Mutations Based on Next-Generation Sequencing May be Complementally to Prognostic Risk in Myelodysplastic Syndromes
Authors: Wang Jing , Jia Jinsong , Liu Xiaohong , Gong Lizhong , Lu Shengye , Wang Yu , Xu Lanping , Zhang Xiaohui , Yan Chenhua , Lai Yueyun , Zhao Xiaosu , Qin Yazhen , Ruan Guorui , Chang Yingjun , Shi Hongxia , Liu Kaiyan , Huang Xiaojun , Jiang Hao 
Published: November 2020

Objective: Established the value of somatic mutations based on next-generation sequencing (NGS) and explore factors associated with prognosis in myelodysplastic syndromes (MDS). Methods: From March 2012 to September 2019, 90 newly diagnosed MDS patients were treated and analysed by a sensitive NGS assay for mutations in 87 candidate genes and target regions. IPSSR higher risk include IPSS-R Intermediate, High, Very High subgroups (risk score &gt;3.5), and IPSSR lower risk include IPSSR risk score ≤3.5. Results: A total of 90 MDS patients were recruited for this study (median age: 51.5 years; range: 16-70 years). Eighty-two (91.1%) patients harbored at least one mutation (median, 3 per patient; range, 0-11), and the most common mutations were found successively in the ASXL1 (28.9%), TP53 (21.1%), TET2 (18.9%), U2AF1 (17.8%), RUNX1 (15.6%), SETBP1 (13.3%), DNMT3A (13.3%), IDH1 (12.2%), NRAS (12.2%), KMT2D (11.1%), CBL (11.1%) and PTPN11 (11.1%) genes. The median follow-up was 32 months (range: 10-96 months). Thirty-seven (92.5%) had at least one point mutation in 40 patients with normal karyotype. ASXL1 and U2AF1 mutations had more frequently platelet levels of &lt;50×109/L (P=0.047, P=0.023; respectively) and hemoglobin concentrations at &lt;80 g/L (P=0.048, P=0.042; respectively). Compared with the lower risk MDS, more TP53 mutations (28% vs. 12.5%, P=0.048), RUNX1 mutations (22% vs. 7.5%, P=0.039), IDH1 mutations (18% vs. 5%, P=0.041), and IDH2 mutations (8% vs. 0, P=0.047) were found in the higher risk MDS. During the follow-up period, 37 (41.4%) patients translate to AML at a median follow-up of 24.5 months (range: 2-96 months). The median time of progress to AML from MDS diagnosis was 46 (2-96) months in MLD, 21 (2-37) months in EB1, and 18.5 (2-73) months in EB2. At 3-year follow-up, the probability of overall survival (OS) and cumulative incidence of AML transformation (CIAT) were 72.3% (95%CI 67.2%-77.8%) and 36.2% (95%CI 30.9%-41.5%), respectively. The univariate analysis results showed that ≥50 years old, IPSSR higher risk, ASXL1mutation, TP53 mutation, TET2 mutation, U2AF1 mutation, RUNX1 mutation, IDH1 mutation, IDH2 mutation, and ≥3 molecular mutations were poor factors for OS. The univariate analysis results associated with CIAT showed that IPSSR higher risk, TP53 mutation, RUNX1 mutation, IDH1 mutation, and IDH2 mutation were poor factors for CIAT.Multivariate adjust analysis showed that IPSSR higher risk, ASXL1 mutation, TP53 mutation, and RUNX1 mutation were independent prognosis factors associated with OS (HR=0.113, 95% CI: 0.093-0.199, P=0.003; HR=0.215, 95% CI: 0.103-0.623, P=0.025; HR=0.147, 95% CI: 0.084-0.506, P=0.012; HR=0.317, 95% CI: 0.122-0.661, P=0.013; respectively), and IPSSR higher risk, TP53 mutation, RUNX1 mutation, IDH1 mutation, and IDH2 mutation were independent prognosis factors associated with CIAT (HR=2.905, 95% CI: 1.155-6.312, P=0.023; HR=2.636, 95% CI: 1.024-5.023, P=0.004; HR=2.350, 95% CI: 1.043-5.789, P=0.024; HR=2.061, 95% CI: 1.036-4.078, P=0.003; HR=2.814, 95% CI: 1.073-5.359, P=0.005; respectively). Patients with mutations in one or more of the three independent survival prognostic genes (TP53, RUNX1, or ASXL1) defined as "mutation high risk" (n=48) and those without anyone of the three prognostic genes defined as "mutation low risk" (n=42). OS were significantly longer in the IPSSR both lower risk and higher risk patients with mutations low risk cohort than IPSSR lower risk patients with mutations high risk cohort (3-year OS, 95.7% vs. 47.1%, P=0.001; 79.9% vs. 47.1%, P=0.045; respectively). In the IPSSR lower risk with mutations high risk group, OS was significantly improved in the allo-HSCT cohort (3-year OS, 75.0% vs. 30.0%, P=0.042). In the IPSSR higher risk with mutations low risk group, no significant difference existed between the transplant and non-transplant arms for the probabilities of OS (3-year OS, 83.3% vs. 75.8%, P=0.972). Conclusions: Somatic mutations are common in MDS and are associated with prognosis. Mutation high risk may be complementally to IPSSR prognostic risk in MDS patients, and allo-HSCT can improved the survival in the IPSSR lower risk with mutations high risk group.
Key words: myelodysplastic syndromes; somatic mutations; Prognostic dichotomization based on 3.5 of the revised international prognostic scoring system; overall survival; allogeneic stem cell transplantation.

Disclosures
No relevant conflicts of interest to declare.