Background and methods: It is uncertain whether mortality rates among patients who have undergone bone marrow transplantation return to the level of the mortality rates of the general population. We analyzed the characteristics of 6691 patients listed in the International Bone Marrow Transplant Registry. All the patients were free of their original disease two years after allogeneic bone marrow transplantation. Mortality rates in this cohort were compared with those of an age-, sex-, and nationality-matched general population. Cox proportional-hazards regression was used to identify risk factors for death more than two years after transplantation (late death).
Results: Among patients who were free of disease two years after transplantation, the probability of living for five more years was 89 percent (95 percent confidence interval, 88 to 90 percent). Among patients who underwent transplantation for aplastic anemia, the risk of death by the sixth year after transplantation did not differ significantly from that of a normal population. Mortality remained significantly higher than normal throughout the study among patients who underwent transplantation for acute lymphoblastic leukemia or chronic myelogenous leukemia and through the ninth year among those who underwent transplantation for acute myelogenous leukemia. Recurrent leukemia was the chief cause of death among patients who received a transplant for leukemia, whereas chronic graft-versus-host disease was the chief cause among those who received a transplant for aplastic anemia. Advanced, long-standing disease before transplantation and active chronic graft-versus-host disease were important risk factors for late death.
Conclusions: In patients who receive an allogeneic bone marrow transplant as treatment for acute myelogenous or lymphoblastic leukemia, chronic myelogenous leukemia, or aplastic anemia and who are free of their original disease two years later, the disease is probably cured. However, for many years after transplantation, the mortality among these patients is higher than that in a normal population.