Clinical Characteristics And Prognostic Analyze Of Acutemyeloid Leukemia Cases With MLL Gene Rearrangement

Objective:To investigate the clinical characteristics and prognosis of acute myoloid leukimia cases with MLL gene rearrangement.Methods:51de novo MLL gene rearrangement AML (non M3) cases hospitalized during2006-2009were compared with51cases without MLL gene rearrangement (the control group) admitted in the same period, all of which were diagnosed in accordance with MICM criteria. Before induction chemotherapy, pretreatment was used to decrease the quantity of WBC when the count was higher than50×109/L. The induction regimen included triple therapy which consisted of homoharringtonine、standard-dose cytarabine and daunorubicin(HAD regimen) or mitoxantrone(HAM regimen) and double therapy which consisted of daunorubicin or mitoxantrone/idarubicin with standard-dose cytarabine. The patients who achived complete remission received allo-HSCT when they had the indication for transplantation and were successful in HLA matching. The rest received1～4cycles of mitoxantrone or daunorubicin/idarubicin with ieter-dose cytarabine (1.0～2.0g/m2·q12h·3d) for the purpose of consolidation chemotherapy. The refractory or relapsed patients were treated with CAG(G-CSF、aclacinomycin and cytarabine) or FLAG(fludarabine、cytarabine and G-CSF)regimen. The clinical features、cytomorphology、immunophenotype、cytogenetics、early death、complete remission rate、recurrence rate、overall survival and response to allo-HSCT of AML patients with MLL gene rearrangement were investigated and compared with the control group at the same time.Results:1. Compared with the control group, the WBC coun、LDH levels、 percentage of peripheral blood blast cells in patients with MLL gene rearrangement increased notably (P<0.05); otherwise, the percentage of M4/M5in these patient was much higher according to FAB classification (P<0.05). 2. The expression of monocytic antigens such as CD14、CD64、CD15、CD11b in patients with MLL gene rearrangement were much higer than the control group (P <0.05).3.(1) The total CR rate of AML patients with MLL gene rearrangement was51.0%. Among the patients who achieved CR in this group,10cases received allo-HSCT and11cases relapsed in half a year, with the recurrence rate of42.3%. Meanwhile, the total CR rate of the control group was72.5%. Among which19cases received allo-HSCT and8cases relapsed in half a year, with the recurrence rate of21.6%. It can be seen that the AML patients with MLL gene rearrangement gained lower CR rate and were easier to relapse compared with the control group (P<0.05).(2) Among the patients with MLL gene rearrangement,14cases survived(6cases after HSCT,8cases after chemotherapy) and37cases died at the end of the follow-up, resulting in32.3%of OS rate. By contrast,29cases survived(14cases after HSCT,15cases after chemotherapy) and22cases died in the control group, resulting in62.5%of OS rate. Therefore, the OS of AML patients with MLL gene rearrangement was lower than that in the control group obviously(P<0.05).(3) Among the patients with MLL gene rearrangement, the cases who received allo-HSCT acquired3-year OS of60.0%vs26.7%in cases with simple chemotherapy, resulting in a higher OS obviously(P<0.05).Conclusions:The AML with MLL gene rearrangement is highly correlated with M4/M5, the patients of which show poor response to chemotherapy, high recurrence rate and poor prognosis. Hematopoietic stem cell transplantation may be a reasonable treatment principle to improve these patients’survival situation.