years old (22 boys, median age 7.8 years). Of the 114 AYA enrolled, (48 women, median age 23 years). Complete remission after two inductions was 28/41 (68.3%) of the children, including 100% of the children in the favorable group and 71/114 (62.3%) of the AYA, 22 of whom (68.7%) were in the favorable group. The number of deaths among children was 6 (14.6%). The evaluation of the AML-MA-2011 National Protocol in the age groups of children and AYA reveals that the objective of treatment is almost achieved in terms of complete remission in the two age groups.

Gemtuzumab ozogamicin in children with relapsed or refractory acute myeloid leukemia: a report by Berlin-Frankfurt-Münster study group

Despite intensified salvage treatments, children with relapsed/refractory acute myeloid leukemia (AML) have poor survival. We evaluated gemtuzumab ozogamicin (CD33-targeted drug) used on a compassionate basis in patients diagnosed from 1995 until 2014 within Acute Myeloid Leukemia Berlin-Frankfurt-Münster studies, and identified 76 patients (<18 years) with highly-advanced and pre-treated AML [refractory de novo acute myeloid leukemia (n=10), de novo AML refractory to relapse (1^st early: n=41; 1^st late: n=10; 2^nd or more: n=10), and secondary AML (n=5)]. At doses of 2.5–10 mg/m², gemtuzumab ozogamicin was administered in 1-4 cycles as single agent (47%), combined with cytarabine (47%), or others (6%). Most common grade 3/4 adverse events were infections or febrile neutropenia (78% of severe adverse events), infusion-related immunological reactions (6%), and gastrointestinal symptoms (5%). Three patients experienced veno-occlusive disease (one fatal due to exacerbation of a pre-existing cardiomyopathy). Sixty-four percent received subsequent hematopoietic stem cell transplantation. Probability of 4-year overall survival was 18±5% in all, 27±7% in patients with and 0% in patients without hematopoietic stem cell transplantation (P<0.0001). Administration of gemtuzumab ozogamicin on a patient-specific, compassionate use basis was frequently considered in our study group and proved to be effective for bridging children with very advanced AML to hematopoietic stem cell transplantation. Uniform prospective studies for these patients are urgently needed.

Hematologic Malignancies Associated With Mediastinal Germ Cell Tumors: 10 Years' Experience at Thailand's National Pediatric Tertiary Referral Center

Mediastinal germ cell tumor (MGCT), which accounts for 1% to 3% of extragonadal germ cell tumors, has unique manifestations; it is associated with several types of hematologic malignancy, particularly myeloid neoplasm. The aim of this study was to report the 10-year incidence, clinical characteristics, and outcomes of MGCT at Thailand's national pediatric tertiary referral center. This retrospective study included patients diagnosed with MGCT at the Department of Pediatrics, Siriraj Hospital during 2005 to 2014. Eight patients (all male) were diagnosed with MGCT. Five of 8 patients were found to have hematologic abnormalities. Three patients were diagnosed with acute myeloid leukemia (AML) (one patient with M1, another having M7, and the other with M0). Another patient had mixed MGCT with mediastinal myeloid sarcoma (MMS). The other patient had malignancy-associated hemophagocytic lymphohistiocytosis syndrome (M-HLH). Isochromosome 12p was detected in 3 patients (AML [2], mixed MGCT/MMS [1]). Four of 5 patients with hematologic abnormalities died of hematologic abnormalities or treatment complication (AML [3], M-HLH [1]). One patient with mixed MGCT/MMS survived with chemotherapy. All patients with AML and MMS were nonseminomatous MGCT and the onset of myeloid malignancies were within 1 year after the diagnosis of MGCT. Associated hematologic malignancies should be suspected in MGCT with abnormal blood count or hematologic symptoms. Isochromosome 12p was the most common cytogenetic finding in MGCT-associated myeloid malignancies patients. Those with nonseminomatous MGCT should have their blood count carefully monitored especially during the first year after the diagnosis of MGCT. Better treatment alternatives for MGCT with associated hematologic malignancies are warranted to ameliorate adverse outcomes.

