People who undergo nonmyeloablative stem cell transplants, or "mini transplants," for leukemia, lymphoma, and other blood cancers have comparable outcomes regardless of whether they receive tissue-matched stem cells from a related or unrelated donor, according to new findings by researchers at Fred Hutchinson Cancer Research Center.
"The main message for referring physicians is that if the patient is a candidate for a nonmyeloablative, or mini, transplant but does not have a suitable related donor, the transplant should not be delayed provided a matched unrelated donor is available," said Marco Mielcarek, MD, PhD, Clinical Research Division Faculty, Fred Hutchinson Cancer Research Center (pictured).
This is a significant finding because historically, "standard" (myeloablative) stem cell transplants from unrelated matched donors have been associated with increased risk of non-relapse mortality and decreased overall survival compared to transplants from matched related donors. Only 30 percent of patients with hematologic malignancies who might benefit from a stem cell transplant have a matched related donor.
The combination of immunosuppressive drugs and the unique biology of the mini transplant may be the reasons behind the research results, Mielcarek said.
The Hutchinson Center's pioneering development 10 years ago of the mini transplant, a kinder, gentler treatment that doesn't require the intensive radiation and chemotherapy associated with standard stem cell transplants, made the therapy available to thousands of older patients who were medically unable to withstand the rigors of traditional transplantation.
Such transplants do not require a patient's marrow be destroyed with high-dose radiation and chemotherapy prior to the infusion of donor cells. The technique involves minimal radiation and substantially reduced side effects. The procedure often can be performed in an outpatient clinic.
Illustration: Fred Hutchinson Cancer Research Center.
Fred Hutchison Cancer Research Center News Release (11/30/07)
Medical News Today (12/04/07)
Science Daily (12/08/07)
Abstract (Biology of Blood and Marrow Transplantation, Volume 13, Issue 12, Pages 1499-1507 (December 2007))