Survival difference between secondary and de novo acute myeloid leukemia by age, antecedent cancer types, and chemotherapy receipt

BACKGROUND

This study compared the survival of persons with secondary acute myeloid leukemia (sAML) to those with de novo AML (dnAML) by age at AML diagnosis, chemotherapy receipt, and cancer type preceding sAML diagnosis.

METHODS

Data from Surveillance, Epidemiology, and End Results 17 Registries were used, which included 47,704 individuals diagnosed with AML between 2001 and 2018. Multivariable Cox proportional hazards regression was used to compare AML-specific survival between sAML and dnAML. Trends in 5-year age-standardized relative survival were examined via the Joinpoint survival model.

RESULTS

Overall, individuals with sAML had an 8% higher risk of dying from AML (hazard ratio [HR], 1.08; 95% confidence interval [CI], 1.05-1.11) compared to those with dnAML. Disparities widened with younger age at diagnosis, particularly in those who received chemotherapy for AML (HR, 1.14; 95% CI, 1.10-1.19). In persons aged 20-64 years and who received chemotherapy, HRs were greatest for those with antecedent myelodysplastic syndrome (HR, 2.04; 95% CI, 1.83-2.28), ovarian cancer (HR, 1.91; 95% CI, 1.19-3.08), head and neck cancer (HR, 1.55; 95% CI, 1.02-2.36), leukemia (HR, 1.45; 95% CI, 1.12-1.89), and non-Hodgkin lymphoma (HR, 1.42; 95% CI, 1.20-1.69). Among those aged ≥65 years and who received chemotherapy, HRs were highest for those with antecedent cervical cancer (HR, 2.42; 95% CI, 1.15-5.10) and myelodysplastic syndrome (HR, 1.28; 95% CI, 1.19-1.38). The 5-year relative survival improved 0.3% per year for sAML slower than 0.86% per year for dnAML. Consequently, the survival gap widened from 7.2% (95% CI, 5.4%-9.0%) during the period 2001-2003 to 14.3% (95% CI, 12.8%-15.8%) during the period 2012-2014.

CONCLUSIONS

Significant survival disparities exist between sAML and dnAML on the basis of age at diagnosis, chemotherapy receipt, and antecedent cancer, which highlights opportunities to improve outcomes among those diagnosed with sAML.

Venetoclax Combination Treatment of Acute Myeloid Leukemia in Adolescents and Young Adult Patients

Over the past two decades, the prognosis in adolescents and young adults (AYAs) diagnosed with acute myeloid leukemia (AML) has significantly improved. The standard intensive cytotoxic treatment approach for AYAs with AML, consisting of induction chemotherapy with anthracycline/cytarabine combination followed by consolidation chemotherapy or stem cell transplantation, has lately been shifting toward novel targeted therapies, mostly in the fields of clinical trials. One of the most recent advances in treating AML is the combination of the B-cell lymphoma 2 (Bcl-2) inhibitor venetoclax with hypomethylating agents, which has been studied in elderly populations and was approved by the Food and Drug Administration (FDA) for patients over 75 years of age or patients excluded from intensive chemotherapy induction schemas due to comorbidities. Regarding the AYA population, venetoclax combination therapy could be a therapeutic option for patients with refractory/relapsed (R/R) AML, although data from real-world studies are currently limited. Venetoclax is frequently used by AYAs diagnosed with advanced hematologic malignancies, mainly acute lymphoblastic leukemia and myelodysplastic syndromes, as a salvage therapeutic option with considerable efficacy and safety. Herein, we aim to summarize the evidence obtained from clinical trials and observational studies on venetoclax use in AYAs with AML. Based on the available evidence, venetoclax is a safe and effective therapeutic option for R/R AML AYA patients. However, further research in larger cohorts is needed to confirm these data, establishing the benefits of a venetoclax-based regimen for this special population.

Association of the social disorganization index with time to first septic shock event in children with acute myeloid leukemia

BACKGROUND

Pediatric acute myeloid leukemia (AML) chemotherapy increases the risk of life-threatening complications, including septic shock (SS). An area-based measure of social determinants of health, the social disorganization index (SDI), was hypothesized to be associated with SS and SS-associated death (SS-death).

METHODS

Children treated for de novo AML on two Children's Oncology Group trials at institutions contributing to the Pediatric Health Information System (PHIS) database were included. The SDI was calculated via residential zip code data from the US Census Bureau. SS was identified via PHIS resource utilization codes. SS-death was defined as death within 2 weeks of an antecedent SS event. Patients were followed from 7 days after the start of chemotherapy until the first of end of front-line therapy, death, relapse, or removal from study. Multivariable-adjusted Cox regressions estimated hazard ratios (HRs) comparing time to first SS by SDI group.

RESULTS

The assembled cohort included 700 patients, with 207 (29.6%) sustaining at least one SS event. There were 233 (33%) in the SDI-5 group (highest disorganization). Adjusted time to incident SS did not statistically significantly differ by SDI (reference, SDI-1; SDI-2: HR, 0.84 [95% confidence interval (CI), 0.51-1.41]; SDI-3: HR, 0.70 [95% CI, 0.42-1.16]; SDI-4: HR, 0.97 [95% CI, 0.61-1.53]; SDI-5: HR, 0.72 [95% CI, 0.45-1.14]). Nine patients (4.4%) with SS experienced SS-death; seven of these patients (78%) were in SDI-4 or SDI-5.

CONCLUSIONS

In a large, nationally representative cohort of trial-enrolled pediatric patients with AML, there was no significant association between the SDI and time to SS.

Outcomes of haploidentical haematopoietic stem cell transplantation for adolescent and young adults with acute myeloid leukaemia

We aimed to identify the efficacy of haploidentical related donor (HID) haematopoietic stem cell transplantation (HSCT) in adolescent and young adults (AYAs) with acute myeloid leukaemia (AML) in a large cohort. Consecutive AML AYAs (15-39 years old, n = 599) receiving HID HSCT in complete remission (CR) were included. The 3-year cumulative incidence of measurable residual disease occurrence, relapse and non-relapse mortality after HID HSCT was 28.6% (95% CI: 25.0-32.2), 11.6% (95% CI: 9.0-14.2) and 6.7% (95% CI: 4.7-8.7) respectively. The 3-year probability of event-free survival, leukaemia-free survival (LFS) and overall survival (OS) after HID HSCT was 60.7% (95% CI: 56.9-64.8), 81.7% (95% CI: 78.7-84.9) and 85.6% (95% CI: 82.8-88.4) respectively. In multivariable analysis, AML risk category at diagnosis and comorbidity burdens before HID HSCT were independently associated with LFS and OS. Compared to the older adults (≥ 40 years, n = 355) with AML receiving HID HSCT in CR during the same time period, AYAs have a lower incidence of non-relapse mortality and higher probabilities of LFS and OS. Thus, we firstly confirmed the safety and efficacy of HID HSCT in AYAs with AML-CR.

