A new hope for leukemia patients that transplantation of umbilical cord blood is as effective for them as bone marrow transplantation. A University of Minnesota-led study has shown that the Patients receiving cord blood had the same five-year leukemia-free survival rates as those who received bone marrow.
Moreover, the cord blood didn’t have to be matched to the recipient; as long as the degree of mismatch was limited and the number of cord blood cells available was sufficient.
“This has tremendous implications,” says senior investigator John Wagner, a University of Minnesota professor of pediatrics and director of the division of pediatric hematology/oncology and bone marrow transplantation. “It means we can find donors now for a majority of our patients. In the United States, for African Americans [the capability is about] twenty percent, confined to partially matched donors in the marrow registries.”
In their study, Wagner and his colleagues analyzed data from transplant centers around the country. The researchers compared 503 cord blood recipients with various degrees of mismatching to 282 “gold standard” matched bone marrow recipients, looking for difference in the five-year survival rate. The results were eye-opening.
In cord blood, “with every increment in mismatch, we found a correspondingly increased anti-leukemia effect. That means the risk of relapse of leukemia became substantially lower with every level of mismatch.”
Umbilical cord blood also was associated with a lower risk of graft versus host disease. “This is quite a surprise finding,” he says. “It’s of particular importance to those patients who can’t even find donors in the marrow donor registries.”
“What this study suggests is that cord blood need not be considered a second line of therapy any longer,” says Wagner. “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.”