Frequency of FLT3 Internal Tandem Duplications in Adult Syrian Patients with Acute Myeloid Leukemia and Normal Karyotype

Objective: Activating mutations of the fms-like tyrosine kinase 3 gene (FLT3) by internal tandem duplications (ITDs) in the juxtamembrane domain (JMD) have been reported in ~30% of adult acute myeloid leukemia (AML) patients with cytogenetically normal karyotype (CN). However, FLT3/ITD mutations are frequently accompanied with leukocytosis, high percentage of blasts in bone marrow (BM), and increased the risk of treatment failure in AML patients. FLT3-ITD mutated AML patients mainly with normal karyotype have higher relapse probability and shorter duration of complete remission (CR) after chemotherapy, so FLT3-ITD mutation is considered as an independent poor prognostic factor in AML. Methods: FLT3-ITD and FLT3-KTD were studied by polymerase chain reaction (PCR) and restriction fragment length polymorphism- PCR (RFLP-PCR) in 44 adults AML patients with cytogenetically normal karyotype (AML-CN) at diagnosis to characterize FLT3 status. The results were correlated with the prognostic factors. Results: In this study, FLT3-ITD mutations were identified in 7 (15.9%) of the 44 AML-CN patients. Among the 7 patients with FLT3/ITD mutations, 6 patients revealed a typical ITDs mutation (fragment size was 329 bp) and one patient showed untypical ITD mutation (fragment size was ~400 bp). Whereas 37 patients (61.7%) were FLT3-ITD. None of all AML-CN patients examined showed FLT3-KTD mutations. Conclusions: Our results support that FLT3-ITD are independent adverse prognostic factors for elderly AML-CN patients and are associated with low overall survival (OS), low rate of CR, high relapse rate (RR), and high percentage of BM blast at diagnosis. We concluded, FLT3 mutation analysis should be performed as a routine test in AML-CN patients.     

Fms-Like Tyrosine Kinase 3 Mutations in Childhood Acute Leukemias and their Association with Prognosis

Introduction: In recent years, Fms-like tyrosin kinase (FLT) 3 has been the subject of several studies as a prognostic marker. Objective: In this study, the presence of FLT3 mutations in childhood acute leukemias patients and their association with prognosis were investigated. Materials and Methods: A total of 120 patients, 80 with acute lymphoblastic leukemia (ALL) and 40 with acute myeloblastic leukemia (AML), were included. Real time polymerase chain reaction methods on a high resolution melting analysis device were used to determine FLT3 mutations. Results: FLT3/ITD (internal tandem duplication) mutations were found in 6 (7.5%) of the patients with ALL and in 9 (22.5%) of those with AML, whereas no FLT3/TKD (trans kinase domain) mutation was evident in any case. There was no difference between the ALL patients positive and negative for FLT3/ITD with regard to overall survival (OS), event free survival (EFS) and disease free survival (DFS) (p=0.37, p=0.23, p=0.023, respectively). However, in FLT3/ITD positive and negative AML patients, there was a statistically significant difference in OS (p=0.0041), but not EFS and DFS (p=0.09, p=0.095, respectively). A significant difference was found between age and FLT3/ITD positivity (p=0.036). Conclusion: We found that FLT3/ITD positivity increased with age and that it was associated with decrease in OS in AML patients, providing further evidence that it is an independent factor negatively influencing prognosis.     

Prognostic Factors in Acute Promyelocytic Leukemia: A Retrospective Study of 67 Cases

In a cohort of 67 adult patients with newly diagnosed untreated acute promyelocytic leukemia (APL), the initial clinical and biological parameters were submitted to multivariate analysis for potential prognostic significance. Median age of the patients was 40 years and the hematologic characteristics of the patients were those regularly seen. Complete remission (CR) was achieved in 43 cases (64%). Fourteen patients died within 4 weeks of diagnosis, due to severe hemorrhage. Factors predictive of hemorrhagic death in the multivariate analysis were hyperuricemia (p = 0.001), splenomegaly (p = 0.009), anemia (p = 0.02), high serum levels of LDH (p = 0.02), increased prothrombin time (p = 0.04), and hypercreatininemia (p = 0.05). Pretreatment patient characteristics for poor prognosis and achieving CR were hyperuricemia (p = 0.0002), splenomegaly (p = 0.01), anemia (p = 0.02), and lymphadenopathy (p = 0.04). The median disease-free survival (DFS) was 15.6 months. Poor prognostic factors for DFS were hyperuricemia (p = 0.007), and splenomegaly (p = 0.03). Maintenance chemotherapy had no statistically significant impact on CR duration. Median survival duration was 10 months. Poor prognostic factors for survival were hyperuricemia (p = 0.0005), and elevated serum LDH levels (p = 0.01).     

