Allogeneic bone marrow tranplantation for young adult patients with newly diagnosed acute myeloid leukemia: HLA-Matched sibling donor availability does not improve treatment ouctome

In order to assess the place of HLA-identical allogeneic bone marrow transplantation (BMT) and to compare it to other post-induction therapies, we analyzed patient outcome in intention-to-treat based on the presence or not of an HLA-identical familial donor in young adults with de novo acute myeloid leukemia (AML) in first complete remission (CR). Between 1985 and 1998, 152 consecutive AML patients aged less than 41 years old, seen in our institution, were treated according to 3 different successive protocols (LYLAM85, LAM90, AML10). 144/152 patients entered our prospective study in which they were registered at time of diagnosis for presence or absence of HLA-identical donor and analyzed in intention-to-treat. In this study, 52 patients (36%), who had at least one identical sibling donor (group 1), were offered allogeneic BMT after CR achievement. The 92 patients without donor were allocated to group 2 and were assigned to receive chemotherapy or autologous transplantation as post-remission according to the protocol they were initially included in. Patients from both groups had similar disease characteristics at diagnosis. Karyotypes at diagnosis were defined as low risk (t(8;21) or t(15;17) or chromosome 16 abnormalities(, intermediate risk (normal karyotypes), or high risk (other abnormalities). Overall, 114/152 patients (75%) achieved a CR. Of the 144 eligible patients, 46/52 (88%) with a donor and 68/92 (74%) without a donor achieved a CR. The median follow-up duration of the 144 patients was 21.2 months. The relapse rate was higher in group 2 (56%) than in group 1 (31%). However, the overall survival was not different between patients with and without donor (median survival respectively at 16.7 months and 26.6 months with estimated survival at 5 years respectively at 32% and 34%). Thirty-four patients from group 1 (65%) were actually transplanted in first CR. The probability of 5-year survival for patients receiving effectively allogeneic BMT was 44% and was not significantly better than that of patients who did not. In univariate as in multivariate analysis, karyotypic status was the main prognostic factor for CR achievement (p = 0.002), CR duration (p < 0.0001), and overall survival (p < 0.0001). There were no significant differences between group 1 and group 2 when survivals were compared with adjustment for karyotypes.We conclude that the availability of an HLA-identical sibling donor did not confer any prognostic advantage in terms of outcome for young adults with AML in first CR. These results make allogeneic BMT process questionable as systemic post-remission therapy in patients with an HLA-identical familial donor.