Clinical Characteristics and Factors of the Impact on the Survival in 133 De Novo FLT3-ITD Acute Myeloid Leukemia with Intermediate Chromosome Karyoptye from a Single Center of China

Objects: Investigate the clinical characteristics and factors of the impact on the survival of FLT-ITD mutation in the acute myeloid leukemia(AML) with intermediate chromosome karyoptye.

Methods: We retrospectively collected and analyzed information regarding clinical characteristics and survival data from 133 patients with newly diagnosed AML with FLT3-ITD mutation and intermediate chromosome karyoptye from 2001-2015.The median follow-up time was 13.02 months.

Results: 1. The median age was 37, median WBC was 50×10⁹/L , the incidence between male and female was similar, the most common FAB subtype was M5(60.2%), the hepatosplenomegaly incidence was 8.4% .

2.The complete remission (CR) was 64.5% after first induction chemotherapy. CR could reached 74.4% or 57.1% when induction regimen included the medium dose cytarabine(100mg/m² d1-4;1g/m² q12h d5-7) or standard dose cytarabine(Ara-C)(100mg/m²d1-7) respectively(p=0.063).

3. Totally 131 patients received chemotherapy, and subsequently 22 patients received transplantation after chemotherapy. When the patients only received chemotherapy, 3-year OS was 39.9%, 3-year DFS was 44.8% and while in the patients who received transplantation, 3-year OS was 73.5%, 3-year DFS was 77.5%, the outcome was better (p<0.05).

4. Univariable analysis showed that OS was related with age, hepatosplenomegaly, transplantation, WBC, the remission of induction chemotherapy. DFS was related with transplantation, courses for CR. Cox regression showed that transplantation and remission of induction chemotherapy were the independent prognosis factor. When the patient only received chemotherapy, FACS-MRD persisted negative was the independent prognosis factor.

Conclusions: The FLT3-ITD de novo AML patients with intermediate chromosome karyoptye had unique characteristics. The patients who attained CR after induction chemotherapy and received transplantation would get better outcome, while in the patients who only received chemotherapy, FACS-MRD persisted negative implied better outcome. The induction regimen that contained medium Ara-C could reach higher CR , that may translated into better survival, therefore it may be the appropriate choice for FLT3-ITD AML patients.