Acute myeloid leukemia (AML) is a rare type of childhood acute leukemia, which has a worse prognosis than childhood acute lymphoblastic leukemia. Over the past decade, significant progress has been made in the treatment of childhood AML and the 5-year event-free survival rate may be as high as 70% in developed countries. This survival improvement is largely attributable to risk-stratified treatments, therapies tailored to individual patients based on the biological characteristics of the disease, and continuously improving supportive care. An accurate diagnosis is the prerequisite for risk stratification, prognostic evaluation and therapeutic decision making. How to reduce early mortality and thus improve overall survival, how to implement appropriate supportive treatment to reduce treatment-associated complications, and how to reduce treatment-related mortality are the key to the improvement of therapies for childhood acute myeloid leukemia.
Child ; Humans ; Leukemia, Myeloid, Acute ; diagnosis ; drug therapy ; genetics ; mortality ; Leukemia, Promyelocytic, Acute ; drug therapy ; genetics

OBJECTIVETo study WT1 gene expression in children with acute myeloid leukemia (AML) and its possible correlations to clinical outcomes.

METHODSBone marrow samples were collected from 45 children with AML (excluding acute promyelocytic leukemia, AML-M3) at different time points of AML treatment and follow-up. WT1 gene expression levels in bone marrow mononuclear cells were assayed by real-time fluorescence quantitative PCR. The correlation between WT1 expression and prognosis was retrospectively analyzed.

RESULTSThe WT1 expression level in AML children with bone marrow blast cell percentage of >60% was significantly higher than in those with bone marrow blast cell percentage of ≤ 60% (p<0.05). The lower WT1 expression level was documented in children with AML-M2 compared with in children with other non-M2 subtypes (p<0.05). WT1 expression level in patients in complete remission was significantly lower than that in patients at diagnosis or relapse (p<0.01). The 2-year disease-free survival (DFS) in patients with higher WT1 expression was significantly lower than in those with lower WT1 expression at the end of induction chemotherapy (p<0.05). The 2-year overall survival (OS) and DFS in patients with ≥1 log WT1 reduction range were significantly higher than those with <1 log reduction of WT1 expression level at the end of induction chemotherapy (p<0.05). WT1 expression levels tended to rise 2-3 months prior to bone marrow relapse.

CONCLUSIONSWT1 expression level is closely correlated prognosis in children with AML. Dynamic monitoring of WT1 expression level is of great clinical importance in terms of individualized management, prognosis evaluation and relapse prediction.

Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Leukemia, Myeloid, Acute ; drug therapy ; genetics ; mortality ; Male ; Recurrence ; WT1 Proteins ; genetics

The objective was to study the incidence and prognosis significance of -7/7q- abnormalities in acute leukemia and myelodysplastic syndrome. Conventional cytogenetic analysis of R-band was used to test -7/7q- chromosome abnormalities in 410 patients with acute leukemia (AL), in 71 cases of myelodysplastic syndrome (MDS) and in 36 cases of chronic myelogenous leukemia in accelerated phase (CML-AP). The results showed that the incidences of -7/7q- abnormalities in AL, MDS and CML-AP patients were 4.88%, 9.86% and 8.33% respectively. The -7/7q- abnormalities could be found in acute myeloblastic leukemia (AML) and acute lymphocytic leukemia (ALL), incidences of which were 4.70% and 6.25% (P > 0.05) respectively. 9 cases had -7 or 7q- as the sole chromosome abnormalities, 22 cases showed other additional chromosome abnormalities: -X, -5, +8, t(3; 3), t(11;16) and t(2;11). Monosomy -7 and 7q- abnormality clone was found in one patient with MDS-RAEB, and the number of cells with -7 abnormality was greater than that of 7q- abnormality cells. Four patients acquired CR among 7 patients with ALL after chemotherapy, but 2 out of 13 patients with AML achieved CR while 6 out of 7 patients with MDS transformed into AL. No patients with CML-AP achieved CR. In conclusion, -7/7q- is a frequent aberration in hematologic malignancies as well as AML and ALL. The monosomy -7 and 7q-abnormalities were detected in the same patient. The patients with -7/7q- abnormalities show poor prognosis.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Chromosome Aberrations ; Chromosomes, Human, Pair 7 ; Female ; Humans ; Leukemia, Myeloid, Acute ; drug therapy ; genetics ; mortality ; Male ; Middle Aged ; Myelodysplastic Syndromes ; drug therapy ; genetics ; mortality ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; genetics ; mortality

OBJECTIVETo explore clinical and experimental features of 28 cases of childhood acute myeloid leukemia (AML) with 11q23/MLL gene rearrangements.

