Outcome of adolescents and young adult acute myeloid leukemia patients compared with middle-aged patients: a single centre retrospective experience

Adult acute myeloid leukemia (AML) patients under the age of 60 often receive similar intensive treatments, while outcomes between the adolescent and young adult (AYA) age group (18-39) and middle-aged adults (40-60 years) were seldom reported. We aim to study the characteristics and outcomes of AYA patients in comparison to middle-aged adults. A retrospective analysis was performed on AYA patients treated at Princess Margaret Cancer Center between 2008 and 2018. The primary outcomes include overall survival (OS), cumulative incidence of relapse (CIR), and non-relapse mortality (NRM). A total of 174 AYA patients and 176 middle-aged patients were included, with propensity score matching adjusting for potential major confounders. Comparing AYA and middle-aged patients, 5-year OS rates were similar at 54.6 % vs. 56.5 % (p=0.91), CIR rates at 29.5 % vs. 23.1 % (p=0.31), and similar NRM rates. Notably, non-transplanted AYA patients had a significantly higher CIR (39.8 %) compared to middle-aged patients (19.6 %) (p=0.0324), with more primary refractory/early relapsing disease. An observed trend toward improved OS in AYA patients post-2015 coincided with FLAG-IDA and haploidentical transplant implementations. In conclusion, the study suggests that AYA patients, particularly those not undergoing transplantation, may benefit from more intensive treatment strategies, emphasizing the need for tailored approaches in this age group.