Comparable long-term outcomes in matched unrelated and sibling donor HCT in older patients with AML

August 2019

In an analysis of 1134 patients age 50 or older with acute myeloid leukemia (AML), two-year hematopoietic cell transplant (HCT) survivors experienced comparable 10-year leukemia-free survival (LFS) and overall survival (OS) with matched sibling or unrelated donors.

Median age of patients was 56 years (range, 50-75) for matched siblings and 58 for patients with an unrelated donor (p=0.005). Patients underwent matched sibling (n=848) or unrelated donor (n=286) HCT between 2000 and 2007, with outcomes reported to the European Society for Blood and Marrow Transplantation.

Eleven percent of matched sibling transplant recipients had advanced disease at time of transplant compared with 25% of matched unrelated donor transplant recipients.

Univariate and multivariate analyses were done on those patients who were alive and leukemia-free 2 years after HCT; the outcomes are shown in the table below. Median follow-up was 8.9 years.

Outcome	Unrelated donor	Sibling donor	p-value
10-year overall survival	66%	74%	0.42
10-year Leukemia-free survival	62%	72%	0.3
Late relapse mortality	17%	15%	0.97
Late non-relapse mortality	21%	13%	0.15

Multivariate analyses found that the prognostic factors contributing to inferior long-term OS and LFS included:

• Active leukemia at time of HCT
• Disease status (transplant in second complete remission vs. first complete remission)
• Poor-risk cytogenetics
• Prior chronic graft-versus-host disease (GVHD)

Age was not found to be prognostic of inferior outcomes in this study.

The researchers concluded that long-term LFS is similar, and patients who are leukemia-free 2 years after HCT can expect favorable outcomes with both donor types.

Shimoni A, et al., Biol Blood Marrow Transplant