Objective: To evaluate the impact of KIT D816 mutation on the salvage therapy in relapsed acute myeloid leukemia (AML) with t(8;21) translocation. Method: The characteristics of the first relapsed AML with t(8;21) translocation from 10 hospitals were retrospectively collected, complete remission (CR(2)) rate after one course salvage chemotherapy and the relationship between KIT mutation and CR(2) rate was analyzed. Results: 68 cases were enrolled in this study, and 30 cases (44.1%) achieved CR(2). All patients received KIT mutation detection, and KIT D816 mutation was identified in 26 cases. The KIT D816 positive group had significantly lower CR(2) compared with non-KIT D816 group (23.1% vs 57.1%, χ(2)=7.559, P=0.006), and patients with longer CR(1) duration achieved significantly higher CR(2) than those with CR(1) duration less than 12 months (74.1% vs 31.9%, χ(2)=9.192, P=0.002). KIT D816 mutation was tightly related to shorter CR(1) duration. No significant difference of 2 years post relapse survival was observed between KIT D816 mutation and non-KIT D816 mutation group. Conclusion: KIT D816 mutation at diagnosis was an adverse factor on the salvage therapy in relapsed AML with t(8;21) translocation, significantly related to shorter CR1 duration, and can be used for prediction of salvage therapy response. KIT D816 mutation could guide the decision-making of salvage therapy in relapsed AML with t(8;21) translocation.
目的： 研究KIT D816突变对伴t（8;21）初次复发急性髓系白血病（AML）挽救化疗疗效的影响。 方法： 回顾性分析自2010年1月至2017年10月10家医院血液科收治的伴t（8;21）初次复发AML接受挽救化疗患者的临床特征，计算其1个疗程挽救化疗完全缓解（CR(2)）率，分析其与KIT突变的相关性。 结果： 共68例患者纳入本研究，所有患者初诊时均进行了KIT基因突变检测，KIT基因突变阳性33例，其中26例为KIT D816突变。复发后1个疗程挽救化疗CR(2)率为44.1%。KIT D816突变组的1个疗程挽救治疗CR(2)率明显低于非KIT D816突变组（23.1%对57.1%，χ(2)=7.559，P=0.006）。第1次完全缓解（CR(1)）维持期≥12个月组CR(2)率显著高于CR(1)维持期<12个月组（74.1%对31.9%，χ(2)=9.192，P=0.002）。CR(1)维持期与KIT D816突变存在显著相关性，CR(1)维持期≥12个月组中KIT D816突变患者比例显著低于CR(1)维持期<12个月组（19.0%对46.8%，χ(2)=4.737，P=0.030）。KIT D816突变组复发后2年总生存率与非KIT D816突变组相比差异无统计学意义[（28.2±15.7）%对（55.1±11.1）%，P=0.060]。 结论： 初诊时KIT D816突变与较短CR(1)维持期显著相关，是伴t（8;21）AML复发后CR(2)率的不良影响因素，可以作为其挽救治疗疗效的预测指标。KIT D816突变对伴t（8;21）复发AML治疗方案的选择有一定的指导意义。.
Keywords: Gene, KIT; Leukemia, myeloid, acute; Mutation; Prognosis; Recurrence.