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1.  Acute myeloid leukaemia with t(8;21) associated with “occult” mastocytosis. Report of an unusual case and review of the literature 
Journal of Clinical Pathology  2004;57(3):324-328.
Approximately 20% of patients with systemic mastocytosis (SM) have an associated haematological, clonal, non-mast cell lineage disease, and most exhibit an associated myelogenous neoplasm. This report describes a 48 year old man with acute myeloid leukaemia (AML) and a type t(8;21) cytogenetic abnormality. Associated bone marrow mastocytosis (a defined subtype of SM) was only detected after successful polychemotherapy in the state of bone marrow aplasia, and persisted after complete remission of AML. The diagnosis of mastocytosis was based on the demonstration of a multifocal dense mastocytic infiltrate. The atypical mast cells showed prominent spindling and an aberrant immunophenotype, with coexpression of tryptase, chymase, KIT, and CD25—which is expressed only on neoplastic (not normal) mast cells. In addition, the transforming somatic mutation D816V of the c-kit gene was detected. Re-examination of the pretherapeutic (initial) bone marrow revealed a slight diffuse increase in partially spindle shaped mast cells also exhibiting an abnormal immunophenotype, with CD25 expression, although compact mastocytic infiltrates were not detected. Because the D816V mutation was detected in the initial bone marrow specimen, strict application of three minor diagnostic criteria (spindling, CD25, D816V) enabled a diagnosis of SM-AML to be confirmed retrospectively in the initial bone marrow tissue.
PMCID: PMC1770248  PMID: 14990611
mastocytosis; bone marrow; CD25; acute myeloid leukaemia; mast cell tryptase; occult; mastocytosis; c-kit mutation
2.  P43. Therapy-related leukemia after lung cancer therapy 
Therapy-related leukemia defined by the World health Organization 2008 classification scheme of hematolymphoid tumors including therapy-related acute myeloid neoplasms (t-AML), myelodysplastic syndrome (t-MDS). They occur as late complication of cytotoxic chemotherapy, radiation therapy and molecular target agents therapy against primary neoplasms. Recently, for lung cancer chemotherapy, new anti-cancer agent and molecular target agents are increased and more intensification chemotherapy performed. We report that we reviewed t-AML cases who survived from lung cancer and suffered t-AML.
We intended for multiple neoplasms 298 cases including hematological malignancy. We reviewed 39 multiple neoplasms including the lung cancer. In 39 cases, second neoplasms that were acute myeloid leukemia cases were two cases. All patients were followed up until death or until December 2013. Survival was measured from the diagnosis of multiple cancer to time of death or last contact. We investigated cytogenetic abnormality, therapy, clinical outcome, prognosis, and cause of death.
There were four cases multiple neoplasms including lung cancer and acute myeloid leukemia. In four cases, metachronous type and primary neoplasms that were lung cancer were two cases. These two cases were diagnosed therapy-related leukemia by WHO 2008 classification. Two of cases were male and female one respectively, primarily diagnosis were small cell carcinoma (male case), squamous carcinoma (female case). Previous cases, he treated operation and radiotherapy, another cases treated operation and chemotherapy that included cisplatin and camptotecin. One case (male case) was acute promyelocytic leukemia (t-APL) that had t(15;17) and PMLRARα, another case (female case) was M2 type (French-American-British Classification) that indicated t(8;21) abnormality. About t-APL, he treated by all-trans retinoic acid and he reached complete response. T-M2 type, he treated by chemotherapy included daunorbicin and Ara-C(DC3-7), she did not achieve complete response. About prognosis, t-APL case, he lived 1 month after complete response, he died by lung cancer, t-AML cases, she lived 25 months after partial response, she died by t-AML relapse and refractory for salvage chemotherapy.
As the number of lung cancer survivors increased due to improvement in chemotherapy, clinician must more take attention of therapy-related leukemia and myelodysplastic syndrome by previous treatments.
PMCID: PMC4367799
Lung cancer; leukemia
3.  Prognosis and Therapy When Acute Promyelocytic Leukemia and Other “Good Risk” Acute Myeloid Leukemias Occur as a Therapy-Related Myeloid Neoplasm 
Treatment for a pre-existing condition using chemotherapy, radiation therapy, immunosuppressive therapy, or a combination of these modalities may lead to the devastating complication of therapy-related myelodysplastic syndrome or acute myeloid leukemia (t-MDS/t-AML), collectively known as therapy-related myeloid neoplasm (t-MN). This disorder arises as a direct consequence of mutational events induced by the primary treatment. The outcomes for these patients have been historically poor compared to people who develop AML de novo. Currently comprising 10–20% of all cases of AML, t-MN is relatively resistant to conventional leukemia therapies, and is associated with s ort survival times. Median life expectancy from diagnosis is about 8–10 months in most series. Although the spectrum of cytogenetic abnormalities in t-AML is similar to AML de novo, the frequency of unfavorable cytogenetics, such as a complex karyotype or deletion or loss of chromosomes 5 and/or 7, is considerably higher in t-MN. Two distinct groups of patients with t-MN have been described. The more common subtype, seen in about 75% of patients, typically occurs 5–7 years after first exposure to alkylating agents or radiation, is often preceded by a myelodysplastic syndrome (MDS), and is frequently accompanied by clonal cytogenetic abnormalities such as the loss of all or part of chromosomes 5 or 7. Mutations of the P53 tumor suppressor gene are also common. The risk is related to total cumulative exposure over time to alkylating agents. In contrast, among individuals who develop t-AML after treatment with topoisomerase II inhibitors, the latency period to the development of t-AML is often only 1–3 years, antecedent MDS is rare, and gene rearrangements involving MLL at 11q23 or RUNX1/AML1 at 21q22 are common. It is now well recognized that APL and other subtypes of AML with balanced translocations sometimes occur as therapy-related myeloid neoplasms (t-MN) in patients who have previously received cytotoxic therapy or ionizing radiation therapy (RT). The most of this review will focus on these “good risk” leukemias, i.e. those with APL or inv(16)/t(16;16) or t(8;21).
PMCID: PMC3152454  PMID: 21869918
4.  Hematopoietic Stem Cell Expansion and Distinct Myeloid Developmental Abnormalities in a Murine Model of the AML1-ETO Translocation 
Molecular and Cellular Biology  2002;22(15):5506-5517.
