Clinical features analysis of B-cell acute lymphoblastic leukemia with KMT2A::AFF1 gene expression / 中华检验医学杂志

ABSTRACT

Objective:To analyze the correlation between clinical features and prognosis or prognostic risk factors in patients with KMT2AAFF1 gene positive B-ALL.Methods:Retrospective cohort study was conducted. 167 cases of B-ALL admitted to the Shanghai General Hospital and the Naval Medical University Affiliated First Hospital from April 1, 2011 to July 31, 2022 were divided into groups according to gene types. 22 cases with KMT2AAFF1 positive B-ALL were enrolled as the experimental group, 54 cases with BCRABL gene positive B-ALL as control group 1 and 91 cases with KMT2AAFF1 and BCRABL gene negative B-All as control group 2. The median age of first diagnosis in the experimental group, control group 1 and control group 2 were 43.5(30.5, 56), 43.5(34, 55) and 32(24, 46) respectively. The median white blood cell counts of the three groups were 142.4(25.7, 247.2)×10 9/L, 37.6(15.7, 102.2)×10 9/L and 13.4(4.3, 33.0)×10 9/L, respectively. Allo-HSCT rates in three groups were 45.5%, 72.2% and 72.5% respectively. Using SPSS 26.0 software, the statistical methods of nonparametric rank sum test, chi-square test, Kaplan-Meier and Cox regression were used to analyze and compare the differences in clinical characteristics, chemotherapy and prognosis between the experimental group and the control groups, and to analyze the risk factors and the differences in prognosis of allo-HSCT in the experimental group. Results:The age difference between the experimental group and the control group 2 was significant ( Z=-2.151, P=0.031). The white blood cell count in experimental group was significantly higher than that in control group 1 ( Z=-2.363, P=0.018) and control group 2 ( Z=-4.886, P<0.001). The rate of allo-HSCT in experimental group was lower than that in control group 1(45.5% vs 72.2%, χ 2=4.890, P=0.027) and control group 2 (45.5% vs 72.5%, χ 2=5.897, P=0.015). The remission rates of the patients in three groups after receiving one course of chemotherapy were 60%(12/20), 83.3%(45/54) and 76.6%(69/90); the remission rates after two courses of chemotherapy were 25%(5/20), 7.4%(4/54) and 12.2% (11/90), and the non-remission rates of more than two courses of treatment were 15%(3/20), 9.3%(5/54) and 11.1%(10/90), respectively. The effect of chemotherapy in experimental group was worse than that in control group 1 ( Z=-1.979, P=0.048). There was no significant difference between the three groups in sex, whether the chromosome is a standard-risk karyotype, hemoglobin at the time of initial onset, platelet count and percentage of bone marrow blast cells. The overall survival rate (OS) of experimental group was significantly lower than that of control group 1 and control group 2(23.9% vs 36.7%, χ 2=7.608, P=0.006 and 23.9% vs. 44.8%, χ 2=6.442, P=0.011), and the 3-year recurrence-free survival (RFS) was also lower than that of the other two groups (14.0% vs 57.6%, χ 2=17.823, P<0.001 and 14.0% vs 48.2%, χ 2=16.432, P<0.001). There was a significant difference in the total OS rate between the experimental group and the group without allo-HSCT (45.0% vs 9.2%, χ 2=15.254, P<0.001). Univariate analysis showed that age was the risk factor of RFS in the experimental group, and allo-HSCT therapy was the protective factor of OS. Multivariate analysis showed that allo-HSCT was an independent protective factor for OS in the experimental group. Conclusions:Patients with KMT2AAFF1 positive B-ALL had higher white blood cells, less sensitivity to chemotherapy and poor prognosis. Age was a risk factor of RFS in KMT2AAFF1 positive B-ALL, and allo-HSCT could improve the prognosis.