RÉSUMÉ
Objective:To analyze the distribution of different SF3B1 genotypes in patients with myelodysplastic syndromes (MDS) and its prognostic value.Methods:Totally, 377MDS patients who were initially diagnosed in the First Affiliated Hospital of Nanjing Medical University from January 2014 to January 2022 were included in the retrospective analysis.The patients were divided into three different groups according to mutation stcote of SF3B1, including 317 patients with SF3B1 wild type (SF3B1 WT) (214 males and 103 females, 63(49, 71) years old),39 patients with SF3B1 K700E mutation(SF3B1 K700E(17 males and 22 females, 65(52, 73)years old)) and 21 patients with SF3B1 non-K700E mutation(SF3B1 non-K700E)(13 males and 8 females, 67(63, 73) years old). MDS-related 20 gene mutations were detected using targeted sequencing technology; Survival curves were constructed by the Kaplan-Meier method; Cox proportional hazards model was established to evaluate different factors at diagnosis on survival by univariate and multivariate analyses.. Results:Compared with SF3B1 non-K700E patients, SF3B1 K700E patients had a higher median absolute neutrophil count ( P=0.002) and were likely to be in the low/int-1 International Prognostic Scoring System (IPSS) categories ( P=0.023). A 20-gene targeted sequencing analysis showed that, compared with SF3B1 WT patients, SF3B1 K700E patients were associated with lower frequency of ASXL1 and U2AF1 mutations ( P=0.018 and P=0.003); while compared with SF3B1 non-K700E patients, the frequency of ASXL1 mutation was significantly lower in SF3B1 K700E cases ( P=0.029). Patients with SF3B1 K700E had better overall survival (OS) in comparison with SF3B1 WT and SF3B1 non-K700E in MDS patients ( P<0.001 and P=0.045, respectively). In comparison with SF3B1 WT patients, SF3B1 MUT patients had more favorable OS and progression-free survival (PFS) in MDS without excess blasts ( P<0.001 and P<0.001, respectively), but no significant difference was found in MDS with excess blasts ( P>0.05). Compared with SF3B1 WT patients, SF3B1 K700E patients had superior OS and PFS in the int-1 IPSS category ( P=0.010 and P=0.013, respectively). By multivariable analysis, the presence of SF3B1 K700Ewas an independent predictor of superior OS ( HR=0.461,95% CI 0.262-0.811, P=0.007). Conclusion:SF3B1 K700E and SF3B1 non-K700E patients had significantly improved OS in comparison with SF3B1 WT MDS patients. Furthermore, SF3B1 K700E patients were associated with a better OS compared with SF3B1 non-K700E MDS patients. SF3B1 mutation could not overcome the poor prognostic effect of excess blasts, which highlights the importance of the SF3B1 mutation subtype in risk assessment of MDS without excess blasts.