Leukemia Mortality Research Articles

Temporal Trends in Early Mortality in Acute Promyelocytic Leukemia in the United States

▪Background: Survival of patients with acute promyelocytic leukemia (APL) has dramatically improved with the use of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Despite this, due to the complexity of initial management and the high risk of fatal thrombotic and hemorrhagic complications at presentation, early mortality (EM) remains the major contributor for treatment failure. It is less known whether advances in treatment, improvements in supportive measures, urgent access to specialized care and broad availability of ATRA and ATO have reduced EM in the last two decades.Methods: We used data from the National Cancer Institute's Surveillance Epidemiology and End Results program (SEER-13) to determine the rates of EM (death within the first 30 days from diagnosis) and overall survival (OS) in patients with APL. Inclusion criteria was the diagnosis of APL as first malignant neoplasm among patients of all ages between 1992 and 2015. Follow up was updated to the end of 2015. Cases were grouped and analyzed according to age, children, adolescent and young adults (< 40 years) and older adults (≥ 40 years), race/ethnicity, gender, county-level income and educational achievement, and residency in rural or urban county. Trends in EM and OS were analyzed across consecutive 4-year eras.Results: A total of 2,224 APL cases (895 <40 and 1,329 ≥ 40 years) were included in the analysis with median follow up of 41 months (range 0-287 months). Median age of patients was 45, and 1,090 (49%) were male. Most patients were White (1,228; 55.2%), 199 (9%) Black, 785 (35.3%) other ethnicity, and 12 (0.5%) unknown. Three-year OS for APL patients diagnosed in 1992-1995 was 49.2% ± 3.5% vs. 76.4 ± 2.1% for patients diagnosed in 2012-2015 (p < 0.001), Figure 1. Early mortality improved for patients < 40 years (27.4% in 1992-1995 vs. 5.4% in 2012-2015, p < 0.001), but not at the same extent for patients ≥ 40 years (35.2% in 1992-1995 vs. 22.2% in 2012-2015, p = 0.02), Figure 2. Improvements in EM are displayed in Table 1. Importantly, improvements in EM were not seen among patients of residents of rural counties.Conclusion: These findings confirm consistent improvements in EM and OS for APL patients in the US and point to the challenge of further extending these improvements in EM rates to older patients and for those living in rural areas. DisclosuresCosta:Celgene: Honoraria, Research Funding; Sanofi: Honoraria; Karyopharm: Research Funding; Janssen: Research Funding; BMS: Research Funding; Abbvie: Research Funding; Amgen: Honoraria, Research Funding.

Gut Colonization with Carbapenem Resistant Enterobacteriaceae(CRE) Leads to More Chemotherapy Inerruptions and Higher Mortality in Patients with Acute Leukemias Receiving Remission Induction Chemotherapy

Background: Neutropenic sepsisis a major cause of induction mortality in acute leukemia. The estimated incidence in various series ranges from 12% to 36% 1-2. Carbapenem resistant enterobacteriaceae (CRE) colonization of the gut can increase the incidence of neutropenic sepsis to 50%3-4. In the present study we report the prevalence of CRE gut colonization and its impact on outcomes of remission induction chemotherapy in patients with acute leukemias.Primary Outcome: To compare induction mortality in patients with acute leukaemia who have CRE colonization of the gut at admission with a cohort of Non-CRE colonizer patients of acute leukemia receiving induction chemotherapy at our centre.Secondary Outcomes: Compare the durations of febrile period, antibiotic use and chemotherapy interruptions in CRE colonizers vs. Non-CRE colonizers.Methods: This is a prospective observational study. Institute ethics clearance was taken. Patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia(ALL) and mixed-phenotype acute leukemia(MPAL) who were admitted to our centre for remission induction chemotherapy from January 2017 to February 2018 were enrolled in our study. Perianal swab for diagnosing CRE colonization was taken at the time of admission. CRE were identified as per the Centre for Diseases Control (CDC) guidelines. On the basis of surveillance culture results patients were divided into cohorts of CRE-colonizers and Non-CRE-colonizers. These cohorts were followed up prospectively and parameters mentioned in primary and secondary outcome were recorded. Patients with probable and proven fungal infections as per EORTC criteria were excluded from our analysis. This was done in order to better dilineate the attributable cause of death to CRE infections.Results:A total of 136 patients with acute leukemia were enrolled in our study. Almost half of the patients (67) had acute myeloid leukemia (49%), sixty four (47%) patients had acute lymphoblastic leukemia and four (3%) patients had mixed-phenotype acute leukmeia. 61% of patients had CRE colonization of the gut at the time of admission. There was no significant difference with regards to median age at presentation, sex and the underlying disease (AML, ALL, MPAL) between the CRE colonizers and non-CRE colonizers. Escherichia coli (E.coli) was the most prevalent bacteria among CRE colonizers and non-CRE colonizers (63% vs. 71%, P=0.42). More patients in the CRE colonizer cohort did not receive remission induction chemotherapy due to life threatening sepsis at the time of presentation (15% vs. 5%, P=0.07). Chemotherapy interruptions due to life threatening sepsis were seen in a significantly higher numebr of CRE colonizers compared to non-CRE colonizers (32% vs. 18%, P=0.02). Induction deaths in CRE colonizers were almost double that seen in non-CRE colonizers (40% vs. 21%, P=0.01). There was no significant difference in duration of fever, duration of antibiotic use and blood culture positivity between the two cohorts.Conclusion:More than half of the patients with acute leukemia had CRE colonization of the gut at the time of presentation. Chemotherapy interruptions and deaths during induction were seen in a significantly higher number of patients colonized with CRE at the time of presentation. Patients with acute leukemia should be screened for CRE colonization of the gut prior to induction chemotherapy. This assumes importance is centres with high prevalence of CRE colonization as CRE colonisation of the gut is a predictor for induction mortality.

