Background: Bone marrow transplantation (BMT) is the therapy of choice for patients with chronic myeloid leukemia (CML) who have a human leukocyte antigen (HLA)-identical donor and are under 50 years of age.
Methods: Here, 45 patients with CML were treated with busulfan (Bu) 16 mg/kg and cyclophosphamide (Cy) 120 mg/kg before allogeneic BMT from an HLA-identical sibling 27 (60%) or a 1-antigen mismatch donor 18 (40%). Eighteen patients (40%) were in the early chronic phase (CP) and 27 (60%) in late CP. We used cyclosporin-A (CsA) in 20 patients and cyclosporin-A-methotrexate (CsA-MTX) in 25 for graft-vs.-host disease (GVHD) prophylaxis.
Results: We observed a high incidence of acute and chronic GVHD (69% and 67%, respectively). A multivariate analysis identified differences in the sex of the donor and the recipient (p = 0.03) and grade III-IV acute GVHD (p = 0.0001) as significant adverse influences on disease-free survival. Age, sex, chronic GVHD, disease phase, one antigen-mismatch and use of CsA or CsA-MTX had no statistical significance. The 3-year probabilities of relapse, disease-free survival, and overall survival were 11%, 55%, and 60%, respectively. Transplant-related mortality occurred in 31% of the cases. The high frequency of GVHD is explained by HLA determination by serological typing, differences in sex between the donor and recipient, and a high proportion (40%) of 1 antigen-mismatch donors.
Conclusions: BMT is a procedure feasible for patients with CML in early and late chronic phase and even in those with an HLA non-identical donor. Strategies directed to decrease acute GVHD could improve the outcome of these patients.