The prognostic value of dynamic minimal residual disease after autologous hematopoietic stem cell transplantation in patients with multiple myeloma in novel-agent era

Abstract

Objective: To investigate the clinical prognostic value of dynamic minimal residual disease (MRD) after autologous hematopoietic stem cell transplantation (AHSCT) in patients with multiple myeloma (MM). Methods: Patients with MM who underwent AHSCT in Beijing Chao-Yang Hospital from February 2016 to December 2019 were enrolled in this study. All the patients in the study had complete baseline data at the diagnosis. AHSCT was performed after induction chemotherapy. Response evaluation was performed after induction therapy. All the patients were assessed at approximately 100 days after AHSCT. Bone marrow MRD by NGF was performed every three months and dynamically monitored for at least 12 months. All the patients were divided into different groups according to cytogenetics and MRD status. Survivals in different groups were analyzed by IBM SPSS 22.0 statistical software. Results: A total of 150 patients with MM were enrolled in this study at last, including 66 patients in the cytogenetic standard risk group and 84 patients in the cytogenetic high-risk group. The median age was 54 years (range 30-68 years) and 87 male patients (58.0%) was in the study. The median follow-up was 36 months (range 16-72 months). Patients in the standard-risk group had better clinical prognosis than those in the high-risk group [median PFS in the standard-risk group was not achieved, and median PFS in the high-risk group was 45 months (P<0.001); median OS of both groups was not reached, and the estimated 3-year OS rate of the standard-risk group and the high-risk group was 95.2% and 78.9%, respectively (P=0.001)]. According to MRD status of patients, patients in each group were divided into three subgroups: persistent positive (Ppos), transient negative (Tneg) and persistent negative (Pneg). The median OS and median PFS of all subgroups in the standard-risk group was not reached (P=0.324 and P=0.086). In high-risk group, the median OS of MRD Pneg subgroup was not reached, and the estimated 3-year OS rate was 100%; The median OS of MRD Ppos subgroup was 52 months, and MRD Tneg subgroup only 31 months (P=0.002); the median PFS of MRD Pneg group was not reached, and the estimated 3-year PFS rate was 85.4%; median PFS of MRD Ppos subgroup was 40 months, and MRD Tneg subgroup only 17 months (P=0.001). Conclusions: MRD Pneg might overcome the adverse prognosis of MM patients with high-risk cytogenetics. However, MRD Tneg might be a poor prognostic factor for the patients with cytogenetic high-risk MM.