We conducted a retrospective study of 155 children who underwent unrelated donor hematopoietic cell transplantation (HCT) between 1990 and 2005 for acute lymphoblastic leukemia in third remission. The median patient age was 11 years, the median time from diagnosis to first relapse was 36 months, and the median time from first relapse to second relapse was 26 months. Stem cell sources were bone marrow (n = 115), peripheral blood (n = 11), and cord blood (n = 29). All patients received a myeloablative pretransplantation conditioning regimen. The 5-year estimates of leukemia-free survival, relapse, and nonrelapse mortality were 30%, 25%, and 45%, respectively. In multivariate analysis, the only risk factor associated with relapse was the interval between the first relapse and the second relapse. Second relapses occurring >26 months from the first relapse were associated with lower risk for post-HCT relapse compared with second relapses occurring at ≤26 months (relative risk, 0.4; P =.01). Relapse risk was lowest when late second relapse was preceded by late first relapse (>36 months from diagnosis), as demonstrated by a 3-year relapse rate of 9% (P =.0009). Our data indicate that long-term leukemia-free survival can be achieved in children with acute lymphoblastic leukemia in third remission using unrelated donor HCT, especially when the second relapse occurs late.
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Financial disclosure: The Center for International Blood and Marrow Transplant Research is supported by Public Health Service Grant/Cooperative Agreement U24-CA76518 from the National Cancer Institute (NCI), the National Heart, Lung and Blood Institute (NHLBI) and the National Institute of Allergy and Infectious Diseases (NIAID) ; Grant/Cooperative Agreement 5U01HL069294 from the NHLBI and NCI ; Contract HHSH234200637015C from the Health Resources and Services Administration ; Grants N00014-06-1-0704 and N00014-08-1-0058 from the Office of Naval Research ; and grants from AABB, Allos Inc, Amgen Inc , an anonymous donation to the Medical College of Wisconsin, Astellas Pharma US Inc, Be the Match Foundation, Biogen IDEC, BioMarin Pharmaceutical Inc, Biovitrum AB, Blood Center of Wisconsin, Blue Cross and Blue Shield Association, Bone Marrow Foundation, Buchanan Family Foundation, CaridianBCT, Celgene Corporation, CellGenix, ClinImmune Labs, CTI Clinical Trial and Consulting Services, Eisai Inc, Genentech Inc, Genzyme Corporation, Histogenetics Inc, HKS Medical Information Systems, Hospira Inc, Kirin Brewery Co Ltd, Merck & Company, Medical College of Wisconsin, Millennium Pharmaceuticals Inc, Miller Pharmacal Group, Milliman USA Inc, Miltenyi Biotec Inc, National Marrow Donor Program, Nature Publishing Group, Novartis Oncology, Oncology Nursing Society, Osiris Therapeutics Inc, Otsuka America Pharmaceutical Inc, Pall Life Sciences, Pfizer Inc, Schering Corporation, Sigma-Tau Pharmaceuticals, Soligenix Inc, StemCyte Inc, StemSoft Software Inc, Sysmex America Inc, THERAKOS Inc, Vidacare Corporation, ViraCor Laboratories, ViroPharma Inc, and Wellpoint Inc. The views expressed in this article do not reflect the official policy or position of the National Institute of Health, the Department of the Navy, the Department of Defense, or any other agency of the US Government. The authors have no conflicts of interest to disclose.
- Advanced ALL
- Nonrelapse mortality