METHODSKaryotypes of 234 cases of de novo childhood AML were analyzed using short-term culture of bone marrow cells and R-banding. The fusion transcripts involving MLL gene and partial tandem duplication of MLL (MLL-PTD) were detected by multiple reverse transcription polymerase chain reaction (RT-PCR) assay. Two cases with 11q23 translocation by karyotypic analysis but with negative result of multiple RT-PCR were studied with MLL-dual-color fluorescence in situ hybridization (D-FISH).

RESULTSR-banding karyotypic analysis has revealed 20 cases with 11q23 translocation (14 cases with M5, 4 cases with M4, 2 cases with M2), including 12 cases with t(9;11)(p22;q23), 3 cases with t(1;11)(q21;q23), 2 cases with t(6;11)(q27;q23), 1 case with t(11;19)(q23;p13), 1 with t(5;11)(q31;q23), and 1 with t(X;11)(q24;q23). Eighteen cases with 11q23 translocation having fusion transcripts involving MLL genes were confirmed with multiple RT-PCR; 2 cases showed negative results, but they were confirmed to have MLL rearrangements by D-FISH. MLL-PTD was also detected in 8 cases (4 cases M5, 2 cases M4, M2 and M6, one case each) from the other childhood AML cases. The total incidence of 11q23/MLL gene rearrangements was 11.97% (28/234), and most of patients(85.7%, 24/28) were M4/M5. The complete remission (CR) rate after treatment for the 28 cases with MLL rearrangements was 53.8%, the difference was significant by statistics (P< 0.05) compared with 90.5% for the control group (M4/M5 childhood AML with other karyotypic abnormalities or normal karyotype). Of them, 2 cases receiving intensive chemotherapy survived for 81 and 66 months, respectively, 4 cases receiving allogeneic stem cell transplantation survived for 21, 20, 16 and 11 months, respectively, and are still alive with CR. The medium survival (MS) time for 28 cases with 11q23/MLL rearrangements was 11 months, whereas the MS for control group was 15 months. The difference was not statistically significant(P> 0.05).

CONCLUSIONThe 11q23/MLL rearrangements is highly correlated with the occurrence of monocytic leukemia (M4 and M5). The 11q23 translocation and MLL-PTD are mutually exclusive, though both are indicative of poor prognosis. Intensive chemotherapy and allogeneic stem cell transplantation may ameliorate the clinical outcome. Multiple RT-PCR combined with karyotypic analysis and D-FISH are useful for screening the 11q23/MLL rearrangements in childhood AML.

Adolescent ; Child ; Child, Preschool ; Chromosomes, Human, Pair 11 ; Female ; Humans ; Immunophenotyping ; In Situ Hybridization, Fluorescence ; Infant ; Karyotyping ; Leukemia, Myeloid, Acute ; diagnosis ; drug therapy ; genetics ; mortality ; Male ; Myeloid-Lymphoid Leukemia Protein ; genetics ; Remission Induction ; Translocation, Genetic ; Treatment Outcome

Hypermethylation of the homeobox (HOX) gene promoter leads to decreased expression of the gene during tumor development and is thought to be correlated with the clinical outcome in leukemia. In this study, we performed pyrosequencing to quantify the methylation level of HOXA5 genes in the bone marrow samples obtained from 50 patients with AML and 19 normal controls. The methylation percentage of HOXA5 in AML patients (median=65.4%, interquartile range=35.9-72.3%) was higher than that of HOXA5 in control patients (median=43.1%, interquartile range=36.7-49.6%, Mann-Whitney U test, P=0.012). The patients of the AML group who had a high methylation percentage (>70%) had a good prognosis with a 3-yr overall survival (OS) of 82.5%, whereas the patients with a low methylation percentage (< or =70%) showed a 3-yr OS of 40.5% (P=0.048). Cox proportional hazards regression showed that the methylation percentages of HOXA5 were independently associated with the 3-yr OS of AML patients, regardless of their karyotypes. We propose that the quantification of HOXA5 methylation by pyrosequencing may be useful for predicting short-term prognosis in AML. However, the limitations of our study are the small sample size and its preliminary nature. Thus, a larger study should be performed to clearly determine the relationships among HOXA5 methylation levels, cytogenetics, and prognosis in AML patients.
Adult ; Aged ; *DNA Methylation ; Female ; Homeodomain Proteins/*genetics ; Humans ; Leukemia, Myeloid, Acute/genetics/*mortality ; Male ; Middle Aged ; Prognosis ; Promoter Regions, Genetic ; ROC Curve ; Sequence Analysis, DNA ; Survival Rate

OBJECTIVETo investigate the influence factors on survival and outcome of acute myeloid leukemia (AML) patients with t(8;21).

