Moderate-To-Severe Bone Marrow Fibrosis Is an Independent Risk Factor For Myelodysplastic Neoplasms Patients With Increased Blasts.

This study, including 412 patients newly diagnosed with myelodysplastic neoplasm (MDS), investigated the clinical, molecular, and prognostic features of MDS with moderate-to-severe bone marrow fibrosis (MF). Among the patients with MDS, 347 (84%) had MF grade 0-1 (MF0-1), and 65 (16%) had MF grade 2-3 (MF2-3). Patients with MDS with MF2-3 showed similar overall survival (OS) (16.6 vs. 21.3 months; p = 0.34) but demonstrated inferior progression-free survival (PFS) (6.6 vs. 15.2 months; p = 0.02) and a higher risk of leukemia transformation (35.4 vs. 16.4%; p < 0.001) compared to those with MF0-1. In the MDS with excess blast (MDS-EB) subtypes, individuals with MF2-3 exhibited shorter OS (4.8 vs. 11.7 months; p = 0.01) and PFS (3.1 vs. 7.9 months; p = 0.006) than those in patients with MF0-1. However, individuals with MF0-1 and MF2-3 showed similar OS and PFS rates among the patients with the MDS non-excess blast (MDS-nonEB) subtypes. Additionally, we reclassified the patients with MDS according to the 2022 World Health Organization (WHO) classification. Patients with MDS with fibrosis (MDS-f) had a shorter OS (5.6 vs. 13.8 months; p = 0.01) and PFS (3.1 vs. 7.9 months; p = 0.006) than MDS with increased blasts (MDS-IB) subtypes. Our study reveals the unique features of patients with MDS-MF2-3 and validates the refinements made in the 5th edition of the WHO proposal.