Objective: To explore the impact of ITD mutation characteristics on the overall survival (OS) and complete remission duration (CRD) in FLT3-ITD positive non-M3 acute myeloid leukemia (AML).
Methods: Capillary electrophoresis was used to detect the FLT3-ITD characteristics after PCR amplication. Single or multiple mutations were identified by the numbers of peak. FLT3-ITD mutation burden was calculated by the peak area of mutant divided by the wild-type and mutant peak areas. Clinical data was collected and followed up in the FLT3-ITD mutation patients.
Results: Multiple ITD mutations were common in patients aged 60 and above. Patients with single ITD mutation had higher percentage of blasts in bone marrow than multiple ITD mutations (0.758 vs 0.638, P=0.028). The numbers and length of FLT3-ITD mutation had no impact on prognosis. Patients with less than 10% of ITD mutation burden showed no difference with the intermediate-risk c-kit group in OS and CRD, but the two groups had longer OS and CRD than ITD mutation burden above 10% (OS: undefined, undefined, 9.9 months, P<0.05; CRD: undefined, undefined, 6.7 months, P<0.05). In patients with ITD mutation burden above 10%, cases with NPM1 or CEBPA mutation alone had markedly longer CRD than ITD mutation alone (25.0 vs 5.1 months, P=0.003), while OS were similar (11.4 vs 8.0 months, P>0.05).
Conclusion: Non-M3 AML patients with less than 10% FLT3-ITD mutation burden had a better prognosis than those above 10%.
目的: 探讨FLT3-ITD突变数量、重排碱基长度和比例与急性髓系白血病（AML）患者的总体生存（OS）时间及持续完全缓解时间（CRD）的关系。
方法: 采用PCR-毛细管电泳法检测130例AML（除外M3）患者的FLT3-ITD突变。根据电泳峰型数量分为单或多个（片段）突变；FLT3-ITD突变比例为突变型峰面积/野生型和突变型峰面积之和；分析FLT3-ITD突变患者临床特征并随访患者预后。
结果: FLT3-ITD多个突变常见于60岁以上患者；FLT3-ITD单个突变患者初诊骨髓原始细胞比例高于多个突变患者（0.758对0.638，P=0.028）；FLT3-ITD突变数量不影响患者预后。FLT3-ITD突变重排碱基长度亦对患者预后无明显影响。FLT3-ITD突变比例<10％患者的OS时间和CRD与同期C-KIT突变的中危组AML患者相似，均显著长于突变比例≥10％患者（中位OS时间分别为未达到、未达到、9.9个月，P<0.05；中位CRD分别为未达到、未达到、6.7个月，P<0.05）。FLT3-ITD突变比例≥10%的AML患者中，FLT3-ITD突变伴随NPM1或CEBPA突变患者的中位CRD显著长于单纯FLT3-ITD突变的患者（25.0个月对5.1个月，P=0.003），但两组中位OS时间差异无统计学意义（11.4个月对8.0个月，P>0.05）。
结论: FLT3-ITD突变阳性的AML（除外M3）患者中，FLT3-ITD突变比例<10％的患者预后好于突变比例≥10％的患者。