Unrelated bone marrow transplantation in patients with myelodysplastic syndromes and secondary acute myeloid leukemia: an EBMT survey. European Blood and Marrow Transplantation Group.

The Chronic Leukemia Working Party of the EBMT has collected data on 118 patients of median age 24 years (range 0.3 to 53 years) who underwent an allogeneic bone marrow transplantation from unrelated donors for treatment of MDS or secondary AML (RA/RARS, n = 24; RAEB, n = 26; RAEB-t, n = 34; CMML, n = 12; sAML, n = 22) between 1986 and 1996. The data were reported by 49 EBMT centers. Thirty-four of 118 patients are alive, relapse was the cause of death in 19 of 84 patients and the remaining patients died of transplant-related mortality. For the whole group the actuarial probability of survival at 2 years is 28%, disease-free survival 28%, relapse risk 35% and transplant-related mortality is 58%. The transplant-related mortality is significantly influenced by the age of the recipient (<18 years 40%, 18-35 years 61%, >35 years 81%). The relapse rate after BMT is influenced by FAB classification of the disease at BMT. Patients with a low blast count (RA, RAEB) have a lower probability of relapse (13%, 15%) compared to patients with RAEB-t or sAML (29%, 45%). Furthermore, we found evidence of a graft-versus-leukemia effect in MDS/sAML. Patients with acute GVHD, grade II-IV, had a probability of relapse of 26% vs 42% in patients with no acute GVHD or grade I only. Allogeneic transplantation with an HLA-matched, unrelated donor may be offered to younger patients (age <35 years) with poor risk myelodysplasia or secondary AML.