Serum circulating free DNA of syncytin-1 as a novel molecular marker for early diagnosis of non-small-cell lung cancer

Background: Liquid biopsy has been receiving attention as an emerging detection technology in the clinical application of non-small-cell lung cancer (NSCLC). Methods: We quantified serum circulating free DNA (cfDNA) of syncytin-1 in 126 patients and 106 controls, analyzed the correlation of level with pathological parameters and explored diagnostic utility. Results: The cfDNA of syncytin-1 levels in NSCLC patients were higher than healthy controls (p < 0.0001). These levels were associated with smoking history (p = 0.0393). The area under the curve of cfDNA of syncytin-1 was 0.802, and combination of cfDNA of syncytin-1/cytokeratin 19 fragment antigen 21-1/carcinoembryonic antigen markers improved diagnostic efficiency. Conclusion: The cfDNA of syncytin-1 was detected in NSCLC patients and can be used as a novel molecular marker for early diagnosis.