Prognostic factors of childhood and adolescent acute myeloid leukemia (AML) survival: evidence from four decades of US population data

Current knowledge about FLT3 gene mutations, exploring the isoforms, and protein importance in AML

Acute myeloid leukaemia (AML) is a complex haematological malignancy characterised by diverse genetic alterations leading to abnormal proliferation of myeloid precursor cells. One of the most significant genetic alterations in AML involves mutations in the FLT3 gene, which plays a critical role in haematopoiesis and haematopoietic homeostasis. This review explores the current understanding of FLT3 gene mutations and isoforms and the importance of the FLT3 protein in AML. FLT3 mutations, including internal tandem duplications (FLT3-ITD) and point mutations in the tyrosine kinase domain (FLT3-TKD), occur in 25-30% in AML and are associated with poor prognosis. FLT3-ITD mutations lead to constitutive activation of the FLT3 signalling pathway, promoting cell survival and proliferation. FLT3-TKD mutations affect the tyrosine kinase domain and affect AML prognosis in various ways. Furthermore, FLT3 isoforms, including shorter variants, contribute to the complexity of FLT3 biology. Additionally, nonpathological polymorphisms in FLT3 are being explored for their potential impact on AML prognosis and treatment response. This review also discusses the development of molecular treatments targeting FLT3, including first-generation and next-generation tyrosine kinase inhibitors, highlighting the challenges of resistance that often arise during therapy. The final chapter describes FLT3 protein domain rearrangements and their relevance to AML pathogenesis.

Children's Oncology Group's 2023 blueprint for research: Epidemiology

The Children's Oncology Group (COG) Epidemiology Committee has a primary focus on better understanding the etiologies of childhood cancers. Over the past 10 years, the committee has leveraged the Childhood Cancer Research Network, and now more recently Project:EveryChild (PEC), to conduct epidemiologic assessments of various childhood cancers, including osteosarcoma, neuroblastoma, germ cell tumors, Ewing sarcoma, rhabdomyosarcoma, and Langerhans cell histiocytosis. More recent studies have utilized questionnaire data collected as part of PEC to focus on specific characteristics and/or features, including the presence of congenital disorders and the availability of stored cord blood. Members of the COG Epidemiology Committee have also been involved in other large-scale National Institutes of Health efforts, including the Childhood Cancer Data Initiative and the Gabriella Miller Kids First Pediatric Research Program, which are improving our understanding of the factors associated with childhood cancer risk. Future plans will focus on addressing questions surrounding health disparities, utilizing novel biospecimens in COG epidemiology studies, exploring the role of environmental factors on the etiologies and outcomes of childhood cancer, collaborating with other COG committees to expand the role of epidemiology in childhood cancer research, and building new epidemiologic studies from the Molecular Characterization Initiative-all with the ultimate goal of developing novel prevention and intervention strategies for childhood cancer.

Ethnic disparities in childhood leukemia survival by border residence: A Texas population-based analysis

BACKGROUND

The US-Mexico border is a medically underserved region where survival disparities have been observed in adults diagnosed and treated for various malignancies. Studies examining survival disparities among children living in this region and diagnosed with cancer are lacking. The objective of this study was to evaluate the impact of border residence on survival among children with acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), and living near the Texas-Mexico border at the time of their diagnosis. The authors hypothesized that this group experiences inferior survival compared with patients with childhood leukemia living in nonborder areas.

METHODS

The authors conducted a retrospective survival analysis leveraging data from the Texas Cancer Registry. The study included patients aged birth to 19 years who were diagnosed with ALL or AML between 1995 and 2017. Cox proportional hazards models were used to evaluate the factors associated with the risk of death. Overall survival estimates were calculated using Kaplan-Meier methods.

RESULTS

During the study period, there were 6002 children diagnosed with ALL and 1279 diagnosed with AML. Inferior 5-year overall survival was observed among children with ALL living along the border region compared with those living in nonborder areas (77.5% vs. 85.8%). In adjusted models, children with ALL living along the border experienced a 30% increased hazard of death versus children living in nonborder areas. In contrast, for children with AML, survival estimates did not vary by border versus nonborder residence.

