Total body irradiation-based versus busulfan-based myeloablative conditioning for single-unit cord blood transplantation in adults

Abstract

Comparative studies between total body irradiation (TBI)-based and busulfan-based myeloablative conditioning (MAC) regimens for cord blood transplantation (CBT) have been limited. We retrospectively analyzed the results of single-unit CBT in 333 adult patients who received either TBI-based (n = 258) or busulfan-based (n = 75) MAC regimens at our institute. After adjusting for significant variables in the univariate analysis, there were no significant differences in neutrophil recovery (hazard ratio (HR), 0.88; p = .460), grade III–IV acute graft-versus-host disease (GVHD) (HR: 1.40, p = .410), extensive chronic GVHD (HR: 0.73, p = .380), relapse (HR: 0.61, p = .270), non-relapse mortality (HR: 1.38, p = .420), overall survival (HR: 1.18, p = .637), or event-free survival (HR: 1.08, p = .773), although platelet recovery was lower with marginal significance for the busulfan-based regimen (HR: 0.67, p = .068). In subgroup analysis, TBI-based regimens were superior to busulfan-based regimens in terms of survival for acute lymphoblastic leukemia, but not for myeloid malignancies. Further investigation is warranted even for CBT.

Keywords:

• Cord blood transplantation
• myeloablative conditioning
• total body irradiation
• busulfan
• engraftment
• survival

Acknowledgements

The authors thank all of the physicians and staff at the hospital and the Cord Blood Banks in Japan for their help in this study. We are also grateful to Prof. Shigetaka Asano for his contributions to the field and for his guidance in this study.

Ethical approval: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Due to the retrospective nature of this analysis, informed consent was not obtained from all individual participants included in this study.

Authors contributions

T.K. conceived the project, designed the research, analyzed data, and wrote the paper. J.O. and Y.N. contributed to the critical review of the manuscript. All the other authors participated in the treatment of the patients, and acquired the clinical data. All authors approved the final version.

Disclosure statement

The authors declare no competing financial interests.