Effect of donor age on adult unrelated donor haemopoietic cell transplant outcome: the Australian experience

Background: Results have been varied regarding the effect of donor age on the outcome of unrelated donor haemopoietic cell transplantation (HCT).

Aims: To determine the influence of donor age on adult unrelated donor HCT outcome in Australia.

Methods: Patients were included in the study if they were aged 16 years or above and underwent first allogeneic unrelated donor HCT in Australia for the indications of acute lymphoblastic leukaemia (ALL), acute myelogenous leukaemia (AML), chronic myelogenous leukaemia (CML) or myelodysplastic syndromes (MDS) between the years of 2001 and 2014 inclusive. The main outcome measure was overall survival (OS), which was tested against independent variables using univariate Kaplan-Meier methods and multivariate Cox regression.

Results: A total of 1158 unrelated donor HCT were represented in the data. Cumulative incidences of engraftment, transplant related mortality (TRM), acute graft-versus-host disease (GvHD), chronic GvHD and relapse were not significantly affected by donor age. OS probability at 5 years post-transplant was 48.3%. In multivariate analysis of OS, year of transplant 2001-2007, recipient age 40 years or greater, poor risk disease, human leukocyte antigen (HLA) match less than 6/6 and poor performance status at transplant (Karnofsky scale) were independently significant adverse OS risk factors. Donor age was not a significant risk factor for OS in univariate or multivariate analysis.

Conclusions: The conclusion from this study was that donor age (up to 59 years) did not influence post-transplant outcome among adult unrelated donor HCT performed in Australia for haematologic malignancies.