Feasibility of high-throughput drug sensitivity screening (HDS)-guided treatment for children with refractory or relapsed acute myeloid leukemia

Relapsed/refractory (rel/ref) acute myeloid leukemia (AML) has a very high mortality rate. At present, hematopoietic stem cell transplantation (HSCT) is the most effective treatment for rel/ref AML. The remission of the primary disease before HSCT is crucial for the transplantation to be effective. Therefore, it is critical to choose a suitable type of chemotherapy before HSCT. Here, we recorded the outcomes of high-throughput drug sensitivity screening (HDS) in children with rel/ref AML. Thirty-seven pediatric rel/ref AML patients who received HDS from September 2017 until July 2021 were analyzed retrospectively. Most of the patients (24 patients, 64.9%) had adverse cytogenetics. Two patients had rel/ref AML with central nervous system leukemia. The complete remission (CR) rate was 67.6%. Eight patients developed IV grade bone marrow suppression. Twenty-three patients (62.2%) underwent HSCT. The 3-year overall survival (OS) and EFS rates were 45.9% and 43.2%, respectively. Infection in the myelosuppression stage was the main cause of death. The outcome of HDS was superior to the commonly reported rates. These results suggest that HDS may be a novel treatment option for pediatric patients with rel/ref AML, and it is a promising transitional regimen prior to HSCT.

Adolescents and young adults (AYA) with acute myeloid leukemia (AML): real-world long-term results and age-specific outcomes

Opposing acute lymphoblastic leukemia, sparse data about AYAs with acute myeloid leukemia (AML) is available. Overall, 125 AYAs (age 10-35 years) treated during the last two decades were evaluated and compared to 385 older patients. CBF leukemia was more frequent in AYAs (21.6% vs. 8%, p < 0.001); however, many presented high-risk features. AYAs showed improved complete remission rate (CR, 80% vs. 65%, p = 0.01), lower cumulative incidence of relapse and TRM and longer survival (5 year-OS 53% vs. 24%, p < 0.0001), observed mainly in intermediate-risk karyotype. Adolescents displayed even better outcomes (5 year-OS 69%). AlloHCT in CR1 was beneficial for nonadolescent AYAs (5 year-OS 66.7% vs. 44.4% without HCT, p = 0.04). Among 50 APL patients, 19 AYAs experienced better outcomes than older, mainly attributed to reduced treatment-related mortality (TRM, 5% vs. 19%, p = 0.1). We observed an important (>10%) survival gain for AYAs during the last decade. However, AYAs have still unmet needs to obtain optimal cure rates.

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.

Clinical Characteristics and Treatment Outcomes of Myeloid Sarcoma in Children: The Experience of the Polish Pediatric Leukemia and Lymphoma Study Group

Introduction

Myeloid sarcoma (MS) is an extramedullary malignant tumor composed of immature myeloid cells. It occurs in patients with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), or chronic myeloid leukemia (CML). MS may coincide with disease diagnosis or precede bone marrow involvement by months or even years; it can also represent the extramedullary manifestation of a relapse (1, 2).

Aim

The aim of this study is to describe clinical characteristics of children diagnosed with MS in Poland as well as to analyze diagnostic methods, treatment, and outcomes including overall survival (OS), relapse-free survival (RFS), and event-free survival (EFS). The study also attempted to identify factors determining treatment outcomes.

Patients

The study group comprised 43 patients (F=18, M=25) aged 0-18 years (median age, 10.0 years; mean age, 8.8 years) diagnosed with MS based on tumor biopsy and immunohistochemistry or identification of underlying bone marrow disease and extramedullary tumor according to imaging findings.

Methods

The clinical data and diagnostic and therapeutic methods used in the study group were analyzed. A statistical analysis of the treatment outcomes was conducted with STATISTICA v. 13 (StatSoft, Inc., Tulsa, OK, USA) and analysis of survival curves was conducted with MedCalc 11.5.1 (MedCalc Software, Ostend, Belgium). Statistical significance was considered at p&lt;0.05.

Results

In the study group, MS was most frequently accompanied by AML. The most common site of involvement was skin, followed by orbital region. Skin manifestation of MS was more common in the age group &lt;10 years. The most frequent genetic abnormality was the t(8;21)(q22;q22) translocation. The 5-year OS probability (pOS), 5-year RFS probability (pRFS), and 5-year EFS probability (pEFS) were 0.67 ± 0.08, 0.79 ± 0.07, and 0.65 ± 0.08, respectively. In patients with isolated MS and those with concurrent bone marrow involvement by AML/MDS, pOS values were 0.56 ± 0.12 and 0.84 ± 0.09 (p=0.0251), respectively, and pEFS values were 0.56 ± 0.12 and 0.82 ± 0.08 (p=0.0247), respectively. In patients with and without the t(8;21)(q22;q22) translocation, pEFS values were 0.90 ± 0.09 and 0.51 ± 0.14 (p=0.0490), respectively.

Conclusions

MS is a disease with a highly variable clinical course. Worse treatment outcomes were observed in patients with isolated MS compared to those with concurrent bone marrow involvement by AML/MDS. Patients with the t(8;21)(q22;q22) translocation were found to have significantly higher pEFS. MS location, age group, chemotherapy regimen, surgery, and/or radiotherapy did not have a significant influence on treatment outcomes. Further exploration of prognostic factors in children with MS is indicated.

Comprehensive Analysis of N6-Methyladenosine-Related Long Noncoding RNA Prognosis of Acute Myeloid Leukemia and Immune Cell Infiltration

N6-Methyladenosine-related long noncoding RNAs play an essential role in many cancers’ development. However, the relationship between m6A-related lncRNAs and acute myelogenous leukemia (AML) prognosis remains unclear. We systematically analyzed the association of m6A-related lncRNAs with the prognosis and tumor immune microenvironment (TME) features using the therapeutically applicable research to generate effective treatment (TARGET) database. We screened 315 lncRNAs associated with AML prognosis and identified nine key lncRNAs associated with m6A by the LASSO Cox analysis. A model was established based on these nine lncRNAs and the predictive power was explored in The Cancer Genome Atlas (TCGA) database. The areas under the ROC curve of TARGET and TCGA databases for ROC at 1, 3, and 5 years are 0.701, 0.704, and 0.696, and 0.587, 0.639, and 0.685, respectively. The nomogram and decision curve analysis (DCA) showed that the risk score was more accurate than other clinical indicators in evaluating patients’ prognoses. The clusters with a better prognosis enrich the AML pathways and immune-related pathways. We also found a close correlation between prognostic m6A-related lncRNAs and tumor immune cell infiltration. LAG3 expression at the immune checkpoint was lower in the worse prognostic cluster. In conclusion, m6A-related lncRNAs partly affected AML prognosis by remodeling the TME and affecting the anticarcinogenic ability of immune checkpoints, especially LAG3 inhibitors. The prognostic model constructed with nine key m6A-related lncRNAs can provide a method to assess the prognosis of AML patients in both adults and children.

Straight to the Point-The Novel Strategies to Cure Pediatric AML

Although the outcome has improved over the past decades, due to improved supportive care, a better understanding of risk factors, and intensified chemotherapy, pediatric acute myeloid leukemia remains a life-threatening disease, and overall survival (OS) remains near 70%. According to French-American-British (FAB) classification, AML is divided into eight subtypes (M0-M7), and each is characterized by a different pathogenesis and response to treatment. However, the curability of AML is due to the intensification of standard chemotherapy, more precise risk classification, improvements in supportive care, and the use of minimal residual disease to monitor response to therapy. The treatment of childhood AML continues to be based primarily on intensive, conventional chemotherapy. Therefore, it is essential to identify new, more precise molecules that are targeted to the specific abnormalities of each leukemia subtype. Here, we review abnormalities that are potential therapeutic targets for the treatment of AML in the pediatric population.