CONCLUSIONS

Living along the border was associated with inferior survival among children with ALL, but not among children with AML. Additional studies are urgently needed to identify the factors driving these disparities to effectively design multilevel interventions and influence state and national cancer control programs.

Childhood cancer survival in the highly vulnerable population of South Texas: A cohort study

This study examines childhood cancer survival rates and prognostic factors related to survival in the majority Hispanic population of South Texas. The population-based cohort study used Texas Cancer Registry data (1995-2017) to examine survival and prognostic factors. Cox proportional hazard models and Kaplan-Meier survival curves were used for survival analyses. The 5-year relative survival rate for 7,999 South Texas cancer patients diagnosed at 0-19 years was 80.3% for all races/ethnicities. Hispanic patients had statistically significant lower 5-year relative survival rates than non-Hispanic White (NHW) patients for male and female together diagnosed at age≥5 years. When comparing survival among Hispanic and NHW patients for the most common cancer, acute lymphocytic leukemia (ALL), the difference was most significant in the 15-19 years age range, with 47.7% Hispanic patients surviving at 5 years compared to 78.4% of NHW counterparts. The multivariable-adjusted analysis showed that males had statistically significant 13% increased mortality risk than females [hazard ratio (HR): 1.13, 95% confidence interval (CI):1.01-1.26] for all cancer types. Comparing to patients diagnosed at ages 1-4 years, patients diagnosed at age < 1 year (HR: 1.69, 95% CI: 1.36-2.09), at 10-14 year (HR: 1.42, 95% CI: 1.20-1.68), or at 15-19 years (HR: 1.40, 95% CI: 1.20-1.64) had significant increased mortality risk. Comparing to NHW patients, Hispanic patients showed 38% significantly increased mortality risk for all cancer types, 66% for ALL, and 52% for brain cancer. South Texas Hispanic patients had lower 5-year relative survival than NHW patients especially for ALL. Male gender, diagnosis at age<1 year or 10-19 years were also associated with decreased childhood cancer survival. Despite advances in treatment, Hispanic patients lag significantly behind NHW patients. Further cohort studies in South Texas are warranted to identify additional factors affecting survival and to develop interventional strategies.

Widening Social Inequalities in Cancer Mortality of Children Under 5 Years in Korea

BACKGROUND

To investigate the effect of parental social class on cancer mortality in children under 5 in Korea, two birth cohorts were constructed by linking national birth data to under-5 death data from the Statistics Korea for 1995-1999 (3,323,613 births) and 2010-2014 (2,297,876 births).

METHODS

The Cox proportional hazards model adjusted for covariates was used in this study.

RESULTS

Social inequalities of under-5 cancer mortality risk in paternal education and paternal employment status were greater in 2010-2014 than in 1995-1999. The gap of hazard ratio (HR) of under-5 cancer mortality between lower (high school or below) and higher (university or higher) paternal education increased from 1.23 (95% confidence interval, 1.041.46) in 1995-1999 to 1.45 (1.11-1.97) in 2010-2014; the gap of HR between parents engaged in manual work and non-manual work increased from 1.32 (1.12-1.56) in 1995-1999 to 1.45 (1.12-1.89) in 2010-2014 for fathers, and from 1.18 (0.7-1.98) to 1.69 (1.03-2.79) for mothers. When the parental social class was lower, the risk of under-5 cancer mortality was higher in not only adverse but normal births.

CONCLUSION

Social inequalities must be addressed to reduce the disparity in cancer mortality of children under 5 years old.

Access to Hematopoietic Stem Cell Transplant in Canada for Patients with Acute Myeloid Leukemia