Relapse-Initiating Clones Preexisting at Diagnosis in B- Cell Acute Lymphoblastic Leukemia Help Predict Molecular Pathways of Relapse

Disease recurrence remains a significant cause of mortality in B-cell acute lymphoblastic leukemia (B-ALL). Genomic analysis of matched diagnosis and relapse samples have demonstrated that relapse arises from a minor subclone already present at diagnosis and not the dominant clone in the majority of patients. However, the reasons why only some clones survive therapy and generate relapse are obscure and elucidation of the mechanisms that underlie these differing fates may be revealed by functional analysis of isolated subclones. Previous work has shown that the subclonal diversity in B-ALL exists at the level of the leukemia-initiating cells capable of generating patient derived xenografts (Notta et al., Nature, 2011). In order to investigate the functional consequences of genetic clonal evolution during disease progression, we performed in-depth genomic and functional analysis of 14 paired diagnosis/relapse samples from adult and pediatric B-ALL patients with varying cytogenetic abnormalities. Diagnosis-specific, relapse-specific, and shared clonal and subclonal variants were identified by whole exome sequencing of the patient samples. Targeted sequencing of these variants in 372 xenografts generated by transplantation of CD19+ cells in a limiting cell dilution assay uncovered clonal variation. This analysis provided for the unequivocal identification of minor subclones ancestral to the relapse, termed diagnosis Relapse-Initiating (dRI) clones, in the diagnostic sample. Our xenografting approach enabled the physical isolation of dRI clones providing a unique opportunity to interrogate their epigenetic and transcriptional landscapes in order to unravel their relapse initiating capacity. To this end, representative diagnosis, dRI and relapse clones from 5 of the 14 patients were subjected to RNAseq and ATACseq (assay for transposase-accessible chromatin using sequencing) analysis. Despite the differences in transcriptional and chromatin openness between patients, principal component analysis of subclones from individual patients positioned the dRI clones as evolutionary intermediates between the diagnosis and relapse clones. Hierarchical clustering of the most significantly differentially expressed genes and open chromatin regions demonstrated that dRI clones shared gene expression and chromatin accessibility signatures with both the dominant diagnosis clone as well as the dominant relapse clone. To gain mechanistic insight into the data we used gene set enrichment analysis (GSEA) and identified common molecular pathways present in all patients that were enriched in dRI clones and persisted at the time of relapse in comparison to the dominant diagnosis clone. dRI and relapse clones converged in the activation of genes involved in cellular functions such as endocytosis, autophagy and innate immune response. In addition, cell surface proteins like ABC transporters and ephrins were also upregulated in dRI and relapse clones. Remarkably, functional interrogation of dRI clones in secondary xenografts, in comparison to more representative diagnosis clones, displayed increased tolerance to standard chemotherapeutic agents (dexamethasone, L-asparaginase and vincristine). Investigation of the molecular pathways and cellular receptors/transporters identified by gene expression analysis are being assessed in vitro and in vivo as potential targets for novel therapeutic approaches and disease monitoring.Overall, we have shown evidence that minor subclones at diagnosis, ancestral to the relapse clone, possess functional advantages and unique properties over other diagnostic subclones prior to treatment exposure. In depth analysis of pathways identified in these dRI subclones will shed light on potential new therapeutic approaches for abrogating and reducing disease recurrence in B-ALL. DisclosuresMullighan:Amgen: Honoraria, Speakers Bureau; Cancer Prevention and Research Institute of Texas: Consultancy; Abbvie: Research Funding; Pfizer: Honoraria, Research Funding, Speakers Bureau; Loxo Oncology: Research Funding.

Independent Association of Male Sex with Presentation and Clinical Outcomes in Myeloproliferative Neoplasms

