Hematopoietic Stem Cell Transplant Recipients Surviving at Least 2 Years from Transplant Have Survival Rates Approaching Population Levels in the Modern Era of Transplantation

Abstract

The health and outcomes of long-term survivors after hematopoietic cell transplant (HCT) are areas of evolving interest as short-term transplant outcomes improve. Because recent changes in transplant practice have likely changed the survivor population, we sought to assess the survival of a contemporary cohort of patients who were alive and free of disease 2 years after HCT. Data were extracted from first transplants documented between 2002 and 2011 in the Australasian Bone Marrow Transplant Recipient Registry on patients who received an allogeneic HCT for acute myeloid leukemia (AML), acute lymphoblastic leukemia, chronic myeloid leukemia (CML), non-Hodgkin lymphoma, and myelodysplastic syndromes or an autologous HCT for myeloma or lymphoma. Patients were included if they had survived at least 2 years without disease relapse or progression. Mortality rates were compared with standard Australian and New Zealand populations using relative-survival analysis. A total of 1562 allogeneic and 3822 autologous HCT patients were included, with a median follow-up of 5.6 years. Compared with a matched group of patients from our previous study from 1992 to 2001, the contemporary cohort of allogeneic HCT recipients was older and more likely to receive peripheral blood stem cells and from unrelated donors. Allogeneic HCT for AML increased, wheresa transplants for CML fell from 32% to 8%. Increasing use of reduced-intensity conditioning and unrelated donors was also seen. Long-term survival after allogeneic and autologous HCT were very similar to the previous 1992 to 2001 cohort despite changes in practice over time. Recipients of autologous HCT for myeloma demonstrated substantially lower overall survival than HCT for other indications with no clear plateau. Annual relative survival for survivors of allogeneic HCT was 96% to 99% of the general population but only 89% to 96% of the general population for recipients of autologous HCT. Late deaths were primarily due to nonrelapse causes after allogeneic HCT, but relapse or disease progression remained prominent for recipients of autologous HCT, particularly for myeloma. The management of late HCT effects is important to improve long-term survival of transplant recipients but should be tailored to the risks specific to the primary disease and transplant type. Future planning should account for the impact of the expected increase in transplant activity and number of survivors on resource utilization.

Keywords: Allogeneic HCT; Autologous HCT; Late effects; Late mortality; Relative survival.