The t(8;21)(q22;q22) translocation, which fuses the ETO gene on human chromosome 8 with the AML1 gene on chromosome 21 (AML1-ETO), is one of the most frequent cytogenetic abnormalities associated with acute myelogenous leukemia (AML). It is seen in approximately 12 to 15% of AML cases and is present in about 40% of AML cases with a French-American-British classified M2 phenotype. We have generated a murine model of the t(8;21) translocation by retroviral expression of AML1-ETO in purified hematopoietic stem cells (HSC). Animals reconstituted with AML1-ETO-expressing cells recapitulate the hematopoietic developmental abnormalities seen in the bone marrow of human patients with the t(8;21) translocation. Primitive myeloblasts were increased to approximately 10% of bone marrow by 10 months posttransplant. Consistent with this observation was a 50-fold increase in myeloid colony-forming cells in vitro. Accumulation of late-stage metamyelocytes was also observed in bone marrow along with an increase in immature eosinophilic myelocytes that showed abnormal basophilic granulation. HSC numbers in the bone marrow of 10-month-posttransplant animals were 29-fold greater than in transplant-matched control mice, suggesting that AML1-ETO expression overrides the normal genetic control of HSC pool size. In summary, AMLI-ETO-expressing animals recapitulate many (and perhaps all) of the developmental abnormalities seen in human patients with the t(8;21) translocation, although the animals do not develop leukemia or disseminated disease in peripheral tissues like the liver or spleen. This suggests that the principal contribution of AML1-ETO to acute myeloid leukemia is the inhibition of multiple developmental pathways.
PMCID: PMC133929  PMID: 12101243
5.  A Case of Systemic Mastocytosis Associated with Acute Myeloid Leukemia Terminating as Aleukemic Mast Cell Leukemia after Allogeneic Hematopoietic Stem Cell Transplantation 
Annals of Laboratory Medicine  2013;33(2):125-129.
In up to 40% of systemic mastocytosis (SM) cases, an associated clonal hematological non-mast cell lineage disease such as AML is diagnosed before, simultaneously with, or after the diagnosis of SM. A 40-yr-old man was diagnosed with AML with t(8;21)(q22;q22). Mast cells were not noted at diagnosis, but appeared as immature forms at relapse. After allogeneic hematopoietic stem cell transplantation (HSCT), leukemic myeloblasts were not observed; however, neoplastic metachromatic blasts strikingly proliferated during the state of bone marrow aplasia, and finally, aleukemic mast cell leukemia developed. As the disease progressed, we observed serial morphologic changes from immature mast cells with myeloblasts to only metachromatic blasts and atypical mast cells as mast cell leukemia; FISH analysis showed that the neoplastic mast cells originated from the same clone as the leukemic myeloblasts of AML.
PMCID: PMC3589638  PMID: 23483057
Systemic mastocytosis; Acute myeloid leukemia; Aleukemic mast cell leukemia; Allogeneic hematopoietic stem cell transplantation
6.  Recurrence of a t(8;21)-Positive Acute Myeloid Leukemia in the Form of a Granulocytic Sarcoma Involving Cranial Bones: A Diagnostic and Therapeutic Challenge 
Case Reports in Hematology  2013;2013:245395.
Granulocytic sarcoma (GS) is a rare extramedullary solid tumor defined as an accumulation of myeloblasts or immature myeloid cells. It can cooccur with or precede the acute myeloid leukemia (AML) as well as following treated AML. The incidence of GS in AML patients is 3–8% but it significantly rises in M2 FAB subtype AML. This variety of AML harbors t(8;21) in up to 20–25% of cases (especially in children and black ones of African origin) and, at a molecular level, it is characterized by the generation of a fusion gene known as RUNX1-RUNX1T1. Approximately 10% of M2 AML patients will develop GS, as a consequence, the t(8;21) and the relative transcript represent the most common cytogenetic and molecular abnormalities in GS. FLT3-ITD mutation was rarely described in AML patients presenting with GS. FLT3 ITD is generally strongly associated with poor prognosis in AML, and is rarely reported in patients with t(8;21). GS presentation is extremely variable depending on organs involved; in general, cranial bones and sinus are very rarely affected sites. We report a rare case of GS occurring as a recurrence of a previously treated t(8;21), FLT3-ITD positive AML, involving mastoid bones and paravertebral tissues.
PMCID: PMC3787645  PMID: 24109526
7.  A Multicenter Experience from Lebanon in Childhood and Adolescent Acute Myeloid Leukemia: High rate of Early Death in Childhood Acute Promyelocytic Leukemia 
Acute myeloid leukemia (AML) is a disease with marked heterogeneity. Despite major improvement in outcome, it remains a life-threatening malignancy. Demographic and clinical data on pediatric AML is lacking among the Lebanese population.
We aimed to identify clinical, molecular and outcome data in children with AML in Lebanon.
A retrospective chart review of children with AML diagnosed in three Lebanese hospitals during the past 8 years was conducted.
From May 2002 through March 2010, we identified 24 children with AML in Saint George Hospital University Medical Center, University Medical Center Rizk Hospital, and Abou-Jaoude Hospital. Males and females were equally represented; median age at diagnosis was 9 years (range 1–24) and median WBC at diagnosis was 31 × 109/L (range: 2.1–376 × 109/L). Twenty five percent of patients (6 out of 24) had acute promyelocytic leukemia (APL). Karyotype was normal in 33% of patients; t(8;21), inv (16), t(8;9), t(7;11), t(9;11), complex chromosomal abnormality, monosomy 7 and trisomy 8 were the most common cytogenetic abnormalities encountered. Patients were treated on different European and North American protocols. Twelve patients (50%) achieved morphologic CR after cycle 1, 6 of them (50%) had bone marrow relapse within 11 months from diagnosis. Nine patients underwent allogeneic stem cell transplant, and 3 of them are alive at 5 years post-transplant. Early death rate was 16.6% of patients, mainly those with APL and a presenting WBC > 10 × 109/L. Fifty per cent of APL patients had an early death due to DIC despite starting ATRA therapy. Overall, median survival for AML patients who died from disease progression was 25.8 months (range: 1–60 months). Overall disease-free survival was 30.4%. Patients < 10 years of age had a 50% survival rate compared to 0% in patients > 10 years.
Our report highlights the needs in Lebanon for better supportive care of children with APL, including faster ATRA administration and, aggressive transfusions, easy access to stem cell transplant for high-risk AML patients and the need for a national homogenous treatment strategy for children with AML.
