Age Is a Prognostic Factor for the Overall Survival of Patients with Multiple Myeloma Undergoing Upfront Autologous Hematopoietic Stem Cell Transplantation

In this retrospective analysis, we evaluated the impact of age on the outcome of patients with multiple myeloma who received an autologous hematopoietic stem cell transplantation (auto-HCT) at our institution. A total of 1128 patients were divided into the older (>70 years; 182 [16%]) and the younger (≤70 years; 946 [84%]) groups. Compared with the younger cohort, older patients had a higher International Staging System (ISS) stage (ISS-II, 57 [31%] versus 215 [23%]; ISS-III, 52 [28%] versus 211 [22%]; P = .01), higher use of reduced-dose melphalan as a conditioning regimen (140 mg/m², 59 [32%] versus 29 [3%]; P < .001), and a higher comorbidity index (median, 3 versus 2; P = .01). Nonrelapse mortality at 1 year after auto-HCT was significantly higher in older patients (7 [4%] versus 9 [1%]; hazard ratio [HR], 4.1; P = .005). Complete remission rates after auto-HCT for the older and the younger groups were 41% and 46%, respectively. With a median follow-up of 52 months, the 5-year progression-free survival (PFS) was 24% (95% confidence interval [CI], 17% to 32%) and 37% (95% CI, 33% to 40%) in the older and younger groups, respectively (HR, 1.3; P = .02). Five-year OS for the older and younger groups was 56% (95% CI, 47% to 64%) and 73% (95% CI, 70% to 76%; P < .001), respectively. Older age emerged as one of the predictors of shorter OS but not PFS in the multivariate classification and regression tree analysis. In conclusion, age ≥70 years was associated with shorter PFS and OS in patients with multiple myeloma who underwent an auto-HCT.