Significant improvement in survival after allogeneic hematopoietic cell transplantation during a period of significantly increased use, older recipient age, and use of unrelated donors

Purpose: Over the past four decades, allogeneic hematopoietic cell transplantation (alloHCT) has evolved as a curative modality for patients with hematologic diseases. This study describes changes in use, technique, and survival in a population-based cohort. Patients and Methods: The study included 38,060 patients with hematologic malignancies or disorders who underwent first alloHCT in a US or Canadian center from 1994 to 2005 and were reported to the Center for International Blood and Marrow Transplant Research. Results: AlloHCT as treatment for acute lymphoblastic (ALL) and myeloid leukemias (AML), myelodysplastic syndrome (MDS), and Hodgkin and non-Hodgkin lymphomas increased by 45%, from 2,520 to 3,668 patients annually. From 1994 to 2005, use of both peripheral (7% to 63%) and cord blood increased (2% to 10%), whereas use of marrow decreased (90% to 27%). Despite a median age increase from 33 to 40 years and 165% increase in unrelated donors for alloHCT, overall survival (OS) at day 100 significantly improved for patients with AML in first complete remission after myeloablative sibling alloHCT (85% to 94%; P < .001) and unrelated alloHCT (63% to 86%; P < .001); 1-year OS improved among those undergoing unrelated alloHCT (48% to 63%; P = .003) but not among those undergoing sibling alloHCT. Similar results were seen for ALL and MDS. Day-100 OS after cord blood alloHCT improved significantly from 60% to 78% (P < .001) for AML, ALL, MDS, and chronic myeloid leukemia. Use of reduced-intensity regimens increased, yielding OS rates similar to those of myeloablative regimens. Conclusion: Survival for those undergoing alloHCT has significantly improved over time. However, new approaches are needed to further improve 1-year OS.