Hematopoietic stem cell transplant is a complicated intervention only offered in specialized centers. Access to transplants may vary based on the location of primary residence, income levels, age, and reported race or ethnicity. Using data from the Canadian Institute of Health (CIH) Discharge abstract database (DAD), all non-Quebec Canadians under the age of 65 with a diagnosis of AML between 2004 and 2015 were included in this study. Descriptive statistics were produced for the variables of interest: time period, age, sex, rurality, transplant status, proportion of visible minorities, proportion identifying as indigenous, and proportion of low-income families. Transplant rates were compared and reported using univariable and multivariable analysis. In multivariable analysis, time period, province of residence, gender, and age were significantly associated with the receipt of an allogeneic hematopoietic stem cell transplant. However, differences in transplant rates observed in indigenous patients, low-income families, and visible minorities were not found to be statistically significant. In non-Quebec Canada, transplant rates vary significantly with province of residence, with the highest rates recorded in Alberta. Contrary to findings previously reported in studies exploring access to transplant in the United States, a low-income level was not associated with lower rates of transplants. This might suggest that Canada’s universal health care insurance program is protective against socioeconomic barriers that impact access to health care services.

A qualitative inquiry of communication based barriers to the diagnosis of pediatric cancer: Perceptions of primarily Spanish-speaking caregivers

BACKGROUND

Primarily Spanish-speaking cancer patients and caregivers often experience non-congruence with healthcare providers about beliefs, values, and knowledge of cancer. Our goal was to describe how communication related to the diagnosis of cancer was influenced by culture and language among primarily Spanish-speaking caregivers of pediatric cancer patients.

METHODS

Caregivers participated in three focus groups about their experiences with their child's diagnosis, communication issues, and understanding of their child's diagnosis and treatment plan. Focus groups were audio recorded, transcribed, and qualitatively analyzed using interpretive description.

RESULTS

Three themes emerged: 1) Negative experiences and barriers during the cancer diagnosis and treatment, 2) Miscommunication and system complexity, and 3) Language barriers throughout the diagnostic process. Due to barriers and negative experiences, some caregivers reported that their child's diagnosis was delayed, that providers sometimes used dehumanizing language, and that they were confused about diagnostic testing and treatment.

CONCLUSION

Cultural and linguistic disparities in pediatric oncology must be systematically addressed at the provider, clinic, and system level.

PRACTICE IMPLICATIONS

High-quality cancer care delivered by oncologists and cancer care teams should include cultural humility when discussing the cancer diagnosis and prognosis.

Regulatory Networks of Prognostic mRNAs in Pediatric Acute Myeloid Leukemia

Acute myeloid leukemia (AML) in children refers to a malignant tumor caused by the abnormal proliferation of immature myeloid cells in the bone marrow and peripheral blood. The prognosis of patients with pediatric acute myeloid leukemia (AML) remains poor, highlighting the need for improved targeted therapy. The expression data of lncRNAs, mRNAs, and miRNAs and survival information of pediatric AML patients were collected from The Cancer Genome Atlas (TCGA) database. Cox regression analysis was used to screen the lncRNAs, mRNAs, and miRNAs that significantly affect the overall survival (OS) of patients as OS-related genes (included lncRNAs, mRNAs, and miRNAs). Enrichment analysis and protein-protein interaction (PPI) network construction were performed for the OS-related mRNAs. We further established a ceRNAs regulatory network. In addition, the potential prognostic role of genes was further evaluated by risk score. We have identified 5275 lncRNAs, 176 miRNAs, and 6221 mRNAs that significantly affect the prognosis of pediatric AML patients. It is worth noting that OS-related mRNAs are mainly involved in ribosome, RNA transport, and spliceosome. We identified the top 10 most connected mRNAs in the PPI network as important mRNAs and constructed a ceRNAs regulatory network (including NCBP2, RPLP0, UBC, RPS2, and RPS9). The risk score and nomogram results suggest that NCBP2 may be a risk factor for pediatric AML, while RPLP0, UBC, RPS2, and RPS9 may be protective factors. Our results construct 5 gene signals as new prognostic indicators for predicting the survival of pediatric AML patients. Our research has demonstrated the ceRNAs regulatory network may become a new target for pediatric AML treatment.

