Purpose: Allogeneic hematopoietic cell transplantation (HCT) is curative but is associated with life-threatening complications. Most deaths occur within the first 2 years after transplantation. In this report, we examine long-term survival in 2-year survivors in the largest cohort ever studied.
Patients and methods: Records of 10,632 patients worldwide reported to the Center for International Blood and Marrow Transplant Research who were alive and disease free 2 years after receiving a myeloablative allogeneic HCT before 2004 for acute myelogenous or lymphoblastic leukemia, myelodysplastic syndrome, lymphoma, or severe aplastic anemia were reviewed.
Results: Median follow-up was 9 years, and 3,788 patients had been observed for 10 or more years. The probability of being alive 10 years after HCT was 85%. The chief risk factors for late death included older age and chronic graft-versus-host disease (GVHD). For patients who underwent transplantation for malignancy, relapse was the most common cause of death. The greatest risk factor for late relapse was advanced disease at transplantation. Principal risk factors for nonrelapse deaths were older age and GVHD. When compared with age, sex, and nationality-matched general population, late deaths remained higher than expected for each disease, with the possible exception of lymphoma, although the relative risk generally receded over time.
Conclusion: The prospect for long-term survival is excellent for 2-year survivors of allogeneic HCT. However, life expectancy remains lower than expected. Performance of HCT earlier in the course of disease, control of GVHD, enhancement of immune reconstitution, less toxic regimens, and prevention and early treatment of late complications are needed.