METHODSEighty seven AML patients with t(8;21) after long-term follow-up were enrolled in the analysis of clinical feature, immunophenotype, chromosome karyotype, treatment regimen, as well as the overall survival (OS) and relapse-free survival (RFS).

RESULTSThe overall complete remission (CR) rate was 95.3%. CR rate after first course therapy was 69.8%, after first course therapy containing medium dose Ara-C was 86.2%, and after first course of therapy containing standard-dose Ara-C was 60.3%. The median OS duration was 16.4 months, median RFS 11.7 months, 3 year OS rate 42%, 5 year OS rate 39%, 3 year RFS rate 55% and 5 year RFS rate 55%. Male gender chromosome 9q(-) had statistical significance for shorter OS and poor outcome, 2 courses of post-remission therapy with intermediate dose Ara-C, induction therapy with intermediate-dose Ara-C and post-remission with 4 courses consolidation therapy had statistically longer OS and RFS.

CONCLUSIONSex, chromosome karyotype, induction and consolidation therapy were important influence factors on OS and RFS. Application of intermediate dose Ara-C to induction and consolidation therapy leads to a higher CR rate, prolong OS and RFS.

Adolescent ; Adult ; Aged ; Female ; Humans ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; mortality ; Male ; Middle Aged ; Prognosis ; Survival Rate ; Translocation, Genetic ; Treatment Outcome ; Young Adult

OBJECTIVETo correlate the clinical features of patients with acute myeloid leukemia (AML) with mutations of FLT3-ITD, NPM1, CEBPA, c-KIT, DNMT3A and ND4 genes as well as chromosomal aberrations.

METHODSSomatic mutations of aforementioned genes in 412 newly diagnosed AML patients were detected with PCR and direct sequencing. All patients were also subjected to R-banding chromosomal analysis. The results were correlated with the clinical features and prognosis of the patients.

RESULTSThe mutation rates of FLT3-ITD, NPM1, CEBPA, c-KIT, DNMT3A and ND4 were 9.0% (26/289), 19.1% (50/262), 18.9% (34/180), 3.4% (7/208), 6.6% (9/137) and 6.9% (4/58), respectively. Patients with poor prognosis based on genetic mutations had lower blood platelet count than those with intermediate and good prognosis (P=0.001 and P=0.001, respectively). None of the three groups attained median overall survival (OS) (P> 0.05). The complete remission (CR) was similar among the three groups (P> 0.05). For patients with different prognosis based on cytogenetic findings, white blood cell count in those with intermediate prognosis was higher than those with good and poor prognosis (P< 0.001 and P=0.004, respectively), while the blood platelet count of the intermediate group was higher than that of the group with good prognosis (P=0.018). No significant difference was found among the three groups in terms of hemoglobin level (P> 0.05). The group with poor prognosis has attained shorter OS compared with those with good and intermediate prognosis (P< 0.001 and P=0.003, respectively). However, the CR rate of the group with good prognosis was higher than that of the intermediate group (P=0.001). For the group with intermediate prognosis, presence of genetic mutations did not correlate with the clinic characteristics such as white blood cell count, blood platelet count, hemoglobin level, OS and CR rate (P> 0.05 for all comparisons).

CONCLUSIONGenetic mutations combined with cytogenetic analysis can facilitate the prognosis and personalized treatment for patients with AML.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Leukemia, Myeloid, Acute ; genetics ; mortality ; Male ; Middle Aged ; Mutation ; Prognosis ; Young Adult

OBJECTIVETo study the relationship between loss of sex chromosomes and prognosis in children with acute myeloid leukemia (AML) M2 subtype.

METHODSAccording to cytogenetic characteristics, 106 children with AML were divided into three groups: patients with normal karyotype (Group A, n=26), patients with abnormal karyotype who had no loss of sex chromosomes (Group B, n=52), and patients with abnormal karyotype who had loss of sex chromosomes (Group C, n=28). Prognosis was compared between the three groups.

RESULTSThe 5-year event-free survival (EFS) rates of Groups A, B, and C were (38.9±11.2)%, (59.3±7.3)%, and (66.5±10.5)%, respectively; the EFS of Group C was significantly higher than that of Group A (P=0.035). The 5-year overall survival (OS) rates of Groups A, B, and C were (54.3±13.5)%, (68.1±7.7)%, and (77.9±9.8)%, respectively (P>0.05). The 5-year EFS of 58 patients with t(8;21) was (63.3±7.3)%, significantly higher than that of patients with normal karyotype (P=0.015). All the 28 cases in Group C had t(8;21), and their 5-year EFS was not significantly different from that of patients with t(8;21) in Group B (P>0.05).

CONCLUSIONSLoss of sex chromosomes is a favorable karyotype in children with AML M2 subtype and the patients in this group mostly have t(8;21). Why loss of sex chromosomes indicates a favorable prognosis is probably because it is accompanied by t(8;21) in the patients.