INTRODUCTION: The chronic MPN, essential thrombocytosis (ET), polycythemia vera (PV) and primary myelofibrosis (PMF), share mutations of JAK2, MPL and CALR, but vary widely with regard to sex distribution, age at diagnosis, disease evolution and outcomes. Given that age at diagnosis influences presenting phenotype, disease progression and clinical outcome, the impact of sex remains undefined. The aim of our study was to evaluate the impact of sex in presenting phenotype, disease progression, complications and mortality in a well-defined, prospective observational cohort.PATIENTS AND METHODS: 630 individuals with ET, PV or PMF were enrolled in our observational cohort between 2005-2015. Median disease duration at the time of evaluation was 7.23 years, whereas 152 were enrolled within one year of diagnosis. All individuals were genotyped for neutrophil JAK V617F variant allele frequency (VAF), and JAK2 V617F-negative individuals were studied for other JAK2 mutations, CALR or MPL mutations. Multivariable logistic regression was used to evaluate associations of sex, age and molecular characteristics with presenting phenotype; multivariable cox regression was used to evaluate associations of sex, age, presenting phenotype, and molecular characteristics with mortality, and survival curves were generated using the Kaplan Meier method.RESULTS: The cohort comprised 630 individuals (246 males and 384 females) with 6819 patient-years of follow up. Over a median follow up of 9 (Q25-75% 6, 15) years, 185 individuals died. Males had a higher mean age of presentation (52.9 versus 48.8 years, P=0.002). Compared with females, males were more likely to present with PMF than PV or ET (P <0.001), and this sex difference remained statistically significant across JAK2 V617F positive and negative groups, and across age groups (≤40 years, >40 and ≤60 years, and >60 years) (Figure 1A). In a multivariable logistic regression model, male sex was significantly associated with PMF as presenting phenotype (P<0.001) after adjusting for age at diagnosis (P=0.4), neutrophil and peripheral blood CD34+ JAK2 V617F VAF (P=0.729 and P=0.064 respectively). Females had a higher rate of venous thromboembolism (15.7% vs. 6.9%, P<0.001) while males had higher rates of progression to acute myeloid leukemia (6.5% vs. 2.9%, P=0.028) and overall mortality (38.2% vs. 23.7% P<0.001). In a multivariable cox regression model, male sex was significantly associated with increased mortality (HR 1.63 [95% CI 1.20-2.22], P=0.002) after adjusting for age at diagnosis (HR 1.10 [95% CI 1.08-1.12), P<0.001), presenting phenotype (PV, HR 1.66 [95% CI 1.13-2.45], P=0.010; PMF 3.70 [95% CI 2.46-5.57), P <0.001), genotype (JAK2V617F+ reference category, CALR HR 0.83 [955 CI 0.49-1.40], P=0.064; MPL HR 0.74 [95% CI 0.23-2.35], P =0.493; triple negative HR 2.72 [95% CI 1.30-5.69], P=0.008), and hydroxyurea therapy (HR 1.00 [95% CI 0.73-1.36], P=0.992). The association of male sex with higher mortality was also seen in subgroup analyses of the JAK2 V617F-positive and JAK2 V617F-negative groups separately (Figure 1B).CONCLUSIONS: Males with MPN have inferior survival compared to females with MPN, even when adjusted for age at presentation, presenting phenotype, and molecular characteristics. Further, males present more frequently with PMF while females present more frequently with ET. These striking sex-based differences in MPN presentation and outcomes demonstrate that male sex is associated with more aggressive disease biology independent of other factors, and further study to dissect the molecular mechanisms are warranted. Moreover, sex stratification should be considered in MPN prognostic risk algorithms and when designing and interpreting results from clinical trials. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

High Mobility Group A1 Chromatin Remodeling Proteins Amplify Inflammatory Networks to Drive Leukemic Transformation in Chronic Myeloproliferative Neoplasia in Humans and JAK2V617F Transgenic Mouse Models

