Allogeneic Hematopoietic Cell Transplant for Acute Myeloid Leukemia: No Impact of Pre-transplant Extramedullary Disease on Outcome

The impact of extramedullary disease (EMD) in AML on the outcomes of allogeneic hematopoietic cell transplantation (alloHCT) is unknown. Using data from the Center for International Blood and Marrow Transplant Research (CIBMTR) we compared the outcomes of patients who had EMD of AML at any time prior to transplant to a cohort of AML patients without EMD. We reviewed data AML from 9,797 patients including 814 with EMD from 310 reporting centers and 44 different countries who underwent alloHCT between and 1995–2010. The primary outcome was overall survival (OS) after alloHCT. Secondary outcomes included leukemia-free survival (LFS), relapse rate, and treatment-related mortality (TRM). In a multivariate analysis, the presence of EMD did not affect either OS (HR 1.00, 95% CI 0.91–1.09), LFS (0.98, 0.89–1.09), TRM (RR 0.92, 95% CI 0.80–1.16, p=0.23) or relapse (RR =1.03, 95% CI, 0.92–1.16; p=0.62). Furthermore, the outcome of patients with EMD was not influenced by the location, timing of EMD, or intensity of conditioning regimen. The presence of EMD in AML does not affect transplant outcomes and should not be viewed as an independent adverse prognostic feature.