In-hospital Mortality and Racial Disparity in Children and Adolescents With Acute Myeloid Leukemia: A Population-based Study

Survival disparities in children and adolescents with acute myeloid leukemia (AML) are documented, however, the etiology of these disparities is understudied. Few studies have evaluated factors that predict in-hospital mortality in childhood AML and racial/ethnic disparities associated with in-hospital death. Our study aimed to investigate factors associated with the risk of in-hospital death among childhood AML hospitalizations. We conducted a retrospective study of childhood AML hospitalizations using the National Inpatient Sample (NIS) from 2003 to 2017. We estimated incidences of in-hospital death among AML hospitalizations. We performed survey logistic regression models to measure the association between patient and hospital characteristics and in-hospital mortality. We identified 71,050 hospitalizations of children with AML. Compared with non-Hispanic (NH) whites, NH-black children had a higher risk of in-hospital mortality (adjusted odds ratio: 1.41, 95% confidence interval: 1.06-1.87, P<0.02). Further, NH-black patients with hematopoietic stem cell transplant experienced the highest risk of mortality (adjusted odds ratio: 5.88, 95% confidence interval: 3.13-11.06, P<0.001) as compared with NH-black children who did not receive hematopoietic stem cell transplant. Our findings highlight that NH-black children with AML continue to experience a disproportionately higher likelihood of in-hospital mortality when compared with their NH-white counterparts. Further studies are needed to delineate the etiology of these disparities.

LSD1 defines erythroleukemia metabolism by controlling the lineage-specific transcription factors GATA1 and C/EBPα

Acute myeloid leukemia (AML) is a heterogenous malignancy characterized by distinct lineage subtypes and various genetic/epigenetic alterations. As with other neoplasms, AML cells have well-known aerobic glycolysis, but metabolic variations depending on cellular lineages also exist. Lysine-specific demethylase-1 (LSD1) has been reported to be crucial for human leukemogenesis, which is currently one of the emerging therapeutic targets. However, metabolic roles of LSD1 and lineage-dependent factors remain to be elucidated in AML cells. Here, we show that LSD1 directs a hematopoietic lineage-specific metabolic program in AML subtypes. Erythroid leukemia (EL) cells particularly showed activated glycolysis and high expression of LSD1 in both AML cell lines and clinical samples. Transcriptome, chromatin immunoprecipitation-sequencing, and metabolomic analyses revealed that LSD1 was essential not only for glycolysis but also for heme synthesis, the most characteristic metabolic pathway of erythroid origin. Notably, LSD1 stabilized the erythroid transcription factor GATA1, which directly enhanced the expression of glycolysis and heme synthesis genes. In contrast, LSD1 epigenetically downregulated the granulo-monocytic transcription factor C/EBPα. Thus, the use of LSD1 knockdown or chemical inhibitor dominated C/EBPα instead of GATA1 in EL cells, resulting in metabolic shifts and growth arrest. Furthermore, GATA1 suppressed the gene encoding C/EBPα that then acted as a repressor of GATA1 target genes. Collectively, we conclude that LSD1 shapes metabolic phenotypes in EL cells by balancing these lineage-specific transcription factors and that LSD1 inhibitors pharmacologically cause lineage-dependent metabolic remodeling.

Double and single mixed-lineage leukemia-rearranged subclones in pediatric acute myeloid leukemia: a case report

Background

Acute myeloid leukemia (AML) is a disease with a significant amount of cytogenetic heterogeneity including mixed-lineage leukemia (MLL) gene rearrangements. Pediatric AML commonly has genetic rearrangements which involve chromosome 11q23 in 15–20% of cases, and these genetic abnormalities have been associated with a poorer prognosis (Grimwade et al. in Blood 92:2322–2333, 1998; Raimondi et al. in Blood 94:3707–3716, 1999; Lie et al. in Br J Haematol 122: 217–225). MLL rearrangements in AML have been shown to have multiple different fusion partners (Meyer et al. in Leukemia 23:1490–1499). Heterogeneity of these cytogenetic abnormalities makes it difficult to determine how to approach patients from a treatment standpoint. This difficulty is further complicated when patients have more than a single MLL rearrangement.

Case presentation

A 10-year-old Caucasian girl presented with easy bruising and was found to have acute myeloid leukemia. Her cytogenetics showed two different MLL rearrangements, t(9;11)(p22;q23) and t(11;19)(q23;p13.3). At initial presentation she had no other cytogenetic findings. She responded well to initial therapy and achieved remission following the first induction cycle and completed four rounds of chemotherapy. She subsequently had a relapse of her AML, and her cytogenetics were consistent with a single MLL rearrangement, t(9;11)(p22;q23), in addition to monosomy 7. She was treated with reduction therapy and a haplo-identical bone marrow transplant but ultimately succumbed to her disease.

