A comparison of busulphan versus total body irradiation combined with cyclophosphamide as conditioning for autograft or allograft bone marrow transplantation in patients with acute leukaemia. Acute Leukaemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT).

We retrospectively compared the outcome in patients in the EBMT database transplanted for acute leukaemia from January 1987 to January 1994 who received busulphan and cyclophosphamide (BU/CY) as a pretransplant regimen versus those who received cyclophosphamide and total-body irradiation (CY/TBI). The patients were matched for type of transplant (autologous bone marrow transplantation (ABMT) versus allogeneic (BMT)), diagnosis (acute lymphoblastic leukaemia (ALL) or acute myeloid leukaemia (AML)), status (early (first complete remission, CR-1) versus intermediate (second or later remission, first relapse)), age, FAB classification for AML, prevention of graft-versus-host disease and year of transplantation. In ABMT recipients (matched paired 530 x 2) with ALL CR-1, AML CR-1 and AML intermediate disease, transplant-related mortalities (TRM) relapse incidence (RI) and leukaemia-free survival (LFS) did not differ significantly in patients treated with BU/CY or CY/TBI. However, in ABMT recipients with ALL intermediate disease, the probability of relapse was 82 +/- 5% (+/- 95% confidence interval) in the BU/CY group compared to 62 +/- 6% in the CY/TBI group (P = 0.002) and the 2-year leukaemia-free survival 14 +/- 4% and 34 +/- 6%, respectively (P = 0.002). In BMT recipients of bone marrow from HLA-identical siblings (matched paired 391 x 2), the TRM, RI and LFS did not differ significantly between the two treatments in all groups. In particular, the 2-year LFS in patients with AML CR-1 was 64 +/- 3% in those treated with BU/CY (n = 237) compared to 66 +/- 3% in those given CY/TBI (n = 237). In all groups the findings were confirmed in a multivariate analysis of prognostic factors. Veno-occlusive disease (VOD) of the liver (P < 0.05) and haemorrhagic cystitis (P < 0.001) was more common in the BU/CY group compared to the CY/TBI group for ABMT and BMT patients. In conclusion, BU/CY and CY/TBI as pretransplant regimens gave similar results in all situations, except ABMT for ALL intermediate stages with more than 2 years from diagnosis to transplantation, where a lower RI and a higher LFS were associated with CY/TBI.