Allogeneic bone marrow transplantation for chronic myeloid leukemia: a retrospective study of busulfan-cytoxan versus total body irradiation-cytoxan as preparative regimen in Koreans

From January 1990 to December 1997, 53 Korean patients with chronic myeloid leukemia (CML) receiving bone marrow transplantation (BMT) from human leucocyte antigen (HLA)-identical sibling donors conditioned with either busulfan and cyclophosphamide (BU/CY regimen) or total body irradiation and cyclophosphamide (TBI/CY regimen) were compared retrospectively. Transplantation-related mortality was 19% in BU/CY and 12% in TBI/ CY, and early death (< 100 d) occurred in 3 patients conditioned with BU/CY. Grade II-IV acute graft-versus-host disease (GVHD) was 9% of BU/CY and 52% of TBI/CY patients. Overall incidence of chronic GVHD was 50% of BU/CY and 52% of TBI/CY patients. In patients with chronic phase, 5-yr overall survival was 73% in the BU/CY group compared with 87% in the TBI/CY group (p = NS), and overall disease-free survival was 75% in the BU/CY group and 59% in the TBI/ CY group (p = NS). So far, with a median follow-up of 45 months, Il patients have relapsed; three relapses occurred after BU/CY and 8 after TBI/CY. The actuarial 5-yr relapse rate was 15% after BU/CY, 34% after TBI/CY (p = 0.46). For patients transplanted in chronic phase within I yr after diagnosis, there was a clear trend for a lower relapse rate in the BU/CY group (5-yr relapse rate 0%) compared with the TBI/CY group (5-yr relapse rate 30%). The BU/CY group had similar BMT-related toxicity and similar overall survival and showed a clear trend of low relapse compared with the TBI/CY group. Therefore, BU/CY is an acceptable alternative for patients with CML during HLA-identical sibling allogeneic BMT.