Unrelated donor umbilical cord blood transplantation versus unrelated donor bone marrow transplantation in adult and pediatric patients: A meta-analysis.

The effect of unrelated donor bone marrow transplantation (UBMT) and unrelated donor cord blood transplantation (UCBT) on the outcome of patients with hematological diseases remains controversial. We conducted a meta-analysis using data from controlled clinical trials comparing UCBT to UBMT in patients undergoing hematopoietic stem cell transplantation. Pooled comparisons of studies of UCBT and UBMT in children found that the incidence of chronic graft-versus-host disease (GVHD) was lower with UCBT (relative risk [RR]=0.41; 95% confidence interval [CI] (0.25, 0.68)), and the incidence of grades II-IV aGVHD was also significantly different (RR=0.69; 95% CI (0.55, 0.86)). The incidence of relapse was also lower with UCBT (RR=0.72; 95% CI (0.59, 0.87)). There was no difference in OS in children when studies were pooled (Hazard ratio [HR]=1.25; 95% CI (0.87, 1.78)). For adults, OS (HR=1.26; 95% CI (1.13, 1.40)) was statistically different. Thus, UCBT led to inferior outcomes than UBMT in adults.