Benefits of Autologous Stem Cell Transplantation for Elderly Myeloma Patients in the Last Quarter of Life

Abstract

Although survival outcomes have improved dramatically over the last few decades in newly diagnosed myeloma patients, elderly patients have not yielded the same magnitude of benefit as evidenced by higher rates of reported myeloma-related deaths in patients over the age of 75. This is of particular importance given this cohort comprises a large proportion of myeloma patients with the median age of diagnosis being 70 years. One contributor to this discrepancy is reduced use of high-dose therapy and autologous stem cell transplantation (HDT/ASCT) in this population because of concerns for increased toxicity and safety. The objective of this retrospective analysis is to evaluate survival and safety outcomes in 53 newly diagnosed patients ≥74 years of age who underwent HDT/ASCT at our institution in comparison to 122 control patients in the same age bracket who did not undergo stem cell transplantation during this same time period. Patients treated at our institution were identified in our institutional myeloma database by age. They were all treated between November 2006 and October 2016 at the Winship Cancer Institute of Emory University. Fifty-three patients were identified who had undergone HDT/ASCT, and, to assess the relative benefit of ASCT, 122 control patients in the same age range were also identified who did not undergo HDT/ASCT during the same time period. The median age for the entire cohort was 77 years (74 years in the ASCT group versus 78 in the non-ASCT group). Median time to ASCT was 6 months (range 2-57 months). There were no gender or race differences between the 2 groups, although a higher proportion of high-risk patients underwent HDT/ASCT. Ninety-three percent of ASCT patients received triplet induction therapy with a proteasome inhibitor and immunomodulatory agent backbone in comparison to only 55% of patients the non-ASCT group. The median progression-free survival (PFS) for the ASCT group was 50 months versus 30 months in the non-ASCT group. The median overall survival (OS) was 80 months versus 40 months, respectively. In high-risk patients, the median PFS was 60.8 months, and the median OS was 77.8 months in the ASCT group compared to 26 months and 38 months in the non-ASCT group, respectively. There were no transplant-related deaths within the first 100 days in the ASCT group. This study offers real-world perspective and data on the safety and survival benefit of ASCT in the elderly population with a near doubling of OS when compared to those treated with similar regimens and modern agents without ASCT. These data provide a rationale for offering ASCT in elderly patients pending a thorough pretransplantation evaluation.