PMCID: PMC4283923  PMID: 25574371
8.  Profile of sapacitabine: potential for the treatment of newly diagnosed acute myeloid leukemia in elderly patients 
Acute myeloid leukemia (AML) is a hematopoietic stem cell disorder that affects approximately 14,000 persons each year in the US. AML occurs at all ages but the incidence increases with age with the median age at diagnosis being 67 years. Advances in the treatment of AML over the past decades have led to improved survival, albeit mostly in younger patients. The prognosis of older patients with this disease over the same time span has not changed much and remains dismal. This review focuses on the epidemiology and characteristics of AML in elderly patients, the rationale for treating elderly AML patients, and the currently available and potential future treatment options such as sapacitabine. Elderly AML patients treated with intensive chemotherapy have a higher mortality rate, and a lower rate of complete remission and overall survival when compared to the younger population. This is due to both the different biology of the disease and the number of patient-specific factors. However, elderly AML patients treated with aggressive chemotherapy can achieve durable remissions, which offer prolonged survival and improved quality of life. Recent data also indicates that elderly AML patients deemed unfit for intensive chemotherapy benefit from leukemia-specific attenuated dose chemotherapy compared to supportive care alone. This has led to renewed interest to look for anti-leukemic therapies designed specifically for older patients. Sapacitabine, a novel oral nucleoside analog, promises good efficacy, favorable toxicity profile, and ease of administration; all of which makes it very appealing. Results from pre-clinical and clinical studies have been very encouraging and sapacitabine is currently being evaluated in a Phase III study, of which the results are eagerly awaited.
PMCID: PMC4018315  PMID: 24851045
AML; elderly; management; sapacitabine
9.  Allogeneic stem cell transplantation for acute myeloid leukemia in first complete remission: a systematic review and meta-analysis of prospective clinical trials 
The optimal treatment of acute myeloid leukemia (AML) in first complete remission (CR1) is uncertain. Current consensus, based on cytogenetic risk, recommends myeloablative allogeneic stem cell transplantation (alloSCT) for poor-risk but not for good-risk AML. AlloSCT, autologous transplant and consolidation chemotherapy are considered of equivalent benefit for intermediate-risk AML. We undertook a systematic review and meta-analysis of prospective trials evaluating alloSCT versus non-alloSCT therapies for AML-CR1.
To quantify relapse-free survival (RFS) and overall survival (OS) benefit of alloSCT for AML in CR1. In subgroup analyses, RFS and OS benefit of alloSCT was determined for good-, intermediate- and poor-risk AML.
Combining the search terms: ‘allogeneic’; ‘acut*’ and ‘leukem*/leukaem*/leucem*/leucaem*/aml’; ‘myelo*’ or ‘nonlympho*’, we searched the PubMed, Embase and Cochrane Registry of Controlled Trials databases in March 2009. 1712 articles were accessed.
Study Selection
Prospective trials assigning adult AML-CR1 patients to alloSCT versus non-alloSCT treatment(s) based on donor availability, and reporting RFS and/or OS outcomes on intent-to-treat, donor versus no-donor basis were identified.
Data Extraction
Two reviewers independently extracted study characteristics, interventions, and outcomes. Hazard ratios (HR) (with 95% CI) were determined.
Data Synthesis
24 trials and 6,007 patients were analyzed. Inter-study heterogeneity was not significant. Fixed effects meta-analysis was performed. HR of relapse or death with alloSCT for AML-CR1 was 0.80 (0.74–0.86). Significant RFS benefit of alloSCT was documented for poor-risk (HR 0.69 (0.57–0.84)) and intermediate-risk AML (HR 0.76 (0.68–0.85)); but not for good-risk AML (HR 1.06 (0.80–1.42)). HR of death with alloSCT for AML-CR1 was 0.90 (0.82–0.97). Significant OS benefit of alloSCT was documented for poor-risk (HR 0.73 (0.59–0.90)) and intermediate-risk AML (HR 0.83 (0.74–0.93)); but not for good-risk AML (HR 1.07 (0.83–1.38)).
AlloSCT has significant RFS and OS benefit for intermediate- and for poor-risk AML, but not for good-risk AML in CR1.
PMCID: PMC3163846  PMID: 19509382
acute myeloid leukemia; allogeneic transplantation; meta-analysis
10.  Acute Myeloid Leukemia with the t(8;21) Translocation: Clinical Consequences and Biological Implications 
The t(8;21) abnormality occurs in a minority of acute myeloid leukemia (AML) patients. The translocation results in an in-frame fusion of two genes, resulting in a fusion protein of one N-terminal domain from the AML1 gene and four C-terminal domains from the ETO gene. This protein has multiple effects on the regulation of the proliferation, the differentiation, and the viability of leukemic cells. The translocation can be detected as the only genetic abnormality or as part of more complex abnormalities. If t(8;21) is detected in a patient with bone marrow pathology, the diagnosis AML can be made based on this abnormality alone. t(8;21) is usually associated with a good prognosis. Whether the detection of the fusion gene can be used for evaluation of minimal residual disease and risk of leukemia relapse remains to be clarified. To conclude, detection of t(8;21) is essential for optimal handling of these patients as it has both diagnostic, prognostic, and therapeutic implications.
PMCID: PMC3100545  PMID: 21629739
11.  Modeling Interactions Between Leukemia-Specific Chromosomal Changes, Somatic Mutations, and Gene Expression Patterns During Progression of Core-Binding Factor Leukemias 
Genes, chromosomes & cancer  2010;49(2):182-191.
In cancer genomes, changes observed during tumor progression can be difficult to separate from non-specific accumulation of cytogenetic changes due to cancer-associated genetic instability. We studied genetic changes occurring over time in cancers presenting with a relatively simple karyotype, namely two related core-binding factor (CBF) acute myeloid leukemias (AMLs), to assess how specific chromosomal changes are selected based on tumor subtype and acquired somatic mutations. Expression profiles for DNA replication/repair genes and the mutation status of KRAS, NRAS, FLT3, and KIT were compared with the karyotypic changes at diagnosis and relapse(s) in 94 cases of inv(16)(p13.1q22)-AML and 82 cases of t(8;21)(q22;q22)-AML. The majority of both AML types demonstrated a simple aneuploid pattern of cytogenetic progression, with highly distinctive patterns of chromosome copy number changes, such as +22 and +13 exclusively in inv(16)-AML and –Y and –X in t(8;21)-AML. Selection of certain cytogenetic changes correlated with particular somatic mutations, such as +8 with RAS mutation, and absence of kinase pathway mutations in t(8;21)-AML with localized deletions at chromosome band 9q22. Alterations in transcript levels of mitotic spindle kinases such as CHEK1, AURKA, and AURKB were associated with the aneuploid progression pattern, particularly in t(8;21) cases. Despite the similarity in the initiating genetics of the two CBF AML types, highly tumor-specific patterns of limited aneuploidy are noted that persist and continue to accumulate at relapse. Thus, activation of genetic instability, possibly through mitotic spindle dysregulation, leads rapidly to selection of advantageous single chromosome aneuploidy.
