Identification of predictive factors for overall survival at baseline and during azacitidine treatment in high-risk myelodysplastic syndrome patients treated in the clinical practice

The outcome of high-risk myelodysplastic syndrome (MDS) patients treated with 5-azacitidine (5-AZA) in the real-life setting remains largely unknown. We evaluated 110 MDS patients (IPSS intermediate 2/high) treated outside of clinical trials at a single institution between September 2003 and January 2017. Median duration of therapy was 9.5 cycles. The overall survival (OS) of the whole cohort was 66.1% at 1year and 38.3% at 2years. No differences in terms of OS were observed with regard to gender (p=0.622) and age at baseline (<65years, 65-75, and >75years, p=0.075). According to the IPSS-R, the very high-risk group had an inferior 2-year OS (17%) compared with intermediate-group patients (64%, p<0.001). Transfusion independency at baseline was identified as a favorable prognostic factor on 1-year (66.8%) and 2-year OS (43.4%) (p<0.001). After four cycles, the persistence of bone marrow blasts >10% identified patients with a worse outcome, with a 2-year OS of 9.4% (p=0.002). The occurrence of an infection during the first four cycles impacted on the 2-year OS (31.6% vs 58.3% in patients without infections, p=0.032). Patients receiving at least 24 cycles of the drug have a 5-year OS of 38.2%. This analysis allowed to identify features at baseline or during treatment with 5-AZA associated with a different 2-year OS.