索拉非尼靶向治疗FLT3-ITD阳性急性髓系白血病

FMS样酪氨酸激酶-3（FLT3）近膜区的的内部串联重复序列（FLT3 internal tandem duplications, FLT3/ITD）突变是急性髓系白血病中常见的基因突变类型,与急性髓系白血病（acute myeloid leukemia, AML）的发生发展及不良预后有密切关系。目前多靶点酪氨酸激酶抑制剂药物的研究成为近几年来治疗FLT3/ITD阳性AML研究的热点,尤其是对多靶点抑制剂索拉非尼（sorafenib）的研究较为深入。本文通过学习国内外相关文献资料,综述酪氨酸激酶抑制剂索拉非尼在治疗FLT3/ITD 阳性AML的疗效和作用机制方面的研究进展。     

Acute Myeloid Leukemia in the Elderly: A Critical Review of Therapeutic Approaches and Appraisal of Results of Therapy

In the elderly, acute myeloid leukemia (AML) is characterized by a poorer prognosis than in younger patients, due to either host related factors (poor performance status, co-morbid diseases, organ function impairment) or the biology of leukemia itself (high incidence of adverse cytogenetic abnormalities, high frequency of preceding myelodysplastic syndromes, intrinsic resistance to cytotoxic drugs). Current therapeutic results are mostly unsatisfactory and studies reporting high rates of complete remission are probably influenced by selection biases as suggested by the low rate of elderly patients inclusion into cooperative trials. Availability of intensive support including hematopoietic growth factors could stimulate clinicians to manage an increasing number of elderly patients with AML with aggressive programs. However, chemotherapy in the elderly is difficult, costly and usually associated with high morbidity and mortality rate. Therefore, all efforts should be made to identify those subset of elderly patients in whom aggressive treatment may result in a true improvement of disease free and overall survival. The critical analysis of our five years experience, as reported here, seems to suggest that older AML patients displaying unfavourable prognostic factors at diagnosis (i.e., adverse karyotype and high serum LDH levels), but clinically eligible for intensive chemotherapy, do not actually benefit from an aggressive approach. A blind attempt to treat these patients aggressively may be associated with a life threatening toxicity not counterbalanced by an actual survival advantage. We suggest therefore that aggressive treatment should be reserved for elderly AML cases in whom the presence of good prognostic factors at diagnosis predicts that the loss of some patients due to toxicity may be balanced by the achievement of a substantial proportion of long term survivors. Finally, given the biological and clinical heterogeneity of elderly AML patients, a more precise prognostic categorization of these patients would be particularly useful in interpreting future therapeutic results.     

Prognostic Relevance of DNMT3A,FLT3 and NPM1 Mutations in Syrian Acute Myeloid Leukemia Patients

Objective: Among all types of hematological neoplasms, acute myeloid leukemia (AML) has the highest death rate. Recently, cytogenetic and molecular genetics are crucial in the management, as a consequence of their effect on AML pathogenesis, classification, risk-stratification, prognosis and treatment. Methods: 100 Syrian adults with Normal Karyotype (NK) newly diagnosed  AML patients were included in this study, all cases confirmed histologically and immunohistochemically. Patients were divided into six subgroups using flow cytometry and cytological results. Polymerase chain reaction (PCR) was performed on exon 11-12 for FMS-like tyrosine kinase-3 internal tandem duplication (FLT3-ITD), exon 12 for Nucleophosmin1 (NPM1), and exon 23 for DNA methyltransferase 3A (DNMT3A) using target primers, the electropherograms were analyzed for gene mutations by comparing with the reference DNA sequence. Data were compared and aligned with different sequences using the NCBI BLAST Assembled Genomes tool. Results: FLT3-ITD, NPM1 and DNMT3A were detected in 24%, 22 % and 4%  patients respectively. M2 subtype had the most frequent incidence of diagnosis in AML. FLT3-ITD mutation patients had the highest mean of death cases, while the DNMT3A mutation patients had the lowest. On the other hand, the highest mean of remission was in patients with NPM1 mutation and the lowest in the carriers of the FLT3-ITD mutation. It was observed that the mean relapsed patients with FLT3-ITD and DNMT3A mutation was 3.4 and 2 months respectively, with no significant differences between (FLT3-ITD and DNMT3A) carriers and non-carriers relapsed. On the contrary,  the mean relapsed for NPM1 mutation carriers was 2.4  months with significant statistical differences. The mean survival time for patients with FLT3-ITD and NPM1  mutation was 5.9 months and 5.85 months respectively, with significant correlation. Between it was 5.88 months in DNMT3A patients with no significant differences. Finally, It was noted that the mean event free survival (EFS) of FLT3-ITD mutation patients was 4.818 months and the mean EFS of NPM1 mutation patients was 4.805 months, with significant statistical differences (p<0.05) between the mutation patients and non-mutated patients regarding to EFS, While this mean was not statistically significant in patients carrying DNMT3A mutation. Conclusion: Patients with FLT3-ITD and NPM1 mutations have the worst prognosis, where the presence of those mutations was significantly related to overall survival (OS) and EFS. Our study reflects that DNMT3A was not an extremely bad prognostic effect as an independent factor. We can declare according to this study that genetic mutation and variants detection could easily be incorporated into the regimen evaluation of AML patients.     