PMCID: PMC4161977  PMID: 19908318
12.  Minimal Residual Disease-Directed Therapy for Childhood Acute Myeloid Leukemia: Results of the AML02 Multicenter Trial 
The lancet oncology  2010;11(6):543-552.
We sought to improve outcome of childhood acute myeloid leukemia (AML) by applying risk-directed therapy based on the genetic abnormalities of the leukemic cells and measurements of minimal residual disease (MRD) as determined by flow cytometry during treatment.
From October 13, 2002 to June 19, 2008, 232 patients with de novo AML (n=206), therapy- or myelodysplasia-related AML (n=12), or mixed-lineage leukemia (n=14) were enrolled at eight centers. Block, nonblinded randomization, stratified by cytogenetic or morphologic subtype, assigned patients to high-dose (18 g/m2, n=113) or low-dose (2 g/m2, n=117) cytarabine (A), given together with daunorubicin (D) and etoposide (E) (Induction I); achievement of MRD negative status was the primary endpoint. Induction II consisted of ADE with or without gemtuzumab ozogamicin (GO); consolidation therapy included three additional courses of chemotherapy or hematopoietic stem cell transplantation (HSCT). Levels of MRD were used to allocate GO and determine the timing of Induction II; both MRD and genetic abnormalities at diagnosis were used to determine final risk classification. Low-risk patients (n=68) received 5 courses of chemotherapy, whereas high-risk patients (n=79), as well as standard-risk patients (n=69) with matched sibling donors, were eligible for HSCT (performed in 48 high and 8 standard-risk patients). All randomized patients (n=230) were analyzed for the primary endpoint. The other analyses were limited to the 216 patients with AML, excluding mixed-lineage leukemia. This trial, closed to accrual, is registered with, number NCT00136084.
The complete remission rates were 80% (173 of the 216) after Induction I and 94% (203 of 216) after Induction II. Induction failures included two toxic deaths and 10 cases of resistant leukemia. The introduction of high-dose cytarabine did not significantly lower the rate of MRD positivity after Induction I therapy (34% vs. 42%, P=0.17). The cumulative incidences of grade 3 or greater infection were 79.3% ± 4.0% and 75.5% ± 4.2% for patients treated on the high-dose or low-dose arms. The 3-year estimates (± SE) of event-free and overall survival were 63.0% ± 4.1% and 71.1% ± 3.8%, respectively. Achievement of MRD < 0.1% after Induction II identified a large group of patients (80%) with a cumulative incidence of relapse of only 17% ± 3%. Post-Induction I MRD ≥ 1% was the only independent adverse prognostic factor that was statistically significant (P < 0.05) for both event-free (HR, 2.41; CI 1.36–4.26; P=0.003) and overall survival (HR, 2.11; CI 1.09–4.11; P=0.028).
Our findings suggest that the use of targeted chemotherapy and HSCT, in the context of a comprehensive risk-stratification strategy based on genetic features and MRD findings, can improve the outcome of childhood AML.
PMCID: PMC3171799  PMID: 20451454
13.  Esculetin Downregulates the Expression of AML1-ETO and C-Kit in Kasumi-1 Cell Line by Decreasing Half-Life of mRNA 
Journal of Oncology  2015;2015:781473.
One of the most frequent genetic aberrations in acute myeloid leukemia (AML) is chromosomal translocation between AML1/RUNX1 on chromosome 21 and ETO gene on chromosome 8 resulting in the expression of chimeric oncogene AML1-ETO. Although patients with t(8;21) translocation have good prognosis, 5-year survival is observed only in 50% of the cases. AML1-ETO translocation is usually accompanied by overexpression of mutant C-Kit, a tyrosine kinase, which contributes to uncontrolled proliferation of premature blood cells leading to relapse and poor prognosis. We illustrate the potential use of esculetin on leukemic cell line, Kasumi-1, bearing t(8;21) translocation and mutated C-Kit gene. Esculetin decreases the expression of AML1-ETO at both protein and transcript level within 24 hours of treatment. Half-life of AML1-ETO mRNA was reduced from 7 hours to 1.5 hours. Similarly half-life of C-Kit mRNA was reduced to 2 hours from 5 hours in esculetin treated cells. Esculetin also perturbed the expression of ectopically expressed AML1-ETO in U937 cells. The decreased expression of AML1-ETO chimeric gene was associated with increased expression of LAT1 and RUNX3 genes, targets of AML1. We envisage that discovery of a drug candidate which could target both these mutated genes would be a considerable breakthrough for future application.
PMCID: PMC4377501  PMID: 25861270
14.  Ratio of bcl-xshort to bcl-xlong is different in good- and poor-prognosis subsets of acute myeloid leukemia. 
Molecular Medicine  1998;4(3):158-164.
BACKGROUND: Acute myeloid leukemia (AML) is a heterogeneous collection of leukemic disorders ranging from chemotherapy-sensitive subsets [inversion 16 and t(8;21)], which often can be cured with cytosine arabinoside alone, to the most resistant subsets, which can survive even supralethal levels of combination alkylator chemotherapy (cytogenetic subsets monosomy 5 and monosomy 7). MATERIALS AND METHODS: To analyze the expression of BCL-2 family genes, which are expressed in these subsets of AML, we used PCR sequence amplification reactions that are dependent on oligonucleotide primers representing the BH1 and BH2 homology domains to generate the unique regions between BH1 and BH2. These primers are conserved among all members of the BCL-2 gene family and are separated by a 150 nucleotide region sequence between the BH1 and BH2 domains. The PCR products unique to each BCL-2 family member were cloned directionally into sequencing vectors. The identity of the insert of each clone was determined by slotblots of the DNA amplified from individual colonies and by hybridization with radioactive probes specific to the bcl-2, bcl-x, or bax genes. RESULTS: We found that bcl-2 is the predominant member expressed in AML samples with a poor prognosis (-5, -7), whereas the transcripts of bcl-x are higher than those of bcl-2 in the AML samples with a good prognosis [inv16, t(8;21)]. No significant difference in bax expression was detected between AML subsets of good and bad prognosis. The ratio of bcl-xlong, which inhibits apoptosis, to bcl-xshort, which promotes apoptosis, was determined by amplification with a pair of primers specific to bcl-x followed by separation of the PCR product on agarose gels. Bcl-xlong and bcl-xshort appeared as bands of different molecular mass on a molecular weight gel and were visualized by ethidium bromide staining or Southern blot analysis with a bcl-x-specific probe. CONCLUSIONS: We found that the ratio of bcl-x long to bcl-x short was higher in the AML patients with a poor prognosis. These experiments showed that the levels of BCL-2 family members in the leukemia cells of good- and poor-prognosis subsets are different. In addition, novel members of the BCL-2 family were isolated from the cells of AML patients of either prognosis.