Introduction: Myeloproliferative neoplasms (MPN) are clonal hematopoietic stem cell (HSC) disorders characterized by overproduction of mature blood cells and increased risk of transformation to myelofibrosis (MF) and acute myeloid leukemia (AML), although molecular mechanisms driving disease progression remain elusive. While most patients who acquire a JAK2V617F mutation in CD34+ cells present with chronic, indolent Polycythemia Vera (PV), ~25% will progress to MF or AML. High Mobility Group A1/2 (HMGA1/2) genes encode oncogenic chromatin remodeling proteins which are overexpressed in aggressive leukemia where they portend adverse outcomes. In murine models, Hmga1/2 overexpression drives clonal expansion and uncontrolled proliferation. HMGA1/2 genes are also overexpressed in MPN with disease progression. We therefore sought to: 1) test the hypothesis that HMGA proteins are required for leukemic transformation and rational therapeutic targets in MPN progression, and, 2) identify mechanisms mediated by HMGA1/2 during disease progression.Methods: We measured HMGA1/2 in JAK2V617F mutant human AML cell lines from MPN patients (DAMI, SET-2), CD34+ cells from PV patients during chronic and transformation phases, and JAK2V617F transgenic murine models of PV (transgenic JAK2V617F) and PV-AML (transgenic JAK2V617F/MPLSV; Blood 2015;126:484). To elucidate HMGA1/2 function, we silenced HMGA1 or HMGA2 via short hairpin RNA in human MPN-AML cell lines (DAMI, SET-2) and assessed proliferation, colony formation, and leukemic engraftment in immunodeficient mice. To further assess Hmga1 function in vivo, we crossed mice with heterozygous Hmga1 deficiency onto murine models of PV and PV-AML. Finally, to dissect molecular mechanisms underlying HMGA1, we compared RNA-Seq from MPN-AML cell lines (DAMI, SET-2) after silencing HMGA1/2 to that of controls and applied Ingenuity Pathway Analysis.Results:HMGA1/2 mRNA are up-regulated in all JAK2V617F-positive contexts, including primary human PV CD34+ cells and total bone marrow from JAK2V617F mouse models for PV compared to controls. Further, there is a marked up-regulation in both HMGA1/2 in CD34+ cells from PV patients after transformation to MF or AML and in leukemic blasts from our PV-AML mouse model compared to PV mice. Overexpression of HMGA1/2 also correlates with clonal dominance of human JAK2V617F-homozygous stem cells and additional mutations of epigenetic regulators (EZH2, SETBP1). Silencing HMGA1 or HMGA2 in human MPN-AML cell lines (DAMI, SET-2) dramatically halts proliferation, disrupts clonogenicity, and prevents leukemic engraftment in mice. Further, heterozygous Hmga1 deficiency decreases splenic enlargement in PV mouse models with advancing age. Moreover, heterozygous Hmga1 deficiency prolongs survival in the transgenic PV-AML murine model with fulminant leukemia and early mortality. PV-AML mice survived a median of 5 weeks whereas PV-AML mice with heterozygous Hmga1 deficiency survive a median of 12 weeks (P< 0.002). The leukemic burden was also decreased in mice with Hmga1 deficiency. Preliminary RNA-Seq analyses from DAMI and SET-2 cells show that HMGA1 drives pathways involved in Th1/Th2 activation, chemotaxis, cell-cell signaling, myeloid cell accumulation and other immune cell trafficking, inflammation, and injury, suggesting that HMGA1 co-opts immune and inflammatory networks to drive tumor progression. Surprisingly, atherosclerosis pathways are also induced by HMGA1.Conclusions:HMGA1/2 genes are overexpressed in MPN with highest levels in more advanced disease (MF, AML) both in primary human tumors and murine models. Strikingly, silencing HMGA1 or HMGA2 halts proliferation and clonogenicity in vitro and prevents leukemic engraftment in vivo. Further, heterozygous Hmga1 deficiency prolongs survival in a murine model of fulminant MPN AML and decreases tumor burdens. Finally, preliminary RNA-Seq analyses suggest that HMGA1 amplifies transcriptional networks involved in immune cell trafficking and inflammation to drive tumor progression. Unexpectedly, HMGA1 also regulates pathways involved in atherosclerosis, implicating HMGA1 as a novel link between clonal hematopoiesis and cardiovascular disease. Our findings further highlight HMGA1/2 as a key molecular switch for leukemic transformation in MPN and opens the door to novel therapeutic approaches to prevent disease progression. DisclosuresNo relevant conflicts of interest to declare.

Effect of Socioeconomic Factors on Survival in Veterans with Acute Myeloid Leukemia (AML)

Background:There is limited information about socioeconomic factors effect on survival in veterans with acute myeloid leukemia (AML). Some studies suggested higher risk of leukemia mortality among veterans who were smokers [1, 2, 3, 4]. Few studies investigated socioeconomic factors like insurance status, care at private or academic center, marital status and median household income effect on outcomes in adults with AML [5, 6, 7].Methods:Medical records of AML patients at the Oklahoma City VAHCS between 2010 and 2017 were reviewed. Information collected included home distance from treatment center (≤ 40 miles vs > 40 miles), marital status at diagnosis, tobacco use in the 3 months preceding diagnosis, history of alcohol abuse, level of college education (college education vs less than college education). Fisher-exact test was used for differences in survival rates. Kaplan-Meier analysis was used to estimate the survival and log-rank test to determine differences among groups.Results:Total number of Veterans were 28. Fifteen patients (56%) had poor risk disease, 8 (30%) had intermediate risk disease, and 4 (15%) had good risk disease. Median survival for the whole group was 9.3 months. Patients with poor and intermediate risk cytogenetic/molecular status had median survival of 5.5 and 37.7 months, respectively (p=0.0066). There was insufficient number of deaths in the good risk group at the time of this analysis. Median survival for veterans with history of alcohol abuse vs none was 66 vs 7 months (p= 0.15). Median survival for veterans who had some college education vs less than college education was 26.1 vs 6.9, (p=0.14). Median survival for veterans with history of tobacco use within 3 months of diagnosis vs others was 6.9 vs 26.1 (p= 0.11). Median survival for veterans who were married at diagnosis vs non married was 14 vs 7.89 (p=0.29). Median survival for veterans who lived > 40 miles from treatment center vs ≤ 40 miles was 7.43 vs 37.7 months (p=0.5).Conclusions:In our retrospective single institute study, poor risk cytogenetic/molecular risk group was associated with inferior survival. While there appeared to be a trend towards worse survival in association with lower education, smoking, non-married status, and longer distance from treatment center, none of these factors had a statistically significant effect. Larger studies are needed to confirm such observations.

Leukemia mortality trends in children and adolescents in Brazilian state capitals: 1980-2015.

to analyze the temporal trend of leukemia mortality in children and adolescents under 20 years old, in Brazilian state capitals and Federal District, between 1980 and 2015. this was a descriptive time series study; age-standardized leukemia mortality rates were calculated; the Prais-Winsten regression model was used. leukemia mortality rates fell from 2.73 to 1.58 per 100,000 inhabitants aged under 20 years in the period studied (annual percentage variation of -7.06%: 95%CI -8.61;5.49), with differences between capitals; there was a reduction in magnitude in all age groups - 0-4 years (9.17%: 95%CI -11.58;-6.69), 5-9 years (-9,27%: 95%CI -11.90;-6.56), 10-14 years (-4.86%: 95%CI -6.69;-3.00) and 15-19 years (-3.77%: 95%CI -5.22;-2.31). there was a falling trend in pediatric leukemia mortality rates, although it was unequal between the capitals, indicating the need for measures to minimize regional differences.

