79例儿童t(8;21)急性髓系白血病的核型及预后分析

目的 调查儿童t(8;21)急性體系白血病(AML)的核型异常情况,评估缓解后治疗强度对预后的影响.方法 采用形态学、免疫学和细胞遗传学(MIC)方法对79例儿童t(8;21)AML患者进行检测确诊.诱导缓解治疗采用高三尖杉酯碱联合阿糖胞苷(HA)/柔红霉素联合阿糖胞苷(DA)/高三尖杉酯碱、阿糖胞苷和柔红霉素联合(HAD)方案.缓解后进行异基因造血干细胞移植或5～7疗程的联合化疗.结果 79例患儿中,55例(69.6%)有附加染色体异常,其中40例(50.6%)伴性染色体丢失,9例(11.4%)为del(9q),7例(8.9%)为复杂变异型t(8;21)异常.3例患儿染色体数量在90条以上且伴双重t(8;21)四倍体核型,预后均不良.1、2疗程完全缓解(CR)率分别力81.7%(49/60)和94.8%(55/58);3年无事故生存率、无病生存(DIS)率和总生存率分别为(26.2 ± 6.8)%、(31.3 ± 6.7)%和(27.6 ± 6.6)%;29例患儿缓解后治疗疗程数为5个或以上,其3年DFS率为(51.7 ± 9.3)%.单纯t(8;21)±性染色体丢失组与伴其他附加染色体异常组患儿的3年DFS率差异无统计学意义(P=0.36).大剂量阿糖胞苷组患儿的3年DFS率明显优于标准化疗组(66.7% vs.27.3%,P=0.03).结论 多数儿童t(8;21)AML患者伴有附加染色体核型异常,附加染色体核型异常对患儿生存没有不良影响.染色体数量在90条以上且伴双重t(8;21)四倍体核型少见,但预后不良.儿童伴t(8;21)AML治疗CR率高,远期疗效好.采用大剂量阿糖胞苷作为缓解后治疗能提高远期疗效.

Prognosis and Chromosomal Abnormalities in 79 Children with t (8;21) Acute Myeloid Leukemia

Objective To investigate the chromosomal abnormalities and evaluate the prognostic value of post-remission chemotherapy in children with t (8;21) acute myeloid leukemia (AML). Methods The diagnosis of AML and its subtyping were performed using morphological, immunological, and cytogenetic methodologies in 79 children. Induction therapies included homoharringtonine and cytarabine (HA), daunorubicin and cytarabine (DA), or homoharringtonine and daunorubicin and cytarabine (HAD). Allogeneic stem cell transplantation or 5-6 cycles of intensive chemotherapy was performed after remission therapy. Results Additional chromosomal abnormalities, including loss of sex chromosome (n = 40, 50. 6%), del (9q) (n = 9, 11. 4%), and complex abnormality (n =7, 8. 9%) were identified in 55 patients (69. 6%). Three patientshad more than 90 chromatosomes and duplicate t (8 ;21) tetraploid karyotype, and their prognoses were poor. The complete remission (CR) rates were 81.7% (49/60) and 94. 8% (55/58), respectively, after one and two cycles of induction chemotherapy. The 3-year event-free survival rate (EFS), disease-free survival rate (DFS), and overall survival rate (OS) were (26. 2 ±6. 8)%, (31. 3 ±6. 7)%, and (27. 6 ±6. 6)%, respectively. Twenty-nine patients received 5 or more cycles of chemotherapy after CR and demonstrated an improved 3-year DFS (51. 7 ±9. 3)%]. The 3-year DFS was not significantly differently in patients with or without additional abnormalities other than sex chromosome (P = 0. 36) . Post-remission consolidation by high dose cytarabine (HDAC) was significantly superior to standard chemotherapy (66.7% vs. 27.3%, P = 0. 03). Conclusions Most children with t (8; 21) AML have additional chromosomal abnormalities, although they do not affect the prognosis and long-term survival. Few patients have more than 90 chromatosomes and duplicate t (8;21) tetraploid karyotype, which may result in poor prognosis. Childhood t (8;21) AML usually has high CR rate with relatively good prognosis, and post-remission consolidation by HDAC can improve the survival.