Are matched unrelated donor transplants justified for AML in CR1?

There has been controversy about the optimal consolidation therapy for patients with acute myeloid leukemia (AML) in first remission. Hematopoietic stem cell transplantation from human leukocyte antigen (HLA)-identical siblings has improved the survival of patients with unfavorable cytogenetics, but has not improved the survival of intermediate- or favorable-risk patients. If an HLA-identical sibling donor is not available, alternative sources of stem cells may be sought. HLA mismatched transplants are associated with an increased risk of graft rejection and graft-versus-host disease, and lower survival. Since large registries of HLA-typed volunteer donors have been established and the newer and more sensitive tissue typing technology can more clearly differentiate between matched and unmatched donors, some AML patients without an HLA-matched sibling have received transplants from an HLA-matched unrelated donor while in first remission. Data from the Center for International Blood and Marrow Transplant Research indicate that survival of patients with unfavorable cytogenetics appears at least as good with unrelated donor grafts as previously reported for matched sibling grafts, and better than consolidation chemotherapy. AML patients in first remission with unfavorable cytogenetics without a matched family donor should be offered an unrelated donor transplant.