Abstract: Objective To compare the clinical efficacy and safety among decitabine combined standard induction regimen at different time points in treatment of acute myeloid leukemia(AML).Methods The clinical data of 45 AML patients enrolled from June 2012 to March 2018 were collected.The differences of clinical outcome and adverse events among the patients treated with decitabine sequentially or simultaneously with "3+7" regimen were analyzed. Results For 45 patients,the overall response rate (ORR)[complete response (CR)+CR with incomplete hematological recovery (CRi)+partial response (PR)] was 75.56%,CR/CRi was up to 55.6%(25/45);The ORR in the sequential and simultaneous group was 75.9% and 75.0%, respectively.However,there is no significant difference was observed among the two groups (P=0.842).Median followed-up time was 8 months,the overall survival(OS)of sequential group and simultaneous group was (7.25±4.61) months vs (8.48±5.42) months(P=0.447).Adverse events in the two groups were similar, mainly including cytopenia and infection,which were more common in the early stages of treatment. After the first induction treatment, the 3/4 grade myelosuppression time in the sequential group was longer than that in the simultaneous treatment group, mainly manifested as agranulocytosis, which was 15.0 d vs 8.5 d (P<0.001),and the incidence of perianal, gastrointestinal and skin and soft tissue infection was increased.The median number of suspended red blood cells and platelet infused was higher in the sequential group(P>0.05).Conclusion Whenever in sequential group or simultaneous group,the induction efficacy of decitabine combined with chemotherapy were similar,but the simultaneous group had better safety, the duration of myelosuppression was shorter, mainly manifested as shortening of the granulosis period, less blood cell infusion, and a lower incidence of infection.

Key words: acute myeloid leukemia(AML), decitabine(DAC), myelosuppression