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

The study was to investigate the biological characteristics of hyperleucocyte acute leukemia (HAL) and its clinical significance. Immunophenotyping was performed in 48 HAL patients and 73 NHAL patients by three-color flow cytometry analysis using CD45/SSC gating, meanwhile the cytogenetic analysis was performed in 74 patients. The results showed that as compared with NHAL group, HAL group had lower proportion of eryth-lineage in bone marrow (P < 0.05); in AML, the CD14 expression of HAL group was apparently higher than that of NHAL group (P < 0.05); in ALL, HAL group had higher expression of CD8 and lower expression of CD22, cCD79a compared with NHAL group (P < 0.05); the two groups had no significant difference in expression of special lineage antigens and overlapping lineage antigens (P > 0.05). The CR rate of HAL group was lower than that of NHAL group. It is concluded that bone marrow inhibition of HAL group is more severe than that of NHAL group. In AML, monocytic leukemia is easier to become into HAL than other leukemias. In ALL, T-lineage antigens of HAL group are more easily expressed than those of NHAL group; the leukemia cells of HAL group are naiver than those of NHAL group, meanwhile the prognosis of HAL is poor.
Adolescent ; Adult ; Aged ; CD79 Antigens ; biosynthesis ; genetics ; CD8 Antigens ; biosynthesis ; genetics ; Child ; Child, Preschool ; Female ; Humans ; Immunophenotyping ; Leukemia, Myeloid, Acute ; drug therapy ; mortality ; pathology ; Leukocyte Count ; Lipopolysaccharide Receptors ; biosynthesis ; genetics ; Male ; Middle Aged ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; mortality ; pathology ; Prognosis ; Sialic Acid Binding Ig-like Lectin 2 ; biosynthesis ; genetics

BACKGROUND: The t (8; 21) (q22; q22), which produces the fusion gene AML1/ETO, is associated with relatively good prognosis and, in particular, with a good response to cytosine arabinoside. Analysis of t (8; 21) positive leukemic blasts has shown characteristic morphological and immunological features. We performed this study to investigate the incidence of AML1/ETO rearrangement in adult acute myelogenous leukemia (AML), especially in M2 subtype, to make a comparison of clinical, morphological and immunophenotypic characteristics between AML1/ETO rearrangement positive and negative group in patients with AML and to analyze the correlation with other biological parameters. METHODS: From May 1995 to Sept. 2000, fifty-nine patients with AML, including twenty-nine AML-M2, were studied. RNAs were extracted from leukemic cells and reverse transcriptase mediated polymerase chain reaction (RT-PCR) for AML1/ETO fusion transcript was done. Chromosome study, immunophenotypic and clinical characteristics were analyzed and statistical analysis was done. RESULTS: The incidence of AML1/ETO fusion transcripts was 22.0% in AML and 44.8% in AML-M2. The morphologic finding of bone marrow in AML-M2 showed higher incidence of Auer rods, large blast with prominent golgi and abnormal granules in AML1/ETO positive patients. There was no significant difference of immunophenotype. AML patients with AML1/ETO had a tendency of higher complete remission rate (81.8% vs 56.6%, p=0.13). The overall survival (median; 82.2 weeks vs 34.4 weeks, p=0.02) and progression free survival (median; 50.9 weeks vs 20.4 weeks, p=0.02) of AML1/ETO positive group were longer than those of the negative group in AML. AML-M2 patients with AML1/ETO rearrangement had also a tendency of longer overall survival and progression free survival, although there was no significant difference between both groups. CONCLUSION: Our data suggest that AML1/ETO rearrangement is detected frequently in AML, especially M2, and is a favorable prognostic factor. Thus, molecular diagnostic approaches should be used routinely to identify patients with this genetic subtype of AML.
Adolescent ; Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols/administration & dosage ; Base Sequence ; Cohort Studies ; Confidence Intervals ; Core Binding Factor Alpha 2 Subunit ; Female ; *Gene Expression Regulation, Leukemic ; *Genetic Predisposition to Disease ; Humans ; Leukemia, Myeloid, Acute/drug therapy/*genetics/*mortality ; Male ; Middle Aged ; Molecular Sequence Data ; Oncogene Proteins, Fusion/*genetics ; Prognosis ; Prospective Studies ; Reference Values ; Reverse Transcriptase Polymerase Chain Reaction/methods ; Sensitivity and Specificity ; Statistics, Nonparametric ; Survival Analysis ; Transcription Factors/*genetics ; Translocation, Genetic ; Treatment Outcome