Background: Umbilical-cord blood (UCB) is increasingly considered as an alternative to peripheral blood progenitor cells (PBPCs) or bone marrow, especially when an HLA-matched adult unrelated donor is not available. We aimed to determine the optimal role of UCB grafts in transplantation for adults with acute leukaemia, and to establish whether current graft-selection practices are appropriate. Methods: We used Cox regression to retrospectively compare leukaemia-free survival and other outcomes for UCB, PBPC, and bone marrow transplantation in patients aged 16 years or over who underwent a transplant for acute leukaemia. Data were available on 1525 patients transplanted between 2002 and 2006. 165 received UCB, 888 received PBPCs, and 472 received bone marrow. UCB units were matched at HLA-A and HLA-B at antigen level, and HLA-DRB1 at allele level (n=10), or mismatched at one (n=40) or two (n=115) antigens. PBPCs and bone-marrow grafts from unrelated adult donors were matched for allele-level HLA-A, HLA-B, HLA-C, and HLA-DRB1 (n=632 and n=332, respectively), or mismatched at one locus (n=256 and n=140, respectively). Findings: Leukaemia-free survival in patients after UCB transplantation was comparable with that after 8/8 and 7/8 allele-matched PBPC or bone-marrow transplantation. However, transplant-related mortality was higher after UCB transplantation than after 8/8 allele-matched PBPC recipients (HR 1·62, 95% CI 1·18-2·23; p=0·003) or bone-marrow transplantation (HR 1·69, 95% CI 1·19-2·39; p=0·003). Grades 2-4 acute and chronic graft-versus-host disease (GvHD) were lower in UCB recipients compared with allele-matched PBPC (HR 0·57, 95% 0·42-0·77; p=0·002 and HR 0·38, 0·27-0·53; p=0·003, respectively), while the incidence of chronic, but not acute GvHD, was lower after UCB than after 8/8 allele-matched bone-marrow transplantation (HR 0·63, 0·44-0·90; p=0·01). Interpretation: These data support the use of UCB for adults with acute leukaemia when there is no HLA-matched unrelated adult donor available, and when a transplant is needed urgently. Funding: National Cancer Institute, National Heart Lung and Blood Institute, National Institute of Allergy and Infectious Disease (U24-CA76518); Health Resources and Services Administration (HHSH234200637015C); Office of Naval Research, Department of Navy (N00014-08-1-1207); Children's Leukemia Research Association; and a Scholar in Clinical Research Award from the Leukemia and Lymphoma Society.
Bibliographical noteFunding Information:
This study was supported by a Public Health Service grant ( U24-CA76518 ) from the National Cancer Institute, National Heart Lung and Blood Institute and National Institute of Allergy and Infectious Disease; Health Resources and Services Administration ( HHSH234200637015C ); the Office of Naval Research, Department of Navy to the National Marrow Donor Program ( N00014-08-1-1207 ), the Children's Leukemia Research Association, and a Scholar in Clinical Research Award from the Leukemia and Lymphoma Society (ME). Grant U24-CA76518 and HHSH234200637015C support the Center for International Blood and Marrow Transplant Research , including data collection. Grant N00014-06-01-0704 supports donor-recipient histocompatibility typing. Opinions, findings, and conclusions or recommendations expressed herein are those of the authors, and do not reflect the views of the Office of Naval Research or the National Marrow Donor Program. We acknowledge Myriam Labopin for providing data from the Acute Leukaemia Working Party, the European Group for Blood and Marrow Transplantation.