Less intensive antileukemic therapies (monotherapy and/or combination) for older adults with acute myeloid leukemia who are not candidates for intensive antileukemic therapy: A systematic review and meta-analysis

Introduction

Elderly patients with acute myeloid leukemia not eligible for intensive antileukemic therapy are treated with less intensive therapies, uncertainty remains regarding their relative merits.

Objectives

To compare the effectiveness and safety of less intensive antileukemic therapies for older adults with newly diagnosed AML not candidates for intensive therapies.

Methods

We included randomized controlled trials (RCTs) and non-randomized studies (NRS) comparing less intensive therapies in adults over 55 years with newly diagnosed AML. We searched MEDLINE and EMBASE from inception to August 2021. We assessed risk of bias of RCTs with a modified Cochrane Risk of Bias tool, and NRS with the Non-Randomized Studies of Interventions tool (ROBINS-I). We calculated pooled hazard ratios (HRs), risk ratios (RRs), mean differences (MD) and their 95% confidence intervals (CIs) using a random-effects pairwise meta-analyses and assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

Results

We included 27 studies (17 RCTs, 10 NRS; n = 5,698), which reported 9 comparisons. Patients were treated with azacitidine, decitabine, and low-dose cytarabine (LDAC), as monotherapies or in combination with other agents. Moderate certainty of evidence suggests no convincing difference in overall survival of patients who receive azacitidine monotherapy compared to LDAC monotherapy (HR 0.69; 95% CI, 0.31–1.53), fewer febrile neutropenia events occurred between azacitidine monotherapy to azacitidine combination (RR 0.45; 95% CI, 0.31–0.65), and, fewer neutropenia events occurred between LDAC monotherapy to decitabine monotherapy (RR 0.62; 95% CI 0.44–0.86). All other comparisons and outcomes had low or very low certainty of evidence.

Conclusion

There is no convincing superiority in OS when comparing less intensive therapies. Azacitidine monotherapy is likely to have fewer adverse events than azacitidine combination (febrile neutropenia), and LDAC monotherapy is likely to have fewer adverse events than decitabine monotherapy (neutropenia).

Pediatric Acute Myeloid Leukemia—Past, Present, and Future

This review reports about the main steps of development in pediatric acute myeloid leukemia (AML) concerning diagnostics, treatment, risk groups, and outcomes. Finally, a short overview of present and future approaches is given.

Analytical study of RUNX1-RUNXT1, PML-RARA, CBFB-MYH11, BCR-ABL1p210 , and KMT2-MLLT3 in Mexican children with acute myeloid leukemia: A multicenter study of the Mexican interinstitutional group for the identification of the causes of childhood leukemia (MIGICCL)

BACKGROUND

The distribution of RUNX1-RUNXT1, PML-RARA, CBFB-MYH11, BCR-ABL1^p210 , and KMT2A-MLLT3 in the pediatric population with acute myeloid leukemia (AML) in many countries of Latin America is largely unknown. Therefore, we aimed to investigate the frequency of these fusion genes in children with de novo AML from Mexico City, which has one of the highest incidence rates of acute leukemia in the world. Additionally, we explored their impact in mortality during the first year of treatment.

METHODS

We retrospectively analyzed the presence of RUNX1-RUNXT1, PML-RARA, CBFB-MYH11, BCR-ABL1^p210 , and KMT2A-MLLT3 by RT-PCR among 77 patients (<18 years) diagnosed with de novo AML between 2019 and 2021 in nine Mexico City hospitals.

RESULTS

The overall frequency of the fusion genes was 50.7%; RUNX1-RUNXT1 (22.1%) and PML-RARA (20.8%) were the most prevalent, followed by CBFB-MYH11 (5.2%) and BCR-ABL1^p210 (2.4%). KMT2A-MLLT3 was not detected. Patients with PML-RARA showed the lowest survival with high early mortality events. However, more studies are required to evaluate the impact of analyzed fusion genes on the overall survival of the Mexican child population with AML.

CONCLUSION

The pediatric population of Mexico City with AML had frequencies of AML1-ETO, PML-RARA, CBFB-MYH11, and BCR-ABL1^p210 similar to those of other populations around the world. Patients with BCR-ABL1^p210 and CBFB-MYH11 were few or did not die, while those with MLL-AF9 was not detected. Although patients with PML-RARA had a low survival and a high early mortality rate, further studies are needed to determine the long-term impacts of these fusion genes on this Latino population.

Increased survival disparities among children and adolescents & young adults with acute myeloid leukemia: A Dutch population-based study

For many cancers, adolescents and young adults (AYAs) have a poorer prognosis than pediatric patients. Our study evaluates survival outcomes of children (0‐17 years) and AYAs (18‐39 years) diagnosed with acute myeloid leukemia (AML) in the Netherlands between 1990 and 2015 (N = 2058) utilizing the population‐based Netherlands Cancer Registry, which includes information on therapy and site of primary treatment. Five‐ and 10‐year relative (disease‐specific) survival were estimated for all patients, children and AYAs. Multivariable analyses were performed using generalized linear models (excess mortality) and logistic regression (early mortality). AYAs with AML had a substantially lower 5‐ and 10‐year relative survival than children (5‐year: 43% vs 58%; 10‐year: 37% vs 51%). The gap in 5‐year relative survival was largest (nearly 20 percent‐points) in 2010 to 2015, despite survival improvements over time across all ages. The multivariable‐adjusted excess risk of dying was 60% higher in AYAs (95% CI: 37%‐86%). Early mortality (death within 30 days of diagnosis) declined over time, and did not differ between children and AYAs. In conclusion, AYAs diagnosed with AML in the Netherlands had a worse prognosis than pediatric patients. The survival gap seemed most pronounced in recent years, suggesting that improvements in care resulting in better outcome for children have not led to equal benefits for AYAs.

Acute leukemia presenting as acute lower limb ischemia

Objectives: Acute lower limb ischemia (ALLI) is a common vascular emergency. However, ALLI presenting as the initial symptom of acute leukemia (AL) is scarce. Here we present a case of ALLI in the setting of acute myeloid leukemia (AML) while systematically reviewing the current literature to withdraw conclusions about the management, prognosis, and treatment for this atypical presentation of AL. Methods: We conducted a systematic electronic research according to Preferred Reporting Items for Systematic Review and Meta-Analysis protocol (PRISMA) for articles published from January 1981 up to January 2021 concerning ALLI in the setting of acute leukemia (AL). Patients' baseline characteristics were recorded and nine outcomes of interest were studied. Results: Twenty-six individuals, 16 males with a mean age of 46.3 years (±20) were included in this review. The diagnosis included 13 AML patients (50%), 11 acute promyelotic leukemia (APL) (42.3%) and two acute lymphoblastic leukemias (ALL) (7.7%). Treatment varied among nine different regimens. Four patients were treated with chemotherapy alone (15.4%), four with thrombectomy alone (15.4%), and 11 with a combination of chemotherapy and thrombectomy (42.3%). Eight major amputations were recorded (30. 8%). Thirty-day mortality was 35.7%. Forty-eight peripheral thrombotic events were recorded with 12 patients suffering recurrent thrombotic events. Conclusion: ALLI as the presenting symptom of AL is a rare condition that carries significant mortality and amputation rates. Timely diagnosis is crucial concerning short-term survival and limb salvage. APL, despite being the rarest form of AL, represented a significant proportion of the patient population in this review. The role of leukostasis in the disease's progression and the efficacy of leukapheresis as a treatment regimen should be further investigated through case-control studies.