Successes and challenges in the treatment of pediatric acute myeloid leukemia: a retrospective analysis of the AML-BFM trials from 1987 to 2012

Overall survival (OS) of pediatric patients with acute myeloid leukemia (AML) increased in recent decades. However, it remained unknown whether advances in first-line treatment, supportive care, or second-line therapy mainly contributed to this improvement. Here, we retrospectively analyzed outcome and clinical data of 1940 pediatric AML patients (younger than 18 years of age), enrolled in the population-based AML-BFM trials between 1987 and 2012. While 5-year probability of OS (pOS) increased from 49 ± 3% (1987-1992) to 76 ± 4% (2010-2012; p < 0.0001), probability of event-free survival only improved from 41 ± 3% (1987-1992) to 50 ± 2% (1993-1998; p = 0.02) after introduction of high-dose cytarabine/mitoxantrone, but remained stable since then. Non-response and relapse rates stayed constant despite intensified first-line therapy (p = 0.08 and p = 0.17). Reduced fatal bleedings and leukostasis translated into fewer early deaths (8.1%vs. 2.2%; p = 0.001). Strikingly, pOS after non-response (13 ± 5% (1987-1992) vs. 43 ± 7% (2005-2010); p < 0.0001) or relapse (19 ± 4% vs. 45 ± 4%; p < 0.0001) improved. After 1999, more relapsed or refractory patients underwent hematopoietic stem cell transplantation (HSCT) with increased pOS after HSCT (29 ± 5% (1993-1998) vs. 50 ± 4% (2005-2010); p < 0.0001). Since efficacy of salvage therapy mainly contributed to better outcome in pediatric AML, our analysis indicates that a better allocation of patients, who cannot be cured with conventional chemotherapy, to an early "salvage-like" therapy is necessary.

The molecular landscape of pediatric acute myeloid leukemia reveals recurrent structural alterations and age-specific mutational interactions

We present the molecular landscape of pediatric acute myeloid leukemia (AML) and characterize nearly 1,000 participants in Children's Oncology Group (COG) AML trials. The COG-National Cancer Institute (NCI) TARGET AML initiative assessed cases by whole-genome, targeted DNA, mRNA and microRNA sequencing and CpG methylation profiling. Validated DNA variants corresponded to diverse, infrequent mutations, with fewer than 40 genes mutated in >2% of cases. In contrast, somatic structural variants, including new gene fusions and focal deletions of MBNL1, ZEB2 and ELF1, were disproportionately prevalent in young individuals as compared to adults. Conversely, mutations in DNMT3A and TP53, which were common in adults, were conspicuously absent from virtually all pediatric cases. New mutations in GATA2, FLT3 and CBL and recurrent mutations in MYC-ITD, NRAS, KRAS and WT1 were frequent in pediatric AML. Deletions, mutations and promoter DNA hypermethylation convergently impacted Wnt signaling, Polycomb repression, innate immune cell interactions and a cluster of zinc finger-encoding genes associated with KMT2A rearrangements. These results highlight the need for and facilitate the development of age-tailored targeted therapies for the treatment of pediatric AML.

Neurocognitive Consequences of Childhood Leukemia and Its Treatment

As survival rates have improved in pediatric patients with leukemia, late side effects from chemotherapeutics and radiotherapy have become important considerations. We investigated these side effects and evaluated their impact on neurocognitive functions. The observational study included 68 patients with acute leukemia who were treated at Eskisehir Osmangazi University Medical Faculty. The study also included 62 of the patients' closest age siblings as a control group. Demographic and clinical data, chemotherapy protocol, use of radiotherapy were recorded, neurological and ophthalmological examinations, cranial imaging, electroencephalography, visual evoked potential, and hearing investigations were performed, and neurocognitive functions were evaluated. At least one or more late effects detected by a neurologic abnormality on physical exam, cranial magnetic resonance imaging, neurological tests, or neurocognitive tests was significantly more likely in the patient group (82.4%) compared to the control group (29%, p < 0.001). A higher rate (82.4%) of delayed neurological and cognitive problems occurred in children who received radiotherapy, intrathecal and/or systemic chemotherapy during leukemia treatment compared to age-matched siblings. Patients being treated for leukemia should be periodically evaluated for treatment-related side effects. Prophylactic interventions such cognitive training and maintenance of academic growth may offer the best hope of preventing late effects.

Characteristics and outcome in patients with central nervous system involvement treated in European pediatric acute myeloid leukemia study groups

BACKGROUND

There is no consensus on the treatment for pediatric patients with acute myeloid leukemia and initial central nervous system (CNS) involvement.

