[Clinical features of SF3B1 mutation in patients with myelodysplastic syndrome with excess blasts]

Objective: To exploring the clinical features of SF3B1-mutated myelodysplastic syndrome with excess blasts (MDS-EB) and analyzing the association between SF3B1 mutation, and efficacy and prognostic significance for patients with MDS-EB. Methods: This was a retrospective case series study. The clinical data of 266 patients with MDS-EB diagnosed in the First Affiliated Hospital of Zhengzhou University between April 2016 and November 2021 were analyzed. The observed indicators included blood routine counts, mutated genes, overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and leukemia-free survival (LFS). The Kaplan-Meier method was used to depict the survival curves. The Log-rank test method was equally used to compare survival across groups and performed the Cox proportional hazard regression model for prognostic analysis. Results: In 266 patients with MDS-EB, 166 (62.4%) were men, and the median age was 57 (17-81) years. Moreover, there were included 26 and 240 patients in the SF3B1-mutated and SF3B1 wild-type groups. Patients in the SF3B1-mutated group were older [median age 65 (51, 69) years vs. 56 (46, 66) years, P=0.033], had higher white blood cell (WBC) counts [3.08 (2.35, 4.78) × 10⁹/L vs. 2.13 (1.40, 3.77) × 10⁹/L], platelet (PLT) counts [122.5 (50.5, 215.0) ×10⁹/L vs. 49.0 (24.3, 100.8) × 10⁹/L], absolute neutrophil counts (ANC) [1.83 (1.01, 2.88) × 10⁹/L vs. 0.80 (0.41, 1.99) × 10⁹/L]and occurrence of DNMT3A mutation [23.1% (6/26) vs. 6.7% (16/240)] (all P<0.05). The ORR were similar in both groups after 2 and 4 cycles of therapy (P=0.348, P=1.000). Moreover, the LFS (P=0.218), PFS (P=0.179) and OS (P=0.188) were similar across the groups. Univariate Cox analysis revealed that SF3B1 mutation did not affect the prognosis of patients with MDS-EB (OS: P=0.193; PFS: P=0.184). Conclusions: Patients with SF3B1 mutation were older, with greater WBC, PLT, and ANC, and SF3B1 mutation easily co-occurred with DNMT3A mutation. From this model, there were no significant differences in efficacy and survival of MDS-EB with or without SF3B1 mutation.