Allogeneic hematopoietic stem cell transplantation for adult AML patients with granulocytic sarcoma

We recently reported that adult acute myeloid leukemia (AML) patients with granulocytic sarcoma (GS) possessed unique clinical features and poor prognosis. However, the optimal therapeutic strategy for this entity has not been established. Therefore, the aim of this study was to assess the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for the management of AML with GS. We retrospectively analyzed 503 consecutive adult AML patients (median age, 44 years; range, 15-73 years) who received allo-HSCT. A total of 44 patients (8.7%) had GS before transplantation. Patients with GS achieved comparable survival to those without GS (5-year overall survival (OS), 47% vs 44%, respectively, P=0.621). In patients with GS, excellent outcomes were seen in those that underwent allo-HSCT while in complete remission, whereas nine out of ten patients with GS at the time of transplant experienced a relapse within 6 months after allo-HSCT. Local irradiation for GS prior to allo-HSCT and acute and chronic graft-versus-host disease did not affect survival significantly. Multivariate analysis identified age, disease status and the use of myeloablative conditioning as independent prognostic factors for OS. These data suggest that better control of GS prior to allo-HSCT is crucial to improve the outcome of transplantation for those with GS.