A cord blood transplant is only considered now as a last resort for leukemia patients without donors, but a new study suggests that the treatment option may be just as effective as current alternatives to bone marrow or stem cell transplants and may even be better than them under certain circumstances.
One of the ways to treat leukemia and myelodyplastic syndrome, a condition related to the disease, is to replace the patient's bone marrow via a transplant. In an ideal situation, a patient will receive bone marrow from a relative, preferably a sibling with compatible blood. Unfortunately, what's ideal is not always possible, which occurs in about 70 percent of leukemia cases.
When this happens, the next step is to find an unrelated but compatible donor. When that too is a problem, an unrelated donor who is mostly compatible with the patient will be the next choice.
In a study published in the New England Journal of Medicine, researchers suggest another option: cord-blood transplant.
To assess how cord-blood transplant fares in comparison to other transplant options, the researchers worked with 582 patients diagnosed with either leukemia or myelodysplastic syndrome. If an unrelated donor was not available, patients were either provided with a cord-blood transplant or a bone marrow or stem cell transplant from an incompatible donor.
"Our study showed that overall survival after cord-blood transplantation was comparable to the one observed after matched unrelated transplants," said Filippo Milano, the study's lead author, adding that cord-blood recipients also lived longer than patients who underwent transplants with non-matching bone marrow or stem cells.
Specifically, cord-blood transplants were most beneficial to a certain subset of patients. Those diagnosed with "minimal residual disease" have small amounts of cancer cells in their body left after undergoing chemotherapy prescribed before a transplant.
Patients with minimal residual disease are at high risk of relapse, but those who got cord-blood transplants enjoyed significantly lower risks than their counterparts who received other transplants.
While the researchers were able to show that cord blood tolerates mismatches between donors and patients, they are not clear on why it is better at keeping cancer at bay than other transplant options in certain situations.
Transplantation experts support the results of the study, but warn against saying that cord-blood transplants can take the place of procedures done with fully matched donors.
According to the Leukemia & Lymphoma Society, a person in the United States receives a diagnosis for a blood cancer every three minutes. And in 2016, some 171,550 people are expected to be diagnosed with myeloma, lymphoma or leukemia, with new cases accounting for 10.2 percent of the 1,685,210 new cancer cases that will be diagnosed in the year in the country.
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