Clinical significance of FLT3-ITD/CEBPA mutations and minimal residual disease in cytogenetically normal acute myeloid leukemia after hematopoietic stem cell transplantation.

PURPOSE Genetic changes have prognostic significance in cytogenetically normal acute myeloid leukemia (CN-AML). We set out to evaluate the prognostic of 6 gene mutations in CN-AML. METHODS We performed a mutational analysis and evaluated prognostic findings of six genes (NPM1, CEBPA, DNMT3A, FLT3-ITD, FLT3-TKD, and C-KIT) in 428 CN-AML patients at our center over 10 years. RESULTS A total of 282 patients (65.9%) had at least one gene mutation, and the mutation frequencies were as follows: 29.7% (NPM1), 24.1% (CEBPA), 20.1% (FLT3-ITD), 4.0% (FLT3-TKD), 11.9% (DNMT3A), and 4.7% (C-KIT). Multivariate analysis indicated that FLT3-ITDmut and CEBPAwt were independent risk factors correlated with poor overall survival (OS) and disease-free survival (DFS) of CN-AML. Compared with patients who received chemotherapy as consolidation, hematopoietic stem cell transplantation (HSCT) significantly improved OS of CN-AML patients. For standard/high risk patients, HSCT improved both OS and DFS. Combined analysis showed that patients with CEBPAmut/FLT3-ITDwt had the best prognosis, and patients with CEBPAwt/FLT3-ITDmut had the worst OS, with 3-year OS of only 44%. In 212 patients who received HSCT, FLT3-ITD/CEBPA mutations and minimal residual disease (MRD) were correlated with OS and DFS in univariate analysis. CONCLUSIONS We found that HSCT significantly improves the prognosis of standard/high risk CN-AML patients with superior OS and DFS. Molecular marker analyses, especially combined analysis of the FLT3-ITD and CEBPA status revealed a correlation with the prognosis of CN-AML. For patients who have received HSCT, MRD before transplantation was a strong prognostic marker predicting patient outcome.