PMCID: PMC2230351  PMID: 9562974
15.  Isoform-Specific Potentiation of Stem and Progenitor Cell Engraftment by AML1/RUNX1  
PLoS Medicine  2007;4(5):e172.
AML1/RUNX1 is the most frequently mutated gene in leukaemia and is central to the normal biology of hematopoietic stem and progenitor cells. However, the role of different AML1 isoforms within these primitive compartments is unclear. Here we investigate whether altering relative expression of AML1 isoforms impacts the balance between cell self-renewal and differentiation in vitro and in vivo.
Methods and Findings
The human AML1a isoform encodes a truncated molecule with DNA-binding but no transactivation capacity. We used a retrovirus-based approach to transduce AML1a into primitive haematopoietic cells isolated from the mouse. We observed that enforced AML1a expression increased the competitive engraftment potential of murine long-term reconstituting stem cells with the proportion of AML1a-expressing cells increasing over time in both primary and secondary recipients. Furthermore, AML1a expression dramatically increased primitive and committed progenitor activity in engrafted animals as assessed by long-term culture, cobblestone formation, and colony assays. In contrast, expression of the full-length isoform AML1b abrogated engraftment potential. In vitro, AML1b promoted differentiation while AML1a promoted proliferation of progenitors capable of short-term lymphomyeloid engraftment. Consistent with these findings, the relative abundance of AML1a was highest in the primitive stem/progenitor compartment of human cord blood, and forced expression of AML1a in these cells enhanced maintenance of primitive potential both in vitro and in vivo.
These data demonstrate that the “a” isoform of AML1 has the capacity to potentiate stem and progenitor cell engraftment, both of which are required for successful clinical transplantation. This activity is consistent with its expression pattern in both normal and leukaemic cells. Manipulating the balance of AML1 isoform expression may offer novel therapeutic strategies, exploitable in the contexts of leukaemia and also in cord blood transplantation in adults, in whom stem and progenitor cell numbers are often limiting.
The truncated "a" isoform of AML1 is shown to have the capacity to potentiate stem and progenitor cell engraftment, both of which are required for successful clinical transplantation.
Editors' Summary
Blood contains red blood cells (which carry oxygen round the body), platelets (which help the blood to clot), and white blood cells (which fight off infections). All these cells, which are regularly replaced, are derived from hematopoietic stem cells, blood-forming cells present in the bone marrow. Like all stem cells, hematopoietic stem cells self-renew (reproduce themselves) and produce committed progenitor cells, which develop into mature blood cells in a process called hematopoiesis. Many proteins control hematopoiesis, some of which are called transcription factors; these factors bind to DNA through their DNA-binding domain and then control the expression of genes (that is, how DNA is turned into proteins) through particular parts of the protein (their transcription regulatory domains). An important hematopoietic transcription factor is AML1—a protein first identified because of its involvement in acute myelogenous leukemia (AML, a form of blood cancer). Mutations (changes) in the AML1 gene are now known to be present in other types of leukemia, which are often characterized by overproliferation of immature blood cells.
Why Was This Study Done?
Because of AML1′s crucial role in hematopoiesis, knowing more about which genes it regulates and how its activity is regulated could provide clues to treating leukemia and to improving hematopoietic cell transplantation. Many cancer treatments destroy hematopoietic stem cells, leaving patients vulnerable to infection. Transplants of bone marrow or cord blood (the cord that links mother and baby during pregnancy contains peripheral blood stem cells) can replace the missing cells, but cord blood in particular often contains insufficient stem cells for successful transplantation. It would be useful, therefore, to expand the stem cell content of these tissues before transplantation. In this study, the researchers investigated the effect of AML1 on self-renewal and differentiation of hematopoietic stem and progenitor cells in the laboratory (in vitro) and in animals (in vivo). In particular, they have asked how two isoforms (closely related versions) of AML1 affect the ability of these cells to grow and differentiate (engraft) in mice after transplantation.
What Did the Researchers Do and Find?
The researchers artificially expressed AML1a and AML1b (both isoforms contain a DNA binding domain, but only AML1b has transcription regulatory domains) in mouse hematopoietic stem and progenitor cells and then tested the cells' ability to engraft in mice. AML1a-expressing cells engrafted better than unaltered cells and outgrew unaltered cells when transplanted as a mixture. AML1b-expressing cells, however, did not engraft. In vitro, AML1a-expressing cells grew more than AML1b-expressing cells, whereas differentiation was promoted in AML1b-expressing cells. To investigate whether the isoforms have the same effects in human cells, the researchers measured the amount of AML1a and AML1b mRNA (the template for protein production) made by progenitor cells in human cord blood. Although AML1b (together with AML1c, an isoform with similar characteristics) mRNA predominated in all the progenitor cell types, the relative abundance of AML1a was greatest in the stem and progenitor cells. Furthermore, forced expression of AML1a in these cells improved their ability to divide in vitro and to engraft in mice.
What Do These Findings Mean?
These findings indicate that AML1a expression increases the self-renewal capacity of hematopoietic stem and progenitor cells and consequently improves their ability to engraft in mice, whereas AML1b expression encourages the differentiation of these cell types. These activities are consistent with the expression patterns of the two isoforms in normal hematopoietic cells and in leukemic cells—the mutated AML made by many leukemic cells resembles AML1a. Because the AML1 isoforms were expressed at higher than normal levels in these experiments, the physiological relevance of these findings needs to be confirmed by showing that normal levels of AML1a and AML1b produce similar results. Nevertheless, these results suggest that manipulating the balance of AML1 isoforms made by hematopoietic cells might be useful clinically. In leukemia, a shift toward AML1b expression might slow the proliferation of leukemic cells and encourage their differentiation. Conversely, in cord blood transplantation, a shift toward AML1a expression might improve patient outcomes by expanding the stem and progenitor cell populations.
Additional Information.
