One-unit versus two-unit cord-blood transplantation for hematologic cancers

Area of Science:

• Hematology
• Transplantation Immunology
• Pediatric Oncology

Background:

• Umbilical cord blood (UCB) is a source of hematopoietic stem cells for transplantation.
• Limited cell numbers in single UCB units can lead to delayed recovery and higher mortality in larger recipients.
• This study investigated if using two UCB units improves outcomes compared to one.

Purpose of the Study:

• To compare the efficacy of double-unit versus single-unit UCB transplantation in pediatric patients with hematologic cancers.
• To determine if increased hematopoietic cell numbers from two UCB units improve survival and reduce complications.
• To evaluate secondary endpoints including disease-free survival, engraftment, and graft-versus-host disease (GVHD).

Main Methods:

• A randomized trial involving 224 pediatric patients (1-21 years) with hematologic cancer.
• Patients received either double-unit (111) or single-unit (113) UCB transplants post-myeloablative conditioning.
• The primary endpoint was 1-year overall survival, with secondary endpoints including GVHD and recovery rates.

Main Results:

• One-year overall survival rates were similar: 65% for double-unit and 73% for single-unit (P=0.17).
• Disease-free survival, neutrophil recovery, relapse, and infection rates were comparable between groups.
• Single-unit UCB transplants demonstrated improved platelet recovery and lower incidences of severe acute and chronic GVHD.

Conclusions:

• Single-unit and double-unit UCB transplantation yield similar survival rates in pediatric hematologic cancer patients.
• Single-unit UCB transplantation is associated with better platelet recovery and a reduced risk of GVHD.
• These findings suggest single-unit UCB may be preferable due to lower GVHD risk and improved platelet recovery.