Stem cell transplantation is often used in patients with hematologic cancers who have had chemotherapy to help rebuild their blood-forming and immune systems. But not every patient has a stem cell donor who is a close enough genetic match. In these cases, doctors may use umbilical cord blood, which is a rich source of stem cells. Cord blood collections from two newborns (a “double-unit” transplant) can be used to increase the number of cord blood cells patients receive, further enhancing their recovery. But even in this case, recovery can take a long time.
“Expansion” is a method of growing cord blood cells in the laboratory to generate a larger number of blood stem cells for transplantation. In this study, researchers want to see if giving a patient with lymphoma or acute leukemia one expanded unit of cord blood plus a non-expanded unit results in faster recovery of blood counts after transplantation than giving two units of non-expanded cord blood.
Patients will be randomly assigned to receive either (a) one expanded unit of cord blood plus one non-expanded unit, or (b) two non-expanded units.