Autologous blood cell transplantation versus HLA-identical sibling transplantation for acute myeloid leukemia in first complete remission: a registry study

©F err at S tor ti F ou nd ati o ling donor myeloablative transplantation conducted in the mid-1990s favored the allogeneic bone marrow strategy because of a lower probability of relapse, despite the high incidence of treatment-related mortality of up to 30%. In all of the prospective studies, and in general during this period, autotransplants were performed with a bone marrow graft and led to treatment-related mortality rates of 820%, considerably more than with consolidation chemotherapy. Since the completion of these trials, the stem cell source for autologous transplantation has shifted from bone marrow to peripheral blood. More recent literature suggests that the treatment-related mortality is significantly lower after autologous peripheral blood cell transplantation and the reported treatment-related mortality in many series was less than 5%. One study analyzed outcomes of patients with acute myeloid leukemia in first complete remission after post-remission consolidation therapy based on donor versus no donor availability, but did not specifically investigate the cohort receiving only autologous peripheral blood cells. A recent, large prospective randomized trial of peripheral blood autotransplantation versus intensive consolidation chemotherapy showed a lower relapse rate and superior relapse-free survival, but similar overall survival for the autotransplanted cohort. The non-relapse mortality rate was 4% versus 1% for patients undergoing only consolidation chemotherapy. The majority of patients in that study had intermediate risk cytogenetics. We were interested in determining the effect of the lower treatment-related mortality rate obtained with peripheral blood autografts reported since the earlier prospective trials and whether the benefit of lower treatment-related mortality with autologous peripheral blood cell transplantation translated into better outcomes compared with those of either allogeneic bone marrow or allogeneic peripheral blood transplantation. The Center for International Blood and Marrow Transplant Research (CIBMTR) database offers a unique opportunity to conduct a comparative evaluation. We recognize the inherent limitations of a retrospective analysis of observational databases, especially in studies of hematopoietic cell transplantation in which factors affecting the patients’ selection cannot be fully determined. Here, we confirm the lower treatment-related mortality associated with autologous peripheral blood cell transplantation and report that survival was similar among patients undergoing allogeneic transplantation with peripheral blood or bone marrow from a matched sibling donor for acute myeloid leukemia in first complete remission. Our data suggest that given the similar survival outcomes, future studies addressing post-remission strategies for acute myeloid leukemia in first complete remission should include consideration of autologous peripheral blood hematopoietic cell transplantation together with post-transplant treatment strategies and appropriate stratification for prognostic factors.