Real-World Clinical Outcomes of Azacitidine Versus Best Supportive Care in Higher-Risk Myelodysplastic Neoplasms: A Single-Center Cohort Study

Background: Higher-risk myelodysplastic neoplasms ( HR-MDS) are associated with poor survival and a substantial risk of leukemic transformation. Although azacitidine is a standard treatment in this setting, comparative real-world data remain limited. We evaluated the association between azacitidine exposure and clinical outcomes in patients with HR-MDS. Methods: We performed a retrospective single-center cohort study including 72 adults with HR-MDS, defined by the Revised International Prognostic Scoring System(IPSS-R) as High or Very High risk. Patients were categorized as azacitidine-treated (Aza, n = 44) or managed with best supportive care alone (No Aza, n = 28). Overall survival (OS) was defined from diagnosis to death from any cause. Progression-free survival (PFS) was defined as the time to acute myeloid leukemia transformation or death. Leukemic transformation (LT) was analyzed using Kaplan–Meier estimates and competing-risk cumulative incidence, with death without prior LT treated as a competing event. Univariable and multivariable Cox regression models were applied. Results: Azacitidine exposure was associated with longer OS compared with best supportive care, with a median OS of 13 vs.10 months and 24-month OS rates of 27% vs. 14% (p = 0.0239). PFS was also prolonged in the Aza group, with a median of 11 vs. 7 months (p = 0.0406). LT-related outcomes similarly favored azacitidine. In multivariable analyses, azacitidine remained independently associated with improved OS, PFS, and LT-related outcomes. IPSS-R Very High risk remained an adverse prognostic factor across endpoints, while a higher baseline bone marrow blast percentage independently predicted leukemic transformation. Conclusions: In this real-world HR-MDS cohort, azacitidine exposure was associated with improved survival outcomes and delayed leukemic transformation compared with best supportive care alone.