Research Shows Umbilical Cord Blood Comparable to Bone Marrow
Cord blood is readily available; leukemia patients currently wait months for a matched bone marrow donor.
University of Minnesota researchers report that umbilical cord blood transplants may offer blood cancer patients better outcomes than bone marrow transplants. Results are from the first study that directly compares matched bone marrow, which is currently preferred, with matched and mismatched umbilical cord blood. There is considerable controversy in the medical community about whether cord blood or marrow stem cells should be considered the “gold standard” for treatment of childhood leukemia.
The research appeared in the June 9, 2007, issue of The Lancet with John E. Wagner, M.D., professor of Pediatrics and director of the University of Minnesota Medical School’s division of Pediatric Hematology/Oncology and Bone Marrow Transplantation, as senior investigator.
Study Aims to Provide Guidelines for Donor Selection
In the study, investigators compared pediatric leukemia patients who received unrelated bone marrow transplants with those who received umbilical cord blood transplants. While all bone marrow donors were matched, nearly all cord blood donors were mismatched.
The objective of the research was to provide guidelines to transplant physicians on the selection of the best donor for children with leukemia. Remarkably, mismatched cord blood performed as well as matched bone marrow as measured by leukemia-free survival rates. Furthermore, study participants who received matched cord blood had a 20 percent higher survival rate than matched bone marrow recipients, though the number of matched cord blood transplants was small.
Umbilical Cord Blood Readily Available
“What this study suggests is that cord blood need not be considered a second line therapy. The fact that cord blood is banked and readily available with little notice is a great advantage. Today, leukemia patients can wait months for an appropriately matched bone marrow donor, during which time their disease might return,” Wagner said. “For the first time, the timing of transplantation can be dictated by the patient’s needs as opposed to the availability of the matched bone marrow.”
The study showed that umbilical cord blood is associated with a lower risk of graft versus host disease (GVHD). Rates of leukemia relapse also are lower with mismatched umbilical cord blood transplants. In addition to having a good match, higher cell doses for umbilical cord blood transplants improved survival rates.
The research suggests that it will become more important to invest in cord blood banks that meet standards of cell dose and donor matching criteria. In addition, increasing the inventory of cord blood will increase the chance of finding donors for ethnic and racial minorities. These populations are currently underrepresented in volunteer marrow registries worldwide.
The study was done in collaboration with the National Cord Blood Program of the New York Blood Center, New York. Mary Eapen, M.D., associate professor of Pediatrics at the Medical College of Wisconsin and Associate Scientific Director of the CIBMTR, is the first author. Outcome data analysis was performed at the Center for International Blood and Marrow Transplant Research (CIBMTR), Medical College of Wisconsin, Milwaukee.
The study was conducted by extensive review of clinical data from transplant centers around the country and reported to the CIBMTR at the Medical College of Wisconsin, Milwaukee and the National Cord Blood Program at the New York Blood Center. The analysis included transplant outcomes in 785 children younger than 16 who had the diagnosis of acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML).