Abstract: Objective To analyze the diagnostic efficacy of ctDNA gene mutations in peripheral blood in patients with NSCLC. Methods 50 patients with non-small cell lung cancer were newly diagnosed and treated in Affiliated Hospital of Hebei University with single-hole thoracoscopic surgery. After collecting the peripheral blood of all the subjects, plasma was separated and ctDNA was extracted. The Illumina HiSeq 3000 platform was applied to examine high-throughput sequencing of the target area, and the frequency of gene mutation served as detection and analysis index for ctDNA. Results The sensitivity and specificity of ctDNA detection of non-small cell lung cancer in 50 patients with non-small cell lung cancer were significantly higher than those of CEA detection(P<0.05). The frequency of ctDNA mutations in different ages, genders, and pathological types, smoking history, etc.had no significant difference between patients(P>0.05), but there were significant differences among patients with different tumor sizes and clinical stages(P<0.05). Conclusion The mutation of ctDNA gene in peripheral blood can be used for sensitive and specific diagnosis of early and mid-stage non-small cell lung cancer, and it is related to the tumor size and clinical stage of NSCLC in the early and middle stages.

Key words: circulating tumor DNA, gene mutation, non-small cell lung cancer, diagnosis, gene mutation frequency