Conclusion

MLL rearrangements are common in AML, but clinical significance continues to be elusive, and there is conflicting data on the prognostic significance. In the setting of multiple MLL rearrangements, there is concern for reduced survival, although treatment modifications are not currently done in this setting. This report details a case with multiple MLL rearrangements that initially responded to therapy but ultimately had disease progression with a selection of a leukemic clone containing a single MLL rearrangement.

Flexible Modeling of Net Survival and Cure by AML Subtype and Age: A French Population-Based Study from FRANCIM

With improvements in acute myeloid leukemia (AML) diagnosis and treatment, more patients are surviving for longer periods. A French population of 9453 AML patients aged ≥15 years diagnosed from 1995 to 2015 was studied to quantify the proportion cured (P), time to cure (TTC) and median survival of patients who are not cured (MedS). Net survival (NS) was estimated using a flexible model adjusted for age and sex in sixteen AML subtypes. When cure assumption was acceptable, the flexible cure model was used to estimate P, TTC and MedS for the uncured patients. The 5-year NS varied from 68% to 9% in men and from 77% to 11% in women in acute promyelocytic leukemia (AML-APL) and in therapy-related AML (t-AML), respectively. Major age-differenced survival was observed for patients with a diagnosis of AML with recurrent cytogenetic abnormalities. A poorer survival in younger patients was found in t-AML and AML with minimal differentiation. An atypical survival profile was found for acute myelomonocytic leukemia and AML without maturation in both sexes and for AML not otherwise specified (only for men) according to age, with a better prognosis for middle-aged compared to younger patients. Sex disparity regarding survival was observed in younger patients with t-AML diagnosed at 25 years of age (+28% at 5 years in men compared to women) and in AML with minimal differentiation (+23% at 5 years in women compared to men). All AML subtypes included an age group for which the assumption of cure was acceptable, although P varied from 90% in younger women with AML-APL to 3% in older men with acute monoblastic and monocytic leukemia. Increased P was associated with shorter TTC. A sizeable proportion of AML patients do not achieve cure, and MedS for these did not exceed 23 months. We identify AML subsets where cure assumption is negative, thus pointing to priority areas for future research efforts.

Survival and risk factors for mortality in pediatric patients with acute myeloid leukemia in a single reference center in low-middle-income country

Despite advances in therapy and care for children with acute myeloid leukemia (AML), survival rates for children in low- and middle-income countries (LMICs) remain poor. We studied risk factors for mortality and survival in children with AML in a LMIC to develop strategies to improve survival for AML children in these countries. This retrospective cohort (2000-2014) analyzed newly diagnosed AML patients (age < 19 years) at a reference center in Brazil. Demographic and clinical variables were reviewed by AML subtype: acute promyelocytic leukemia (APL), AML with Down syndrome (AML-DS), and other AML subtypes. Cumulative hazard risk for early death (ED) until 6 weeks of treatment and risk factors for mortality were determined by the multivariate Cox hazard models. Survival was assessed for each AML subtypes. A total of 220 patients were diagnosed: APL 50 (22.7%), AML-DS 16 (7.3%), and other AML subtypes 154 (70.0%). The cumulative hazard function values for ED for all patients with AML were 12.5% (95% CI 8.5-18.4%); for each AML patients subtypes: APL, 21.7% (95% CI 11.7-40.5%); AML-DS, 6.2% (95% CI 0.9-44.4%); and other AML subtypes, 10.2% (95% CI 6.2-17.0%). White blood cell count (cutoff 10 × 10⁹/L for APL and 100 × 10⁹/L for other AML subtypes) and Afro-descendance were significant risk factors for mortality in APL and other AML subtypes, respectively. Overall survival for patients with APL, AML-DS, and other AML subtypes was 66.8%, 62.5%, and 38.0%, respectively. APL patients had the highest incidence of ED and those with other subtypes had increased relapse risk. We also observed high rates of death in complete remission mainly due to infection. Better risk classification and identification of risk factors for infection may improve the survival of these patients.

