Age alone should not determine whether an older patient with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) receives a blood stem cell transplant from a matched donor, researchers of the Center for International Blood and Marrow Transplant Research reported.
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. (pictured), professor in The University of Texas M. D. Anderson Cancer Center Department of Stem Cell Transplantation and Cellular Therapy.
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."
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 4 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.
Illustration: University of Texas M. D. Anderson Cancer Center.
University of Texas M. D. Anderson Cancer Center News Release (12/10/08)
Science Daily (12/07/08)
Medical News Today (12/09/08)
Abstract (Blood; 50th Annual Meeting of the American Society of Hematology; 112, Abstract 346 (11/08))