Who is the better donor for older hematopoietic transplant recipients: an older-aged sibling or a young, matched unrelated volunteer?

Abstract

Older patients are increasingly undergoing allogeneic hematopoietic transplantation. A relevant question is whether outcomes can be improved with a younger allele-level 8/8 HLA-matched unrelated donor (MUD) rather than an older HLA-matched sibling (MSD). Accordingly, transplants in leukemia/lymphoma patients age ≥50 years were analyzed comparing outcomes for recipients of MSD ≥50 (n = 1415) versus MUD <50 years (n = 757). Risks of acute graft-versus-host disease (GVHD) grade 2 to 4 (hazard ratio [HR], 1.63; P < .001), 3 to 4 (HR, 1.85; P < .001), and chronic GVHD (HR, 1.48; P < .0001) were higher after MUD compared with MSD transplants. The effect of donor type on nonrelapse mortality (NRM), relapse, and overall mortality was associated with performance score. For patients with scores of 90 or 100, NRM (HR, 1.42; P = .001), relapse (HR, 1.45; P < .001), and overall mortality (HR, 1.28; P = .001) risks were higher after MUD transplants. For patients with scores below 90, NRM (HR, 0.96; P = .76), relapse (HR, 0.86; P = .25), and overall mortality (HR, 0.90; P = .29) were not significantly different after MUD and MSD transplants. These data favor an MSD over a MUD in patients age ≥50 years.

Figure 1

The probabilities of acute and chronic GVHD, non-relapse mortality, and overall survival. (A)The unadjusted cumulative incidence of grade 2 to 4 acute GVHD for recipients of MSD transplants with donors age 50 years or older and MUD transplants with donors age younger than 50 years. (B) The unadjusted cumulative incidence of chronic GVHD for recipients of MSD transplants with donors age 50 years or older and MUD transplants with donors age younger than 50 years. (C) The unadjusted cumulative incidences of NRM for recipients of MSD transplants with donors age 50 years or older and performance scores 90 or 100 (group A), MSD transplants with donors age 50 years or older and performance scores 80 or lower (group B), MUD transplants with donors age younger than 50 years and performance scores 90 or 100 (group C) and MUD transplants with donors age younger than 50 years and performance scores 80 or lower (group D). (D) Probabilities of OS adjusted for conditioning regimen, patient age, disease, and disease status for recipients of MSD transplants with donors age 50 years or older and performance scores 90 or 100 (group A), MSD transplants with donors age 50 years or older and performance scores 80 or lower (group B), MUD transplants with donors age younger than 50 years and performance scores 90 or 100 (group C) and MUD transplants with donors age younger than 50 years and performance scores of 80 or lower (group D).