Far from Health: The Bone Marrow Microenvironment in AML, A Leukemia Supportive Shelter

Acute myeloid leukemia (AML) is the second most common leukemia among children. Although significant progress in AML therapy has been achieved, treatment failure is still associated with poor prognosis, emphasizing the need for novel, innovative therapeutic approaches. To address this major obstacle, extensive knowledge about leukemogenesis and the complex interplay between leukemic cells and their microenvironment is required. The tremendous role of this bone marrow microenvironment in providing a supportive and protective shelter for leukemic cells, leading to disease development, progression, and relapse, has been emphasized by recent research. It has been revealed that the interplay between leukemic cells and surrounding cellular as well as non-cellular components is critical in the process of leukemogenesis. In this review, we provide a comprehensive overview of recently gained knowledge about the importance of the microenvironment in AML whilst focusing on promising future therapeutic targets. In this context, we describe ongoing clinical trials and future challenges for the development of targeted therapies for AML.

Genomic Variants of Cytarabine Sensitivity Associated with Treatment-Related Mortality in Pediatric AML: A Report from the Children's Oncology Group

PURPOSE

Cytarabine is an effective treatment for AML with associated toxicities including treatment related mortality (TRM). The purpose is to determine the clinical relevance of SNPs identified through the use of HapMap lymphoblastoid cell-based models, in predicting cytarabine response and toxicity in AML.

EXPERIMENTAL DESIGN

We tested clinical significance of SNPs associated with cytarabine sensitivity in children with AML treated on Children's Oncology Group regimens (CCG 2941/2961). Endpoints included overall survival (OS), event-free survival (EFS), and TRM. Patients who received bone marrow transplant were excluded. We tested 124 SNPs associated with cytarabine sensitivity in HapMap cell lines in 348 children to determine whether any associated with treatment outcomes. In addition, we tested five SNPs previously associated with TRM in children with AML in our independent dataset of 385 children.

RESULTS

Homozygous variant genotypes of rs2025501 and rs6661575 had increased in vitro cellular sensitivity to cytarabine and were associated with increased TRM. TRM was particularly increased in children with variant genotype randomized to high-dose cytarabine (rs2025501: P = 0.0024 and rs6661575 P = 0.0188). In analysis of previously reported SNPs, only the variant genotype rs17202778 C/C was significantly associated with TRM (P < 0.0001).

CONCLUSIONS

We report clinical importance of two SNPs not previously associated with cytarabine toxicity. Moreover, we confirm that SNP rs17202778 significantly impacts TRM in pediatric AML. Cytarabine sensitivity genotypes may predict TRM and could be used to stratify to standard versus high-dose cytarabine regimens, warranting further study in prospective AML trials.

Pediatric acute myeloid leukemia: updates on biology, risk stratification, and therapy

PURPOSE OF REVIEW

Despite advances in therapy over the past decades, overall survival for children with acute myeloid leukemia (AML) has not exceeded 70%. In this review, we highlight recent insights into risk stratification for patients with pediatric AML and discuss data driving current and developing therapeutic approaches.

RECENT FINDINGS

Advances in cytogenetics and molecular profiling, as well as improvements in detection of minimal residual disease after induction therapy, have informed risk stratification, which now relies heavily on these elements. The treatment of childhood AML continues to be based primarily on intensive, conventional chemotherapy. However, recent trials focus on limiting treatment-related toxicity through the identification of low-risk subsets who can safely receive fewer cycles of chemotherapy, allocation of hematopoietic stem-cell transplant to only high-risk patients and optimization of infectious and cardioprotective supportive care.

SUMMARY

Further incorporation of genomic and molecular data in pediatric AML will allow for additional refinements in risk stratification to enable the tailoring of treatment intensity. These data will also dictate the incorporation of molecularly targeted therapeutics into frontline treatment in the hope of improving survival while decreasing treatment-related toxicity.

Ontogenic Changes in Hematopoietic Hierarchy Determine Pediatric Specificity and Disease Phenotype in Fusion Oncogene-Driven Myeloid Leukemia

Fusion oncogenes are prevalent in several pediatric cancers, yet little is known about the specific associations between age and phenotype. We observed that fusion oncogenes, such as ETO2-GLIS2, are associated with acute megakaryoblastic or other myeloid leukemia subtypes in an age-dependent manner. Analysis of a novel inducible transgenic mouse model showed that ETO2-GLIS2 expression in fetal hematopoietic stem cells induced rapid megakaryoblastic leukemia whereas expression in adult bone marrow hematopoietic stem cells resulted in a shift toward myeloid transformation with a strikingly delayed in vivo leukemogenic potential. Chromatin accessibility and single-cell transcriptome analyses indicate ontogeny-dependent intrinsic and ETO2-GLIS2-induced differences in the activities of key transcription factors, including ERG, SPI1, GATA1, and CEBPA. Importantly, switching off the fusion oncogene restored terminal differentiation of the leukemic blasts. Together, these data show that aggressiveness and phenotypes in pediatric acute myeloid leukemia result from an ontogeny-related differential susceptibility to transformation by fusion oncogenes. SIGNIFICANCE: This work demonstrates that the clinical phenotype of pediatric acute myeloid leukemia is determined by ontogeny-dependent susceptibility for transformation by oncogenic fusion genes. The phenotype is maintained by potentially reversible alteration of key transcription factors, indicating that targeting of the fusions may overcome the differentiation blockage and revert the leukemic state.See related commentary by Cruz Hernandez and Vyas, p. 1653.This article is highlighted in the In This Issue feature, p. 1631.

Morphological characteristics, cytogenetic profile, and outcome of RUNX1-RUNX1T1-positive acute myeloid leukemia: Experience of an Indian tertiary care center

INTRODUCTION

A prototype of good prognosis, t(8;21)-positive AML, has diverse clinical and genetic features which affect its outcome. This study aimed at evaluating the clinico-pathological spectrum of t(8;21)-positive AML and ascertaining prognostic factors influencing its outcome in the Indian subcontinent.

METHODS

A retrospective analysis of 75 cases of t(8;21)-positive AML diagnosed over a period of six years (2013-2018) was carried out. Detailed clinical and laboratory data of the patients were collected from the electronic medical records and reviewed.

RESULTS

Median age was 19.5 years (range 5-75 years) with a M:F of 1.7. Myeloid sarcoma was observed in 9.3% cases. There were 85% FAB AML-M2, 8% AML-M1, and 7% AML-M4 subtypes. Prominent morphological characteristics included dyspoiesis in maturing myeloid cells (83%), long thin tapered Auer rods (58%), cytoplasmic vacuoles (58%), eosinophilia (50%), and mast cells (22%). Auer rods in maturing granulocytes (4% cases) were highly suggestive of the translocation. Additional cytogenetic abnormalities were present in 53% cases. Seventy-one percent (25/35) achieved CR. The overall survival (OS) was 40%, with a median follow-up of 27 months (range 4-57 months). None of the hematological or cytogenetic factors correlated with OS, except for the presence of myeloid sarcoma which had a trend toward poor survival (P = .07).

