Cytogenetic characteristics of acute myeloid leukemia and effect of DA regimen with different doses of daunorubicin

Objective To analyze the genetic characteristics of chromosomes and related fusion genes in acute myeloid leukemia (AML) (non-M3), and to evaluate the prognosis of patients with chemotherapy of DA regimen with different doses of daunorubicin. Methods Fifty-six patients with newly diagnosed non-M3 AML from January 2013 to January 2015 were collected. Adopted short-term culture method was used to treat bone marrow, R-binding chromosome karyotyping was used to detect cytogenetic. Thirty-one types of fusion gene were identified by PCR and 10% agarose gel electrophoresis. All patients treated by DA regimen were divided into group A, group B and group C according to different dosage of daunorubicin. Then, complete remission (CR) rate and survival time in the 3 groups were observed. The effect of cytogenetic and molecular biology abnormality on the chemotherapy, CR rate and overall survival (OS) of the 3 groups were analyzed by the chi-square test. Results Among the 56 patients, 18 cases (32.1%) had abnormal chromosome karyotype, 6 cases (10.7%) had abnormal number of chromosome, 16 cases (28.6%) had abnormal structure of chromosome, and 4 cases (7.1%) had both abnormal number and structure of chromosome. Meanwhile, the most common abnormal structure was t(8;21), and the most common abnormal quantity were+8,-Y. Detective rate of genetic abnormality was raised to 62.00% through fusion gene and chromosome karyotype analysis. The total CR rate of DA-induced chemotherapeutic regimen was 73.2%, and the two-year OS rate was 42.9%. The remission rate of chemotherapy in the middle-risk group was significantly lower than that in the low-risk group (χ 2= 8.976, P= 0.002), but there was no significant difference between the low-dose chemotherapy group and the standard dose chemotherapy group (P > 0.05). The standard dose group showed a significant advantage in the OS rate (χ 2= 8.045, P= 0.005). Conclusions Adult acute leukemia has its unique cytogenetic characteristics, which can assist in guiding clinical diagnosis, classification and prognosis. The prognosis of middle-risk patients is significantly lower than the low-risk group. Low-risk patients could benefit from a reduced dose of DA regimen, but the standard dose DA regimen has a significant advantage in long-term survival. Key words: Leukemia, myeloid, acute; Chromosome karyotype; Fusion gene; Drug therapy, combination