OBJECTIVETo evaluate the treatment outcome of HLA-identical sibling allogeneic hematopoietic stem cell transplantation (allo-HSCT) for chronic myelogenous leukemia (CML) patients in first chronic phase (CP(1)).

METHODSFifty-one patients with CML-CP(1) received HLA-identical sibling allo-HSCT with conditioning regimens of TBI plus Cy or Bu plus Cy. Allogeneic peripheral blood stem cell transplantation (PBSCT) and bone marrow transplantation (BMT) were performed for 28 and 23 patients, respectively. The median follow-up duration was 1434 (60 - 4062) days.

RESULTSFifty (98.0%) patients were successfully engrafted. Transplant-related mortality occurred in 8 (15.7%) patients. Acute graft-versus-host disease (aGVHD) occurred in 35 (68.6%) patients and 11 (21.6%) patients were grade II-IV, while chronic GVHD (cGVHD) did in 17 (37.8%) patients. Five (7.4%) patients relapsed. The 5-year probability of disease-free survival (DFS) was (79.2 +/- 6.4)%. There was no significant difference in 5-year DFS, death rate and treatment related syndromes between the two conditioning regimens (P > 0.05), and in 5-year DFS, relapse rate and death rate between two transplant choices (P > 0.05). However, the rate of relapse was lower in Bu/Cy group (P < 0.01) and the rate of cGVHD was higher in allo-PBSCT group (P < 0.05).

CONCLUSIONSAllo-HSCT can cure a significant proportion of patients with CML-CP(1). There was no significant difference in DFS between the two different conditioning regimens and between the different transplant choices. Donor lymphocyte infusion is a therapeutic alternative for CML patients relapsed after transplantation.