Abstract: Background　Patients with moderate to high-risk myelodysplastic syndrome（MDS） and elderly patients with acute myeloid leukemia（AML） have poor prognosis with poor tolerance of intensive conventional chemotherapy.Decitabine，a demethylated drug，may be a new promising option for them.Objective　To investigate the clinical efficacy and adverse reactions of decitabine monotherapy in the treatment of moderate-to-high-risk MDS cases and elderly cases of AML.Methods　Twenty patients （10 cases of moderate-to-high-risk MDS and 10 elderly cases of AML） who were admitted to Department of Hematology，Beijing Jishuitan Hospital from April 2016 to July 2019 were enrolled.All of them were treated with decitabine at 20 mg•（m2）-1•d-1×5 d.Follow-up was conducted once every 28 days starting from the first course of treatment till October 13，2019 or the patient's death.Routine blood test and bone marrow aspiration were performed for each follow-up.Results　Of the 20 patients，6 and 10 achieved complete response（CR） and partial response（PR），respectively，1 had stable disease（SD），1 had progressive disease（PD），and 2 died.The disease control rate was 85.0%（17/20），and the overall response rate was 80.0% （16/20）.Of the 18 elderly patients，6 and 8 achieved CR and PR，respectively，1 had SD，with a disease control rate of 83.3%（15/18），and an overall response rate of 77.8%（14/18），in particular，6 were aged over 70，but 5 of them reached CR and 1 reached SD.The rate of CR did not vary notably by diagnosis，sex，ECOG score，white blood cells，high-risk MDS，or having underlying disease（P>0.05）.There was significant difference in CR rate between those who received at least 3 courses of treatment and those did not（P<0.05）.The overall survival of 20 patients ranged from 2 to 27 months.The 1-year overall survival rate was 30.0%（6/20），and the 2-year survival rate was 20.0%（4/20）.Median progression-free survival was（14.1±3.4） months，and the median survival was（17.4±2.5） months.There were 15 cases（75.0%） of grade Ⅲ to Ⅳ myelosuppression，15 of pulmonary infection and 2 of bloodstream infection.Conclusion　Decitabine monotherapy may achieve high disease control rate in moderate-to-high-risk MDS cases and elderly cases of AML.And the main adverse reactions are myelosuppression and infection.

Key words: Myelodysplastic syndromes；Leukemia, myeloid, acute；Decitabine；Treatment outcome

摘要： 背景　中高危骨髓增生异常综合征（MDS）和老年急性髓系白血病（AML）预后差，不能耐受高强度的传统化疗，去甲基化药物地西他滨成为新的治疗选择。目的　观察地西他滨单药治疗中高危MDS和老年AML的临床疗效及不良反应。方法　选取2016年4月—2019年7月北京积水潭医院血液科收治并应用地西他滨单药治疗的中高危MDS和老年AML患者20例为研究对象，均应用地西他滨单药20 mg•（m2）-1•d-1×5 d治疗。从地西他滨第1疗程开始随访，每28 d随访1次，随访内容包括血常规检查、骨髓穿刺，随访终点事件为死亡，随访截止时间为2019-10-13。结果　20例患者中完全缓解（CR）6例、部分缓解（PR）10例、病情稳定（SD）1例、病情进展（PD）1例、死亡2例，疾病控制率85.0%（17/20），总有效率80.0%（16/20）。18例老年患者中CR 6例、PR 8例、SD 1例、疾病控制率83.3%（15/18），总有效率77.8%（14/18）。其中70岁以上老年患者为6例，5例达到CR，1例SD。不同诊断、性别、美国东部肿瘤协作组体力状态（ECOG）评分、白细胞计数、是否高危、是否合并基础疾病患者CR率比较，差异无统计学意义（P>0.05）；是否接受≥3个疗程治疗患者CR率比较，差异有统计学意义（P<0.05）。20例患者总生存时间2~27个月。1年总生存率为30.0%（6/20）、2年生存率为20.0%（4/20）。中位无进展生存期为（14.1±3.4）个月。中位生存时间为（17.4±2.5）个月。15例患者出现Ⅲ~Ⅳ度骨髓抑制，15例出现肺部感染，2例出现血流感染。结论　地西他滨单药治疗中高危MDS和老年AML疾病控制率高，不良反应主要为骨髓抑制和感染。

关键词: 骨髓增生异常综合征；白血病, 髓样, 急性；地西他滨；治疗结果