Molecular Involvement and Prognostic Importance of Fms-like Tyrosine Kinase 3 in Acute Myeloid Leukemia

AML (Acute myeloid leukemia) is a form of blood cancer where growth of myeloid cells occurs in the bonemarrow. The prognosis is poor in general for many reasons. One is the presence of leukaemia-specific recognitionmarkers such as FLT3 (fms-like tyrosine kinase 3). Another name of FLT3 is stem cell tyrosine kinase-1 (STK1),which is known to take part in proliferation, differentiation and apoptosis of hematopoietic cells, usually beingpresent on haemopoietic progenitor cells in the bone marrow. FLT3 act as an independent prognostic factor forAML. Although a vast literature is available about the association of FLT3 with AML there still is a need of abrief up to date overview which draw a clear picture about this association and their effect on overall survival.     

FLT3 Inhibition as Therapy in Acute Myeloid Leukemia: A Record of Trials and Tribulations

Acute myeloid leukemia (AML) is a hematologic malignancy with a poor prognosis. Approximately one quarter of the patients with AML also carry an internal tandem duplication (ITD) mutation in the gene encoding FMS-like tyrosine kinase 3 (FLT3), which has a significantly deleterious impact on prognosis. The ITD mutation renders FLT3 constitutively active and leads to uncontrolled proliferation of the leukemic blast. Over the course of the last decade, a variety of compounds have been developed in preclinical and clinical studies as potent inhibitors of FLT3. Many of the earlier agents under investigation, such as lestaurtinib, midostaurin, and sunitinib, were initially developed as inhibitors of other tyrosine kinases and as targeted therapies in a variety of malignancies. These compounds have been demonstrated to have some efficacy in clinical trials of AML, mainly manifesting as transient decreases in circulating blasts correlating with effective in vivo suppression of the FLT3 target. Nevertheless, the cumbersome pharmacokinetics of some compounds and the suboptimal specificity and potency of others have limited their therapeutic efficacy. In the last few years, newer, more potent and specific agents have been under investigation, with the leading example being AC220. This agent has shown significant promise in early phases of clinical investigation, and is currently in more advanced clinical trials. Hope remains that FLT3 inhibition will be become an effective therapeutic adjunct to our current treatment approach to AML.     

CDC6在成人急性白血病中的表达与临床意义

目的：探讨细胞分裂周期蛋白6（Cell Division Cycle6，CDC6）在急性白血病中的异常表达及其临床意义。方法：以CDC6 mRNA为分子标志物，应用巢式PCR技术，分别检测未缓解及完全缓解的急性白血病患者和非肿瘤患者外周血待测基因的表达。结果：标志基因CDC6阳性表达率分别为，对照组27．66％，急性白血病完全缓解组56．25％，急性白血病未缓解组100％；CDC6在对照组的阳性表达率显著低于其它各组（P〈0．05）；在急性白血病未缓解组的表达率显著高于急性白血病完全缓解组（P〈0．05）。结论：CDC6的异常高表达与急性白血病细胞增殖有关．可作为成人急性白血病病情监测的分子生物学指标。     

