伴4号染色体三体异常的t（8；21）急性髓系白血病c-kit基因突变的发生及患者预后

目的：探讨伴有4号染色体三体异常的t（8；21）急性髓系白血病（AML）c-kit基因突变的发生率及患者预后。方法回顾性分析2005年2月至2013年1月145例初治t（8；21）AML患者的实验室及临床资料。所有骨髓样本均采用R显带技术进行核型分析。采用PCR方法检测c-kit基因8号、17号外显子突变情况，并分析患者的临床预后。结果145例t（8；21）AML患者中，12例（8.3%）伴有4号染色体三体异常，其c-kit基因突变发生率为91.7%（11／12），明显高于其他患者[26.3%（35／133）]（P＜0.01）。生存分析显示，伴有4号染色体三体异常的t（8；21）AML患者的3年总体生存（OS）率及无病生存（DFS）率（15%、0）均低于其他t（8；21）AML患者（56%、51%）（P＜0.01）。同时伴有4号染色体三体及c-kit基因突变的t（8；21） AML患者的OS率及DFS率均较不伴有或不同时伴有4号染色体三体及c-kit基因突变的患者低（均P＜0.05）。结论伴有4号染色体三体异常的t（8；21）AML患者c-kit基因突变发生率高，且预后不佳。4号染色体三体异常或联合c-kit基因突变是影响t（8；21）AML患者生存的主要因素。

Frequency of c-kit mutation and prognosis in t(8;21) acute myeloid leukemia patients with trisomy 4

Objective To investigate the frequency of c-kit mutation and prognosis in t (8;21) acute myeloid leukemia (AML) patients with trisomy 4. Methods A total of 145 de novo t(8;21) AML patients from February 2005 to January 2013 were analyzed retrospectively. Detection of exons 8 and 17 mutation of c-kit by PCR and cytogenetic analysis by R-banding technologies were performed on bone marrow samples of all patients at diagnosis. Clinical data were collected and analyzed statistically. Results Among 145 t (8;21) AML patients, 12 cases (8.3 %) were trisomy 4, 91.7 % (11/12) of them were identified with c-kit mutation, which was significantly higher than that without trisomy 4 [26.3 % (35/133), P< 0.01]. The follow-up data showed that the patients with trisomy 4 were correlated with the lower overall survival (OS) rate (15 % vs 56 %, P< 0.01) and disease-free survival (DFS) rate (0 vs 51 %, P< 0.01) when compared with patients without trisomy 4. Furthermore, the subgroup of patients with both trisomy 4 and c-kit mutation had a worse OS and DFS (P< 0.05). Conclusions Trisomy 4 is associated with high frequency of c-kit mutation and demonstrates poor prognosis in t(8;21) AML patients. Trisomy 4 or it combined with c-kit gene mutation is the main influencing factor on the survival of the patients with t(8;21) AML.