ABSTRACT
<p><b>OBJECTIVE</b>To investigate the therapeutic effects of the conditioning regimen with busulfan plus cyclophosphamide (BU+CY) or total body irradiation plus cyclophosphamide (TBI+CY) on haploidentical stem cell transplantation (HSCT) in hematologic malignancy.</p><p><b>METHODS</b>The clinical outcomes of 77 HSCT recipients with hematologic malignancy from January 2001 to December 2010, including 21 AML, 33 ALL, 19 CML and 4 MDS were retrospectively evaluated. Among them, 65 patients obtained complete remission (CR) and 12 non-remission (NR) before transplantation; 39 patients received conditioning regimen with BU+CY, and 38 with TBI+CY.</p><p><b>RESULTS</b>There were no statistically significant differences in hematopoietic reconstitution, disease free survival (DFS), and transplant- related mortality (TRM) between two groups. The estimated 3- years overall survival (OS) was 56.4% for BU+CY and 31.6% for TBI + CY (P=0.0283). The overall relapse rate was similar between two groups (15.4% vs 34.2%; P=0.1538). However, the accumulative probability of relapse at 1-year was significantly lower in BU+CY than that in TBI+CY group (2.56% vs 26.67%; P=0.0116). The incidence of grade II-IV graft-versus-host disease (GVHD) was similar between two regimens (20.5% in BU+CY group and 18.4% in TBI+CY group; P=0.8168). The incidence of chronic GVHD (cGVHD) was higher in the TBI+CY group than that of BU+CY group (84.6% vs 41.1%; P=0.0007). The extensive GVHD obtained the similar outcome (30.8% vs 10.5%; P=0.0416).</p><p><b>CONCLUSION</b>Patients using BU+CY as conditioning regimen before transplant could obtain a better 3 year OS and lower short-term relapse rate. The TBI+CY conditioning regimen could significantly increase the incidence of cGVHD without increasing the acute GVHD. BU+CY conditioning regimen could be used for HSCT, but the attention should be paid to prevent the related hemorrhagic cystitis.</p>