Value of molecular genetics combined with bone marrow imaging detection in the prognosis judgement of acute myeloid leukemia with normal karyotype / 白血病·淋巴瘤

ABSTRACT

Objective To investigate the value of NPM1 and FLT3 gene mutation combined with bone marrow imaging detection in the prognosis judgement of initial treatment cytogenetically normal acute myeloid leukemia (CN-AML). Methods The clinical data of 100 patients (non-M3 type) with primary and initial treatment CN-AML from January 2010 to January 2014 in the Peace Hospital Affiliated of Changzhi Medical College were retrospectively analyzed. All patients were enrolled in the bone marrow imaging examination on the end day of induction treatment or the first day after the end of induction treatment (T time point). Univariate and multivariate prognostic analyses were performed on AML patients according to FLT3 and NPM1 gene status, bone marrow juvenile cell ratio at T time point. Results A total of 100 patients included 36 cases with FLT3 gene mutation and 44 cases with NPM1 gene mutation. The complete remission (CR) rate of CN-AML patients was 13.9% (5/36) and 71.9% (46/64), respectively (P< 0.01), 2-year recurrence-free survival (RFS) rate was 5.6% and 59.8%, respectively (P< 0.01), 2-year overall survival (OS) rate was 15.6% and 66.2%, respectively in FLT3+group and FLT3-group (P<0.01). The median RFS and median OS time in FLT3+ group was 6.9 months and 9.4 months, respectively, and the median RFS and median OS time in FLT3-group had not yet reached. There were no significant differences of all the indexes between the two groups (all P< 0.01). And there were no significant differences in CR rate, 2-year RFS rate and 2-year OS rate between NPM1+group and NPM1-group (all P＞0.05). The CR rate, 2-year RFS rate and 2-year OS rate in NPM1+ FLT3-group were better than those in NPM1- FLT3-, NPM1-FLT3+and NPM1+FLT3+groups; NPM1-FLT3+and NPM1+FLT3+groups had the worst prognosis, and there were no statistical differences in the CR rate, RFS and OS time between the two groups (all P＞ 0.05). The prognosis of the patients in bone marrow juvenile cell ratio < 0.05 group at T time point was better than that in ratio ≥0.05 group (all P< 0.05). CN-AML patients were classified into the good prognosis group (NPM1-FLT3-), the medium prognosis group (NPM1+FLT3-), and the poor prognosis group (NPM1-FLT3+and NPM1+FLT3+) according to the FLT3 and NPM1 genes. The good prognosis group+the ratio of bone marrow juvenile cells at T time point<0.05 group, the good prognosis group+the ratio of bone marrow juvenile cells at T time point≥0.05 group, the medium prognosis group + the ratio of bone marrow juvenile cells at T time point < 0.05 group had no statistical differences in CR rate, 2-year RFS rate and 2-year OS rate (all P ＞0.05). The medium prognosis group + the ratio of bone marrow juvenile cells at T time point ≥0.05 group, the poor prognosis group+the ratio of bone marrow juvenile cells at T time point<0.05 group had the equivalent prognosis, and the average prognosis was moderate; the poor prognosis group + the ratio of bone marrow juvenile cells at T time point ≥ 0.05 group had the worst prognosis. According to Cox multivariate regression analysis, FLT3 gene mutation and the ratio of bone marrow juvenile cells at T time point were independent influencing factors for RFS and OS in CN-AML patients (all P< 0.05). NPM1 was an independent prognosis factor affecting RFS and OS of FLT3-patients (all P < 0.05). Conclusions After induction chemotherapy, the responsiveness and sensitivity of AML patients to chemotherapy regimen can be assessed early and objectively according to molecular genetics and the ratio of bone marrow juvenile cells at T time point, which has a certain value in the prognosis judgement.