The therapeutic effect and prognostic value of oligoclonal bands after autologous stem cell transplant in patients with multiple myeloma

Abstract

Objective: To investigate the therapeutic effect and prognostic value of oligoclonal bands (OB) in multiple myeloma (MM) patients after autologous stem cell transplant (ASCT). Methods: The data of 156 patients with MM who underwent ASCT after inductive treatment in the Department of Hematology, Jiangsu Provincial People's Hospital from December 2013 to February 2022 were retrospectively analyzed, including 91 males and 65 females. The median age was 56 (26, 71) years. Patients were divided into two groups according to OB formation after ASCT treatment, including OB group (n=60) and non-OB group (n=96). The last follow-up date was August 31, 2023, and the follow-up period was 42 (18, 117) months. The clinical baseline characteristics and efficacy of the two groups were compared. Progression-free survival (PFS) and overall survival (OS) were compared between the two groups by Kaplan-Meier method. Cox risk regression modal was used to analyze the risk factors associated with prognosis. Results: There were no significant differences in age, type, stage, risk stratification, extramedullary disease (EMD), proportion of circulating plasma cells and induction therapy regimen between OB and non-OB groups (all P>0.05). The proportion of patients in OB group who achieved complete response (CR) or above after ASCT treatment was 93.3% (56/60), which was higher than that in non-OB group (80.2%, 77/96) (P=0.024). The negative rate of minimal residual disease (MRD) in OB group was 66.7% (40/60), which was higher than that in non-OB group (34.4%, 33/96) (P=0.001). The median PFS and OS in the OB group were not reached, and the median PFS and OS in the non-OB group were 28 (2, 80) months and 86 (2, 100) months, respectively. The PFS (P<0.001) and OS (P=0.017) of patients with OB were considerably longer. In the Cox multivariate analysis, OB was an independent prognostic factor for PFS in MM patients (HR=0.314, 95%CI: 0.153-0.644, P=0.002). Subgroup analysis showed that among high-risk patients with mSMART, the OS of patients in OB group was not reached, which was significantly better than that of non-OB group [71 (2, 90) months, P=0.046]. However, no significant difference was observed in the OS of patients with OB and those with non-OB in standard risk group (not reached vs not reached, P=0.103). In those with EMD at diagnosis, patients with OB had significantly better OS than those with non-OB [not reached vs 47 (6, 74) months, P=0.037]. However, no significant difference was observed in the OS of patients with OB and those with non-OB in those without EMD at diagnosis [not reached vs 86 (2, 100) months, P=0.130]. Conclusions: OB formation after ASCT treatment in MM patients is related to the efficacy and prognosis. OB formation can increase the negative MRD rate, prolong the OS and improve the prognosis, especially for newly diagnosed patients with extramedullary disease or patients with high-risk genetic characteristics.