The EBMT Risk Score in the Presence of Graft Versus Host Disease in Allogeneic Stem Cell Transplantation in Adult Acute Myelogenous Leukemia: A Multistate Model for Competing Risks

The aim of this study was to assess the predictive effect of the EBMT risk score on the outcomes of allogeneic stem cell transplantation in a relatively homogenous group of acute myelogenous leukemia (AML) patients regarding the occurrence of acute and chronic graft versus host disease (GVHD). This historical cohort study included adult patients (≥ 15 years old) with AML (n=363) who received allogeneic peripheral blood stem cell transplantation from HLA-identical sibling donors in the first or higher complete remission following myeloablative conditioning regimens between 2004 and 2011.The patients recruited in this study were followed-up until January 2013. Patients with acute promyelocytic leukemia (APL) were excluded from the study. Early outcomes until day +100 and events after day +100 were regarded for acute and chronic GVHD, respectively. A multi state model for competing risks was applied.We found that the EBMT risk score was a good predictor for overall survival (OS) and relapse incidence; however, it was not associated with transplant-related mortality (TRM). The EBMT risk score was not associated with acute and chronic GVHD. For early outcomes, the predictive effect of the EBMT risk score was not statistically significant in the presence of acute GVHD; however, in the presence of chronic GVHD, it was a significant predictor of relapse but not for TRM. It seems that the effect of EBMT risk score on OS and relapse incidence cannot be affected by GVHD. Although the results were insignificant, there was evidence that the EBMT risk score can predict early outcomes, while for late outcomes, it works well for relapse and OS but not for TRM.