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A cord blood transplant (CBT) may be the best option for patients with acute leukemia or myelodysplastic syndrome who have minimal residual disease (MRD) and no related donor, according to the senior author of a study published in NEJM.
This retrospective study showed that patients with MRD at the time of transplant were less likely to relapse if they received CBT rather than a graft from an unrelated adult donor, whether HLA-matched or mismatched.
In addition, the risk of death was significantly higher for patients with a mismatched donor than for CBT recipients, although there was no significant difference between those with a matched donor and CBT recipients.
Among patients without MRD, there were no significant differences between the transplant types for the risk of relapse or death.
“This paper shows that if you’ve got high-risk disease and are at high risk for relapse post-transplant, transplant with a cord blood donor may be the best option,” said Colleen Delaney, MD, of Fred Hutchinson Cancer Research Center in Seattle, Washington.
Dr Delaney and her colleagues analyzed data on 582 patients—300 with acute myeloid leukemia, 185 with acute lymphoblastic leukemia, and 97 with myelodysplastic syndromes.
Most patients received a transplant from an HLA-matched unrelated donor (n=344), 140 received a CBT from an unrelated donor, and 98 received a transplant from an HLA-mismatched unrelated donor.
The researchers calculated the relative risks of death and relapse for each transplant group, and they found that a patient’s MRD status prior to transplant played a role.
Presence of MRD
Among patients with MRD, the risk of death was significantly higher for recipients of mismatched grafts than for CBT recipients, with a hazard ratio (HR) of 2.92 (P=0.001).
However, the risk of death was not significantly different for recipients of matched grafts compared to CBT recipients. The HR was 1.69 (P=0.08).
The risk of relapse was about 3 times higher for recipients of mismatched grafts (HR=3.01, P=0.02) or matched grafts (HR=2.92, P=0.007) than for CBT recipients.
No MRD
Among patients without MRD, there was no significant difference in the risk of death for recipients of CBT, mismatched grafts (HR=1.36, P=0.30), or matched grafts (HR=0.78, P=0.33).
And there was no significant difference in the risk of relapse for recipients of CBT, mismatched grafts (HR=1.28, P=0.60), or matched grafts (HR=1.30, P=0.46).
“This brings home the point that cord blood shouldn’t be called an alternative donor,” Dr Delaney said. “The outcomes are the same as a conventional donor.”
