Abstract
BACKGROUND: Multiple myeloma (MM) is a hematologic malignancy characterized by the proliferation of abnormal clonal plasma cells in the bone marrow. The heterogeneity in Chinese MM populations remains underexplored. METHODS: We conducted whole-exome sequencing (WES) on 241 tumor samples, complemented by RNA sequencing (RNA-seq) on 131 samples from 212 Chinese MM patients. RESULTS: We identified a novel mutational signature and analyzed molecular differences between newly diagnosed MM (NDMM) and relapsed/refractory MM (RRMM) patients. NFKBIA mutations were notably more frequent in NDMM patients compared to the MMRF-COMMPASS cohort (4/50 vs 22/937, p = 0.048), with additional recurrent mutations in several genes like TTN, IGLL5 and SYNE1. In RRMM patients, UBR5 mutations were more prevalent (4/24 vs 0/50, p = 0.01), alongside frequent mutations in OBSCN, CACNA1H, and HSPG2. Clonal evolution was assessed through multiple time points and locations, identifying genes potentially linked to circulating plasma cell formation. Cox regression analysis revealed that age and mutations in OBSCN and RB1 were significant predictors of progression-free survival (PFS) in NDMM patients. Additionally, albumin, β2-microglobulin, and RB1 mutations were correlated with overall survival (OS). CONCLUSIONS: In summary, we characterized the genomic landscape of MM in diverse Chinese populations, confirmed clonal evolution, and identified prognostic genes.