MiRNA‐155 and miRNA‐181a as prognostic biomarkers for pediatric acute lymphoblastic leukemia

Mortality rates of acute lymphoblastic leukemia (ALL) have improved over the past 20 years; however, a significant portion of deaths stems from the lack of prognostic biomarkers, which can direct therapy and overcome drug resistance. microRNA-155a (miRNA-155a) and miRNA-181a are two single-stranded miRNAs involved in the pathogenesis of many types of leukemia and lymphoma and is linked to drug resistance. We investigated their expression levels in 55 patients, 45 diagnosed with ALL and 10 as a control group. We found that miRNA-155a and miRNA-181a were significantly upregulated in the ALL group with both being linked to high levels of minimal residual disease and poor prognosis. miRNA-155a cutoff value was significant in discriminating between high- and low-risk ALL patients as well as between ALL patients and healthy controls, miRNA-181a cutoff value, however, was not significant. Both markers levels were significantly downregulated after therapy. We conclude that miR-155 is correlated with poor prognosis in ALL, whereas we couldn't link miRNA-181a to the prognosis in ALL. Moreover, the marked decrease in their expression after therapy could reflect their impact on disease outcome.

Effectiveness of antibacterial prophylaxis in children with acute leukemia: A report from a single institution over a 20-year period

BackgroundInfection is the major cause of treatment-related mortality in childhood acute leukemia, mainly due to bacterial translocation across the intestinal mucosa. Only a few studies have reported the impact of different antibacterial prophylaxis treatments on digestive tract flora and infection-related mortality. ProceduresWe performed a retrospective analysis of two different digestive tract decontamination modalities (selective or total digestive decontamination) in a large single-center series of 323 children during the induction treatment of acute leukemia between January 1995 and December 2014. We examined the impact of antibiotic prophylaxis and food regimen (sterile or selected) on the digestive tract flora during the period of antibacterial prophylaxis, on the frequency of bacteremia, and on antibiotic sensitivity. ResultsOnly one Gram-negative (Klebsiella pneumonia) translocation occurred in the SDD group. No infection-related death occurred. Extended-spectrum beta-lactamase (ESBL) bacteria were observed in seven of 170 (4%) patients in the SDD group. The faecal-flora total suppression and faecal-flora Gram-negative bacilli suppression was 67 and 77%, respectively, in the TDD group with sterile food, 0 and 58%, respectively, in the SDD group with sterile food, and 6 and 63%, respectively, in the SDD group with selective food. ConclusionsThis study gives a rationale not to use antibacterial prophylaxis systematically in children who receive induction treatment for acute leukemia; additionally, antibiotics should only be used in case of stool contamination by highly pathogenic bacteria with a high potential of translocation.

Temporal and Spatial Excess Leukemia Deaths Around the Nuclear Power Plant in Kyushu, Japan (1970-2005)

Background/AimExcess incidence of cancer including leukemia among people living in the vicinity of Nuclear Power Plant (NPP) in normal operation has been reported on from Germany, France, the United Kingdom, Korea, and others. But in Japan, any epidemiologic investigations have not been conducted yet while 18 NPP facilities have discharged radioactive substances e.g. tritium. 13 among 47 prefectures in Japan had NPPs until 2010, and 7 of them were ranked in top 15 leukemia mortality. We estimated the Standardized Mortality Ratios (SMRs) on leukemia of municipalities around the NPPs in Kyushu area, the western parts of Japan, and then summarized their temporal-spatial changes with using empirical Bayesian estimates.MethodsWe estimated leukemia SMRs with using data of age-sex specific five-year municipal population among 1965-2005 of Japanese Census, age-sex specific cause-specific leukemia deaths of Japanese Vital Statistics, and leukemia deaths of each municipalities. To adjust spatial variations of SMRs in the towns and villages with sparse population, we have applied empirical Bayes method with Poisson distribution model.ResultsSMRs of leukemia in the study region increased after beginnings of the operation of NPPs. The municipalities located the nearest to NPP had excess SMR (3.69: 95% CI, 3.11-5.56) comparing to farther areas of the prefecture. NPP Reactor type of the study areas was Pressurized Water Reactor (PWR) which released more radioactive substances comparing to Boiling Water Reactor (BWR). The study suggests the relationship between leukemia and NPPs normally operated in Japan.

Invasive Fungal Disease in Pediatric Acute Leukemia in the Nontransplant Setting: 8 Years’ Experience From a Tertiary Care Center in North India

The aim of this article is to study the spectrum, changing prevalence, and predictors for mortality of invasive fungal disease (IFD) in pediatric leukemia in a resource-limited setting. Prevalence was 7% (proven, 69%; probable, 16.4%; possible, 14.6%) and did not differ between acute lymphoblastic leukemia and acute myeloid leukemia. Lungs were frequently involved (46%). Aspergillus was the commonest fungus (47%). Visceral abscesses were frequent with candidiasis as compared with invasive molds (P=0.016). IFD resulted in a prolonged admission (mean, 12.6±2 d; P=0.014) and death (44%) (Aspergillus, 50%; Candida, 50%; Mucor, 34%). Diagnosis of acute myeloid leukemia predicted mortality (P=0.03). IFD was an important cause of treatment related mortality in pediatric leukemia (odds ratio, 8.39). Protocolled use of computed tomography-chest and galactomannan-assay aided diagnosis (P<0.05).

