在这项以人群为基础的研究中，我们旨在表征和比较治疗相关骨髓增生异常综合症(t-MDS)的子组，并定义以前治疗类型和原发病的影响。我们将2009年至2017年之间诊断为MDS的患者的数据(n=2705)，来自瑞典全国MDS登记表和几个卫生登记表的数据结合起来。此外，使用匹配的人口对照，我们比较了MDS患者和一般人群中先前恶性肿瘤的患病率。这是首次进行的关于t-MDS的全国性研究，证实了t-MDS的中位生存期较短，相比de novo MDS(15.8个月对31.1个月，p<0.001)。使用放疗治疗的t-MDS患者的疾病特点与de novo-MDS非常相似，而接受化疗的患者则有更高的风险概率。IPSS-R和WHO分类将t-MDS区分为不同的风险组。与对照组相比，MDS患者先前患有血液恶性肿瘤的患病率增加了6倍，但先前实体恶性肿瘤的患病率仅增加了34%。具有先前血液恶性肿瘤的t-MDS患者预后不佳，这既与其原发病有关的死亡率有关，也与高风险的MDS有关。 ©2023. 作者。

In this population-based study, we aimed to characterize and compare subgroups of therapy-related Myelodysplastic syndromes (t-MDS) and define the implications of type of previous treatment and primary disease. We combined data from MDS patients, diagnosed between 2009 and 2017 (n = 2705), in the nationwide Swedish MDS register, with several health registers. Furthermore, using matched population controls, we investigated the prevalence of antecedent malignancies in MDS patients in comparison with the general population. This first ever nationwide study on t-MDS confirms a shorter median survival for t-MDS compared to de novo MDS (15.8 months vs 31.1 months, p < 0.001). T-MDS patients previously treated with radiation only had disease characteristics with a striking resemblance to de novo-MDS, in sharp contrast to patients treated with chemotherapy who had a significantly higher risk profile. IPSS-R and the WHO classification differentiated t-MDS into different risk groups. As compared with controls, MDS patients had a six-fold increased prevalence of a previous hematological malignancy but only a 34% increased prevalence of a previous solid tumor. T-MDS patients with a previous hematological malignancy had a dismal prognosis, due both to mortality related to their primary disease and to high-risk MDS.© 2023. The Author(s).