Study Discounts Age Limit on Stem Cell Transplants

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The following news release was issued by Elsevier's Global Medical News. This and other Elsevier Global Medical News releases are available by subscription at sites such as OncologySTAT.

Study Discounts Age Limit on Stem Cell Transplants

Elsevier Global Medical News
December 8, 2008
S. Boschert

SAN FRANCISCO (EGMN) - Age should no longer be a contraindication to allogeneic stem cell transplantation, according to the investigators in a large retrospective study presented at the annual meeting of the American Society of Hematology.

The study included data on more than 1,000 patients older than 65 years who underwent nonmyeloablative hematopoietic stem cell transplantation to treat acute myeloid leukemia or myelodysplastic syndromes at 89 medical centers. Outcomes were similar in different age groups after adjustment for other risk factors, investigator Dr. Sergio Giralt said at a press conference Dec. 8.

The only factors that significantly predicted outcomes were disease status at the time of transplantation and the degree of tissue-type match between recipient and donor, said Dr. Giralt, professor of medicine at the University of Texas M. D. Anderson Cancer Center, Houston.

The lead investigator, Dr. Brian McClune of the University of Minnesota, Minneapolis, was to formally present the study in a separate session later at the meeting.

The researchers stratified patients into four age groups, ranging from 40-54 years to 65 years or older. The groups did not differ significantly in rates of acute graft-versus-host disease (31%-35% at 100 days after transplant), chronic graft-versus-host disease (36%-53% after 2 years), disease relapse (29%-39% after 3 years), transplant-related mortality, leukemia-free survival, or overall survival.

The data came from the U.S.-based Center for International Blood and Marrow Transplant Research for patients who underwent reduced-intensity conditioning regimens and allogeneic hematopoietic stem cell transplantation from 1995 to 2005.

The Centers for Medicare and Medicaid Services covers hematopoietic cell transplantation for older adults with acute myeloid leukemia but not myelodysplastic syndromes, Dr. Giralt said.

Many physicians are hesitant to do allogeneic stem cell transplants in older patients regardless of payment issues, added Dr. Armand Keating, who moderated the press conference. "The reluctance is based on physicians' perceptions about toxicity," said Dr. Keating, director of hematology and professor of medicine at the University of Toronto. "One of the reasons this study is important is that it dispels that notion," he added.

Most patients in the study underwent fludarabine-containing regimens for conditioning, received peripheral blood stem cell transplants (in 76%-79% of patients across age groups), and got cyclosporine-containing regimens for prophylaxis against graft-versus-host disease.

The 565 patients with acute myeloid leukemia were more likely to present with de novo disease instead of previously diagnosed disease and to receive an allograft from a matched related donor rather than an unrelated donor. Among patients aged 65 years or older with acute myeloid leukemia, 51% received stem cell transplants from matched related donors.

The 551 patients with myelodysplastic syndromes were more likely to get allografts from unrelated donors, especially in the oldest age group; 73% of patients aged 65 years or older with myelodysplastic syndromes received stem cell transplants from unrelated donors.

The 1-year overall survival rates were 35%-62% in patients with myelodysplastic syndromes and 39%-68% in patients with acute myeloid leukemia in a univariate analysis. The 1-year leukemia-free survival rates were 29%-65% in patients with myelodysplastic syndromes and 35%-61% in patients with acute meyloid leukemia.

The investigators had no relevant conflicts of interest.