CONCLUSION

Outcome of t(8;21) AML is not influenced by any of the clinico-pathological parameters, except for a myeloid sarcoma, which may herald a poor prognosis. Recognition of this distinct subtype of AML would facilitate further molecular screening for risk stratification in resource-constrained settings.

MicroRNA-206 serves as a tumor suppressor in pediatric acute myeloid leukemia by targeting Cyclin D1

Pediatric acute myeloid leukemia (AML) is a complex and heterogeneous disease. Several studies have shown the regulatory functions of microRNAs (miRNAs) in pediatric AML progression, and in this study, we aimed to evaluate the biological role of miR-206 in pediatric AML. The results demonstrated that miR-206 expression levels in the bone marrow and serum of pediatric AML patients were remarkably decreased than those in normal controls, and low serum miR-206 expression was closely associated with the unfavorable clinicopathological characteristics and prognosis of pediatric AML patients. In addition, in vitro functional experiments revealed that overexpression of miR-206 significantly inhibited AML cell proliferation partly through induction of cell cycle arrest. Further studies showed that Cyclin D1 might be a direct target of miR-206 in AML cells, and the impaired proliferation ability of miR-206-overexpressing AML cells was notably rescued by Cyclin D1 restoration. Accordingly, the findings of our study suggested that miR-206 might serve as a promising prognostic marker and a potential therapy target for patients with pediatric AML.

Comparable on-therapy mortality and supportive care requirements in Black and White patients following initial induction for pediatric acute myeloid leukemia

BACKGROUND

Black patients with acute myeloid leukemia (AML) are more likely to present with high acuity and consequently experience higher rates of induction mortality than white patients. Given the consistently identified racial disparities in overall survival (OS) among patients with AML, we aimed to evaluate whether there were sustained on-therapy racial differences in inpatient mortality, intensive care unit (ICU) requirements, or supportive care beyond initial induction.

PROCEDURE

Within a retrospective cohort of 1239 children diagnosed with AML between 2004 and 2014 in the Pediatric Health Information System (PHIS) database who survived their initial course of induction chemotherapy, we compared on-therapy inpatient mortality, ICU-level care requirements, treatment course duration, cumulative length of hospital stay (LOS), and resource utilization after induction I by race.

RESULTS

Over the period from the start of induction II through completion of frontline chemotherapy, there were no significant differences in mortality (adjusted odds ratios [OR], 1.01; 95% confidence intervals [CI], 0.41-2.48), ICU-level care requirements (adjusted OR, 0.93; 95% CI, 0.69-1.26), LOS (adjusted mean difference, 3.2 days; 95% CI, -2.3-9.6), or supportive care resource utilization for black patients relative to white patients. Course-specific analyses also demonstrated no differences by race.

CONCLUSION

Although black patients have higher acuity at presentation and higher induction mortality, such disparities do not persist over subsequent frontline chemotherapy treatment. This finding allows interventions aimed at reducing disparities to be directed at presentation and induction.

[Pediatric de novo acute megakaryoblastic leukemia: an affair of complexes]

Pediatric acute megakaryoblastic leukemia (AMKL) are generally associated with poor prognosis and the expression of fusion oncogenes involving transcriptional regulators. Recent results indicate that the ETO2-GLIS2 fusion, associated with 25-30 % of pediatric AMKL, binds and alters the activity of regulatory regions of gene expression, called "enhancers", resulting in the deregulation of GATA and ETS factors essential for the development of hematopoietic stem cells. An imbalance in GATA/ETS factor activity is also found in other AMKL subgroups. This review addresses the transcriptional bases of transformation in pediatric AMKL and therapeutic perspectives.

Clinical management of Australian adolescents and young adults with acute lymphoblastic and myeloid leukemias: A national population-based study

BACKGROUND

While several studies have examined the treatment of adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL), studies of acute myeloid leukemia (AML) are rare. Using national data for Australia, we describe (i) the number and type of treatment centers caring for AYAs, (ii) induction/first-line treatments, and (iii) survival outcomes.

PROCEDURE

National population-based study assessing treatment of 15- to 24-year-olds diagnosed with ALL or AML between 2007 and 2012. Treatment details were abstracted from hospital medical records. Treatment centers were classified as pediatric or adult (adult AYA-focused or other adult; and by AYA volume [high/low]). Cox proportional hazard regression analyses examined associations between treatment and overall, event-free, and relapse-free survival outcomes.

RESULTS

Forty-seven hospitals delivered induction therapy to 351 patients (181 ALL and 170 AML), with 74 (21%) treated at pediatric centers; 70% of hospitals treated less than two AYA leukemia patients per year. Regardless of treatment center, 82% of ALL patients were on pediatric protocols. For AML, pediatric protocols were not used in adult centers, with adult centers using a non-COG 7+3-type induction protocol (51%, where COG is Cooperative Oncology Group) or an ICE-type protocol (39%, where ICE is idarubicin, cytarabine, etoposide). Exploratory analyses suggested that for both ALL and AML, AYAs selected for adult protocols have worse overall, event-free, and relapse-free survival outcomes.

CONCLUSIONS

Pediatric protocols were commonly used for ALL patients regardless of where they are treated, indicating rapid assimilation of recent evidence by Australian hematologists. For AML, pediatric protocols were only used at pediatric centers. Further investigation is warranted to determine the optimal treatment approach for AYA AML patients.

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.

Acute myelogenous leukemia in adolescents and young adults

The incidence of acute myelogenous leukemia (AML) increases progressively with age. Favorable genetic mutations are most prevalent in children, and unfavorable profiles increase proportionately in adolescents and young adults (AYA) and into later adulthood. Survival rates of AYA have improved over recent decades to 50-60%, but their accrual to clinical trials remains poor. In contrast to AYA with acute lymphoblastic leukemia, the prognostic benefit for AYA with AML enrolled in pediatric compared with adult trials is minor and only seen when different protocols are used. The distinctive needs of AYA, including intensive psychological services, call for their treatment within specialized centers that offer complex supportive care.

Impact of age on the survival of pediatric leukemia: an analysis of 15083 children in the SEER database

BACKGROUND & AIMS

Age at diagnosis is a key factor for predicting the prognosis of pediatric leukemia especially regarding the survivorship assessment. In this study, we aimed to assess the impact of this prognostic factor such as age in children with pediatric leukemia.

METHODS

In this study, Surveillance, Epidemiology, and End Results Program-registered children with leukemia during 1988-2013 were analyzed. All patients were divided into five groups according to the age at the time of diagnosis (<1, 1-4, 5-9, 10-15, >15 years old). Kaplan-Meier and multivariable Cox regression models were used to evaluate leukemia survival outcomes and risk factors.

RESULTS

There was significant variability in pediatric leukemia survival by age at diagnosis including ALL, AML and CML subtypes. According to the survival curves in each group, survival rate were peaked among children diagnosed at 1–4 years and steadily declined among those diagnosed at older ages in children with ALL. Infants (<1 year) had the lowest survivorship in children with either ALL or AML. However, children (1-4 years) harbored the worst prognosis suffering from CML. A stratified analysis of the effect of age at diagnosis was validated as independent predictors for the prognosis of pediatric leukemia.

