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 leuc ocyte antigen (HLA)-identical sibling donors conditioned with either busulf an and cyclophosphamide (BU/CY regimen) or total body irradiation and cyclo phosphamide (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 gra ft-versus-host disease (GVHD) was 9% of BU/CY and 52% of TBI/CY patients. O verall incidence of chronic GVHD was 50% of BU/CY and 52% of TBI/CY patient s. 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 diseas e-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 relap sed; 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 pat ients 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 rat e 0%) compared with the TBI/CY group (5-yr relapse rate 30%). The BU/CY gro up 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.