Age and Modified European LeukemiaNet Classification to Predict Transplant Outcomes: An Integrated Approach for Acute Myelogenous Leukemia Patients Undergoing Allogeneic Stem Cell Transplantation

Abstract

We evaluated the prognostic significance of a modified European LeukemiaNet (ELN) classification for patients with acute myelogenous leukemia (AML) undergoing hematopoietic stem cell transplantation (HSCT) while in first complete remission (CR1). We analyzed 464 AML patients with matched related (n= 211, 45.5%), matched unrelated (n= 176, 37.9%), and mismatched donors (n= 77, 16.6%). Patients were classified into 4 modified ELN risk groups (favorable, intermediate-I, intermediate-II, and adverse) separately for 354 patients age < 60 years and 110 patients age ≥ 60 years. In this modified version of ELN classification, patients with normal cytogenetic were classified by FLT3-ITD mutational status: favorable risk if FLT3-ITDwild and intermediate-I if FLT3-ITDmut. The best outcomes occurred in the ELN favorable and intermediate-II groups in younger AML patients and in the favorable and intermediate-I groups in older AML patients. Older AML patients had worse transplant outcomes within each modified ELN risk group except intermediate-I when compared with younger patients; leukemia-free survival at 3 years was 67.8% versus 49.8% in favorable, 53.4% versus 50.7% in intermediate-I, 65.7% versus 20.2% in intermediate-II, and 44.6% versus 23.8% in adverse group younger and older patients, respectively. Among lesion-specific abnormalities, del5q/-5 and abnl(17p) had the worse transplant outcomes, with 3-year leukemia-free survival rates of 18.4% and 20% in younger CR1 patients. In conclusion, the modified ELN prognostic classification developed for chemotherapy outcomes also identifies prognostic groups for HSCT, which is useful for a selection of patients for post-transplant strategies to improve outcomes.