Patients get equal survival benefit, even with less-than-perfect match, study finds
HealthDay Reporter
 
FRIDAY, June 8 (HealthDay News) -- Transplanted blood cells from umbilical cords appear to give better results than the bone marrow transplants that have been standard for leukemia patients, a new study finds.
 
"From my point of view, it now demonstrates that cord blood can be considered a first-line therapy and not an afterthought," said lead researcher Dr. John E. Wagner, director of the bone marrow transplant program at the University of Minnesota.
 
His team published its findings in the June 9 issue of The Lancet.
 
One way to treat various leukemias is to wipe out the old blood cell system and replace it with a new one via transplant. This study of 785 children under 16 who got such transplants found essentially equal five-year survival rates for the 503 patients who underwent transplantation with umbilical cord blood and the 282 who got bone marrow transplants.
 
That held true even when the transplanted blood cord cells did not match the immunological system of the recipients, a mismatch that can lead to severe side effects or rejection of the transplant, Wagner said.
 
"With bone marrow, you have to match eight antigens," he said. "In cord blood, you need to look at only six, and only need four matches."
 
Indeed, five-year survival was identical for recipients of perfectly matched bone marrow and cord blood recipients with two mismatches, Wagner said. That matching flexibility could expand the field considerably, because right now bone marrow matches cannot be found for half of all leukemia patients who need transplants, he said.
 
"With cord blood you can find a match for most patients, where with marrow you cannot," Wagner said. "The take-home message is that when cord blood is so promising, it should have an impact on public policy."
 
And yet the system for extracting and storing cord blood cells still has many gaps, he said. For example, "there is no [cord] banking effort" in Wagner's home city of Minneapolis, he said.
 
Cord blood transplants, originally done only in children, now are performed routinely for adults with leukemia, Wagner added. "Of the 8,000 transplants done to date, half have been in adults," he said. "Our next study will be to look at the outcome in adults."
 
Other studies also are needed, Wagner said, including those that compare the cost of the two types of transplant. "There is no economic analysis comparing bone marrow and cord blood transplants," he said. "We also need to look at the quality of life."