Please access these Web sites via the online version of this summary at
Wikipedia has pages on hematopoiesis and hematopoietic stem cells (note: Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The US National Cancer Institute has a fact sheet on bone marrow and peripheral blood stem cell transplantation (in English and Spanish) and information for patients and professionals on leukemia (in English)
The American Society of Hematology provides patient information about blood diseases, including information on bone marrow and stem cell transplantation
PMCID: PMC1868041  PMID: 17503961
16.  Plasma Exosomes as Markers of Therapeutic Response in Patients with Acute Myeloid Leukemia 
Purpose: Exosomes isolated from the plasma of newly diagnosed acute myeloid leukemia (AML) patients have elevated protein and transforming growth factor-beta 1 (TGF-β1) contents and inhibit natural killer (NK) cell cytotoxicity (Haematologica 96, p. 1302, 2011). A potential role of exosomes in predicting responses to chemotherapy (CT) was evaluated in AML patients undergoing treatment.
Experimental Design: Plasma was obtained from AML patients at diagnosis (n = 16); post-induction CT (n = 9); during consolidation CT (n = 10); in long-term remission (Lt-CR, n = 5); and from healthy volunteers (n = 7). Exosomes were isolated by size-exclusion chromatography and ultracentrifugation. The exosomal protein, soluble TGFβ-1 levels (ELISA), and the TGF-β1 profiles (western blots) were compared among patients’ cohorts. The results were correlated with the patients’ cytogenetic profile, percentage of leukemic blast, and outcome.
Results: At diagnosis, protein and TGF-β1 levels were higher (p < 0.009 and p < 0.004) in AML than control exosomes. These values decreased after induction CT (p < 0.05 and p < 0.004), increased during consolidation CT (p < 0.02 and p < 0.005), and normalized in Lt-CR. While TGF-β1 and protein levels tracked one another, TGF-β1 pro-peptide, latency-associated peptide (LAP), or mature TGF-β1 differentially decorated exosomes isolated before, during, and after CT. Only TGF-β1 pro-peptide was seen in exosomes of controls or Lt-CR patients. During consolidation CT, exosomes carried TGF-β1 pro-peptide, LAP, and low levels of mature TGF-β1. NK cell co-incubation with AML exosomes carrying all three TGF-β1 forms induced down-regulation of NKG2D expression.
Conclusion: Changes in exosomal protein and/or TGF-β1 content may reflect responses to CT. The exosomal profile may suggest the presence of residual disease in patients considered to have achieved complete remission.
PMCID: PMC3989594  PMID: 24782865
acute myelogenous leukemia; exosomes; TGF-β1; protein levels; chemotherapy
17.  High Expression of c-kit mRNA Predicts Unfavorable Outcome in Adult Patients with t(8;21) Acute Myeloid Leukemia 
PLoS ONE  2015;10(4):e0124241.
The reason that a certain subgroup of acute myeloid leukemia (AML) patients with t(8;21) translocation (generating the AML1/ETO fusion gene) displays a poor survival remains elusive. The proto-oncogene c-kit is expressed in approximately 80% of AML cases. The kinase domain mutation of the c-kit gene, one of the most common gain-of-function mutations associated with t(8;21) AML, predicts higher relapse risk and poor prognosis. However, the role of c-kit high expression in t(8;21) AML remains poorly understood. Here we evaluated the prognostic significance of c-kit expression levels in AML patients. The mRNA expression of c-kit was determined by real-time quantitative reverse transcription PCR in 132 adult AML patients. Patients were grouped into quartiles according to c-kit expression levels (Q1–Q4, each quartile containing 25% of patients) and divided into c-kit high (Q4; n = 33) and c-kit low (Q1–Q3; n = 99). High c-kit expression was associated with AML1/ETO-positive and with c-kit mutation. Of note, 35.8% of the AML1/ETO-positive AML patients carrying wild-type c-kit expressed high levels of c-kit, suggesting that other factors are involved in c-kit overexpression. High c-kit expression was associated with inferior overall and event-free survival in AML1/ETO-positive patients and was independently predictive for overall and event-free survival in multivariate analyses in a c-kit mutation-independent manner. Thus, high c-kit expression serves as a reliable molecular marker for poor prognosis, supporting a pathogenetic role of c-kit signaling in AML1/ETO-positive AML. AML1/ETO-positive patients with high c-kit expression might benefit from early treatment modifications and molecular target therapies.
PMCID: PMC4393018  PMID: 25860287
18.  Timed sequential chemotherapy with concomitant Granulocyte Colony-Stimulating Factor for high-risk acute myelogenous leukemia: a single arm clinical trial 
BMC Cancer  2002;2:12.
The timed-sequential chemotherapy regimen consisting of etoposide, mitoxantrone and cytarabine (EMA) is an effective therapy for relapsed or refractory acute myelogenous leukemia (AML). We postulated that granulocyte colony-stimulating factor (G-CSF) might enhance the cytotoxicity of EMA by increasing the proportion of leukemic blasts in S-phase. We added G-CSF to EMA (EMA-G) for therapy of advanced high-risk AML patients.
High-risk AML was defined as refractory, relapsed or secondary to either an antecedent hematologic disorder or exposure to cytotoxic agents. The patients were treated with one course of EMA-G consisting of mitoxantrone and cytarabine on days 1–3, and etoposide and cytarabine on days 8–10. G-CSF was started on day 4 and continued until absolute neutrophil count recovered.
Thirty patients were enrolled. The median age was 51 years (range, 25–75). Seventeen (61%) patients had unfavorable cytogenetic karyotypes. Twenty (69%) patients had secondary AML. Ten (34%) had relapsed disease. Four (14%) had refractory AML. Three (10%) patients died from febrile neutropenia and sepsis. Major non-hematologic toxicity included hyperbilirubimenia, renal insufficiency, mucositis, diarrhea, nausea and vomiting, skin rash. A complete remission was achieved in 13 (46%) patients. Median overall survival was 9 months (range, 0.5–66). Median relapse-free survival (RFS) for those who had a CR was 3 months (range, 0.5–63) with RFS censored at the time of allogeneic bone marrow transplantation or peripheral stem cell transplantation for 6 of the patients.
EMA-G is a safe and efficacious option for induction chemotherapy in advanced, high-risk AML patients. The activity of EMA may be increased if applied in patients with less advanced disease.
PMCID: PMC113260  PMID: 12019034
19.  Dose Escalation of Lenalidomide in Relapsed or Refractory Acute Leukemias 
Journal of Clinical Oncology  2010;28(33):4919-4925.
Lenalidomide is effective in myeloma and low-risk myelodysplastic syndromes with deletion 5q. We report results of a phase I dose-escalation trial of lenalidomide in relapsed or refractory acute leukemia.
