Hematopoietic Stem Cell Transplantation (HSCT) Benefits the Survival of Acute Myeloid Leukemia (AML) Patients with IDH1, NRAS and DNMT3A Mutations
Authors: Xu Yang , Yang Zhen , Tian Hong , Qiu Huiying , Sun Aining , Chen Suning , Depei Wu 
Published: October 2019

Abstract
Abstract 1981

Background:
Gene mutations may serve as potential markers to extend the prognostic parameters in acute myeloid leukemia (AML) patients. In this study, we detected distribution of mutations in the nucleophosmin gene (NPM1), C-KIT, the fms-related tyrosine kinase 3 gene (FLT3), Isocitrate dehydrogenase gene 1 and 2 (IDH1, IDH2), the neuroblastoma RAS viral oncogene homolog (NRAS) and DNA methyltransferase 3A gene (DNMT3A) in 442 newly diagnosed AML patients (none-APL). Associations of gene mutations with clinical outcomes in these patients followed HSCT treatment or chemotherapy were further evaluated.

Methods:
Between February 2005 and December 2011, 442 newly diagnosed AML (none-APL) patients in our centre were retrospectively analyzed. There are 248 males and 194 females, and the median ages were 40 (16–60) years. 393 patients (88.9%) of patients were with single or normal karyotype and 49 patients (11.1%) were with complex abnormal karyotype. In addition to MICM examination, direct sequencing was employed to access the distribution of mutations in of FLT3-ITD (exon14), FLT3-TKD (exon 20), NPM1 (exon12), C-KIT (exon8, 17), IDH2 (exon 4), NRAS (exon1, 2), DNMT3A (exon23) of 445 AML patients. Complete remission (CR) was achieved in 258 patients (58.4%) followed the standard induction therapy, 128 patients received HSCT (Allo-HSCT: 121 vs. Auto-HSCT: 7) therapy after first remission or second remission while 258 patients received consolidation chemotherapy contained 4–6 cycles high dose Ara-C (HD-Ara-C). Overall survival (OS) and Event-free survival (EFS) were measured at last follow-up (censored), and Kaplan-Meier analysis was used to calculate the distribution of OS and EFS.

Results:
In 442 AML (None-APL) patients, 44 patients (9.7%) had C-KIT mutations, 97 patients (21.9%) had NPM1 mutations, 95 patients (21.5%) had FLT3-ITD mutations, 26 patients (5.9%) had FLT3-TKD mutations, 23 patients (5.2%) had IDH1 mutations, 48 patients (10.9%) had IDH2 mutations, 31 patients (7.0%) had DNMT3A mutations, and 40 patients (9.0%) had NRAS mutations. Using COX regression, we found that mutations in FLT3-ITD (HR:2.113; 95%CI: 1.1420 to 3.144),IDH1 (HR:3.023; 95%CI: 1.055 to 3.879), NRAS (HR:1.881; 95%CI: 1.021 to 2.945), and DNMT3A (HR: 2.394; 95%CI: 1.328 to 4.315) were independent unfavorable prognostic indicators of overall survival of AML patients. We further compared the outcomes of AML patients with such gene mutations followed different therapy (HSCT vs. HD Ara-C), and results shown that patients with mutations in IDH1, NRAS and DNMT3A received HSCT therapy had better survival. The median OS and EFS of patients with FLT3-ITD, IDH1, NRAS and DNMT3A in the two groups (HSCT vs. HD Ara-C) were as follows: IDH1 (OS: 35 months vs. 11 months, p=0.016; EFS: 34 months vs. 8 months, p=0.012), NRAS (OS: 27months vs. 8 months, p=0.008; EFS: 23 months vs. 4 months, p=0.049), DNMT3A (OS: 66 months vs. 19 months, p=0.008; EFS: 54 months vs. 13 months, p=0.002).

Conclusions:
Taken together, our data proved that mutant FLT3-ITD, IDH1, NRAS, and DNMT3A might serve as poor prognostic markers and hematopoietic stem cell transplantation as first-line treatment could favor the outcome of AML patients carrying IDH1, NRAS, and DNMT3A mutations.

Disclosures:
No relevant conflicts of interest to declare.