Distinctive Molecular Risk Factors Between MDS and MDS/AML Defined by ICC.

Myelodysplastic syndromes/neoplasms (MDS) represent a heterogeneous group of clonal hematopoietic stem cell diseases with high risks of acute myeloid leukemia (AML) transformation. To emphasize the characteristics of AML transformation, the International Consensus Classification (ICC) has classified MDS with excess blasts (10%-19%) as MDS/AML. Recently, a clinical-molecular prognostic model International Prognostic Scoring System Molecular (IPSS-M) is developed, which improves the risk stratification of MDS. However, these molecular risk factors were analyzed in a cohort of highly heterogeneous patients with MDS including MDS/AML. Herein, we re-evaluated and compared the molecular risk factors in MDS (blasts < 10%) and MDS/AML (blasts 10%-19%) defined by ICC. Notably, there is a significant difference in molecular landscape between MDS and MDS/AML. Importantly, most of the risk factors presented in MDS was not shown in MDS/AML except for TP53 aberrations and FLT3-ITD mutation. Since the IPSS-R and IPSS-M showed a poorly prognostic separation for MDS/AML patients, we further established a new prognostic model MDS/AML-IPSS-M and significantly improved its prognostic discrimination ability. Taking together, our research findings enhance the understanding of the molecular biology of MDS and can provide important guidance for the clinical identification of MDS/AML patients that might benefit clinical decision-making and therapeutic research.