Stem cells derived from umbilical cord blood are a viable and effective transplant source for leukemia patients who have no other treatment options, according to an article in the November 24th issue of the New England Journal of Medicine.

Nearly 16,000 American leukemia patients diagnosed each year require a bone marrow transplant, but have no matched relative or cannot find a match in the national bone marrow registry, according to Mary Horowitz, MD, senior author of the study.

Horowitz, who is scientific director of the Center for International Blood and Marrow Transplant Research, pointed out that “umbilical cords that are normally discarded after birth could provide real hope for these patients.”

In the current study, researchers led by Mary J. Laughlin, MD, analyzed and compared treatment results for more than 500 adult leukemia patients undergoing transplant. Investigators directly compared patients who had cord−blood stem cell transplants with patients who had fully−matched unrelated bone marrow transplants and patients who had one−antigen−mismatched unrelated bone marrow transplants. The study included patients ages 16 to 60 years who underwent transplants in the United States during 1996 to 2001.

Survival rates were highest (33 percent) for people whose bone marrow transplants were done with matched unrelated donors. Survival rates were the same (22 percent) for cord blood and one−antigen−mismatched unrelated bone marrow transplant patients−results that clearly indicate the efficacy of cord blood stem cells when matched bone marrow donors are unavailable, according to Dr. Laughlin.

She said, “These are very high risk patients who undergo cord blood transplants only as a last resort effort to stay alive. Even with a cord blood transplant, these patients often suffer from life−threatening infections. But the fact is, without attempting this innovative therapy, none of them would survive.”

“Techniques that extend the availability of stem cell transplantation to those patients in desperate need are an important and valuable step in the right direction,” said Marshall Lichtman, MD, The Leukemia & Lymphoma Society’s Executive Vice President. “The study gives renewed hope to adult patients without a sibling stem cell donor. Continued research is needed, however, to improve the outlook for the large proportion of patients who do not yet benefit from these approaches.” The Society helped fund the study.

“The fact is, approximately 20,000 leukemia patients nationwide need transplants but only 20 percent of them have a sibling match, so there remains a large group−about 16,000 patients−who are forced to seek donors from a marrow donor registry in hopes of finding a match from donors who aren’t related to them,” Dr. Laughlin says. “But only a small percentage of patients are lucky enough to find a transplant match at the registry, which is why the cord blood transplant is so important.”