3147 - Loss-of-Function Mutation in TET2 in Zebrafish Leads to Early MDS Like Phenotype

Abstract Myelodysplastic syndrome (MDS) is a pre-leukemic state characterized by the failure of the bone marrow to produce mature and functional blood cells. Nearly one-third of MDS patients progress to acute myeloid leukemia (AML). AML is the most common form of acute leukemia in adults and accounts for a high level of mortality in pediatric leukemia. Loss-of-function mutations in the Ten-11 Translocation 2 (TET2) gene are implicated in MDS and AML, but evidence that TET2 mutations are also found in healthy individuals as a result of clonal hematopoiesis calls into question the contribution of TET2 to leukemogenesis. Many studies have tried to mutate the DNA binding domain in TET2 both in mouse and zebrafish, but the blood phenotypes observed have been inconsistent. We created a tet2 zebrafish mutant using CRISPR-Cas9 technology, where we deleted 2.1 kb from exon 2, confirmed by cDNA analysis. A recent publication suggests the importance of Ser99 in the stability of the TET2 protein (Wu et al., 2018) and this conserved serine residue is contained in the region of deletion in our zebrafish tet2 mutant. These tet2 mutant fish were incrossed to create a maternal-zygotic mutant with no tet2 expression. Importantly, quantitative PCR demonstrated that there was no compensatory effect from tet1 and tet3 in the context of tet2 loss. Whole mount in situ hybridization performed on 24-48h tet2 mutant zebrafish embryos provided evidence of a significant reduction of early and mature myeloid and erythroid cells through staining for spi1/pu.1 (myeloid), gata1 (erythroid) myeloperoxidase (mpx; neutrophils), carboxypeptidase A5 (cpa5; mast cells) and l-plastin (lcp1; macrophages). The stem cell compartment was not impacted, as shown by wild-type runx1/c-myb expression. Further, o-dianisidine staining revealed low hemoglobin content in tet2 mutants compared with control embryos. Overall, the early embryos elucidate a refractory anemia like phenotype. Flow cytometry analysis of kidney marrow from 3-month-old adult tet2 mutant fish similarly demonstrated a decrease in the myeloid and erythroid compartments, in keeping with characteristics typical of low stage MDS. We are currently employing RNAseq and MeDIP analysis on blood cell populations from tet2 mutants to determine the genetic and epigenetic signatures associated with this mutation. This zebrafish model of tet2 loss uniquely provides with a dynamic phenotype that starts with refractory anemia with progression through low stage MDS. Thus this model will be beneficial in elucidating the mechanisms underlying how tet2 contributes to MDS and AML and provide a preclinical platform to screen for therapeutic interventions. Disclosures No relevant conflicts of interest to declare.

Hospital Variation in Intensive Care Resource Utilization and Mortality in Newly Diagnosed Pediatric Leukemia.

To evaluate hospital-level variability in resource utilization and mortality in children with new leukemia who require ICU support, and identify factors associated with variation. Retrospective cohort study. Children's hospitals contributing to the Pediatric Health Information Systems administrative database from 1999 to 2011. Inpatients less than 25 years old with newly diagnosed acute lymphocytic leukemia or acute myeloid leukemia requiring ICU support (n = 1,754). Evaluated exposures included leukemia type, year of diagnosis, and hospital-wide proportion of patients with public insurance. The main outcome was hospital mortality. Wide variability existed in the ICU resources used across hospitals. Combined acute lymphocytic leukemia and acute myeloid leukemia mortality varied by hospital from 0% (95% CI, 0-14.8%) to 42.9% (95% CI, 17.7-71.1%). A mixed-effects model with a hospital-level random effect suggests significant variation across hospitals in mortality (p = 0.007). When including patient and hospital factors as fixed effects into the model, younger age, acute myeloid leukemia versus acute lymphocytic leukemia diagnosis, leukemia diagnosis prior to 2005, hospital-wide proportion of public insurance patients, and hospital-level proportion of leukemia patients receiving ICU care are significantly associated with mortality. The variation across hospitals remains significant with all patient factors included (p = 0.021) but is no longer significant after adjusting for the hospital-level factors proportion of public insurance and proportion receiving ICU care (p = 0.48). Wide hospital-level variability in ICU resource utilization and mortality exists in the care of children with leukemia requiring ICU support. Hospital payer mix is associated with some mortality variability. Additional study into how ICU support could be standardized through clinical practice guidelines, impact of payer mix on hospital resources allocation to the ICU, and subsequent impact on patient outcomes is warranted.