CMOAP方案治疗成人初治急性淋巴细胞白血病疗效观察

目的：观察CMOAP(环磷酰胺、米托蒽醌、长春新碱、阿糖胞苷、泼尼松)方案治疗成人初治急性淋巴细胞白血病(ALL)的疗效。方法：对42例成人初治ALL患者采用CMOAP方案进行诱导治疗。环磷酰胺0.6 g·m-2·d-1iv，第1天、第15天；米托蒽醌5mg／div第1天～第5天；长春新碱1.5 mg·m-2·d-1iv，第1天、第8天、第15天、第22天；阿糖胞苷(100～150)mg·m-2·d-1iv，第1天～第7天；泼尼松1mg·kg-1·d-1po，第1天～第8天，d(15)后逐渐减量。结果：42例成人初治ALL患者34例1个疗程获完全缓解(CR)，3例2个疗程获CR，CR率为88.1％，有效率为92.6％。结论：CMOAP方案可作为治疗成人初治ALL首选方案之一。     

IL-2和IL-10在急性髓性白血病患儿血清中的水平及其临床意义

目的 观察急性髓性白血病患儿血清中白细胞介素(IL)-2和IL-10的水平及其临床意义.方法 纳入急性髓性白血病患儿80例,其中初发27例、缓解25例、复发28例.同期纳入体检健康者50例患儿为对照组.应用酶联免疫吸附法(Elisa)检测血清中IL-2和IL-10水平.结果 与对照组比较,急性髓性白血病患儿血清中IL-2水平显著降低,IL-10水平显著升高(P<0.01).血清中IL-2和IL-10水平与急性髓性白血病患儿的年龄、性别、骨髓中白血病细胞比例、FAB分型无显著相关性(P>0.05).急性髓性白血病初发和复发组患儿血清中IL-2和IL-10水平与缓解组比较,有统计学差异(P<0.01).急性髓性白血病初发与复发患儿血清中IL-2和IL-10水平比较,无统计学意义(P>0.05).结论 急性髓性白血病患儿血清中IL-2和IL-10水平变化明显,与该病的预后联系密切.     

Detection of TET2 Mutation in Patients with De Novo Acute Myeloid Leukemia: A Mutation Analysis of 51 Iranian Patients

Acute myeloid leukemia (AML) is a heterogeneous clonal disease that is considered to originate from hematopoietic stem cells, which are characterized by impaired myelopoiesis and blast proliferation. TET oncogene family member 2 (TET2) mutations are frequent in myeloid malignancies and several studies have assessed the clinical importance of TET2 mutations. However, its frequency ratio has not yet been fully clarified. Method: Hence, our study was aimed to analyze TET2mut in patients with de-novo AML and their association with clinical, molecular characteristics and Nucleophosmin 1 (NPM1), Fms-like tyrosine kinase 3 (FLT3), CCAAT Enhancer Binding Protein Alpha (CEBPA) and Wilms’ tumor protein (WT1) gene expression. Fifty-one Iranian patients were screened by polymerase chain reaction (PCR) and direct sequencing to evaluate TET2 mutations frequency. Results: Out of all patients, 10 mutations in 8 patients (15.6%) were detected and closely associated with higher age and higher hemoglobin levels (p-value <0.05). Although FLT3, NPM1 and CEBPA gene expression did not show any significant correlation with TET2mut, cytogenetically normal acute myeloid leukemia (CN-AML)  patients appear to bear TET2mut more frequently with lower platelet counts. Monocyte-lineages leukemia has seemed to be more linked with TET2mut in these patients. Conclusion: Our study suggests the frequency of TET2mut in our study (15.6%) is in line with previous studies and reveals the critical role of TET2 in myeloid transformation, especially in leukemia with monocytic subtypes.     

急性髓系白血病患者HOX11基因的表达及意义

目的 探讨HOX11基因在急性髓系白血病(acute myeloid leukemia,AML)中的表达及对预后的影响,为个体化治疗提供依据.方法 应用多重巢式RT-PCR方法对73例初诊AML患者的融合基因进行检测,对HOX11基因表达阳性和阴性的患者进行标准治疗后的疗效进行分析.结果 在预后良好组、预后中等组及预后不良组AML患者的标准治疗中,HOX11基因阳性表达患者的第一疗程完全缓解率(complete remission rate)并不高于阴性表达的患者(P＞0.05),而复发或死亡率(relapse or mortality rate)与HOX11基因阴性表达的患者比较差异有统计学意义(P＜0.05).结论 HOX11基因的表达可能影响AML患者的预后.     

