Open AccessSaliva‐derived cfDNA is applicable for EGFR mutation detection but not for quantitation analysis in non‐small cell lung cancer
Author(s) -
Ding Shanshan,
Song Xingguo,
Geng Xinran,
Liu Lele,
Ma Hongxin,
Wang Xiujuan,
Wei Ling,
Xie Li,
Song Xianrang
Publication year - 2019
Publication title -
thoracic cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.823
H-Index - 28
eISSN - 1759-7714
pISSN - 1759-7706
DOI - 10.1111/1759-7714.13178
Subject(s) - medicine , concordance , lung cancer , saliva , oncology , cell free fetal dna , digital polymerase chain reaction , mutation , epidermal growth factor receptor , rank correlation , cancer , gene , polymerase chain reaction , biology , genetics , pregnancy , fetus , prenatal diagnosis , machine learning , computer science
Background Both quantitative and qualitative aspects of plasma cell‐free DNA (plasma cfDNA, pcfDNA) have been well‐studied as potential biomarkers in non‐small cell lung cancer (NSCLC). Accumulating evidence has proven that saliva also has the potential for the detection and analysis of circulating free DNA (saliva cfDNA, scfDNA). Methods In the current study, we aimed to explore the potential application of scfDNA in NSCLC diagnostics and consistency of epidermal growth factor receptor ( EGFR ) mutation detection in paired pcfDNA and scfDNA using droplet digital PCR (ddPCR) and analyze the relationship between EGFR mutations and clinical treatment response. Results In the quantitative cohort study, scfDNA concentration in NSCLC patients was no different from that in healthy donors, or in benign patients. ScfDNA concentration was significantly lower than pcfDNA concentration, yet they were not statistically significant in relevance (Spearman's rank correlation r = −0.123, P = 0.269). In the qualitative cohort study, the overall concordance rate of EGFR mutations between pcfDNA and scfDNA was 83.78% (31 of 37; k = 0.602; P < 0.001). EGFR mutation detection in paired pcfDNA and scfDNA was significantly correlated with the clinical treatment response (Spearman's rank correlation r = 0.664, P = 0.002). Conclusions Our results demonstrated that saliva might not be the idea material for a cfDNA quantitative test, and scfDNA concentration is not applicable for NSCLC diagnostics. Conversely, scfDNA was capable of acting as the supplement for EGFR mutations due to the coincidence rate of EGFR mutation detection between scfDNA and pcfDNA.