Patients and Methods
Thirty-one adults with acute myeloid leukemia (AML) and four adults with acute lymphoblastic leukemia (ALL) were enrolled. Lenalidomide was given orally at escalating doses of 25 to 75 mg daily on days 1 through 21 of 28-day cycles to determine the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD), as well as to provide pharmacokinetic and preliminary efficacy data.
Patients had a median age of 63 years (range, 22 to 79 years) and a median of two prior therapies (range, one to four therapies). The DLT was fatigue; 50 mg/d was the MTD. Infectious complications were frequent. Plasma lenalidomide concentration increased proportionally with dose. In AML, five (16%) of 31 patients achieved complete remission (CR); three of three patients with cytogenetic abnormalities achieved cytogenetic CR (none with deletion 5q). Response duration ranged from 5.6 to 14 months. All responses occurred in AML with low presenting WBC count. No patient with ALL responded. Two of four patients who received lenalidomide as initial therapy for AML relapse after allogeneic transplantation achieved durable CR after development of cutaneous graft-versus-host disease, without donor leukocyte infusion.
Lenalidomide was safely escalated to 50 mg daily for 21 days, every 4 weeks, and was active with relatively low toxicity in patients with relapsed/refractory AML. Remissions achieved after transplantation suggest a possible immunomodulatory effect of lenalidomide, and results provide enthusiasm for further studies in AML, either alone or in combination with conventional agents or other immunotherapies.
PMCID: PMC3020696  PMID: 20956622
20.  POU4F1 is associated with t(8;21) acute myeloid leukemia and contributes directly to its unique transcriptional signature 
The t(8;21)(q22;q22) translocation, present in ~5% of adult acute myeloid leukemia (AML) cases, produces the AML1/ETO fusion protein. Dysregulation of the POU domain-containing transcription factor POU4F1 is a recurring abnormality in t(8;21) AML. Here, we show that POU4F1 over-expression is highly correlated with, but not caused by AML1/ETO. AML1/ETO markedly increases the self-renewal capacity of myeloid progenitors from murine bone marrow or fetal liver and drives expansion of these cells in liquid culture. POU4F1 is neither necessary nor sufficient for these AML1/ETO-dependent properties, suggesting that it contributes to leukemia through novel mechanisms. To identify targets of POU4F1, we performed gene expression profiling in primary mouse cells with genetically defined levels of POU4F1 and identified 140 differentially expressed genes. This expression signature was significantly enriched in human t(8;21) AML samples and was sufficient to cluster t(8;21) AML samples in an unsupervised hierarchical analysis. Among the most highly differentially expressed genes, half are known AML1/ETO targets, implying that the unique transcriptional signature of t(8;21) AML is, in part, attributable to POU4F1 and not AML1/ETO itself. These genes provide novel candidates for understanding the biology and developing therapeutic approaches for t(8;21) AML.
PMCID: PMC2868953  PMID: 20376082
POU4F1; AML1/ETO; acute myeloid leukemia; gene expression profiling
21.  Genome-wide co-occupancy of AML1-ETO and N-CoR defines the t(8;21) AML signature in leukemic cells 
BMC Genomics  2015;16(1):309.
Many leukemias result from chromosomal rearrangements. The t(8;21) chromosomal translocation produces AML1-ETO, an oncogenic fusion protein that compromises the function of AML1, a transcription factor critical for myeloid cell differentiation. Because of the pressing need for new therapies in the treatment of acute myleoid leukemia, we investigated the genome-wide occupancy of AML1-ETO in leukemic cells to discover novel regulatory mechanisms involving AML-ETO bound genes.
We report the co-localization of AML1-ETO with the N-CoR co-repressor to be primarily on genomic regions distal to transcriptional start sites (TSSs). These regions exhibit over-representation of the motif for PU.1, a key hematopoietic regulator and member of the ETS family of transcription factors. A significant discovery of our study is that genes co-occupied by AML1-ETO and N-CoR (e.g., TYROBP and LAPTM5) are associated with the leukemic phenotype, as determined by analyses of gene ontology and by the observation that these genes are predominantly up-regulated upon AML1-ETO depletion. In contrast, the AML1-ETO/p300 gene network is less responsive to AML1-ETO depletion and less associated with the differentiation block characteristic of leukemic cells. Furthermore, a substantial fraction of AML1-ETO/p300 co-localization occurs near TSSs in promoter regions associated with transcriptionally active loci.
Our findings establish a novel and dominant t(8;21) AML leukemia signature characterized by occupancy of AML1-ETO/N-CoR at promoter-distal genomic regions enriched in motifs for myeloid differentiation factors, thus providing mechanistic insight into the leukemic phenotype.
Electronic supplementary material
The online version of this article (doi:10.1186/s12864-015-1445-0) contains supplementary material, which is available to authorized users.
PMCID: PMC4434520  PMID: 25928846
AML; Runx1; t(8;21); Chromosomal translocation; Myeloid cell differentiation; Epigenetic control
22.  HLA-Identical Sibling Allogeneic Transplants versus Chemotherapy in Acute Myelogenous Leukemia with t(8;21) in First Complete Remission: Collaborative Study Between the German AML Intergroup and CIBMTR 
We studied the role of HLA-matched sibling hematopoietic cell transplantation (HCT) in treating t(8;21) AML in first remission. Outcomes of 118 patients receiving HCT and reported to the Center for International Blood and Marrow Transplant Research were compared with 132 similar patients receiving chemotherapy selected from eight German AML Intergroup multicenter trials. Characteristics of the cohorts were similar except that chemotherapy recipients were significantly older. To adjust for time to treatment bias, outcomes were compared using left-truncated Cox regression models. Transplants were associated with higher treatment-related mortality [relative risk (RR) 6.76, 95% confidence interval (CI) 2.95–15.45, p<0.001], lower relapse (RR 0.47, 95% CI 0.25–0.85, p=0.01) and similar relapse-free survival (p=0.2). Loss of sex chromosomes (LOS) in addition to t(8;21) negatively impacted overall survival in patients receiving chemotherapy. Patients without LOS experienced shorter survival after HCT comparing to chemotherapy (RR 3.05, p=0.02), whereas patients with LOS had similar survival regardless of postremission therapy. In both cohorts, white blood cell count (WBC) at diagnosis > 25 x109/L was associated with a higher relapse risk (RR=2.09, p=0.03), lower relapse-free (RR=1.9, p=0.008) and overall survival (RR=1.91, p=0.01). In this cohort of patients with t(8;21) AML , HCT did not improve overall survival, since reduction of relapse was offset by high transplant-related mortality. In the group without LOS, survival after chemotherapy was far superior to HCT. These results suggest that patients with t(8;21) AML without poor prognostic factors have higher rates of survival after chemotherapy as a post remission therapy compared to HCT.