CONCLUSIONS

Age at diagnosis remained to be a crucial determinant of the survival variability of pediatric leukemia patients.

Acute Myeloid Leukemia With Central Nervous System Involvement in Children: Experience From the French Protocol Analysis ELAM02

Central nervous system (CNS) involvement at diagnosis of pediatric acute myeloid leukemia (AML) is not considered as an independent prognostic factor. This study describes the prognostic value of pediatric AML with CNS involvement at diagnosis. Pediatric patients were treated for de novo AML in the French multicenter trial ELAM02. Lumbar puncture was carried out in the first week, and the treatment was adapted to the CNS status. No patient received CNS radiotherapy. The patients were classified into 2 groups: CNS+ and CNS-. Of the 438 patients, 16% (n=70) had CNS involvement at diagnosis, and 29% showed clinical signs. The patients with CNS disease were younger (40% were below 2 y old), had a higher white blood cell count (median of 45 vs. 13 G/L), and had M4 and M5 morphologies. The complete remission rate was similar at 92.8% for CNS+ and 88.5% for CNS-. There was no significant difference between the CNS+ and the CNS- group in overall survival (76% and 71%, respectively) and event-free survival (57% and 52%, respectively). Regarding the occurrence of first relapse, the CNS+ group had a higher combined relapse rate of 26.1% compared with 10% for the CNS- group. The results indicate that CNS involvement at diagnosis of pediatric AML is not an independent prognostic factor. Triple intrathecal chemotherapy combined with high-dose intravenous cytarabine should be the first-line treatment for CNS disease.

Prognostic value of genetic mutations in adolescent and young adults with acute myeloid leukemia

Clinical outcomes and the genetic background of acute myeloid leukemia (AML) in adolescent and young adults (AYAs) are known to differ in younger children and older adults. To clarify the impact of genetic mutations on clinical outcomes of AYAs with AML, we analyzed data from the JPLSG AML-05 and JALSG AML201 studies. AYAs aged 15-39 years (n = 103) were included. FLT3-ITD, KIT, CEBPA, NRAS, KRAS, WT1, MLL-PTD, and NPM1 mutations were analyzed. Overall survival (OS) of the AYAs was 61% and event-free survival was 38% at 3 years. FLT3-ITD (HR 2.10; 95% CI 1.07-4.12; p = 0.031) and NPM1 (HR 0.24; 95% CI 0.06-1.00; p = 0.050) mutations were associated with risk of overall mortality in multivariate analysis. OS was significantly different according to FLT3-ITD and NPM1 mutation status (p = 0.03). Survival was 100% with NPM1 mutations in the absence of FLT3-ITD and 35% (95% CI 14-57%) with FLT3-ITD in the absence of NPM1 mutations. The OS of AYAs, children (n = 413) and older adults (n = 124) of the AML-05 and AML201 participants were significantly different (p < 0.0001). This is the first report to combine clinical and genetic data of AYA AML from the major Japanese pediatric and adult study groups.

Allogeneic Hematopoietic Stem Cell Transplantation for Adolescents and Young Adults with Acute Myeloid Leukemia

Few reports have focused on adolescent and young adult (AYA) patients with acute myeloid leukemia (AML) treated with hematopoietic stem cell transplantation (HSCT). We performed a retrospective analysis based on data obtained from a Japanese nationwide registration database to compare HSCT outcomes in AYA patients with AML with those in children with AML. An analysis of the 2973 patients with de novo AML who received allogeneic HSCT from 1990 to 2013 showed inferior 5-year overall survival (OS) (54% versus 58%, P <.01) and increased treatment-related mortality (TRM) (16% versus 13%, P = .02) in AYA patients. Multivariate analysis for both OS and TRM showed a significant negative impact on AYAs. However, the negative impact of older age lost its significance in an additional analysis focusing on 1407 recent transplant recipients with high-resolution HLA typing (2000 to 2013). Finally, we analyzed the impact of transplantation center type on HSCT outcomes in 317 adolescent patients (15 to 18 years old) and found no difference in outcomes between patients treated at a pediatric or an adult hospital. Higher age was a strong predictive factor for inferior OS resulting from increased TRM, which can be eliminated with better donor selection using high-resolution HLA typing.

Pediatric haematopoiesis and related malignancies

Survival after acute paediatric (0–14 years), adolescent (15–19 years) and young adult (20–39 years) leukaemia has improved substantially over the last five decades, particularly for acute lymphoblastic leukaemia (ALL) and acute promyelocytic leukaemia. This progress represents one of the most successful achievements in the history of medicine and has been attributed to the development of effective chemotherapy regimens, improvement in supportive care, better risk stratification, use of targeted therapies, and advances in haematopoietic stem cell transplantation. Recent studies have revealed improvement in survival over time for all age groups and subtypes of leukaemia. However, these outcomes varied widely by age and are associated with sociodemographic and clinical factors. The present review concludes that survival and early death after acute leukaemia has greatly improved among young patients. However, inequalities in outcomes remain and are likely a result of multiple factors.

Adolescents and Young Adults with Acute Lymphoblastic Leukemia and Acute Myeloid Leukemia: Impact of Care at Specialized Cancer Centers on Survival Outcome

Background: Adolescents and young adults (AYA; 15-39 years) with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) experience inferior survival when compared with children. Impact of care at NCI-designated Comprehensive Cancer Centers (CCC) or Children's Oncology Group sites (COG) on survival disparities remains unstudied.Methods: Using the Los Angeles cancer registry, we identified 1,870 ALL or AML patients between 1 and 39 years at diagnosis. Cox regression analyses assessed risk of mortality; younger age + CCC/COG served as the referent group. Logistic regression was used to determine odds of care at CCC/COG, adjusting for variables above.Results: ALL outcome: AYAs at non-CCC/COG experienced inferior survival (15-21 years: HR = 1.9, P = 0.005; 22-29 years: HR = 2.6, P < 0.001; 30-39 years: HR = 3.0, P < 0.001). Outcome at CCC/COG was comparable between children and young AYAs (15-21 years: HR = 1.3, P = 0.3; 22-29 years: HR = 1.2, P = 0.2) but was inferior for 30- to 39-year-olds (HR = 3.4, P < 0.001). AML outcome: AYAs at non-CCC/COG experienced inferior outcome (15-21 years: HR = 1.8, P = 0.02; 22-39 years: HR = 1.4, P = 0.06). Outcome at CCC/COG was comparable between children and 15- to 21-year-olds (HR = 1.3, P = 0.4) but was inferior for 22- to 39-year-olds (HR = 1.7, P = 0.05). Access: 15- to 21-year-olds were less likely to use CCC/COG than children (P < 0.001). In 22- to 39-year-olds, public/uninsured (ALL: P = 0.004; AML<0.001), African American/Hispanics (ALL: P = 0.03), and 30- to 39-year-olds (ALL: P = 0.03) were less likely to use CCC/COG.Conclusions: Poor survival in AYAs with ALL and AML is mitigated by care at CCC/COG. Barriers to CCC/COG care include public/uninsured, and African American/Hispanic race/ethnicity.Impact: Care at CCC/COG explains, in part, inferior outcomes in AYAs with ALL and AML. Key sociodemographic factors serve as barriers to care at specialized centers. Cancer Epidemiol Biomarkers Prev; 26(3); 312-20. ©2017 AACR.