Haploidentical IL-15/41BBL activated and expanded natural killer cell infusion therapy after salvage chemotherapy in children with relapsed and refractory leukemia

Primary refractory or relapsed pediatric leukemia yield significant morbidity and mortality, with long-term survival rates <40%. Here we present a post-hoc analysis assessing safety and efficacy of infusing activated and expanded Natural Killer cells (NKAE) from haploidentical donors in patients from 2 clinical trials. In total, 18 children, adolescents and young adults with relapse or refractory acute leukemia were treated with two cycles of rescue chemotherapy followed by fresh NKAE cells infusions and low doses of IL-2. The overall response rate, complete remission achievement at the end of the study, was 72% (13 of 18). We infused 52 NKAE cell products containing a median of 6.76 × 106 NK cells/kg (0.7–34.16) and 0.49 × 106 T cells/kg (0–11). All infusions were well tolerated with no graft versus host disease nor other serious adverse events. Among the 14 patients who completed treatment, 4 of them are alive and leukemia-free more than 750 days post-transplant. We conclude that infusion of fresh NKAE cell therapy is feasible and safe in heavily pretreated pediatric population, and should be further investigated in advanced-phase clinical trials as well as a consolidation therapy to decrease relapse in patients with high-risk leukemia.Trials registration: Registered at www.clinicaltrials.gov as NCT01944982 and NCT02074657.

Megakaryocyte-derived excessive transforming growth factor β1 inhibits proliferation of normal hematopoietic stem cells in acute myeloid leukemia

Impaired production of healthy hematopoietic cells from residual hematopoietic stem cells (HSCs) leads to high mortality in acute myeloid leukemia (AML). Previous studies have identified p21 and Egr3 as intrinsic factors responsible for the growth arrest and differentiation blockade of normal HSCs in leukemia; however, the related extrinsic factors remain unknown. In this study, we found that transforming growth factor β (TGFβ) signaling was upregulated in HSCs from bone marrow of mice with MLL-AF9-induced acute myeloid leukemia (AML) because of excessive production of TGFβ1, especially from megakaryocytes, and overactivation of latent TGFβ1 protein. We also found that SMAD3, a signal transducer of TGFβ1, directly bound to Egr3 and upregulated its expression to arrest proliferation of HSCs. Our study provides evidence for targeting TGFβ1 in AML to rectify normal hematopoiesis defects in clinical practice.

Occupational Radiation Exposure and Leukemia Mortality among Nuclear Workers in Japan: J-EPISODE, 1991-2010

Occupational Radiation Exposure and Leukemia Mortality among Nuclear Workers in Japan: J-EPISODE, 1991-2010

Computer-Assisted formulas predicting radiation-exposure-induced-cancer risk in interplanetary travelers: Radiation safety for astronauts in space flight to mars

A clear quantitative relationship between the dose of total body ionizing radiation and mortality in humans is not known because of lack of human data that would enable us to determine the lethal dose for 50% of cases (LD50) in total body irradiation on earth or in probable future interplanetary travels. Analysis of human data has been primarily from radiation accidents, radiotherapy, and the atomic bomb victims. The author published the general mathematical formula that predicts mortality probability as a function of dose rate and duration of exposure to acute ionizing radiation in humans on the basis of data presented by Cerveny et al., employing the author's mathematical probacent model. Further, the author applied the general formula to the data on dose versus cancer mortality risk published by the United Nations Scientific Committee on the effects of atomic radiation and other investigators to construct general formulas expressing a relationship between dose and solid cancer or leukemia mortality probability after exposure to acute low-dose ionizing radiation in humans on earth. There is a remarkable agreement between formula-derived and published values of dose and solid cancer or leukemia mortality probability (P > 0.99). In this study, the above mortality formulas are applied to the measurements of the Mars Science Laboratory spacecraft containing the Curiosity rover (2012–2013) in estimating radiation safety for astronauts in a future space flight to Mars planned by the National Aeronautics and Space Administration. Results of the estimation obtained with a mathematical approach are presented in this study.

Acute Lymphoblastic Leukaemia’s Burden Of Disease In Portugal

Acute lymphoblastic leukaemia (ALL) is a haematological malignancy with a rapid progression, affecting both children and adults. Although rare, it is the most common leukaemia in childhood. The main objective of this study was to estimate the burden of disease impact of ALL measured by Disability Adjusted Life Years (DALY) in Portugal, for 2015. DALY combines Years Lost due to Disability (YLD), and Years of Life Lost (YLL) due to premature death. Deaths due to ALL were estimated based on lymphoblastic leukaemia (LL) mortality data from national statistics. The disability weights used to estimate YLD were based on the 2015 Global Burden of Disease (GBD 2015). Four disease states were considered: 1) diagnosis and primary therapy; 2) controlled disease; 3) relapsed/refractory disease; and 4) terminal phase. The incidence of states 1) and 4) was based on national registries and statistics for LL, and on international registries for ALL. The incidence of states 2) and 3) was estimated for children and adults separately through partitioned survival models based on clinical trials in ALL patients. State 1) was assumed to last 2 years (experts’ opinion), and other states durations were based on GBD 2015. In 2015, 130 new ALL cases and 58 ALL deaths were estimated to have occurred in Portugal. The total disease burden attributable to ALL was estimated at 1,039 DALY, with 89% due to YLL and the remaining due to YLD. Per average ALL patient, a burden of 1.78 DALY was estimated. Children and adults share YLD equally, but 69% of YLL took place in adults. ALL is an important cause of disease burden, both in children and adults, with a higher impact on YLL in Portuguese adults. ALL is therefore an important target for health policy interventions due to its burden by average patient.

