[Allogeneic hematopoietic stem cell transplantation for treatment of refractory and relapsed acute myeloid leukemia: outcomes and prognostic factors].

Objective: To evaluate the outcomes and prognostic factors of patients with refractory and relapsed acute myeloid leukemia (AML) who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: The overall survival (OS) , disease free survival (DFS) , acute and chronic graft-versus-host disease (GVHD) , relapse rate (RR) , transplantation related mortality (TRM) and their related risk factors were analyzed retrospectively. Results: All the patients (median age 35 years, range 6 to 58) received myeloablative conditioning regimens. All patients had successful engraftment, and the median time of neutrophils engraftment was 14 days (range 9 to 25) . Of the patients who survived more than 100 days, the accumulative incidence of grade Ⅱ-Ⅳ acute GVHD and chronic GVHD (cGVHD) were 27.3% (95% CI 18.9%-36.3%) , 33.9% (95% CI 24.6%-43.5%) , respectively. Meanwhile, the accumulative incidence of extensive cGVHD was 9.3% (95% CI 4.5%-16.1%) . The 3-year OS, DFS, RR, and TRM was 45.0% (95% CI 34.6%-55.4%) , 45.0% (95% CI 34.8%-55.2%) , 36.6% (95% CI 26.9%-46.4%) and 19.7% (95% CI 12.4%-28.3%) respectively. Multivariate analysis revealed four independent risk factors: non remission status before transplantation[ P =0.009, HR =2.21 (95% CI 1.22-4.04) ], WBC at diagnosis>50×10(9)/L[ P =0.024, HR =2.11 (95% CI 1.11-4.02) ], donor age>35 years [ P =0.031, HR =1.96 (95% CI 1.06-3.60) ]and without cGVHD[ P =0.008, HR =0.38 (95% CI 0.18-0.78) ]. According to the risk factors before transplantation (non remission status, WBC at diagnosis>50×10(9)/L, donor age>35 years) , we then defined three subgroups with striking different OS at 3 years: no adverse factor (75.0%) ; one adverse factor (46.9%) ; two or three adverse factors (15.4%) ( χ (2)=26.873, P <0.001) . Conclusion: Allo-HSCT is a promising and safe choice for patients with refractory and relapsed AML and relapse is the major cause of the transplantation failure. Disease status before transplantation, donor age, WBC at diagnosis and cGVHD are confirmed as prognostic factors for these patients who received allo-HSCT.