The role of acuity of illness at presentation in early mortality in black children with acute myeloid leukemia

Black patients with acute myeloid leukemia (AML) experience higher mortality than White patients. We compared induction mortality, acuity of illness prior to chemotherapy, and insurance type between Black and White patients to assess whether acuity of presentation mediates the disparity. Within a retrospective cohort of 1,122 children with AML treated with two courses of standard induction chemotherapy between 2004 and 2014 in the Pediatric Health Information System (PHIS) database, the association between race (Black versus White) and inpatient mortality during induction was examined. Intensive Care Unit (ICU)-level resource utilization during the first 72 hours following admission for initial AML chemotherapy was evaluated as a potential mediator. The total effect of race on mortality during Induction I revealed a strong association (unadjusted HR 2.75, CI: 1.18, 6.41). Black patients had a significantly higher unadjusted risk of requiring ICU-level resources within the first 72 hours after initial presentation (17% versus 11%; RR 1.52, CI: 1.04, 2.24). Mediation analyses revealed the indirect effect of race through acuity accounted for 61% of the relative excess mortality during Induction I. Publicly insured patients experienced greater induction mortality than privately insured patients regardless of race. Black patients with AML have significantly greater risk of induction mortality and are at increased risk for requiring ICU-level resources soon after presentation. Higher acuity amongst Black patients accounts for a substantial portion of the relative excess mortality during Induction I. Targeting factors affecting acuity of illness at presentation may lessen racial disparities in AML induction mortality.

Outcome of Adolescents and Young Adults Compared With Pediatric Patients With Acute Myeloid and Promyelocytic Leukemia

BACKGROUND

Studies on the outcome of adolescents and young adults (AYAs) with acute myeloid leukemia (AML) and acute promyelocytic leukemia (APL) are limited.

METHODS

We compared the outcome of AYA (19-30 years) patients with AML and PML and pediatric (0-18 years) patients with AML (pAMLs) and APL (pAPLs) utilizing the Surveillance Epidemiology and End Results-18 registry. Early mortality rate (EMR), defined as mortality within 1 month of diagnosis, was used as a surrogate for treatment-related mortality. Survival statistics were computed using the Kaplan-Meier method. Multivariate analysis was done using logistic regression and the Cox proportional hazard regression model.

RESULTS

A total of 6343 patients with AML were identified; 44.7% were AYAs. pAMLs had lower EMR (6.2% vs. 9.2%; P < .01) and higher overall survival (OS) (1-year, 70.3% vs. 62.1%; 5-year, 48.2% vs. 36.4%; P < .01). Nine hundred twenty patients with APL were also identified; 59.5% were AYAs. No statistically significant difference was found between AYAs with APL and pAPLs in EMR (11.4% vs. 14.1%; P = .23) and OS (1-year, 83.8% vs. 81.2%; P = .31 and 5-year, 68.2% vs. 73.1%; P = .11]. Comparing all patients with AML and APL, AYAs with APL and pAPLs had higher EMR (11.4% and 14.1% vs. 6.2% and 9.2%; P ≤ .01) but better OS than AYAs with AML and pAMLs (5-year OS, 68.2% and 73.1% vs. 48.2% and 36.4%; P ≤ .01).

CONCLUSION

Our analysis shows AYAs with AML have worse EMR and OS compared with pAMLs. AYAs with APL and pAPLs have similar outcomes. To our knowledge, this is the first study reporting outcomes of AYAs with APL and pAPLs using a large population-based registry and their comparison with same age patients with AML.

Effect of age and body weight on toxicity and survival in pediatric acute myeloid leukemia: results from NOPHO-AML 2004

Treatment for pediatric acute myeloid leukemia is very toxic and the association between outcome and age and Body Mass Index is unclear. We investigated effect of age and Body Mass Index on toxicity and survival in pediatric acute myeloid leukemia. We studied all patients who completed first induction course of NOPHO-AML 2004 (n=318). Toxicity following induction and consolidation courses (n=6) was analyzed. The probabilities of toxicity and death were determined using time-to-event analyses with Cox multivariate proportional hazard regression for comparative analyses. Age 10-17 years was associated with sepsis with hypotension [hazard ratio 2.3 (95% confidence interval 1.1-4.6)]. Being overweight (>1 standard deviation) was associated with requiring supplemental oxygen [1.9 (1.0-3.5)]. The 5-year event-free and overall survival were 47% and 71%. Children aged 10-17 years showed a trend for inferior 5-year overall survival compared to children aged 2-9 (64% vs. 76%; P=0.07). Infants showed a trend for superior 5-year event-free survival (66% vs. 43%; P=0.06). Overweight children aged 10-17 years showed a trend for superior survival [5-year event-free survival 59% vs. 40% (P=0.09) and 5-year overall survival 78% vs. 56% (P=0.06)] compared to healthy weight children aged 10-17 years. In conclusion, children aged 10-17 years and overweight children had a higher risk of grade 3-4 toxicity. Children aged 10-17 years showed inferior survival, but, unexpectedly, in this age group overweight children tended to have increased survival. This suggests different pharmacokinetics of chemotherapeutic drugs in adolescents and warrants further studies.

Adoptive transfer of T cells transduced with a chimeric antigen receptor to treat relapsed or refractory acute leukemia: efficacy and feasibility of immunotherapy approaches

Treatment outcomes of acute leukemia (AL) have not improved over the past several decades and relapse rates remain high despite the availability of aggressive therapies. Conventional relapsed leukemia treatment includes second allogeneic hematopoietic stem cell transplantation (allo-HSCT) and donor lymphocyte infusion (DLI), which in most cases mediate, at best, a modest graft-versus-leukemia effect, although their clinical efficacy is still limited. Although allo-HSCT following myeloablative conditioning is a curative treatment option for younger patients with acute myeloid leukemia (AML) in a first complete remission (CR), allo-HSCT as a clinical treatment is usually limited because of treatment-related toxicity. The overall DLI remission rate is only 15%-42% and 2-year overall survival (OS) is approximately 15%-20%, with a high (40%-60%) incidence of DLI-related graft-versus-host disease (GVHD). Therefore, development of new, targeted treatment strategies for relapsed and refractory AL patients is ongoing. Adoptive transfer of T cells with genetically engineered chimeric antigen receptors (CARs) is an encouraging approach for treating hematological malignancies. These T cells are capable of selectively recognizing tumor-associated antigens and may overcome many limitations of conventional therapies, inducing remission in patients with chemotherapy-refractory or relapsed AL. In this review, we aimed to highlight the current understanding of this promising treatment modality, discussing its adverse effects and efficacy.