ABO identical and washed blood transfusions as candidate strategies to reduce early mortality in acute promyelocytic leukemia

BackgroundDespite dramatically improved long term outcomes seen with all-trans retinoic acid therapy, and now arsenic trioxide, in acute promyelocytic leukemia (APL), early mortality remains a substantial challenge. Recent data from a single center study and the Surveillance, Epidemiology and End Results (SEER) registry report 30day mortality rates of 26% (n=18 of 70) and 17% (n=238 of 1400), respectively. Early deaths are predominately due to hemorrhage. Patients with APL invariably have abnormal laboratory hemostasis tests. The standard of practice is to prophylactically transfuse platelets, plasma and cryoprecipitate to mitigate abnormal platelet counts, PT/PTT and fibrinogen levels. Standard blood bank practice is to transfuse platelets, plasma and cryoprecipitate largely without regard to ABO blood group (platelets, cryoprecipitate), and, in some centers, transfusing ABO non-identical universal donor group AB plasma. Evidence from observational studies suggests that use of ABO non-identical blood components may be associated with increased bleeding. We hypothesized that use of ABO identical blood components and saline washed transfusions (red cells and platelets) would be associated with reduced early mortality in APL by avoidance of transfusion induced hemostatic dysfunction. MethodsThis is a single center cohort study of APL patients treated in an 800 bed university community and referral hospital. Novel approaches to transfusion support, based upon randomized trials, include implementation of ABO identical platelet transfusions for all patients with acute leukemia in 1990, use of only ABO identical cryoprecipitate in 2005, and washed transfusions of red cells and platelets for all patients with acute leukemia <50years of age beginning in 2006. Plasma transfusion has always been ABO identical. Two comparison populations were recent literature reports and the New York State Cancer Registry. We characterized 30 day mortality in APL patients seen in our institution since 2000 as a convenience sample comparable to literature reports, beginning approxcimately when ATRA therapy became uniform for induction therapy. Only patients receiving their induction therapy in our hospital were included. ResultsOf 41 patients there were 2 early (30 day) deaths (5%; a 71–81% reduction from expected). Early mortality at 100 days was 7% (n=3). The 30 day mortality in the younger cohort <50years of age (n=16) receiving washed transfusions was 0%. Restricting the analysis to patients treated since 2006 (ABO identical transfusions, mostly washed) (n=27; mean age 43 years; median 41 years; range 12–79), the early mortality rate at 30days was 3.7%. Long-term survival (5 years) of our APL patients was similar to New York State Cancer Registry and literature reports (80–83%). DiscussionAPL patients supported with transfusion regimens including ABO identical blood components, with or without washing, experienced early mortality at 30 days that was strikingly improved (71% to 86% lower) compared with that reported in the recent literature (3.7% to 5% vs. 17% to 26%). If these observed low rates of early mortality are related to transfusion practices, avoidance of ABO immune complex formation, and subsequent interference with hemostasis, is a plausible contributing mechanism. These favorable results provide a rationale for randomized trials of relatively simple and inexpensive approaches to reducing early hemorrhagic mortality in APL: use of ABO identical transfusions and washing to remove supernatant plasma.

Genetic association with B-cell acute lymphoblastic leukemia in allogeneic transplant patients differs by age and sex.

The incidence and mortality rates of B-cell acute lymphoblastic leukemia (B-ALL) differ by age and sex. To determine if inherited genetic susceptibility contributes to these differences we performed 2 genome-wide association studies (GWAS) by age, sex, and subtype and subsequent meta-analyses. The GWAS included 446 B-ALL cases, and 3027 healthy unrelated blood and marrow transplant (BMT) donors as controls from the Determining the Influence of Susceptibility Conveying Variants Related to One-Year Mortality after BMT (DISCOVeRY-BMT) study. We identified 1 novel variant, rs189434316, significantly associated with odds of normal cytogenetic B-ALL (odds ratio from meta-analysis [ORmeta] = 3.7; 95% confidence interval [CI], 2.5, 6.2; P value from meta-analysis [Pmeta] = 6.0 × 10-9). The previously reported pediatric B-ALL GWAS variant, rs11980379 (IKZF1), replicated in B-ALL pediatric patients (ORmeta = 2.3; 95% CI, 1.5, 3.7; Pmeta = 1.0 × 10-9), with evidence of heterogeneity (P = .02) between males and females. Sex differences in single-nucleotide polymorphism effect were seen in those >15 years (OR = 1.7; 95% CI, 1.4, 2.2, PMales = 6.38 × 10-6/OR = 1.1; 95% CI, 0.8, 1.5; PFemales = .6) but not ≤15 years (OR = 2.3; 95% CI, 1.4, 3.8; PMales = .0007/OR = 1.9; 95% CI, 1.2, 3.2; PFemales = .007). The latter association replicated in independent pediatric B-ALL cohorts. A previously identified adolescent and young-adult onset ALL-associated variant in GATA3 is associated with B-ALL risk in those >40 years. Our findings provide more evidence of the influence of genetics on B-ALL age of onset and we have shown the first evidence that IKZF1 associations with B-ALL may be sex and age specific.