The stem cell-associated gene expression signature allows risk stratification in pediatric acute myeloid leukemia

Despite constant progress in prognostic risk stratification, children with acute myeloid leukemia (AML) still relapse. Treatment failure and subsequent relapse have been attributed to acute myeloid leukemia-initiating cells (LSC), which harbor stem cell properties and are inherently chemoresistant. Although pediatric and adult AML represent two genetically very distinct diseases, we reasoned that common LSC gene expression programs are shared and consequently, the highly prognostic LSC17 signature score recently developed in adults may also be of clinical interest in childhood AML. Here, we demonstrated prognostic relevance of the LSC17 score in pediatric non-core-binding factor AML using Nanostring technology (ELAM02) and RNA-seq data from the NCI (TARGET-AML). AML were stratified by LSC17 quartile groups (lowest 25%, intermediate 50% and highest 25%) and children with low LSC17 score had significantly better event-free survival (EFS: HR = 3.35 (95% CI = 1.64-6.82), P < 0.001) and overall survival (OS: HR = 3.51 (95% CI = 1.38-8.92), P = 0.008) compared with patients with high LSC17 scores. More importantly, the high LSC17 score was an independent negative EFS and OS prognosticator determined by multivariate Cox model analysis (EFS: HR = 3.42 (95% CI = 1.63-7.16), P = 0.001; OS HR = 3.02 (95% CI = 1.16-7.85), P = 0.026). In conclusion, we have demonstrated the broad applicability of the LSC17 score in the clinical management of AML by extending its prognostic relevance to pediatric AML.