The Value Of Maintenance Hypomethylating Agents In Patients With Medium And Low-risk Acute Myeloid Leukemia

Objective:To investigate the value of decitabine maintenance therapy in patients with medium and low-risk acute myeloid leukemia(AML)Methods:The clinical data of newly diagnosed middle and low risk AML patients admitted to the second affiliated Hospital of Anhui Medical University from December 2016 to June 2021 were analyzed retrospectively.83 patients with AML who were still in remission after induction consolidation therapy were divided into maintenance group(n=36)and control group(n=47)according to whether they received maintenance therapy or not.Maintenance therapy was given 20mg/(m~2*d),intravenous drip,D1-5,as a course of treatment,every 3 months for a cycle,continuous use of 6 courses of treatment,the control group was only observed and detected regularly.Follow-up is completed by telephone or by viewing outpatient or in-patient medical records.The primary observation index was the overall survival time(OS),and the secondary observation indicators included recurrence-free survival(RFS),minimal residual disease(MRD),tolerance,cellular immune function and survival-related risk factors.Results:The MRD negative rate in the maintenance treatment group increased from41.7%to 47.2%,while the MRD negative rate in the control group decreased from48.9%to 25.5%in the same period.There was no statistical difference in the negative state of MRD between the two groups after consolidation therapy(χ~2=0.655,P=0.513,P>0.05),but there was significant difference in MRD negative after maintenance therapy(χ~2=2.042,P=0.041,P<0.05).The results of paired test of MRD negative before and after treatment in the same group showed that there was no significant difference in the maintenance treatment group(χ~2=0.426,P=0.670,P>0.05),but there was significant difference in MRD in the control group(χ~2=2.200,P=0.028,P<0.05),suggesting that more patients in the control group lost MRD negative.The median RFS of patients in maintenance treatment group and control group was37.6(35.3-40.6)months and 24.3(21.6-30.3)months(P=0.002).The median OS of patients in maintenance treatment group and control group was 53.7months(46.3-61.1)months and 26.9(23.9-33.1)months(P=0.005).The results of univariate and multivariate Cox regression analysis showed that only MRD after consolidation treatment(HR=0.390,P<0.05)and treatment method(HR=0.293,P<0.05)affected OS.After maintenance therapy,the levels of CD3+T cells,CD8+T cells and NK cells in peripheral blood increased significantly,while the level of regulatory T cells decreased significantly in maintenance treatment group.Conclusion:The maintenance therapy of dexitabine significantly prolonged the survival of patients with medium and low risk AML.The mechanism may be that more patients in the treatment group remained MRD negative,inhibited the regulation of T cell proliferation,and induced and enhanced the cytotoxic effect of CD8+T cells on tumor antigen.