The lives of both adults and children with leukemia can be saved with bone marrow or stem cell transplants, but it’s difficult to find a match. Well, a new study shows that (umbilical) cord-blood may work just as well, if not better. 
Lead study author Dr. Filippo Milano says:
“Often, cord-blood transplant is thought to be only as the last resource for patients without donors. But cord blood does not have to be considered only an alternative donor source. In centers with experience, it can yield to great outcomes.”
Doctors recommend bone marrow transplants, in which health blood cells are taken from a donor, then given to patients with leukemia when chemotherapy and radiation fail to halt the spread of cancerous blood cells, which destroy a person’s immune system. 
Traditional Transplants can be Problematic
In traditional transplants, blood cells are taken from either the bone marrow or the blood. Before a transplant is undertaken, the patient is typically given high doses of chemotherapy and radiation to wipe out the individual’s faulty blood cells so they can be replaced by the healthy ones from a donor.
It’s an extremely risky process, because it leaves the patient vulnerable to life-threatening infection for months before the rejuvenated immune system begins to function.
A patient’s body would almost always reject blood cells from anyone who wasn’t a perfect or near-perfect match, which usually proved to be fatal. However, umbilical-cord stem cells are about as pristine as cells can get – they haven’t been exposed to many bacteria or viruses.
Even when umbilical-cord stem cells aren’t a perfect match, they are more easily accepted by the recipient’s body.
The Hope of Cord-Blood
For the study, Milano and his colleagues reviewed nearly 600 leukemia and blood-disorder patients who received any stem-cell transplant at the Fred Hutchinson Cancer Research Center in Seattle between 2006 and 2014. They found that the chance of survival was at least as high, and sometimes higher, in patients who received cord-blood rather than the standard transplants. 
They also found that patients who received cord-blood had a lower risk of relapse overall, even compared to those who received a traditional bone marrow or stem cell transplant from donors who were a close match.
Many people die while waiting for a bone marrow or blood cell donor. According to Be the Match, which operates the national donor program, a patient’s likelihood of finding a donor match on the registry ranges from 66% to 97%, depending on ethnic background. 
With cord-blood, however, nearly everyone has a match.
Dr. Juliet Barker, director of the cord-blood-transplant program at Memorial Sloan Kettering Cancer Center in New York, who wasn’t involved in the work, says:
“This report supports not only cord blood taking the priority over a mismatched unrelated donor, but the consideration of cord blood as an immediate alternative source of stem cells to matched adult volunteer donor transplants, especially in high-risk patients.” 
Barker is calling for a national, randomized, controlled trial of patients with high-risk leukemia, comparing individuals who receive matched unrelated donor transplants and those who receive cord-blood transplants.
A larger trial using umbilical cord blood that had been expanded in a lab is underway. 
The study appears in The New England Journal of Medicine.