Matched unrelated or matched sibling donors result in comparable survival after allogeneic stem-cell transplantation in elderly patients with acute myeloid leukemia: a report from the cooperative German Transplant Study Group.

Abstract

In patients with acute myeloid leukemia (AML), differential indications for matched sibling and unrelated hematopoietic stem-cell transplantation (HCT) are considered, and arbitrary age limits for HCT exist. We sought to determine whether donor type is a prognostic factor in elderly patients in the era of high-resolution DNA-based HLA typing. We performed univariate and multivariate analyses of event-free survival (EFS) and overall survival (OS) in patients older than 50 years with standard- or high-risk AML who had received an allogeneic HCT between 1995 and 2005. Available DNA from donors and recipients of unrelated HCT was retyped so that the HLA-A, -B, -C, and -DRB1 alleles could be characterized in detail. Unrelated donors (UDs) were classified as matched (8/8), possibly matched (matched, but incomplete information), partially matched (one mismatch), or poorly matched (two or more mismatches) according to the final typing results. Data from 368 patients with a median age of 57 years (range, 50 to 73 years) were included. Multivariate Cox regression analysis revealed that patients' disease status at HCT (P < .001) and the cytogenetic risk (P < .001) highly significantly predicted EFS and OS. Compared with patients with matched sibling donors, the adjusted relative risk of EFS was 0.7 (95% CI, 0.4 to 1.1) for patients with matched UDs and 1.0 (95% CI, 0.7 to 1.6) for patients with partially matched UDs. Donor type is not a major prognostic factor for HCT in elderly patients with standard- or high-risk AML.