Age alone should not determine whether an older patient with acute myeloid leukemia or myelodysplastic syndrome receives a blood stem cell transplant from a matched donor, researchers of the Center for International Blood and Marrow Transplant Research reported today at the 50th annual meeting of the American Society of Hematology.
Patients older than 65 do just as well as younger patients with transplants that are preceded by a milder chemotherapy regimen, according to an intensive analysis of every such transplant for AML or MDS conducted in North America between 1995-2005, said senior researcher Sergio Giralt, M.D., professor in The University of Texas M. D. Anderson Cancer Center Department of Stem Cell Transplantation and Cellular Therapy. The analysis also included international transplant data.
The retrospective study of 551 transplants for MDS and 565 for AML showed that age had no statistically significant impact on transplant-related mortality, relapse, leukemia-free survival or overall survival.
"These findings will be important in changing practice for the treatment of older patients," Giralt said. "We also hope the findings persuade the Centers for Medicaid and Medicare Services to recommend coverage of this therapy for MDS patients, as it does now for AML."
Findings will be presented at the meeting Monday morning by Dan McClune, D.O., of the University of Minnesota Masonic Cancer Center Department of Leukemia.
Matched donor, or allogenic, blood stem cell transplants originally were preceded with high-dose chemotherapy that destroyed the patient's blood supply before transplant. For patients over 65, this "myeloablative" chemotherapy was too toxic and therefore outcomes were poor.
Giralt and colleagues at M. D. Anderson pioneered the use of less-intensive chemotherapy that did not annihilate a patient's blood supply. This "non-myeloablative" preparation opened the door for older patients to receive the potentially curative transplants.
Still, some hesitancy has remained even for non-myeloablative transplants for older patients. Lack of Medicare coverage also reduces the number of patients who can receive the treatment, Giralt said.
The research project divided patients into four age groups: 40 to 54, 55-59, 60-64, and 65-plus. In addition to finding no statistically significant difference in survival across age groups, the researchers found no difference in acute or chronic graft-vs.-host disease.
The two most important prognostic variables were disease type and status of disease at transplant, which affected survival in the first year, and affected transplant-related mortality and relapse in the second year after transplant.
Giralt and Daniel Weisdorf, M.D., of the School of Medicine at Washington University, designed and proposed the research project to the Center for International Blood and Marrow Transplant Research. The CIBMTR is a joint effort of all stem cell transplant centers, which report their results to the center to facilitate research such as this study.
Co-authors on the study with McClune, Giralt and Weisdorf are John DiPersio, M.D., Ph.D. of Princess Margaret Hospital in Toronto; Armand Keating, M.D., and Tanya Pederson of the CIBMTR in Milwaukee; Gisela Tunes da Silva, Ph.D., of the Medical College of Wisconsin; J. Sierra, M.D., of the Hospital De Sant Pau in Barcelona, Spain; and Martin Tallman, M.D., of the Northwestern University Feinberg School of Medicine.
The research was funded by the CIBMTR.