Abstract: Objective To investigate the relationship between 1q21 amplification (1q21+) and the treatment efficacy and prognosis of the newly diagnosed multiple myeloma (NDMM) patients, and to explore the advantage of 1q21+ in the risk stratification of MM. Methods The patients with NDMM treated in Beijing Lu-He Hospital, Capital Medical University, from November 2015 to November 2021 were selected as the research objects. The cytogenetic abnormalities were detected by the interphase fluorescence in situ hybridization (iFISH). The relationship between 1q21+ and the efficacy and prognosis of bortezomib based induction chemotherapy and autologous stem cell transplant (ASCT) were analyzed. The stratification advantages of MM R2-ISS and R-ISS were compared. Results A total of 159 NDMM patients were included in this study, 79 patients with 1q21+ and 80 patients with no 1q21+, of whom 41 patients were treated with RVD regimens and 118 patients with no-RVD regimens. Among 1q21+ patients, the complete remission (CR) rate of the RVD group was higher than that of the no-RVD group (P<0.001). In RVD group, the CR rate of 1q21+ patients was lower than that of no 1q21+ patients (P=0.004). Multivariable analysis showed that 1q21+ was an independent risk factor for the progression-free survival (PFS) and the overall survival (OS) in the patients with NDMM (P<0.05). Among the 50 patients receiving ASCT, the 1-year and 3-year OS and PFS rates of 1q21+ patients were shorter than those of no 1q21+ patients (P=0.055, 0.002). The 1-year PFS rates of patients with stageⅠ, Ⅱ,Ⅲ and Ⅳ of R2-ISS were 96.3%, 95.0%, 92.0% and 85.4%, respectively, and the 3-year PFS rates were 88.9%, 80.5%, 74.0% and 61.5%, respectively, with statistical significance (P=0.005). Conclusions 1q21+ is an independent risk factor for the OS and PFS in the patients with NDMM, which is associated with poor prognosis. RVD can improve the remission depth of 1q21+ NDMM patients, while ASCT can improve the prognosis of patients, but neither of them can completely overcome the adverse effects of 1q21+. Clinically, the R2-ISS has advantages in the MM risk stratification.

Key words: Multiple myeloma, 1q21+, Efficacy, Prognosis, ASCT, R2-ISS staging