Precision oncology in AML: validation of the prognostic value of the knowledge bank approach and suggestions for improvement

Recently, a novel knowledge bank (KB) approach to predict outcomes of individual patients with acute myeloid leukemia (AML) was developed using unbiased machine learning. To validate its prognostic value, we analyzed 1612 adults with de novo AML treated on Cancer and Leukemia Group B front-line trials who had pretreatment clinical, cytogenetics, and mutation data on 81 leukemia/cancer-associated genes available. We used receiver operating characteristic (ROC) curves and the area under the curve (AUC) to evaluate the predictive values of the KB algorithm and other risk classifications. The KB algorithm predicted 3-year overall survival (OS) probability in the entire patient cohort (AUC KB = 0.799), and both younger (< 60 years) (AUC KB = 0.747) and older patients (AUC KB = 0.770). The KB algorithm predicted non-remission death (AUC KB = 0.860) well but was less accurate in predicting relapse death (AUC KB = 0.695) and death in first complete remission (AUC KB = 0.603). The KB algorithm’s 3-year OS predictive value was higher than that of the 2017 European LeukemiaNet (ELN) classification (AUC 2017ELN = 0.707, p < 0.001) and 2010 ELN classification (AUC 2010ELN = 0.721, p < 0.001) but did not differ significantly from that of the 17-gene stemness score (AUC 17-gene = 0.732, p = 0.10). Analysis of additional cytogenetic and molecular markers not included in the KB algorithm revealed that taking into account atypical complex karyotype, infrequent recurrent balanced chromosome rearrangements and mutational status of the SAMHD1 , AXL and NOTCH1 genes may improve the KB algorithm. We conclude that the KB algorithm has a high predictive value that is higher than those of the 2017 and 2010 ELN classifications. Inclusion of additional genetic features might refine the KB algorithm.