title: Tumor volume determines the feasibility of cell-free DNA sequencing for mutation detection in non-small cell lung cancer.
abstract: Next-generation sequencing (NGS) and digital PCR technologies allow analysis of the mutational profile of circulating cell-free DNA (cfDNA) in individuals with advanced lung cancer. We have now evaluated the feasibility of cfDNA sequencing for mutation detection in patients with non-small cell lung cancer at earlier stages. A total of 150 matched tumor and serum samples were collected from non-small cell lung cancer patients at stages IA-IIIA. Amplicon sequencing with DNA extracted from tumor tissue detected frequent mutations in EGFR (37% of patients), TP53 (39%), and KRAS (10%), consistent with previous findings. In contrast, NGS of cfDNA identified only EGFR, TP53, and PIK3CA mutations in three, five, and one patient, respectively, even though adequate amounts of cfDNA were extracted (median of 4936 copies/mL serum). Next-generation sequencing showed a high accuracy (98.8%) compared with droplet digital PCR for cfDNA mutation detection, suggesting that the low frequency of mutations in cfDNA was not due to a low assay sensitivity. Whereas the yield of cfDNA did not differ among tumor stages, the cfDNA mutations were detected in seven patients at stages IIA-IIIA and at T2b or T3. Tumor volume was significantly higher in the cfDNA mutation-positive patients than in the negative patients at stages T2b-T4 (159.1 ± 58.0 vs. 52.5 ± 9.9 cm3, P = 0.014). Our results thus suggest that tumor volume is a determinant of the feasibility of mutation detection with cfDNA as the analyte.
authors: Department of Surgery, Tokyo Medical University, Tokyo, Japan.
authors: Tatsuo
authors: T
authors: Ohira
authors: Department of Genome Biology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan.
authors: Kazuko
authors: K
authors: Sakai
authors: Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan.
authors: Jun
authors: J
authors: Matsubayashi
authors: Department of Surgery, Tokyo Medical University, Tokyo, Japan.
authors: Naohiro
authors: N
authors: Kajiwara
authors: Department of Surgery, Tokyo Medical University, Tokyo, Japan.
authors: Masatoshi
authors: M
authors: Kakihana
authors: Department of Surgery, Tokyo Medical University, Tokyo, Japan.
authors: Masaru
authors: M
authors: Hagiwara
authors: Department of Genome Biology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan.
authors: Masaaki
authors: M
authors: Hibi
authors: Department of Surgery, Tokyo Medical University, Tokyo, Japan.
authors: Koichi
authors: K
authors: Yoshida
authors: Department of Surgery, Tokyo Medical University, Tokyo, Japan.
authors: Junichi
authors: J
authors: Maeda
authors: Department of Surgery, Tokyo Medical University, Tokyo, Japan.
authors: Keishi
authors: K
authors: Ohtani
authors: Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan.
authors: Toshitaka
authors: T
authors: Nagao
authors: Department of Genome Biology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan.
authors: Kazuto
authors: K
authors: Nishio
authors: Department of Surgery, Tokyo Medical University, Tokyo, Japan.
authors: Norihiko
authors: N
authors: Ikeda
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood* / Q000235:genetics* / Q000473:pathology; D004252:DNA Mutational Analysis / Q000379:methods* / Q000592:standards; D004273:DNA, Neoplasm / Q000097:blood*; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000235:genetics* / Q000473:pathology; D009154:Mutation / Q000235:genetics*; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction / Q000379:methods / Q000592:standards; D047368:Tumor Burden
chemical_list: D004273:DNA, Neoplasm
keywords: Cell-free DNA; mutation; non-small cell lung cancer; sequencing; tumor volume