Study Evaluates Chronic Graft-vs-Host Disease Burden and Complications in Patients Receiving Bone Marrow Transplants
A University of Colorado Cancer Center study compared outcomes of leukemia patients receiving bone marrow transplants from 2009 to 2014, finding that 3 years post transplant, the incidence of severe chronic graft-vs-host disease was significantly higher in patients who had received transplants from matched unrelated donors than in patients who had received umbilical cord blood transplants. Patients who received umbilical cord blood transplants were also more likely to no longer need immunosuppression and less likely to experience late infections and hospitalizations. There was no difference in overall survival between these two techniques. Results are published by Gutman et al in Bone Marrow Transplant.
Sources of Transplant
“When you do an allogeneic transplant…the new blood system has the potential to attack the patient. This is graft-vs-host disease, which can be debilitating and even fatal. Our results show that, long-term, receiving a cord blood transplant is less likely than receiving a transplant from an unrelated, matched donor to result in graft-vs-host disease,” said Jonathan Gutman, MD, investigator at the CU Cancer Center and Clinical Director of Allogeneic Stem Cell Transplantation at University of Colorado Hospital.
A common treatment for blood cancers is to erase a patient's leukemic blood system and then regrow a new blood system using donor blood stem cells. There are four possible sources of donor cells: a matched, related donor; a matched, unrelated donor; umbilical cord blood; and haploidentical transplant. The closer the match between donor cells and a patient's blood system, the less chance of graft-vs-host disease.
A matched, related donor is the accepted first choice. Genetics dictate that siblings have a 25% chance of matching. Caucasians without a matched, related donor have a 70% chance for finding a match from databases of donors; other or mixed ethnicities have only a 10% chance of finding a matched, unrelated donor in databases of people who have agreed to give if needed. Cord blood is immature and thus does not need to be as closely matched to be acceptable as a donor source.
“Historically, doctors have reserved cord blood for patients without a match,” Dr. Gutman said.
However, this flow of preference is increasingly questioned as data including the current study demonstrate that cord blood may be equal to or better than transplant from a matched, unrelated donor.
“A lot of centers reserved cord blood transplants for their worst cases, and so it got an early reputation for being less successful. It also costs a bit more—it takes cord blood cells a little longer to get going and so patients need to be supported a little longer. However, when you look past the first 100 days—a point at which many centers stop collecting data—there is clear evidence that cord blood outperforms cells from matched, unrelated donors,” Dr. Gutman said.
Study Findings
The current study, specifically, compared 51 consecutive patients receiving umbilical cord blood transplants with 57 consecutive patients receiving transplants from matched, unrelated donors. At 3 years post-transplant, the incidence of severe chronic graft-vs-host disease was 44% in patients who had received matched, unrelated donor transplants and 8% in patients who had received umbilical cord blood transplants. Overall rates of chronic graft-vs-host disease were 68% following matched, unrelated donor transplant and 32% following umbilical cord blood transplants. Again at 3 years, patients receiving umbilical cord blood transplants had been off immunosuppression since a median 268 days from transplant; patients receiving transplants from matched, unrelated donors had not ceased immunosuppression to a degree that allowed researchers to determine the median.
“As a result, we have chosen to use cord blood as our first choice in cases where a matched, related donor is unavailable,” Dr. Gutman concluded.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