Does socioeconomic status account for racial and ethnic disparities in childhood cancer survival?

BACKGROUND

For many childhood cancers, survival is lower among non-Hispanic blacks and Hispanics in comparison with non-Hispanic whites, and this may be attributed to underlying socioeconomic factors. However, prior childhood cancer survival studies have not formally tested for mediation by socioeconomic status (SES). This study applied mediation methods to quantify the role of SES in racial/ethnic differences in childhood cancer survival.

METHODS

This study used population-based cancer survival data from the Surveillance, Epidemiology, and End Results 18 database for black, white, and Hispanic children who had been diagnosed at the ages of 0 to 19 years in 2000-2011 (n = 31,866). Black-white and Hispanic-white mortality hazard ratios and 95% confidence intervals, adjusted for age, sex, and stage at diagnosis, were estimated. The inverse odds weighting method was used to test for mediation by SES, which was measured with a validated census-tract composite index.

RESULTS

Whites had a significant survival advantage over blacks and Hispanics for several childhood cancers. SES significantly mediated the race/ethnicity-survival association for acute lymphoblastic leukemia, acute myeloid leukemia, neuroblastoma, and non-Hodgkin lymphoma; SES reduced the original association between race/ethnicity and survival by 44%, 28%, 49%, and 34%, respectively, for blacks versus whites and by 31%, 73%, 48%, and 28%, respectively, for Hispanics versus whites ((log hazard ratio total effect - log hazard ratio direct effect)/log hazard ratio total effect).

CONCLUSIONS

SES significantly mediates racial/ethnic childhood cancer survival disparities for several cancers. However, the proportion of the total race/ethnicity-survival association explained by SES varies between black-white and Hispanic-white comparisons for some cancers, and this suggests that mediation by other factors differs across 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.

Survival differences in childhood and young adult acute myeloid leukemia: A cross-national study using US and England data

BACKGROUND

Acute myeloid leukemia (AML) is a serious disease with complex etiology and marked variation in survival. Known prognostic factors include AML subtypes, age at diagnosis and sex. However, survival outcomes may vary across healthcare systems. In this study, we evaluated the survival patterns in individuals diagnosed with AML at ages 0-24 years in the US and England between prognostic features and across countries.

METHODS

We obtained data on 4387 and 2194 subjects from the US Surveillance Epidemiology and End Result registries and UK National Cancer Data Repository. Subjects were diagnosed and followed in 1995-2014. Kaplan-Meier curve and stratified Cox proportional hazards regression were used in the analysis.

RESULTS

Overall risk of mortality was 23% lower in English patients compared to that in the US patients (adjusted hazard ratio (aHR), 95% confidence Interval (CI): 0.77, 0.71-0.84). Survival difference of similar extent was observed in subgroups of sex and age at diagnosis. However, mortality risks between two countries varied substantially across AML subtypes, especially in AML inv(16) (1.81, 0.61-5.34), AML with minimal differentiation (0.54, 0.25-1.17), AML without maturation (0.38, 0.20-0.74) and AML with maturation (0.52, 0.31-0.86).

CONCLUSIONS

Similar to the population trend, mortality risk across sex, age at diagnosis, and most AML subtypes was lower in England. Survival outcome for AML with and without maturation in England was better than the population trend, while that for AML inv(16) was worse. Our findings suggest that future etiologic and policy research may uncover the underlying mechanisms and contribute to closing these morality gaps.

Incidence, Survival, and Risk Factors for Adults with Acute Myeloid Leukemia Not Otherwise Specified and Acute Myeloid Leukemia with Recurrent Genetic Abnormalities: Analysis of the Surveillance, Epidemiology, and End Results (SEER) Database, 2001-2013

BACKGROUND/AIM

As the knowledgebase of acute myeloid leukemia (AML) has grown, classification systems have moved to incorporate these new findings.

