Evaluating oncogenic pathway dysregulation in adolescents and young adults with acute myeloid leukemia.

Abstract

7107 Background: Adolescent and young adults (AYAs) with Acute Myeloid Leukemia (AML) have been shown to have better outcomes with induction chemotherapy when compared to older young adults (OYAs). Multiple psychosocial, treatment, and host-related factors unique to AYAs have been identified but the contribution of disease biology to these outcomes has not yet been fully characterized. The purpose of this study was to evaluate disease biology as it relates to age-specific differences in outcomes for AYAs with AML. Methods: Clinically annotated, microarray data from 425 patients with newly diagnosed AML from two publicly available datasets: GSE1159; and GSE12417 were analyzed. Age-specific cohorts (AYAs ≤ 30 years; n = 58 and OYAs >30 but ≤ 60 years; n=276) were prospectively identified. Patients in GSE1159 were treated according to protocols of the Dutch–Belgian Hematology–Oncology Cooperative group and included 111 patients who ultimately underwent stem-cell transplantation. Patients in GSE12417 were treated per the AMLCG-1999 protocol. Gene expression analysis was conducted by applying previously defined and tested signature profiles reflecting deregulation of oncogenic signaling pathways and altered tumor environment. All statistical analysis was performed using S-plus and survival analysis by Cox proportional-hazards regression was used to assess differences in overall survival (OS) between age-specified study cohorts and a one-sided p-value ≤ 0.05 was considered statistically significant. Results: AYA patients had a significantly better OS (median survival 24.1 months vs. 13.0 months in OYAs; p=0.0285), but there was no difference in Event Free Survival (p=0.23). Analysis of oncogenic pathways revealed that AYA patients likely had better OS because of lower TNF (p=0.03) and higher myc (p=0.02) pathway activation. Conclusions: AML arising in AYAs may represent a distinct biologic entity characterized by unique patterns of deregulated signaling pathways that contributes to OS. We hope these findings will enable clinically meaningful adjustments of treatment strategies in the AYA AML patient population.