Prognostic impact of DTA mutation and co-occurring mutations in patients with myelodysplastic syndrome

To evaluate the frequency and prognostic significance of DTA (DNMT3A、TET2、ASXL1) gene mutation and co-occurring mutations in patients with myelodysplastic syndrome (MDS).

The clinical data of 102 newly diagnosed MDS patients who accepted Next Generation Sequencing (NGS) was retrospectively analyzed. According to whether the patients had DTA gene mutation, the patients were divided into DTA mutated (DTA-mut) group and wild type (DTA-wt) group, and the relationship between gene mutation and clinical characteristics and prognosis was analyzed.

Among the 102 MDS patients, 96% (98/102) presented with mutation, while the mean number of mutations was 3.04 mutations/patient. DTA-mut was detected in 56.9% (58/102) patients. The most frequent co-mutated genes in DTA-mut group were SF3B1 (25.8%), RUNX1 (24.1%), U2AF1 (18.9%), SRSF2, EZH2, SETBP1 (17.2%), STAG2 (15.5%), IDH2 (12.1%) and BCOR, CBL (10.3%). The two groups showed no significant differences in ages, blood parameters, bone marrow blasts, WHO 2022 classification, IPSS-R risk category and rate of conversion to leukemia. Compared with the DTA-wt group, the mutation frequency of RUNX1 was higher (P = 0.02), while mutation frequency of TP53 was lower (P = 0.001) and the mutation frequency of ≥ 3 co-mutated genes was higher in DTA-mut group (P = 0.00). Survival analysis showed that the overall survivals (OS) of DTA-mut patients was significantly inferior to that of DTA-wt patients (P = 0.0332). According to IPSS-R classification, a statistically significant difference in OS was only observed in higher risk (IPSS-R > 3.5) group (P = 0.0058). In the context of DTA mutation, the OS of patients with RUNX1 mutation was shorter than that of patients without RUNX1 mutation significantly (P = 0.0074). The OS of patients with SF3B1 mutation was longer than that of patients without SF3B1 mutation, but there was no statistical difference (P = 0.0827). DTA mutations were not independent prognostic factors when DTA and co-mutated genes with frequency > 10% were considered in Cox regression model (P = 0.329). However, multivariate analysis confirmed an independently adverse prognosis of RUNX1 co-mutation (P = 0.042, HR = 2.426, 95% CI:1.031-5.711) in DTA-mut cohort. Moreover, our multivariable analysis suggests that SRSF2-mut was an independent poor prognostic factor for all MDS patients (P = 0.047), but lost significance (P = 0.103) for DTA-mut patients.

DTA mutations are frequently observed in patients with MDS, often accompanied by genes involved in RNA splicing and transcription factors like SF3B1 and RUNX1. DTA and concomitant mutations affect prognosis in MDS patients and RUNX1 was identified as an independent poor prognostic factor in patients with DTA mutations.