Functional Decline Among Older Adults with Multiple Myeloma Undergoing Autologous Hematopoetic Stem Cell Transplantation

Introduction: Prior studies have shown that older adults with multiple myeloma (MM) value functional independence over survival. Autologous hematopoietic stem cell transplantation (ASCT) is an intensive treatment that is utilized for patients with MM of all ages. Over 50% of adults undergoing ASCT were 60 years (y) or older. How ASCT impacts functional independence among older adults undergoing this treatment is unknown. Methods: We used data from a single institution prospective study enrolling older adults ≥ 60 y with MM who were presenting for an initial consultation for ASCT. Participants underwent a comprehensive geriatric assessment within 30 days before planned ASCT and at 100 days post-ASCT, which comprised of subjective and objective measures of physical function. Subjective functional status was assessed using Older Americans Resources and Services Basic Activities of Daily Living (ADL, 3 items) and Instrumental Activities of Daily Living (IADL, 6 items) questionnaires where each item was scored as 0 (completely unable), 1 (with some help) and 2 (without help) with total ADL score ranging from 0-6 and IADL score ranging from 0-12 points. Objective physical function was assessed using Short Physical Performance Battery protocol (SPPB), gait speed (m/s) and handgrip strength (in kg) which was measured using a hand-grip dynamometer in the non-dominant hand. For ADL/IADL, a 1-point decline (or increased dependence) post-ASCT was deemed clinically significant whereas for SPPB, gait speed and handgrip strength a decline of 1 point, 0.1 m/s and 5 kg respectively were considered clinically significant. Results: We included 60 older adults with MM who underwent ASCT between 02/2021 to 08/2022, with a median age at ASCT of 67 (Interquartile Range (IQR): 64 - 71) y, 65% men, 65% non-Hispanic Whites, 28% International Staging System Stage 3 and 28% with high-risk cytogenetics (del 17/17p, t4;14 or t14;16). The baseline ADL score ranged from 4-6 and the baseline IADL score ranged from 6-12. At baseline, the median SPPB score was 9 (IQR: 8-11), the median gait speed was 0.837 (IQR: 0.666 - 0.980) m/s and the median handgrip strength was 26.91 (IQR: 20.87 - 32.13) kg. At 100 day follow up, the median SPPB score was 9 (IQR: 8-11), the median gait speed was 0.808 (IQR: 0.734 - 0.978) m/s and the median handgrip strength was 22.60 (IQR: 17.49 - 28.39) kg. Among 52 patients with complete data, 13% reported ≥1-point ADL decline, 27% reported ≥1-point IADL decline with 33% reporting decline in either ADL/IADL at 100 days post-ASCT. Among 56 patients completing objective physical assessment at 100 day follow up, 41% experienced clinically significant decline in SPPB, 34% had decline in gait speed and 36% had decline in handgrip strength. Conclusion: Our study showed that one in three older adults with MM undergoing ASCT experience functional decline. This finding was further corroborated with objective physical function data that showed a decline in SPPB, gait speed and handgrip strength in 34-41% of patients at follow up visit. Additional studies are needed to better understand longer term trajectories of functional status. Furthermore, interventions to preserve and improve functional status in this population are critically needed.