骨髓增生异常性肿瘤(myelodysplastic neoplasms, MDS)是起源于造血干经细胞和（或）祖细胞的一组异质性髓系肿瘤。欧美流行病学调查揭示，MDS发病率为（4~5）/10万，且随年龄增长而增加，中位诊断年龄为73~76岁。根据世界卫生组织（World Health Organization， WHO）2001年诊断标准，在2004年至2007年对中国上海地区约390万人的调查中发现，MDS平均发病率为1.51/10万，中位发病年龄为62岁，其中约1/3的患者会转化为急性髓系白血病（acute myeloid leukemia，AML）；53%的患者因血细胞减少引发的感染、出血或合并症而死亡。老年MDS患者由于合并症较多、体质较弱，无论是治疗选择、疾病转归都有其特点。老年MDS患者的白细胞计数、血红蛋白水平和骨髓原始细胞比例均稍高于年轻患者，而其中性粒细胞计数和血小板计数较年轻患者明显增高。此外，老年MDS患者发生基因突变的数量更多，平均每例患者可发生1.8个基因突变，其中以ASXL1、TET2、SF3B1、STAG2、SRSF2和TP53突变更多见；而年轻患者的突变数量为平均每例患者发生1.2个基因突变，且以U2AF1、ASXL1和RUNX1突变较常见。异基因造血干细胞移植（allogeneic hematopoietic stem cell transplantation, allo-HSCT）是MDS唯一的根治疗法，年轻患者可行清髓性移植，但老年患者只能行减低剂量预处理（reduced-intensity conditioning, RIC）的allo-HSCT治疗。老年MDS患者的自然病程和预后差异很大，由年龄(>70岁)、脆弱指数、分子国际预后评分系统（international prognosis scoring system, IPSS）分组等组成的MDS综合预后评分，能更好地预测MDS患者化疗的耐受性和治疗不良反应。本共识根据国内外老年MDS研究的最新循证证据，经学组专家共同讨论后制定，旨在规范中国老年MDS患者的诊断和治疗的全程管理。

Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid tumours originating from haematopoietic stem/progenitor cells, with a high prevalence in the elderly. Epidemiological surveys in Europe and the United States have revealed that the incidence of MDS is (4-5)/100 000, which increases with age，and the median age at diagnosis of MDS patients reaches 73-76 years. In Shanghai, China, according to the World Health Organization (WHO) 2008 diagnostic criteria, the average incidence rate was 1.51/100 000, and the median age of onset of MDS was found to be 62 years old in a survey conducted in 3.9 million people from 2004 to 2007, of which about one-third of the patients would be transformed into acute myeloid leukemia (AML), and 53% of the patients would die due to infections, haemorrhages, or comorbidities triggered by cytopenias. Elderly MDS patients have their own characteristics in terms of both treatment choices and disease prognosis due to more comorbidities and weaker health. Clinical characteristics of elderly MDS patients include slightly higher white blood cell count, haemoglobin level and more bone marrow blasts than those of young patients, while neutrophil count and platelet count are significantly higher than those of young patients; the number of mutations in elderly MDS patients is higher, with an average of 1.8 mutations per patient, among which the mutations in ASXL1, TET2, SF3B1, STAG2, SRSF2 and TP53 are more common; while the number of mutations in younger patients averages 1.2 per person, among which U2AF1, ASXL1 and RUNX1 mutations are more common. Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is the only curative treatment for MDS, and myeloablative transplantation is feasible in young patients, but only reduced-intensity conditioning (RIC) allo-HSCT can be performed in elderly patients.The natural course and prognosis of elderly MDS patients varies considerably, and the MDS Composite Prognostic Score, which is composed of the composite age (>70 years old), vulnerability index, and IPSS prognostic subgroups, is able to better predict the tolerance of chemotherapy and adverse treatment effects in MDS patients. This consensus is based on the latest evidence-based data in the study of MDS in the elderly at home and abroad, and has been discussed by the experts of the group, which aims to standardise the diagnosis and the whole management of treatment for elderly MDS patients in China.