[Clinical characteristics and prognosis of myelodysplastic neoplasms with chromosome 1 abnormalities]

Objective: To characterize the clinical and molecular features and evaluate the prognostic outcomes of patients with myelodysplastic neoplasms (MDS) with chromosome 1 abnormalities. Methods: We retrospectively analyzed 1 498 newly diagnosed MDS patients treated at the Institute of Hematology, Chinese Academy of Medical Sciences from August 2016 to June 2024. The clinical features, molecular characteristics, and overall survival (OS) of patients with chromosome 1 abnormalities were analyzed. Results: Chromosome 1 abnormalities were identified in 128 patients (8.54%), with 1q trisomy representing the most frequent cytogenetic alteration (85 cases, 66.4%). Compared to 1q trisomy patients, non-1q trisomy patients demonstrated significantly higher bone marrow blast percentages (5.0% vs 2.5%, P=0.030), TP53 mutation rates (30.2% vs 12.9%, P=0.033), and median TP53 variant allele frequencies (VAF) (46.7% vs 19.7%, P=0.034). No significant difference in OS was observed between patients with and without chromosome 1 abnormalities [29 (95% CI: 17-41) months vs 34 (95%CI: 25-43), P=0.800]. However, among patients with chromosome 1 abnormalities, the 1q trisomy patients showed markedly superior median OS compared to the non-1q trisomy patients [58 (95% CI: 24-107) vs 10 (95% CI: 5-15) months, P=0.005]. Multivariate analysis identified increased blast (IB) counts (HR=2.23, 95% CI: 1.10-4.54, P=0.027) and SF3B1 mutations (HR=5.61, 95% CI: 2.06-15.29, P=0.001) as independent adverse prognostic factors for survival in this cohort. Conclusion: Among MDS patients with chromosome 1 abnormalities, 1q trisomy is associated with lower blast counts and reduced TP53 mutation rates/VAF, correlating with significantly improved OS. IB and SF3B1 mutations independently predict poorer survival outcomes in this patient population.