Outcomes of upfront autologous hematopoietic cell transplantation in patients with multiple myeloma who are 75 years old or older.

Abstract

Consolidative autologous hematopoietic stem cell transplantation (AHCT) is commonly used for patients with multiple myeloma (MM). We studied AHCT use and outcomes in patients with MM ≥75 years old. Patients with MM ≥75 years old receiving AHCT between 2013 and 2017 in the United States were identified using the Center for International Blood and Marrow Transplant Research database. Relapse and/or progression (REL), progression-free survival (PFS), and overall survival (OS) were modeled using Cox proportional hazards models. Covariates used were age, sex, Karnofsky performance score (KPS), HCT-comorbidity index (HCT-CI), International Staging System and/or Durie-Salmon stage, high-risk cytogenetics, melphalan dose, and disease status at and 1 year after transplant. AHCT utilization rate using the Surveillance, Epidemiology, and End Results database was used to estimate specific incidence among ≥75 years old by race and gender. Of 360 patients, 63% were male, 84% were White, 56% had KPS <90, and 57% had HCT-CI ≥3. The 100-day transplant-related mortality was 1% (0%-2%) with a 2-year REL rate of 27% (95% confidence interval [CI], 22%-33%), PFS of 66% (95% CI, 60%-72%), and OS of 83% (95% CI, 78%-87%). On multivariate analysis, only high-risk cytogenetics was associated with REL risk and decreased PFS. In White males, transplant utilization rate was 5.2%-5.8% compared to 3.5%-4.0% in African American males (P = .02). There was 3.37-3.79% transplant utilization in White females compared to 1.88-2.12% in African American females (P < .01). The use of AHCT was associated with excellent 2-year outcomes in this selected MM population ≥75 years old. Transplant utilization for patients ≥75 years old remains low with significant racial and gender disparities.