Bone Marrow or Peripheral Blood Stem Cell Transplantation From Unrelated Donors in Adult Patients With Acute Myeloid Leukemia

In leukemia patients, peripheral blood stem cells (PBSC) have replaced bone marrow (BM) as stem cell source. No study has shown any benefit using PBSC versus BM in matched unrelated donor (MUD) transplantation. We therefore compared PBSC and BM in MUD recipients with acute myeloid leukemia (AML). Between 1997 and 2008, 760 patients received BM and 1,502 PBSC from a MUD. The PBSC group were older age (p < 0.01), had more advanced disease (p < 0.0001), received less total body irradiation (p < 0.0001), and more antithymocyte globulin (p = 0.01). Recovery of neutrophils and platelets was faster with PBSC (p < 0.0001). Acute GVHD was similar, but chronic GVHD was increased in the PBSC group (HR 1.29, p = 0.02). Non-relapse mortality (NRM), relapse and leukemia-free survival (LFS) did not differ between the two groups, in AML patients in remission. However, in patients with advanced AML, NRM was decreased (HR 0.61, p = 0.02) and LFS was improved (HR 1.49, p = 0.002) using PBSC. At 3 years, LFS for all patients, regardless of remission status, was 41±1% for both groups. PBSC compared to BM in MUD transplants in AML resulted in: faster neutrophil and platelet recovery, not statistically different acute GVHD, increased chronic GVHD and same rates of LFS in remission patients. In advanced AML, the PBSC group had decreased NRM and improved LFS.