Adolescent ; Child ; Child, Preschool ; Chromosomes, Human, Pair 21 ; Chromosomes, Human, Pair 8 ; Female ; Humans ; Karyotype ; Leukemia, Myeloid, Acute ; genetics ; mortality ; Male ; Prognosis ; Sex Chromosome Aberrations ; Translocation, Genetic

OBJECTIVETo evaluate the frequency of the nucleophosmin (NPM1) gene and the CCAAT/enhancer binding protein α gene (CEBPA) through polymerase chain reaction (PCR) array in pediatric patients with cytogenetically normal acute myeloid leukemia (CN-AML) and explore the clinical significances of these mutations.

METHODBetween August 2009 and December 2012, 30 children (<16 years old) with newly diagnosed CN-AML were included. The clinical characteristics were analyzed in these patients. PCR combined with direct sequencing was used to detect NPM1, CEBPA gene mutations. All the data were statistically analyzed using SPSS17.0 software.

RESULTThe gene mutations were detected in each of the 30 patients. NPM1 mutation was positive in three patients (10%) with type A mutation, while CEBPA mutation was positive in two patients (6.7%) with double mutations (TAD, bZIP) . Besides, FLT3/ITD mutation was positive in three patients. Patients with NPM1 or FLT3/ITD had a significantly elevated diagnostic WBC count with a median diagnostic WBC count of 102.80×10(9)/L compared with 18.56×10(9)/L for the patients without mutations(t = 2.353, P = 0.043), as well as the marrow blast percentage (94.0% vs. 80.0%, t = 3.804, P = 0.002). The complete remission was achieved in all the 3 patients with NPM1 mutations and 2 patients with CEBPA mutations. All the patients with these mutations also achieved 2-year event-free survival (EFS) and 2-year overall survival (OS), while 2-year EFS and 2-year OS of the other patients were (40.1 ± 11.2)% and (51.8 ± 10.9)% (P = 0.044, 0.091, respectively).

CONCLUSIONNPM1 and CEBPA mutations may indicate a favorable prognosis in pediatric CN-AML.

Adolescent ; CCAAT-Enhancer-Binding Proteins ; genetics ; Child ; Child, Preschool ; DNA Mutational Analysis ; Disease-Free Survival ; Female ; Genotype ; Humans ; Infant ; Leukemia, Myeloid, Acute ; genetics ; mortality ; pathology ; Male ; Mutation ; Nuclear Proteins ; genetics ; Prognosis ; Retrospective Studies ; fms-Like Tyrosine Kinase 3 ; genetics

OBJECTIVE: To investigate the expression of Wilms'tumor 1 () gene in patients with acute myeloid leukemia (AML), and to explore its application in predicting prognosis of AML in patients with wild or mutated nucleophosmin 1() and Fms-like tyrosine kinase 3-internal tandem duplication (). METHODS: One hundred and sixty-seven newly diagnosed AML patients(exclued M3 type) were enrolled in this study. The survival of patients were analyzed with Kaplan-Meier method. The clinical data, laboratory findings and the survival of patients were analyzed and compared between patients with high expression (high- group) and those with low expression (low- group), as well as among the patients with or wild type and mutants. RESULTS: The overall response rates (ORR) in high- and low- groups were 65.9% (83/126) and 95.1% (39/41), respectively (<0.01). Compared with the low- group, the high- group had lower 2-y overall survival (OS) rate (46.1% vs. 75.2%, <0.05) and 2-y disease free survival (DFS) rate (43.5% vs. 68.5%, <0.05). After induction chemotherapy, the patients with decreased gene expression ≥ 1log was associated with higher ORR and 2-y OS rate (all <0.05), but the advantage of 2-y DFS rate was not shown (>0.05). In patients with wild type, the high- group had inferior ORR and 2-y OS rate (all <0.05), while in the patients with wild type, the high- group had inferior ORR, 2-y OS rate and 2-y DFS rate (all <0.05). In patients with or FLT3 -ITD mutations, the expression had no significantly predicting values in treatment efficacy and survival (all >0.05). CONCLUSIONS gene overexpression indicated poor prognosis of AML patients; the patients with decreased gene expression ≥ 1 log after the first induction therapy show better prognosis than those with<1 log. The gene expression level at diagnosis can be used as an unfavorable prognostic factor for AML patients with or wild types.
Disease-Free Survival ; Gene Expression Profiling ; Humans ; Kaplan-Meier Estimate ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; mortality ; Mutation ; Nuclear Proteins ; genetics ; Prognosis ; WT1 Proteins ; genetics ; fms-Like Tyrosine Kinase 3 ; genetics