[Clinical value of droplet digital polymerase chain reaction method in detecting plasma circulating tumor deoxyribonucleic acid epidermal growth factor receptor mutations in advanced pulmonary adenocarcinoma patients]

Zhonghua Yi Xue Za Zhi. 2018 Aug 7;98(29):2336-2340. doi: 10.3760/cma.j.issn.0376-2491.2018.29.012.
[Article in Chinese]

Abstract

Objective: To determine the clinical value of droplet digital polymerase chain reaction (ddPCR) method to detect plasma circulating tumor DNA (ctDNA) epidermal growth factor receptor (EGFR) mutations in advanced pulmonary adenocarcinoma. Methods: One hundred and thirty six patients with advanced pulmonary adenocarcinoma diagnosed in the Beijing Chest Hospital were collected from May 2015 to April 2017 for initial treatment. EGFR gene mutation in the plasma ctDNA was detected by both ddPCR and amplification refractory mutation system (ARMS) assays. EGFR gene mutation in the tumor tissue was detected by ARMS assay. Patients with EGFR sensitive mutations received first-line oral treatment with EGFR tyrosine kinase inhibitor (EGFR-TKI) drugs. The Kaplan-Meier survival analysis was used to compared the progression-free survival (PFS) in EGFR gene mutated patients detected with different methods. Results: Total of 111 samples (81.6%) were detected with EGFR gene mutations in 136 tumor tissue samples. In the 111 samples, 48 samples were found with exon21 L858R mutation (48/111, 43.2%), 59 samples were found with exon19 deletion mutations (59/111, 53.2%), and 4 cases were found with other mutations (4/111, 3.6%). Using tumor specimens as the gold standard, the sensitivity, specificity, and concordance rate of ARMS assay were 58.6%, 96.0%, and 65.4%, respectively; and those in ddPCR assay were 79.3%, 100%, and 83.1%, respectively; the coincidence rate was 83.1% (Kappa=0.685, P<0.001). Kaplan-Meier survival analysis showed that patients with EGFR gene mutation detected by both ddPCR and ARMS methods had shortest PFS when compared with those in patients detected positive with a single method of ddPCR or ARMS assay (11.6 moths vs 14.8 months, χ(2)=2.517, P=0.026). Conclusions: ddPCR is a reliable technology with high sensitivity and high specificity to detect EGFR gene mutations in plasma ctDNA in patients with advanced pulmonary adenocarcinoma. Plasma EGFR gene mutation may predict the efficacy of EGFR-TKI drugs.

目的: 探讨微滴数字聚合酶链反应法(ddPCR)检测晚期肺腺癌患者血浆循环肿瘤脱氧核糖核酸(ctDNA)中表皮生长因子受体(EGFR)基因突变的临床价值。 方法: 收集2015年5月至2017年4月在北京胸科医院确诊的初治晚期肺腺癌患者共136例,突变扩增系统(ARMS)检测肺癌肿瘤组织中EGFR基因突变情况;ddPCR和ARMS技术检测血浆中EGFR的基因突变情况。EGFR敏感突变患者均接受比较不同检测技术的符合率。EGFR敏感突变患者一线接受EGFR酪氨酸激酶抑制剂(EGFR-TKI)口服治疗。通过生存分析比较不同技术检测EGFR基因突变患者无进展生存时间(PFS)。 结果: 136例肺癌肿瘤组织样本中,共检测到111例EGFR敏感突变(81.6%),其中含Exon21 L858R突变48例(43.2%),含Exon19 del突变59例(53.2%),其他突变4例(3.6%)。ARMS检测血浆EGFR基因突变的敏感度为58.6%,特异度为96.0%。ddPCR检测血浆EGFR突变的敏感度为79.3%,特异度为100%,与肿瘤组织检测的符合率达83.1%(Kappa=0.685,P<0.001)。Kaplan-Meier生存分析显示,在组织检测EGFR基因突变的亚组分析中,与单一技术检测阳性的病例相比,ddPCR和ARMS两种技术均为阳性的患者无进展生存时间最短(11.6个月比14.8个月,χ(2)=2.517,P=0.026)。 结论: 作为一种可靠的、高敏感度和特异度的技术,ddPCR有望应用于检测血浆ctDNA EGFR基因突变情况,血液检测EGFR基因突变可预测患者对EGFR-TKI的疗效。.

Keywords: Amplification refractory mutation system; Circulating tumor DNA; Droplet digital polymerase chain reaction; Epidermal growth factor receptor; Gene mutation; Lung neoplasms.

MeSH terms

  • Adenocarcinoma of Lung*
  • ErbB Receptors
  • Humans
  • Lung Neoplasms*
  • Mutation
  • Polymerase Chain Reaction
  • Protein Kinase Inhibitors

Substances

  • Protein Kinase Inhibitors
  • EGFR protein, human
  • ErbB Receptors