PBSCT is associated with poorer survival and increased chronic GvHD than BMT in Japanese paediatric patients with acute leukaemia and an HLA-matched sibling donor

Background: Peripheral blood stem cells (PBSC) may be used as an alternative to bone marrow (BM) for allogeneic transplantation. Since peripheral blood stem cell bank from unrelated volunteer donor has been started in Japan, use of PBSC allografts may be increased. Therefore we surveyed the outcomes of Japanese leukemia children after PBSC and BM transplantation. Procedure: This retrospective study compared the outcomes of 661 children (0-18 years) with acute lymphoblastic leukaemia (ALL) or acute myeloid leukaemia (AML) who received their first allogeneic peripheral blood stem cell transplantation (PBSCT; n=90) or bone marrow transplantation (BMT; n=571) from HLA-matched siblings between January 1996 and December 2007. Result: Neutrophil recovery was faster after PBSCT than after BMT (ALL: P<0.0001; AML: P=0.0002), as was platelet recovery (ALL: P=0.0008; AML: P=0.0848). However, the cumulative incidence of chronic graft-versus-host disease (GvHD) was higher after PBSCT than after BMT (ALL: 26.0% vs. 9.9%, P=0.0066; AML: 41.6% vs. 11.1%, P<0.0001). The 5-year disease-free survival (DFS) was lower after PBSCT than after BMT for ALL (40.6% vs. 57.1%, P=0.0257). The 5-year overall survival (OS) was lower after PBSCT than after BMT for ALL (42.4% vs. 63.7%, P=0.0032) and AML (49.8% vs. 71.8%, P=0.0163). Multivariate analysis revealed the use of PBSC was a significant risk factor for DFS and OS. PBSCT and BMT did not differ in relapse rate, acute GvHD for ALL and AML, or in DFS for AML. Conclusion: PBSC allografts in Japanese children engraft faster but are associated with poorer survival and increased chronic GvHD.