PMCID: PMC2531160  PMID: 18215779
t(8;21); AML; hematopoietic stem cell transplantation; chemotherapy
23.  The 5’ flanking region of miR-378 is hypomethylated in acute myeloid leukemia 
Background: Aberrant expression of miR-378 has been observed in various malignancies including acute myeloid leukemia (AML). However, the mechanism regulating of miR-378 expression remains unknown. This study was aimed to investigate miR-378 methylation and to explore its clinical significance in AML. Methods: Methylation status of miR-378 5’-flanking region was investigated by real-time quantitative methylation-specific PCR (RQ-MSP) and bisulfite-sequencing PCR (BSP). The expression of miR-378 was evaluated by real-time quantitative PCR (RQ-PCR). The correlation between expression of miR-378 and 5’-flanking region methylation was analyzed using 5-aza-2’-deoxycytidine (5-aza-dC) treatment. Results: miR-378 5’-flanking region was significantly hypomethylated in AML patients compared to controls (median 0.109 vs. 0.058) (P=0.048). miR-378 expression was correlated with miR-378 5’-flanking region in leukemic cell line treated with 5-aza-dC, but not in AML patients. The level of miR-378 hypomethylation significantly increased in M2 subtype compared to other subtypes. Moreover, patients with t(8;21) harbored the highest level of miR-378 hypomethylation. However, there was no significant difference in overall survival between patients with high and low miR-378 hypomethylation. The association of miR-378 expression with methylation was not observed in AML patients, but miR-378 expression in THP-1 line was increased while methylation status of miR-378 5-flanking region was decreased after 5-aza-dC treatment. Conclusions: Our findings suggest that miR-378 is reactivated by demethylation after 5-aza-dC treatment. 5’-flanking region of miR-378 is hypomethylated in AML especially in those with t(8;21).
PMCID: PMC4502996  PMID: 26191124
miR-378; hypomethylation; acute myeloid leukemia; 5-aza-dC
24.  The G516T CYP2B6 Germline Polymorphism Affects the Risk of Acute Myeloid Leukemia and Is Associated with Specific Chromosomal Abnormalities 
PLoS ONE  2014;9(2):e88879.
The etiology of acute myeloid leukemia (AML) underlies the influence of genetic variants in candidate genes. The CYP2B6 enzyme detoxifies many genotoxic xenobiotics, protecting cells from oxidative damage. The CYP2B6 gene is subjected to a single-nucleotide polymorphism (G516T) with heterozygotes (GT) and homozygotes (TT) presenting decreased enzymatic activity. This case-control study aimed to investigate the association of CYP2B6 G516T polymorphism with the susceptibility of AML and its cytogenetic and clinical characteristics. Genotyping was performed on 619 AML patients and 430 healthy individuals using RCR-RFLP and a novel LightSNip assay. The major finding was a statistically higher frequency of the variant genotypes (GT and TT) in patients compared to the controls (GT:38.8% vs 29.8% and TT:9.3% vs 5.3% respectively) (p<0.001). More specifically, a significantly higher frequency of GT+TT genotypes in de novo AML patients (46.6%) and an immensely high frequency of TT in secondary AML (s-AML) (20.5%) were observed. The statistical analysis showed that the variant T allele was approximately 1.5-fold and 2.4-fold higher in de novo and s-AML respectively than controls. Concerning FAB subtypes, the T allele presented an almost 2-fold increased in AML-M2. Interestingly, a higher incidence of the TT genotype was observed in patients with abnormal karyotypes. In particular, positive correlations of the mutant allele were found in patients carrying specific chromosomal aberrations [-7/del(7q), -5/del(5q), +8, +21 or t(8;21)], complex or monosomal karyotypes. Finally, a strikingly higher frequency of TT genotype was also observed in patients stratified to the poor risk group. In conclusion, our results provide evidence for the involvement of the CYP2B6 polymorphism in AML susceptibility and suggest a possible role of the CYP2B6 genetic background on the development of specific chromosomal aberrations.
PMCID: PMC3933334  PMID: 24586425
25.  Improved outcome of pediatric patients with acute megakaryoblastic leukemia in the AML-BFM 04 trial 
Annals of Hematology  2015;94(8):1327-1336.
Despite recent advances in the treatment of children with acute megakaryoblastic leukemia (AMKL) using intensified treatment protocols, clear prognostic indicators, and treatment recommendations for this acute myeloid leukemia (AML) subgroup are yet to be defined. Here, we report the outcome of 97 pediatric patients with de novo AMKL (excluding Down syndrome [DS]) enrolled in the prospective multicenter studies AML-BFM 98 and AML-BFM 04 (1998-2014). AMKL occurred in 7.4 % of pediatric AML cases, at younger age (median 1.44 years) and with lower white blood cell count (mean 16.5 × 109/L) as compared to other AML subgroups. With 60 ± 5 %, children with AMKL had a lower 5-year overall survival (5-year OS; vs. 68 ± 1 %, Plog rank = 0.038). Yet, we achieved an improved 5-year OS in AML-BFM 04 compared to AML-BFM 98 (70 ± 6 % vs. 45 ± 8 %, Plog rank = 0.041). Allogeneic hematopoietic stem cell transplantation in first remission did not provide a significant survival benefit (5-year OS 70 ± 11 % vs. 63 ± 6 %; PMantel-Byar = 0.85). Cytogenetic data were available for n = 78 patients. AMKL patients with gain of chromosome 21 had a superior 5-year OS (80 ± 9 %, Plog rank = 0.034), whereas translocation t(1;22)(p13;q13) was associated with an inferior 5-year event-free survival (38 ± 17 %, Plog rank = 0.04). However, multivariate analysis showed that treatment response (bone marrow morphology on day 15 and 28) was the only independent prognostic marker (RR = 4.39; 95 % CI, 1.97–9.78). Interestingly, GATA1-mutations were detected in six patients (11 %) without previously known trisomy 21. Thus, AMKL (excluding DS) remains an AML subgroup with inferior outcome. Nevertheless, with intensive therapy regimens, a steep increase in the survival rates was achieved.
Electronic supplementary material
The online version of this article (doi:10.1007/s00277-015-2383-2) contains supplementary material, which is available to authorized users.
PMCID: PMC4488462  PMID: 25913479
Acute megakaryoblastic leukemia; AMKL; FAB M7; AML-BFM 98; AML-BFM 04

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