METHODS

We assessed 32,941 patients with AML whose records are contained in the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

Half of all patients diagnosed between 2001 and 2013 did not have a World Health Organization (WHO) classification. Acute promyelocytic leukemia and acute panmyelosis with myelofibrosis were associated with the longest leukemia-specific survival (110 and 115 months, respectively), and AML with minimal differentiation and acute megakaryoblastic leukemia with the shortest (30 and 28 months, respectively). For patients in the WHO groups AML not otherwise specified (AML-NOS) and AML with recurrent genetic abnormalities (AML-RGA), the risk of death was greater for older patients and less for married patients. Black patients with any type of AML-NOS also had a higher risk of death. Patients whose case of AML did not receive a WHO classification were older and this group had a higher risk of death when compared to patients with a WHO type of AML-NOS.

CONCLUSION

Our findings highlight the divergent outcomes of patients with AML and the importance of using the WHO classification system and demographic factors to gauge their prognosis.

Ethnic disparities relative to disease features and outcomes in children with acute myeloid leukemia

Hispanics with acute leukemias have poorer outcomes than non-Hispanic whites (NHWs), despite an increased likelihood of favorable prognostic features. We reviewed medical records from 167 children ages 0-18 years diagnosed with de novo AML over an 18-year period at Texas Children's Cancer Center, among whom 129 self-identified as Hispanic or NHW. Although Hispanics were significantly more likely to have the favorable prognostic cytogenetic feature t(8;21) (P = 0.04), the expected survival benefit was not observed. This lack of survival benefit was primarily due to significantly poorer event-free and overall survival among Hispanics treated with upfront stem cell transplantation after achieving first clinical remission (P = 0.008).

Socioeconomic status (SES) and childhood acute myeloid leukemia (AML) mortality risk: Analysis of SEER data

Socioeconomic status (SES) is a complex construct of multiple indicators, known to impact cancer outcomes, but has not been adequately examined among pediatric AML patients. This study aimed to identify the patterns of co-occurrence of multiple community-level SES indicators and to explore associations between various patterns of these indicators and pediatric AML mortality risk. A nationally representative US sample of 3651 pediatric AML patients, aged 0-19 years at diagnosis was drawn from 17 Surveillance, Epidemiology, and End Results (SEER) database registries created between 1973 and 2012. Factor analysis, cluster analysis, stratified univariable and multivariable Cox proportional hazards models were used. Four SES factors accounting for 87% of the variance in SES indicators were identified: F1) economic/educational disadvantage, less immigration; F2) immigration-related features (foreign-born, language-isolation, crowding), less mobility; F3) housing instability; and, F4) absence of moving. F1 and F3 showed elevated risk of mortality, adjusted hazards ratios (aHR) (95% CI): 1.07(1.02-1.12) and 1.05(1.00-1.10), respectively. Seven SES-defined cluster groups were identified. Cluster 1 (low economic/educational disadvantage, few immigration-related features, and residential-stability) showed the minimum risk of mortality. Compared to Cluster 1, Cluster 3 (high economic/educational disadvantage, high-mobility) and Cluster 6 (moderately-high economic/educational disadvantages, housing-instability and immigration-related features) exhibited substantially greater risk of mortality, aHR(95% CI)=1.19(1.0-1.4) and 1.23 (1.1-1.5), respectively. Factors of correlated SES-indicators and their pattern-based groups demonstrated differential risks in the pediatric AML mortality indicating the need of special public-health attention in areas with economic-educational disadvantages, housing-instability and immigration-related features.

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.

Evaluation of D-dimer and lactate dehydrogenase plasma levels in patients with relapsed acute leukemia

