title: Highly Sensitive Droplet Digital PCR Method for Detection of EGFR-Activating Mutations in Plasma Cell-Free DNA from Patients with Advanced Non-Small Cell Lung Cancer.
abstract: Epidermal growth factor receptor (EGFR) mutation testing in plasma cell-free DNA from lung cancer patients is an emerging clinical tool. However, compared with tissue testing, the sensitivity of plasma testing is not yet satisfactory because of the highly fragmented nature of plasma cell-free DNA, low fraction of tumor DNA, and limitations of available detection technologies. We therefore developed a highly sensitive and specific droplet digital PCR method for plasma EGFR mutation (exon19 deletions and L858R) testing. Plasma from 86 EGFR-tyrosine kinase inhibitor-naive lung cancer patients was tested and compared with EGFR mutation status of matched tumor tissues tested by amplification refractory mutation system. By using EGFR mutation-positive cell DNA, we optimized the droplet digital PCR assays to reach 0.04% sensitivity. The plasma testing sensitivity and specificity, compared with the matched tumor tissues tested by amplification refractory mutation system, were 81.82% (95% CI, 59.72%-94.81%) and 98.44% (95% CI, 91.60%-99.96%), respectively, for exon19 deletions, with 94.19% concordance rate (κ = 0.840; 95% CI, 0.704-0.976; P < 0.0001), whereas they were 80.00% (95% CI, 51.91%-95.67%) and 95.77% (95% CI, 88.14%-99.12%), respectively, for L858R, with 93.02% concordance rate (κ = 0.758; 95% CI, 0.571-0.945; P < 0.0001). The reported highly sensitive and specific droplet digital PCR assays for EGFR mutation detection have potential in clinical blood testing.
authors.affiliation: Translational Science, Asia & Emerging Markets Innovative Medicine, AstraZeneca R&D, Shanghai, China. Electronic address: mike.zhu@amoydx.com.
authors.forename: Guanshan
authors.initials: G
authors.lastname: Zhu
authors.affiliation: Translational Science, Asia & Emerging Markets Innovative Medicine, AstraZeneca R&D, Shanghai, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.affiliation: Translational Science, Asia & Emerging Markets Innovative Medicine, AstraZeneca R&D, Shanghai, China.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Dong
authors.affiliation: Translational Science, Asia & Emerging Markets Innovative Medicine, AstraZeneca R&D, Shanghai, China.
authors.forename: Ya Chao
authors.initials: YC
authors.lastname: Lu
authors.affiliation: Translational Science, Asia & Emerging Markets Innovative Medicine, AstraZeneca R&D, Shanghai, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Affiliated Hospital of Academy of Military Medical Science, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Global Medicine Development, AstraZeneca R&D, Cheshire, United Kingdom.
authors.forename: Rose
authors.initials: R
authors.lastname: McCormack
authors.affiliation: Translational Science, Asia & Emerging Markets Innovative Medicine, AstraZeneca R&D, Shanghai, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Affiliated Hospital of Academy of Military Medical Science, Beijing, China. Electronic address: liuxq@medmail.com.cn.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000235:genetics*; D004273:DNA, Neoplasm / Q000097:blood / Q000235:genetics*; D066246:ErbB Receptors / Q000097:blood / Q000235:genetics*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D004273:DNA, Neoplasm; D066246:ErbB Receptors