儿童急性髓系白血病M2型性染色体缺失的预后意义

Prognostic impact of loss of sex chromosomes in children with acute myeloid leukemia subtype M2

目的探讨儿童急性髓系白血病(AML)M2型性染色体缺失与预后的关系。方法根据细胞遗传学结果将106例AML患儿分为正常核型组(A组,n=26)、不伴性染色体缺失的非正常核型组(B组,n=52)和伴性染色体缺失的非正常核型组(C组,n=28),比较各组患儿预后差异。结果 A、B、C组5年无事件生存率(EFS)分别为38.9%±11.2%、59.3%±7.3%和66.5%±10.5%,其中C组明显高于A组(P=0.035);A、B、C组5年总生存率(OS)分别为54.3%±13.5%、68.1%±7.7%和77.9%±9.8%,三组间比较差异无统计学意义(P>0.05)。发生t(8;21)易位的AML患儿58例,5年EFS率为63.3%±7.3%,明显高于正常核型患儿(P=0.015);C组中28例伴性染色体缺失的AML患儿均伴有t(8;21)易位,与不伴性染色体缺失的t(8;21)易位患儿相比,5年EFS率差异无统计学意义(P>0.05)。结论儿童AML M2型中性染色体缺失是预后好的染色体核型,该类型大多同时伴有t(8;21)易位;在伴有t(8;21)易位的患儿中,性染色体缺失并没有显示出更好的预后,推测性染色体缺失的非正常核型预后好可能与伴有t(8;21)易位有关。

Objective To study the relationship between loss of sex chromosomes and prognosis in children with acute myeloid leukemia（AML） M2 subtype. Methods According to cytogenetic characteristics, 106 children with AML were divided into three groups： patients with normal karyotype（Group A, n=26）, patients with abnormal karyotype who had no loss of sex chromosomes（Group B, n=52）, and patients with abnormal karyotype who had loss of sex chromosomes（Group C, n=28）. Prognosis was compared between the three groups. Results The 5-year event-free survival（EFS） rates of Groups A, B, and C were（38.9±11.2）%,（59.3±7.3）%, and（66.5±10.5）%, respectively; the EFS of Group C was significantly higher than that of Group A（P=0.035）. The 5-year overall survival（OS） rates of Groups A, B, and C were（54.3±13.5）%,（68.1±7.7）%, and（77.9±9.8）%, respectively（P〉0.05）. The 5-year EFS of 58 patients with t（8;21） was（63.3±7.3）%, significantly higher than that of patients with normal karyotype（P=0.015）. All the 28 cases in Group C had t（8;21）, and their 5-year EFS was not significantly different from that of patients with t（8;21） in Group B（P〉0.05）. Conclusions Loss of sex chromosomes is a favorable karyotype in children with AML M2 subtype and the patients in this group mostly have t（8;21）. Why loss of sex chromosomes indicates a favorable prognosis is probably because it is accompanied by t（8;21） in the patients.