A retrospective study of the association of pre-autologous stem cell transplantation disease status with outcomes in patients with multiple myeloma: A single-center study.

Abstract

e20013 Background: Autologous stem cell transplantation (ASCT) has improved long-term survival for many patients with multiple myeloma (MM), but not all patients respond to ASCT favorably, and many experience disease relapse. Our goal was to explore various disease parameters in patients with MM that might be associated with adverse outcomes after receiving ASCT. Methods: We performed a retrospective medical record review of adult patients with MM who underwent ASCT at Henry Ford Hospital between January 1, 2010 and November 1, 2020. Age, sex, international staging system stage, type of induction therapy, bone marrow cytogenetics and/or fluorescence in situ hybridization, International Myeloma Working Group (IMWG) treatment response criteria categories before ASCT, and the use of maintenance therapy were collected. Outcomes analyzed were time to relapse (TTR) and overall survival (OS). Cox regression analysis was performed. Results: A total of 321 patient records were analyzed: 194 (60.4%) patients were < 65 years old; 185 (57.6%) were men; 162 (50.5%) were Black, and 140 (43.6%) were White. IMWG treatment response categories before ASCT included 250 (78.2%) patients with partial response (PR) and very good partial response (VGPR) combined, and 40 (12.5%) with complete response (CR). There were 69 (21.4 %) patients classified with high-risk cytogenetics. Commonly used induction therapies included 96 (29.9%) patients receiving bortezomib/lenalidomide/dexamethasone, 21 patients (9%) receiving lenalidomide/dexamethasone, 80 patients (24.9%) receiving bortezomib/dexamethasone, and 30 patients (9.3%) receiving cyclophosphamide/bortezomib/dexamethasone, while other patients received a combination of other induction therapies. Mean time from ASCT and last follow-up date was 3.94 years. The overall mean TTR was 29.4 months and OS was 44.8 months. Univariate analysis showed that pre-ASCT treatment response status of combined PR/VGPR was associated with higher hazard of dying than CR (hazard ratio 3.03; 95% CI, 1.23-7.46); however, multivariate analysis showed that PR/VGPR status before ASCT was not significantly associated with increased TTR compared to CR (hazard ratio 1.29; CI, 0.65-2.59). Patients with pre ASCT CR status had longer OS than those with PR/VGPR status (hazard ratio 2.75; CI, 0.995-7.61; p < 0.05). No other variables, including cytogenetic risk were associated with a difference in OS or TTR. Conclusions: Being at CR status before receiving ASCT may indicate a reduced risk of death in MM patients compared to PR and VGPR status, regardless of upfront therapies. Since multiple factors, including treatment type, impact CR status in patients with MM, we believe that studying evolving risk-adapted front-line therapies will help guide optimized treatment strategies to improve overall survival.