Incorporation mutational profile might reduce the importance of blast count in prognostication of low-risk myelodysplastic syndromes.

Addition of molecular data to prognostic models has improved risk stratification of myelodysplastic neoplasms (MDS). However, the role of molecular lesions, particularly in the group of low-risk disease (LR-MDS), is uncertain. We evaluated a set of 227 patients with LR-MDS. Overall survival (OS) and probability of leukaemic progression were the main endpoints. RUNX1 was associated with lower OS and SF3B1 with a reduced risk of death (HR: 1.7, 95% CI, 1.1-2.9; p = 0.05; and HR: 0.23, 95% CI 0.1-0.5; p < 0.001; respectively). TP53 and RUNX1 mutations were predictive covariates for the probability of leukaemic progression (p < 0.001). Blast percentage, neither analysed as categorical (<5% vs. 5%-9%; HR: 1.3, 95% CI, 0.7-2.9; p = 0.2) nor as a continuous variable (HR: 1.07, 95% CI, 0.9-1.1; p = 0.07), had impact on survival or probability of progression (sHR: 1.05, 95% CI, 0.9-1.1; p = 0.2). These results retained statistical significance when analysis was restricted to the definition of LR-MDS according to the WHO 2022 and ICC classifications (<5% blasts). Thus, with the incorporation of molecular data, blast percentage happens to lose clinical significance both for survival and probability of progression in the group of patients with LR-MDS.