NEW YORK (Reuters Health) – Transfusion of two rather than one unit of partially HLA-matched umbilical cord blood (UCB) appears to reduce the risk of relapse in leukemia patients in first or second complete remission, new research shows.
“Our analysis showed that patients in first or second remission from the leukemia had a significantly lower likelihood of leukemia recurrence if they were transplanted with two UCB units than if they were transplanted with one (19% vs. 34%),” lead author Dr. Michael Verneris, from the University of Minnesota Medical School, Minneapolis, said in a statement.
The findings, reported in the November 5th issue of Blood, stem from a study of 88 patients with acute lymphoblastic leukemia (ALL) and 89 with acute myeloid leukemia (AML) who were treated at a single center.
Fifty-three percent of the subjects received two units of UCB and 47% received one unit. Cyclophosphamide and total body irradiation with or without fludarabine were used for conditioning.
The median time to relapse was 209 days, and the relapse rate was 26% at 5 years, the report indicates. The relapse rates for patients with ALL and AML were comparable, hovering around 26%.
Patients with advanced disease (three or more complete remissions in the past) were 3.6-times more likely to experience a relapse than were those with less advanced disease (one or two complete remissions). Use of 2 units of UCB rather than 1 unit reduced the risk of relapse in patients with advanced disease by 40%, but this was not statistically significant.
In subjects with less advanced disease, use of 2 UCB units rather than 1 cut the risk of relapse by 50% (p < 0.03).
No significant difference in leukemia-free survival at 5 years was noted between subjects given 1 UCB unit and those given 2 units: 40% vs. 51%.
“We believe our finding provides evidence that using two units of UCB for transplantation may be more effective in preventing leukemia relapse and gives hope to patients with hematological malignancies so that they may live cancer-free,” Dr. Verneris concluded.