Comparative Single Institute Analysis of Cord Blood Transplantation From Unrelated Donors with Unrelated Bone Marrow or Related Peripheral Blood Stem-Cell Transplants in Adult Patients with Acute Myeloid Leukemia / Myelodysplastic Syndrome.
Authors: Masuoka Kazuhiro , Ishiwata Kazuya , Tsuji Masanori , Takagi Shinsuke , Yamamoto Hisashi , Mori Yuki , Matsuno Naofumi , Uchida Naoyuki , Wake Atsushi , Makino Shigeyoshi , Yoneyama Akiko , Taniguchi Shuichi 
Published: October 2019

Abstract
Abstract 3382
Poster Board III-270
Recently, unrelated cord blood transplant (UCBT) has been widely applied to those who lack available related or unrelated donors. However, some results in those reports were conflicting, especially for transplantation-related mortality (TRM). The US study demonstrated a poor outcome for TRM in CBT recipients compared with human leukocyte antigen (HLA)–matched bone marrow transplant (BMT) recipients (NEJM. 2004; 351:2265). On the other hand, Takahashi et al showed excellent outcome (TRM 9% and disease free survival, DFS 70%) in CBT (Blood. 2007; 109:1322). Since there has been not much data available regarding this issue, we retrospectively extracted to adult patients with acute myeloid leukemia (AML) / myelodysplastic syndrome (MDS) and analyzed retrospectively the results of 245 recipients who underwent allogeneic stem cell transplantation (allo-SCT).
We reviewed medical records of 290 patients with AML/MDS who had received allo-SCT from an unrelated donor between June 2000 and March 2009 at our institute, Tokyo, Japan. Since patients who had previous hematopoietic stem cell transplantations, active serious infection and performance status > 2, were excluded, 45 were subjected to the following analysis. Finally, the study includes 245 recipients of UCB (n = 140), UBM (n = 63), and related mobilized peripheral blood (RPB, n = 42) for de novo AML (n = 132), MDS overt AML (n = 79), refractory anemia (RA, n = 15), and refractory anemia with excess of blasts (RAEB, n = 19).
Patient s median age for UCB, UBM, and RPB recipients were 59 (17 - 72), 55 (23 – 70), and 55 (22 – 67), respectively. UCB recipients had more serologically HLA-mismatched grafts (97% vs. 38% vs. 22%, P < .01), were conditioned more frequently with melphalan (75% vs. 27% vs. 20%, P < .01) and with total body irradiation (86% vs. 80% vs. 12%, P < .01 and used more tacrolimus (78% vs. 81% vs. 15%, P < .01) and less methotrexate (0% vs. 98% vs. 85%, P < .01) for graft-versus-host disease (GVHD) prophylaxis. Disease status consisted of standard (CR1 or CR2 of AML and RA, n = 62) and advanced groups(other status, n = 183). UCB recipients had significantly advanced status relative to UBM and RPB recipients (84% vs. 57% vs. 69%, P < .01) at the time of transplantation. Other characteristics such as sex, diagnosis, and body weight were balanced among three groups. Median follow-up time of survivors was 787 days (119 – 2314), 1050 days (244 – 3059), and 1287 days (141 – 3004) for UCB, UBM, and RPB recipients, respectively. The incidence of grade II–IV acute GVHD among evaluable UCB recipients was lower than those of UBM and RPB recipients (32% vs. 54% vs. 59%, P < .01). Similarly, the incidences of chronic GVHD for evaluable UCB, UBM, and RPB recipients were 36%, 69%, and 66%, respectively (P < .01). The estimated overall survival (OS) and DFS rates at 5 years post-transplantation were 36% (95% confidence interval Åm95%CIÅn; 25 - 47%) and 35% (95%CI; 26 - 44%) for UCB, 55% (95%CI; 40 - 69%) and 51% (95%CI; 37 - 64%) for UBM, and 39% (95%CI; 22 - 55%) and 25% (95%CI; 8 - 41%) for RPB (OS, P < .01 and DFS, P < .01). In the standard group, OS and DFS rates were not significantly different in the three groups (OS, UCB 63% vs. UBM 70% vs. RPB 49%, P = .39 and DFS, UCB 63% vs. UBM 70% vs. RPB 39%, P = .10). Similarly, in the advanced group, there were not significantly difference in the three groups (OS, UCB 30% vs. UBM 41% vs. RPB 35%, P = .23 and DFS, UCB 29% vs. UBM 38% vs. RPB 24%, P = .27). Compared with UBM and RPB recipients, UCB recipients had delayed hematopoietic recovery at 60 day (UCB 85% vs. UBM 97% vs. RPB 100%, Hazard ratio ÅmHRÅn= 0.49; 95%CI: 0.40 0.59; P < .01). Five-year estimated TRM and relapse rate (RR) were not significantly different in the three groups (TRM, UCB 34% vs. UBM 29% vs. RPB 50%, P = .39 and RR, UCB 30% vs. UBM 20% vs. RPB 28%, P = .28).

< Conclusion>
In this analysis, there was no apparent difference in the risks of TRM and RR between the UCB and UBM/RPB recipient groups. OS and DFS in both groups were also comparable among standard and advanced groups. Finally, our clinical results suggest that UCBT could be as safe and effective a stem-cell source as UBMT or RPB transplant for adult AML/MDS patient.

Disclosures:
No relevant conflicts of interest to declare.