Monosomal Karyotypes among 1147 Chinese Patients with Acute Myeloid Leukemia: Prevalence,Features and Prognostic Impact

A monosomal karyotype (MK), defined as ≥2 autosomal monosomies or a single monosomy in the presenceof additional structural abnormalities, was recently identified as an independent prognostic factor conveying anextremely poor prognosis in patients with acute myeloid leukemia (AML). In the present study, after excludingpatients with t(15;17), t(8;21), inv(16) and normal karyotypes, 324 AML patients with cytogenetic abnormalitieswere the main subject of analysis. The incidences of MK were 13% in patients aged 15 to 60 years and 18% inthose between 15 and 88 years old. MK was much more prevalent among elderly patients (p < 0.001) and wassignificantly associated with the presence of -7, -5, del(5q), abn12p, abn17p, -18 or 18q-, -20 or 20q- and CK (forall p < 0.001 except for abn12p p=0.009), and +8 or +8q was less frequent in MK+ AML(p=0.007). No correlationwas noted between monosomal karyotype and FAB subtype (p > 0.05); MK remained significantly associatedwith worse overall survival among patients with complex karyotype (p= 0.032); A single autosomal monosomycontributed an additional negative effect in OS of patients with structural cytogenetic abnormalities (P=0.008).This report presents the prevalence, feature and prognostic impact of MK among a large series of Chinese AMLpatients from a single center for the first time.     

Prognostic Significance of Immunoglobulin and T Cell Receptor Gene Rearrangements in Patients with Acute Myeloid Leukemia: Taiwan Experience

We investigated the prognostic significance of lymphoid antigen receptor gene rearrangement in patients with newly diagnosed acute myeloid leukemia (AML). Thirty-nine patients were included in the study. Clonal gene rearrangement of immunoglobulin heavy chain (IgH) and T cell receptor β chain (TCRβ) was found in leukemic cells in 11 (28.2%) and 10 (25.6%) patients, respectively. Five (12.8%) had both IgH and TCRβ gene rearrangements. Three of the seven (42.9%) B-lymphoid marker-positive and eight of the 32 (25%) B-lymphoid marker-negative patients had clonal IgH gene rearrangements. Five of the 11 (45.5%) T-lym-phoid marker-positive and 5 of the 28 (17.9%) T-lymphoid marker-negative patients had clonal TCRβ gene rearrangements. All patients were treated with similar regimens. The complete remission rate (62.5% vs 65.296, p=1.000) and median survival (13 vs 14 months, p=4.366) were similar in patients with and without clonal IgH or TCRβ gene rearrangements. In conclusion, while clonal rearrangements of IgH or TCRβ genes were found in AML patients, they did not appear to effect the prognosis.     

Prognostically Significant Fusion Oncogenes in Pakistani Patients with Adult Acute Lymphoblastic Leukemia and their Association with Disease Biology and Outcome

Background and objectives: Chromosomal abnormalities play an important role in genesis of acute lymphoblastic leukemia (ALL) and have prognostic implications. Five major risk stratifying fusion genes in ALL are BCR-ABL, MLL-AF4, ETV6-RUNX11, E2A-PBX1 and SIL-TAL1. This work aimed to detect common chromosomal translocations and associated fusion oncogenes in adult ALL patients and study their relationship with clinical features and treatment outcome. Methods: We studied fusion oncogenes in 104 adult ALL patients using RT-PCR and interphase-FISH at diagnosis and their association with clinical characteristics and treatment outcome. Results: Five most common fusion genes i.e. BCR-ABL (t 9; 22), TCF3-PBX1 (t 1; 19), ETV6-RUNX1 (t 12; 21), MLL-AF4 (t 4; 11) and SIL-TAL1 (Del 1p32) were found in 82/104 (79%) patients. TCF3-PBX1 fusion gene was associated with lymphadenopathy, SIL-TAL positive patients had frequent organomegaly and usually presented with a platelets count of less than 50 x109/l. Survival of patients with fusion gene ETV6-RUNX1 was better when compared to patients harboring other genes. MLL-AF4 and BCR-ABL positivity characterized a subset of adult ALL patients with aggressive clinical behaviour and a poor outcome. Conclusions: This is the first study from Pakistan which investigated the frequency of 5 fusion oncogenes in adult ALL patients, and their association with clinical features, treatment response and outcome. Frequencies of some of the oncogenes weredifferent from those reported elsewhere and they appear to be associated with distinct clinical characteristics and treatment outcome. This information will help in the prognostic stratification and risk adapted management of adult ALL patients.