Clinical outcomes of unrelated donor umbilical cord blood transplantation for 30 adults with hematological malignancies

Background: Umbilical cord blood transplantation (CBT) has increasingly been used as a therapeutic option for adult patients for whom allogeneic stem- cell transplantation is not indicated, due to the availability of cord blood. However, myeloablative conditioning regimens are associated with significant mortality, and high relapse rates in reduced-intensity regimens may result in a poor rate of disease-free survival for those with advanced stages of hematological malignancies. Therefore, it remains unknown whether CBT is a truly effective option for such adults with high-risk disease, as well as for those with standard-risk disease. Patients and Methods: Thirty adult patients with a median age of 45 years (range: 16-67) with standard or high-risk disease underwent CBT from unrelated donors at Okayama University Hospital between October 2002 and May 2007. Twenty-one patients had diseases classified as high-risk for transplantation. The median number of nucleated cells in infused cord blood was 2.65×10⁷/kg (range: 1.73-4.87). Results: Twenty-three patients achieved neutrophil engraftment at a median time of 22 days (range: 13-42) after CBT. The cumulative incidence of grade II to IV acute graft-versus-host disease (GVHD) was 53.6%. Out of the 30 patients, 11 were alive and disease-free at a median time of 446 days (range: 124-1153) after CBT. The cumulative 1-year overall survival in patients with standard-risk or high-risk disease was 63.5% and 15.4%, respectively (p=0.01). Conclusion: Although from a retrospective study, these results suggest that unrelated donor CBT could be safe and effective for adult patients with standard-risk disease who cannot find a suitable HLA-matched volunteer marrow or peripheral blood donor.