When a patient is diagnosed with Leukemia or another blood cancer, they generally undergo long, painful rounds of chemotherapy to eradicate the disease. But for many patients, the type of Leukemia they have or a remission in their disease means they will need a more extreme treatment — a stem cell transplant.
Generally this means a bone marrow transplant, pioneered at Seattle’s Fred Hutchinson Cancer Research Center more than 40 years ago. But about 70 percent of patients who need a transplant will need to search for a bone marrow donor on the national registry, and may never find a match.
However, there is another option for these patients, one that can easily match them with donors and may even be more effective: an umbilical cord blood transplant.
At the moment this procedure is still considered ‘alternative’ instead of standard, but a study published today in the New England Journal of Medicine by researchers from Fred Hutch’s Cord Blood Program found that patients who received cord blood transplants fared the same or even better than those who had bone marrow transplants.
Researchers hope that these findings will encourage the medical community to accept widespread use of the procedure, and open the door to more in-depth studies.
The study examined 582 patients treated at the Seattle Cancer Care Alliance, who had either Leukemia or myelodysplastic syndrome, a blood disease that is also treated with stem cell transplants. The patients all received either a traditional bone marrow transplant or a cord blood transplant.
Dr. Colleen Delaney, director of the Cord Blood Program and a pioneer of research in the field, said that patients who received cord blood transplants had the same outcome as those who received bone marrow transplants.
“Most importantly, there is an advantage to the use of cord blood when patients had any evidence of disease coming into their transplant,” Delaney said.
Because cord blood contains less stem cells than bone marrow, it takes longer to act on a patient’s immune system, leaving them vulnerable to infection and other diseases in the short term, Delaney said.
But in the long run, these patients have a lower risk of relapse and mortality than those who received bone marrow transplants, and for high-risk patients who have relapsed or who have resistant strains of Leukemia, the cord blood actually gave them an advantage over bone marrow. In addition to being as or more effective, cord blood is also more flexible than bone marrow in matching patients to donors.
“With the inventory that we have right now worldwide, we can find cord blood that is suitable in about 95% of the cases, which is very unique,” said Dr. Filippo Milano, the lead author of the study.
Delaney and Milano are hoping that this finding will push caregivers and hospitals to consider cord blood transplants, particularly for patients who cannot find a related donor.
Delaney said the short-term risk to patients is a large reason caregivers are hesitant to adopt the procedure. This risk could be reduced by increasing the number of stem cells in a cord blood donation, which Delaney is working to do both at Fred Hutch and biotech startup Nohla Therapeutics, where she serves as the Chief Medical Officer.
Delaney explained that another huge advantage to cord blood is the ease of donation. While bone marrow donors must undergo surgery or take strong medications, “there’s no risk to the patient or the mother to collect a cord blood unit at birth,” Delaney said.
“It’s easy, as long as a mom is delivering in a facility that will collect and is working with a public cord blood bank,” she said, adding that Seattle’s BloodWorks NW has a public cord blood bank and many mothers delivering at Seattle hospitals can choose to donate their cord blood there.
“Unfortunately, the vast majority is still thrown in the trash,” Delaney said, because mothers don’t know about the process or because there is no public cord blood bank in their area.
Although this is still an emerging area of study, and widespread adoption of cord blood transplants would require changes to medical culture and infrastructure, the research points to a promising solution for patients in dire circumstances.