Haploidentical hematopoietic stem cell transplantation without total body irradiation for pediatric acute leukemia: a single-center experience

Hematopoietic stem cell transplantation (HSCT) is a promising method for therapy of pediatric patients with acute leukemia. However, less availability of matched donors limited its wide application. Recently, haploidentical HSCT has become a great resource. Here, we have retrospectively reported our experience of 20 pediatric patients with acute leukemia who underwent haploidentical HSCT without total body irradiation (TBI) myeloablative regimen in our center from November 2007 to June 2014. All the patients attained successful HSCT engraftment in terms of myeloid and platelet recovery. Thirteen patients developed grade I–IV acute graft-versus-host disease (a-GVHD). The incidence of grade I–II a-GVHD, grade III–IV a-GVHD, and chronic GVHD (c-GVHD) was 45%, 20%, and 25%, respectively. The mean myeloid and platelet recovery time was 13.20±2.41 and 19.10±8.37 days. The median follow-up time was 43.95±29.26 months. During the follow-up, three patients died. The overall survival (OS) rate was 85%. The present study indicated that haploidentical HSCT without TBI myeloablative regimen significantly improved the OS rate of pediatric patients with acute leukemia.

Patient Characteristics and Outcomes in Adolescents and Young Adults (AYA) With Acute Myeloid Leukemia (AML)

BACKGROUND

Little is known about outcomes of acute myeloid leukemia (AML) in adolescents and young adults (AYA). The purpose of this study is to determine the characteristics and outcomes of AYA AML patients in comparison to older adult patients with AML.

PATIENTS AND METHODS

We retrospectively analyzed all AML patients treated at our institution from 1965 to 2009 who were aged 16 to 29 years.

RESULTS

Among 3922 adult AML patients treated during this period, 432 (11%) were identified as AYA. Median age was 23 years (range, 16-29 years); 73 (17%) patients had core binding factor (CBF)-AML [inversion (16), translocation (8:21)], and 51 (12%) had acute promyelocytic leukemia. Complete remission (CR) rates were 93% for CBF AML, 78% for APL, 77% with diploid karyotype, and 68% for other AML. Univariate analysis demonstrated higher rates of CR, CR duration, and overall survival (OS) in the AYA group compared with older patients. On multivariate analysis, AYA age group was independently associated with improved CR rate and CR duration, with a trend for longer OS (P = .085).

CONCLUSION

Outcome of AYA AML patients is overall better than for older adults with AML. Despite improvements in treatments and outcomes over time, there is still need for improvement in AYA with AML particularly for those with AML other than CBF and APL.

Acute Myeloid Leukemia in Adolescents and Young Adults Treated in Pediatric and Adult Departments in the Nordic Countries

BACKGROUND

Studies on adolescents and young adults with acute lymphoblastic leukemia suggest better results when using pediatric protocols for adult patients, while corresponding data for acute myeloid leukemia (AML) are limited.

PROCEDURE

We investigated disease characteristics and outcome for de novo AML patients 10-30 years old treated in pediatric or adult departments. We included 166 patients 10-18 years of age with AML treated according to the pediatric NOPHO-protocols (1993-2009) compared with 253 patients aged 15-30 years treated in hematology departments (1996-2009) in the Nordic countries.

RESULTS

The incidence of AML was 4.9/million/year for the age group 10-14 years, 6.5 for 15-18 years, and 6.9 for 19-30 years. Acute promyelocytic leukemia (APL) was more frequent in adults and in females of all ages. Pediatric patients with APL had similar overall survival as pediatric patients without APL. Overall survival at 5 years was 60% (52-68%) for pediatric patients compared to 65% (58-70%) for adult patients. Cytogenetics and presenting white blood cell count were the only independent prognostic factors for overall survival. Age was not an independent prognostic factor.

CONCLUSIONS

No difference was found in outcome for AML patients age 10-30 years treated according to pediatric as compared to adult protocols.

Insights into cell ontogeny, age, and acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogenous disease of hematopoietic stem cells (HSCs) and progenitor cells (HSPCs). The pathogenesis of AML involves cytogenetic abnormalities, genetic mutations, and epigenetic anomalies. Although it is widely accepted that the cellular biology, gene expression, and epigenetic landscape of normal HSCs change with age, little is known about the interplay between the age at which the cell becomes leukemic and the resultant leukemia. Despite its rarity, childhood AML is a leading cause of childhood cancer mortality. Treatment is in general extrapolated from adult AML on the assumption that adult AML and pediatric AML are similar biological entities. However, distinct biological processes and epigenetic modifications in pediatric and adult AML may mean that response to novel therapies in children may differ from that in adults with AML. A better understanding of the key pathways involved in transformation and how these differ between childhood and adult AML is an important step in identifying effective treatment. This review highlights both the commonalities and differences between pediatric and adult AML disease biology with respect to age.

The applicability of the WHO classification in paediatric AML. A NOPHO-AML study

The World Health Organization (WHO) classification of myeloid leukaemia was revised in 2008. It incorporates newly recognized entities and emphasizes the pivotal role of cytogenetic abnormalities. The aim of this study was to evaluate the usability of the WHO classification when applied to a large population-based paediatric acute myeloid leukaemia (AML) cohort. We included children diagnosed with de novo AML, 0-18 years of age from the Nordic countries and Hong Kong from 1993 to 2012. Data were retrieved from the Nordic Society for Paediatric Haematology and Oncology AML database and patients classified according to the WHO 2008 classification. A successful karyotype was available in 97% of the cases. AML with recurrent genetic abnormalities were present in 262 (41%) and 94 (15%) were classified as AML with myelodysplasia-related changes (AML-MDS). WHO classifies patients with monosomy 7 and del(7q) into one group. We found that -7 (n = 14) had significantly poorer outcome than del(7q) (n = 11); 5-year event-free survival 26% vs. 67%, (P = 0·02), and 5-year overall survival 51% vs. 90%, (P = 0·04). The largest group was the highly heterogeneous AML not otherwise specified (NOS) (n = 280) (44%). In conclusion, the WHO classification allocated 15% to AML-MDS, 44% to NOS and grouped together entities with clearly different outcome, therefore limiting the applicability of the current WHO classification in children with AML.

Treatment of Acute Myeloid Leukemia in Adolescent and Young Adult Patients

The objectives of this review were to discuss standard and investigational treatment strategies for adolescent and young adult with acute myeloid leukemia, excluding acute promyelocytic leukemia. Acute myeloid leukemia (AML) in adolescent and young adult patients (AYAs) may need a different type of therapy than those currently used in children and older patients. As soon as AML is diagnosed, AYA patient should be offered to participate in well-designed clinical trials. The standard treatment approach for AYAs with AML is remission induction chemotherapy with an anthracycline/cytarabine combination, followed by either consolidation chemotherapy or stem cell transplantation, depending on the ability of the patient to tolerate intensive treatment and cytogenetic features. Presently, continuing progress of novel drugs targeting specific pathways in acute leukemia may bring AML treatment into a new era.

Prognosis and monitoring of core-binding factor acute myeloid leukemia: current and emerging factors

Core-binding factor acute myeloid leukemia (CBF-AML) - including AML with t(8;21) and AML with inv(16) - accounts for about 15% of adult AML and is associated with a relatively favorable prognosis. Nonetheless, relapse incidence may reach 40% in these patients. In this context, identification of prognostic markers is considered of great interest. Due to similarities between their molecular and prognostic features, t(8;21) and inv(16)-AML are usually grouped and reported together in clinical studies. However, considerable experimental evidences have highlighted that they represent two distinct entities and should be considered separately for further studies. This review summarizes recent laboratory and clinical findings in this particular subset of AML and how they could be used to improve management of patients in routine practice.