Outcomes after matched unrelated donor versus identical sibling hematopoietic cell transplantation in adults with acute myelogenous leukemia.

Approximately one-third of patients with an indication for hematopoietic cell transplantation (HCT) have an HLA-matched related donor (MRD) available to them. For the remaining patients, a matched unrelated donor (MUD) is an alternative. Prior studies comparing MRD and MUD HCT provide conflicting results, and the relative efficacy of MRD and MUD transplantation is an area of active investigation. To address this issue, we analyzed outcomes of 2223 adult acute myelogenous leukemia patients who underwent allogeneic HCT between 2002 and 2006 (MRD, n = 624; 8/8 HLA locus matched MUD, n = 1193; 7/8 MUD, n = 406). The 100-day cumulative incidence of grades B-D acute GVHD was significantly lower in MRD HCT recipients than in 8/8 MUD and 7/8 MUD HCT recipients (33%, 51%, and 53%, respectively; P < .001). In multivariate analysis, 8/8 MUD HCT recipients had a similar survival rate compared with MRD HCT recipients (relative risk [RR], 1.03; P = .62). 7/8 MUD HCT recipients had higher early mortality than MRD HCT recipients (RR, 1.40; P < .001), but beyond 6 months after HCT, their survival rates were similar (RR, 0.88; P = .30). These results suggest that transplantation from MUD and MRD donors results in similar survival times for patients with acute myelogenous leukemia.