Despite the outstanding advances made over the past decade regarding our knowledge of acute leukemia (AL), relapsed AL remains to be associated with a dismal prognosis. A better understanding of AL relapse and monitoring of the D-dimer and lactate dehydrogenase (LDH) plasma levels following chemotherapy may aid clinicians in determining whether relapse may occur in the subsequent phases of the disease. The present study evaluated D-dimer and LDH levels in 204 patients with relapsed AL. Data were collected at the initial onset of AL, at complete remission (CR) and in patients with relapsed AL. D-dimer plasma levels were significantly increased in patients with initial AL and in patients with relapsed AL (P=0.005 and P=0.007, respectively) but not in those with CR. LDH levels were significantly increased in AL patients at the initial onset of disease and at relapse compared with patients achieving CR, irrespective of cell type. Plasma prothrombin time, activated partial thromboplastin time and fibrinogen levels were not significantly different across patients (with the exception of acute promyelocytic leukemia patients) at the initial onset, relapsed AL or CR. Routine hematological parameters (white blood cell count, hemoglobin, platelet count) were significantly different at the initial onset of AL (P=0.002, P<0.001 and P=0.001, respectively) and during relapsed AL (P=0.009, P=0.003 and P<0.001, respectively) compared with patients achieving CR, suggesting an association between D-dimer, LDH and relapsed AL. These results also indicate that determination of D-dimer and LDH levels may be useful for predicting the probability of relapse during chemotherapy, but should also be combined with routine hematological parameters.

Low expression of Toll-like receptors in peripheral blood mononuclear cells of pediatric patients with acute lymphoblastic leukemia

Cancer is the second most common cause of death among children aged 1-14 years. Leukemia accounts for one-third of all childhood cancers, 78% of which is acute lymphoblastic leukemia (ALL). The development of cancer has been associated with malignant cells that express low levels of immunogenic molecules, which facilitates their escape from the antineoplastic immune response. It is thought that it may be possible to rescue the antineoplastic immune response through the activation of recognition receptors, such as Toll-like receptors (TLRs), which activate the innate immune system. TLRs are type I membrane glycoproteins expressed mainly in immune system cells such as monocytes, neutrophils, macrophages, dendritic cells, T, B and natural killer cells. The aim of the present study was to evaluate the expression of TLR1, TLR3, TLR4, TLR7 and TLR9 in peripheral blood mononuclear cells (PBMCs) in patients with ALL and prior to any treatment. PBMCs were obtained from 50 pediatric patients diagnosed with ALL and from 20 children attending the ophthalmology and orthopedics services. The mean fluorescence intensity was obtained by analysis of immunofluorescence. We found lower expression levels of TLR1, TLR3, TLR4, TLR7 and TLR9 in PBMCs from patients with ALL compared with those from control patients. We also observed that the PBMCs from patients with Pre-B and B ALL had lower TLR4 expression than controls and patients with Pro-B, Pre-B, B and T ALL had lower TLR7 expression than controls. The present study is the first to demonstrate reduced expression of TLRs in PBMCs from pediatric patients with ALL. This finding is of great relevance and may partly explain the reduction in the antineoplastic immune response in patients with ALL.

Sex disparity in childhood and young adult acute myeloid leukemia (AML) survival: Evidence from US population data

Sex variation has been persistently investigated in studies concerning acute myeloid leukemia (AML) survival outcomes but has not been fully explored among pediatric and young adult AML patients. We detected sex difference in the survival of AML patients diagnosed at ages 0-24 years and explored distinct effects of sex across subgroups of age at diagnosis, race-ethnicity and AML subtypes utilizing the United States Surveillance Epidemiology and End Results (SEER) population based dataset of 4865 patients diagnosed with AML between 1973 and 2012. Kaplan-Meier survival function, propensity scores and stratified Cox proportional hazards regression were used for data analyses. After controlling for other prognostic factors, females showed a significant survival advantage over their male counterparts, adjusted hazard ratio (aHR, 95% confidence interval (CI): 1.09, 1.00-1.18). Compared to females, male patients had substantially increased risk of mortality in the following subgroups of: ages 20-24 years at diagnosis (aHR1.30), Caucasian (1.14), acute promyelocytic leukemia (APL) (1.35), acute erythroid leukemia (AEL) (1.39), AML with inv(16)(p13.1q22) (2.57), AML with minimum differentiation (1.47); and had substantially decreased aHR in AML t(9;11)(p22;q23) (0.57) and AML with maturation (0.82). Overall, females demonstrated increased survival over males and this disparity was considerably large in patients ages 20-24 years at diagnosis, Caucasians, and in AML subtypes of AML inv(16), APL and AEL. In contrast, males with AML t(9;11)(p22;q23), AML with maturation and age at diagnosis of 10-14 years showed survival benefit. Further investigations are needed to detect the biological processes influencing the mechanisms of these interactions.