METHODS

To evaluate different CNS-directed treatment options (intrathecal [IT] therapy, CNS irradiation, hematopoietic stem cell transplantation [HSCT]), 261 patients (excluding acute promyelocytic leukemia) with initial CNS involvement treated in trials with similar intensive chemotherapy by four cooperative European study groups (1998-2013) were studied and compared with CNS-negative patients from the Berlin-Frankfurt-Münster group.

RESULTS

Patient characteristics in the different study groups were comparable. Young age, high white blood cell count, extramedullary involvement other than the CNS, monoblastic morphology, and inv(16) were associated with CNS involvement (each P < 0.0001). There were no major differences in outcome between the study groups. The cumulative incidence of relapse (CIR) regarding the CNS was higher in initially CNS-positive versus initially CNS-negative patients (all: 8 ± 2% vs. 3 ± 1%, P_(Gray) = 0.001; isolated: 4 ± 1% vs. 1 ± 0%, P_(Gray) = 0.03). However, global outcome of the CNS-positive cohort (overall survival, 64 ± 3%; event-free survival 48 ± 3%; and CIR 33% ± 3%) did not differ significantly from CNS-negative patients. Risk groups defined by cytogenetics were of likewise prognostic significance in CNS-positive and -negative patients. CNS treatment with cranial irradiation was not superior compared to IT therapy and systemic chemotherapy (± HSCT).

CONCLUSION

Although CNS relapses occurred more frequently in initially CNS-positive patients, their global outcome was similar as in CNS-negative patients. Intensified IT therapy was heterogeneous; however, at least eight applications, preferably with triple IT chemotherapy, seem to be appropriate to accompany dose-intensive systemic chemotherapy.

Peptide microarray profiling identifies phospholipase C gamma 1 (PLC-γ1) as a potential target for t(8;21) AML

The t(8;21) (q22;q22) chromosomal translocation is one of the most frequent genetic alterations in acute myeloid leukemia (AML) which has a need for improved therapeutic strategies. We found PLC-γ1 as one of the highest phosphorylated peptides in t(8;21) AML samples compared to NBM or CN-AML in our previous peptide microarray. PLC-γ1 is known to play a role in cancer progression, however, the impact of PLC-γ1 in AML is currently unknown. Therefore, we aimed to study the functional role of PLC-γ1 by investigating the cellular growth, survival and its underlying mechanism in t(8;21) AML.

In this study, PLC-γ1 expression was significantly higher in t(8;21) AML compared to other karyotypes. The PLC-γ1 protein expression was suppressed in AML1-ETO knock down cells indicating that it might induce kasumi-1 cell death. ShRNA-mediated PLC-γ1 knockdown in kasumi-1 cells significantly blocked cell growth, induced apoptosis and cell cycle arrest which was explained by the increased activation of apoptotic related and cell cycle regulatory protein expressions. Gene expression array analysis showed the up-regulation of apoptotic and DNA damage response genes together with the downregulation of cell growth, proliferation and differentiation genes in the PLC-γ1 suppressed kasumi-1 cells, consistent with the observed phenotypic effects. Importantly, PLC-γ1 suppressed kasumi-1 cells showed higher chemosensitivity to the chemotherapeutic drug treatments and lower cell proliferation upon hypoxic stress.

Taken together, these in vitro finding strongly support an important role for PLC-γ1 in the survival of t(8;21) AML mimicking kasumi-1 cells and identify PLC-γ1 as a potential therapeutic target for t(8;21) AML treatment.

Impact of post-transplant minimal residual disease on the clinical outcome of pediatric acute leukemia

This retrospective study examined the clinical significance of FCM-MRD in 36 patients with ALL and 29 patients with AML after their first allogeneic HSCT. Hematological (FCM-MRD ≥5.0%) and molecular relapse (FCM-MRD <5.0%) were first detected in 10 and two patients with ALL and in seven and eight patients with AML, respectively. Eight of 10 patients with molecular relapse eventually progressed to hematological relapse, although most were treated with immunological intervention by aggressive discontinuation of immunosuppressive therapy or donor lymphocyte infusion. Among these 12 patients, four of seven patients that obtained MRD^neg CR following post-transplant chemotherapy remain alive and disease-free after their second HSCT; however, all five patients who underwent a second HSCT in non-CR died of disease or treatment-related complications. As the FCM-MRD monitoring system used in the current study was probably not sensitive enough to detect MRD, which could be elucidated by immunological intervention, more sensitive diagnostic tools are mandatory for post-transplant MRD monitoring. Additional studies are required to address the impact of presecond transplant MRD on the clinical outcome of second HSCT.

