Zhang Yu, Xu Yan, Zhong Wei, Zhao Jing, Chen Minjiang, Zhang Li, Li Longyun, Wang Mengzhao
Department of Respiratory Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
Oncotarget. 2017 Jan 24;8(4):5861-5873. doi: 10.18632/oncotarget.14390.
We evaluated the use of droplet digital PCR (ddPCR) to detect plasma cell-free DNA (cfDNA) epidermal growth factor receptor (EGFR) mutations in advanced non-small cell lung cancer (NSCLC) patients. Compared with tumor-tissue-based detection, the sensitivity of ddPCR for detecting plasma cfDNA tyrosine kinase inhibitor (TKI)-sensitizing EGFR mutations was 61.3%, the specificity was 96.7%, and the consistency rate was 81.4% (κ=0.605, 95% confidence interval: 0.501-0.706, p <0.0001). The sensitivity declined from 82.6% to 46.7% with decreasing cfDNA inputs (p=0.028). The plasma cfDNA concentration correlated with gender (males vs.females =11.69 ng/mL vs. 9.508 ng/mL; p=0.044), EGFR mutation status (tumor-tissue EGFR mutation-positive (EGFR M+) vs. EGFR mutation-negative (EGFR M-) = 9.61 ng/mL vs. 12.82 ng/mL; p =0.049) and specimen collection time (≤2 years vs. >2 years=13.83 ng/mL vs. 6.575 ng/mL; p <0.001), and was greater in tumor-tissue EGFR M+ / plasma EGFR M+ patients than in tumor-tissue EGFR M+/plasma EGFR M- patients (11.61 vs. 7.73 ng/mL, respectively; p=0.003). Thus total cfDNA input crucially influences the sensitivity of plasma cfDNA EGFR mutation testing with ddPCR. Such analysis could be an effective supplemental test for advanced NSCLC patients.
我们评估了采用液滴数字PCR（ddPCR）检测晚期非小细胞肺癌（NSCLC）患者血浆游离DNA（cfDNA）表皮生长因子受体（EGFR）突变的情况。与基于肿瘤组织的检测相比，ddPCR检测血浆cfDNA酪氨酸激酶抑制剂（TKI）敏感性EGFR突变的灵敏度为61.3%，特异性为96.7%，一致性率为81.4%（κ=0.605，95%置信区间：0.501-0.706，p<0.0001）。随着cfDNA输入量的减少，灵敏度从82.6%降至46.7%（p=0.028）。血浆cfDNA浓度与性别相关（男性与女性分别为11.69 ng/mL与9.508 ng/mL；p=0.044）、EGFR突变状态相关（肿瘤组织EGFR突变阳性（EGFR M+）与EGFR突变阴性（EGFR M-）分别为9.61 ng/mL与12.82 ng/mL；p=0.049）以及样本采集时间相关（≤2年与>2年分别为13.⑧3 ng/mL与6.575 ng/mL；p<0.001），并且在肿瘤组织EGFR M+/血浆EGFR M+患者中高于肿瘤组织EGFR M+/血浆EGFR M-患者（分别为11.61与7.73 ng/mL；p=0.003）。因此，cfDNA的总输入量对采用ddPCR检测血浆cfDNA EGFR突变的灵敏度至关重要。这种分析对于晚期NSCLC患者可能是一种有效的补充检测方法。
