Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Nagano 390-8621, Japan.
Shinshu University School of Medicine, Matsumoto, Nagano 390-8621, Japan.
Int J Oncol. 2018 Jun;52(6):2110-2118. doi: 10.3892/ijo.2018.4334. Epub 2018 Mar 27.
Epidermal growth factor receptor (EGFR) mutations are associated with responses to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small-cell lung cancer (NSCLC). Our previous study revealed a rapid point-of-care system for detecting EGFR mutations. This system analyzes cell pellets from cytology specimens using droplet-polymerase chain reaction (d-PCR), and has a reaction time of 10 min. The present study aimed to validate the performance of the EGFR d-PCR assay using cell-free DNA (cfDNA) from supernatants obtained from cytology specimens. Assay results from cfDNA supernatant analyses were compared with those from cell pellets for 90 patients who were clinically diagnosed with, or suspected of having, lung cancer (80 bronchial lavage fluid samples, nine pleural effusion samples and one spinal fluid sample). EGFR mutations were identified in 12 and 15 cases using cfDNA supernatants and cell pellets, respectively. The concordance rates between cfDNA-supernatant and cell‑pellet assay results were 96.7% [kappa coefficient (K)=0.87], 98.9% (K=0.94), 98.9% (K=0.79) and 98.9% (K=0.79) for total EGFR mutations, L858R, E746_A750del and T790M, respectively. All 15 patients with EGFR mutation-positive results, as determined by EGFR d-PCR assay using cfDNA supernatants or cell pellets, also displayed positive results by conventional EGFR assays using tumor tissue or cytology specimens. Notably, EGFR mutations were even detected in five cfDNA supernatants for which the cytological diagnoses of the corresponding cell pellets were 'suspicious for malignancy', 'atypical' or 'negative for malignancy.' In conclusion, this rapid point-of-care system may be considered a promising novel screening method that may enable patients with NSCLC to receive EGFR-TKI therapy more rapidly, whilst also reserving cell pellets for additional morphological and molecular analyses.
表皮生长因子受体 (EGFR) 突变与非小细胞肺癌 (NSCLC) 中 EGFR 酪氨酸激酶抑制剂 (EGFR-TKI) 的反应相关。我们之前的研究揭示了一种用于检测 EGFR 突变的即时护理系统。该系统使用液滴聚合酶链反应 (d-PCR) 分析细胞学标本中的细胞沉淀，反应时间为 10 分钟。本研究旨在使用细胞学标本上清液中的无细胞 DNA (cfDNA) 验证 EGFR d-PCR 检测的性能。分析 cfDNA 上清液的检测结果与细胞沉淀的检测结果进行比较，共纳入 90 名临床诊断或疑似患有肺癌的患者（80 例支气管灌洗液样本、9 例胸腔积液样本和 1 例脑脊液样本）。使用 cfDNA 上清液和细胞沉淀分别鉴定出 12 例和 15 例 EGFR 突变。cfDNA 上清液与细胞沉淀检测结果的一致性率分别为 96.7%（kappa 系数 (K)=0.87）、98.9%（K=0.94）、98.9%（K=0.79）和 98.9%（K=0.79），用于总 EGFR 突变、L858R、E746_A750del 和 T790M。通过使用 cfDNA 上清液或细胞沉淀进行 EGFR d-PCR 检测，所有 15 例 EGFR 突变阳性的患者，也通过使用肿瘤组织或细胞学标本的常规 EGFR 检测呈阳性结果。值得注意的是，在细胞学诊断为“疑似恶性”、“非典型”或“无恶性”的相应细胞沉淀的 5 例 cfDNA 上清液中，甚至检测到了 EGFR 突变。总之，这种快速即时护理系统可以被认为是一种有前途的新型筛查方法，使 NSCLC 患者能够更快地接受 EGFR-TKI 治疗，同时也为额外的形态学和分子分析保留了细胞沉淀。