Residual disease detected by flow cytometry is an independent predictor of survival in childhood acute myeloid leukaemia; results of the NOPHO-AML 2004 study

Early response after induction is a prognostic factor for disease outcome in childhood acute myeloid leukaemia (AML). Residual disease (RD) detection by multiparameter flow cytometry (MFC) was performed at day 15 and before consolidation therapy in 101 patients enrolled in the Nordic Society of Paediatric Haemato-Oncology AML 2004 study. A multicentre laboratory approach to RD analysis was used. Event-free survival (EFS) and overall survival (OS) was significantly different in patients with and without RD at both time points, using a 0·1% RD cut-off level. RD-negative and -positive patients after first induction showed a 5-year EFS of 65 ± 7% and 22 ± 7%, respectively (P < 0·001) and an OS of 77 ± 6% (P = 0·025) and 51 ± 8%. RD-negative and -positive patients at start of consolidation therapy had a 5-year EFS of 57 ± 7% and 11 ± 7%, respectively (P < 0·001) and an OS of 78 ± 6% and 28 ± 11%) (P < 0·001). In multivariate analysis only RD was significantly correlated with survival. RD before consolidation therapy was the strongest independent prognostic factor for EFS [hazard ratio (HR):5·0; 95% confidence interval (CI):1·9-13·3] and OS (HR:7·0; 95%CI:2·0-24·5). In conclusion, RD before consolidation therapy identifies patients at high risk of relapse in need of intensified treatment. In addition, RD detection can be performed in a multicentre setting and can be implemented in future trials.

The Time to Clearance of Peripheral Blood Blasts Predicts Complete Remission and Survival in Chinese Adults with Acute Myeloid Leukemia

The value of clearance of peripheral blood blasts (PBB) as a predictor of outcomes in acute myeloid leukemia (AML) is controversial. To investigate the prognostic significance of the time to clearance of PBB after induction in Chinese patients with AML, a retrospective analysis of 146 patients with newly diagnosed AML at Shanghai Ruijin Hospital was performed. Patients were categorized into early blast clearance (EBC; ≤5 days) and delayed blast clearance (DBC; >5 days) groups based on a receiver operating characteristic analysis. Complete remission (CR) after induction chemotherapy was related to the time to clearance of PBB (p < 0.001). Relapse-free survival (RFS; p = 0.003) and overall survival (p < 0.001) were longer in the EBC group. Multivariate analysis demonstrated that the time to clearance of PBB and cytogenetic risk independently predicted CR and RFS. Early clearance of PBB after induction chemotherapy can be a significant predictor of survival outcomes in AML patients.

Comparison of a fludarabine and melphalan combination-based reduced toxicity conditioning with myeloablative conditioning by radiation and/or busulfan in acute myeloid leukemia in Japanese children and adolescents

BACKGROUND

The relative efficacy of allogeneic hematopoietic cell transplantation (allo-HCT) after reduced toxicity conditioning (RTC) compared with standard myeloablative conditioning (MAC) in pediatric patients with acute myeloid leukemia (AML) has not been studied extensively. To address whether RTC is a feasible approach for pediatric patients with AML in remission, we performed a retrospective investigation of the outcomes of the first transplant in patients who had received an allo-HCT after RTC or standard MAC, using nationwide registration data collected between 2000 and 2011 in Japan.

PROCEDURE

We compared a fludarabine (Flu) and melphalan (Mel)-based regimen (RTC; n = 34) with total body irradiation (TBI) and/or busulfan (Bu)-based conditioning (MAC; n = 102) in demographic- and disease-criteria-matched childhood and adolescent patients with AML in first or second complete remission (CR1/CR2).

RESULTS

The incidence of engraftment, early complications, grade II-IV acute graft-versus-host disease (GVHD), and chronic GVHD were similar in each conditioning group. The risk of relapse (25% vs. 26%) and non-relapse mortality (13% vs. 11%) after 3 years did not differ between these groups, and univariate and multivariate analyses demonstrated that the 3-year overall survival (OS) rates after Flu/Mel-RTC and MAC were comparable (mean, 72% [range, 51-85%] and 68% [range, 58-77%], respectively).

CONCLUSIONS

The results suggest that the Flu/Mel-RTC regimen is a clinically acceptable conditioning strategy for childhood and adolescent patients with AML in remission. Although this retrospective, registry-based analysis has several limitations, RTC deserves to be further investigated in prospective trials.

