非小细胞肺癌外周血游离DNA及肿瘤细胞EGFR基因突变检测方法的研究进展

Research Advancement on EGFR Mutation Detection of Cell-free DNA and Tumor Cell in Peripheral Blood of Patients with Non-small Cell Lung Cancer

非小细胞肺癌(non-small cell lung cancer,NSCLC)是肺癌中最常见的类型。表皮生长因子受体(epidermal growth factor receptor,EGFR)酪氨酸激酶受体抑制剂(tyrosine kinases inhibitors,TKIs)是目前最重要的靶向治疗药物,对于有EGFR敏感突变的NSCLC,采用EGFR-TKIs治疗能取得明显的临床疗效;T790M突变是最常见的EGFR-TKIs耐药机制,通过对外周血进行EGFR基因突变检测,可以筛选出EGFR-TKIs治疗有效或治疗过程中对其产生耐药的患者。其定量分析不仅在肿瘤的早期诊断中具有重要意义,而且是疗效评价及随访的重要生物学指标。目前,用于检测外周血EGFR突变的方法有很多,其中以在数字PCR基础上建立起来的dd PCR灵敏度最高,实现了对样本的高通量检测,定量程度较其他方法更为精确,在临床基因诊断中具有广阔的应用前景。

Non-small cell lung cancer（NSCLC） is the most common type of lung cancer. Epideral growth factor receptor tyrosine kinase inhibitors（EGFR-TKIs） are the most important treatments currently for advanced NSCLC patients harboring activating EGFR gene mutations, and achieve significant clinical efficacy. T790 M mutation occurs in half of NSCLC patents with acquired EGFR-TKI resistance. Screening for EGFR gene mutations in histological and/or circulating tumor cell or DNA samples of NSCLC patients can identify patients who would have a response to EGFR-TKIs or acquire resistance during the treatment. Quantitative analysis of plasma EGFR mutation is of great importance not only in early diagnosis of tumors, but also in curative effect evaluation and for follow-up. However, a strict requirement is proposed on the detection technique because of low DNA content and the fragmentation of the genes. To date, many methods have been applied to detect cf DNA EGFR mutations, including sequencing, real-time PCR（RT-PCR）, amplification refractory mutation system（ARMS）, mutantenriched PCR（ME-PCR）, denaturing high-performance liquid chromatography（DHPLC）, digital PCR, and droplet digital PCR（dd PCR）. However, of all the methods above, dd PCR has the highest sensitivity, allows high throughput operation. In conclusion, the dd PCR has a lot of future promise in clinical gene diagnosis.