Improved outcome of pediatric patients with acute megakaryoblastic leukemia in the AML-BFM 04 trial

Despite recent advances in the treatment of children with acute megakaryoblastic leukemia (AMKL) using intensified treatment protocols, clear prognostic indicators, and treatment recommendations for this acute myeloid leukemia (AML) subgroup are yet to be defined. Here, we report the outcome of 97 pediatric patients with de novo AMKL (excluding Down syndrome [DS]) enrolled in the prospective multicenter studies AML-BFM 98 and AML-BFM 04 (1998-2014). AMKL occurred in 7.4 % of pediatric AML cases, at younger age (median 1.44 years) and with lower white blood cell count (mean 16.5 × 10⁹/L) as compared to other AML subgroups. With 60 ± 5 %, children with AMKL had a lower 5-year overall survival (5-year OS; vs. 68 ± 1 %, P_{log rank} = 0.038). Yet, we achieved an improved 5-year OS in AML-BFM 04 compared to AML-BFM 98 (70 ± 6 % vs. 45 ± 8 %, P_{log rank} = 0.041). Allogeneic hematopoietic stem cell transplantation in first remission did not provide a significant survival benefit (5-year OS 70 ± 11 % vs. 63 ± 6 %; P_Mantel-Byar = 0.85). Cytogenetic data were available for n = 78 patients. AMKL patients with gain of chromosome 21 had a superior 5-year OS (80 ± 9 %, P_{log rank} = 0.034), whereas translocation t(1;22)(p13;q13) was associated with an inferior 5-year event-free survival (38 ± 17 %, P_{log rank} = 0.04). However, multivariate analysis showed that treatment response (bone marrow morphology on day 15 and 28) was the only independent prognostic marker (RR = 4.39; 95 % CI, 1.97–9.78). Interestingly, GATA1-mutations were detected in six patients (11 %) without previously known trisomy 21. Thus, AMKL (excluding DS) remains an AML subgroup with inferior outcome. Nevertheless, with intensive therapy regimens, a steep increase in the survival rates was achieved.

Acute myeloid leukaemia: challenges and real world data from India

The management of acute myeloid leukaemia (AML) in India remains a challenge. In a two-year prospective study at our centre there were 380 newly diagnosed AML (excluding acute promyelocytic leukaemia, AML-M3) patients. The median age of newly diagnosed patients was 40 years (range: 1-79; 12.3% were ≤ 15 years, 16.3% were ≥ 60 years old) and there were 244 (64.2%) males. The median duration of symptoms prior to first presentation at our hospital was 4 weeks (range: 1-52). The median distance from home to hospital was 580 km (range: 6-3200 km). 109 (29%) opted for standard of care and were admitted for induction chemotherapy. Of the 271 that did not take treatment the major reason was lack of financial resources in 219 (81%). There were 27 (24.7%) inductions deaths and of these, 12 (44.5%) were due to multidrug-resistant gram-negative bacilli and 12 (44.5%) showed evidence of a fungal infection. The overall survival at 1 year was 70.4% ± 10.7%, 55.6% ± 6.8% and 42.4% ± 15.6% in patients aged ≤ 15 years, 15 - 60 years and ≥ 60 years, respectively. In conclusion, the biggest constraint is the cost of treatment and the absence of a health security net to treat all patients with this diagnosis.

Arginine dependence of acute myeloid leukemia blast proliferation: a novel therapeutic target

Acute myeloid leukemia (AML) is one of the most common acute leukemias in adults and children, yet significant numbers of patients relapse and die of disease. In this study, we identify the dependence of AML blasts on arginine for proliferation. We show that AML blasts constitutively express the arginine transporters CAT-1 and CAT-2B, and that the majority of newly diagnosed patients' blasts have deficiencies in the arginine-recycling pathway enzymes argininosuccinate synthase and ornithine transcarbamylase, making them arginine auxotrophic. BCT-100, a pegylated human recombinant arginase, leads to a rapid depletion in extracellular and intracellular arginine concentrations, resulting in arrest of AML blast proliferation and a reduction in AML engraftment in vivo. BCT-100 as a single agent causes significant death of AML blasts from adults and children, and acts synergistically in combination with cytarabine. Using RNA sequencing, 20 further candidate genes which correlated with resistance have been identified. Thus, AML blasts are dependent on arginine for survival and proliferation, as well as depletion of arginine with BCT-100 of clinical value in the treatment of AML.