Abstract: Objective To explore the application of circulating tumor cells(CTCs)combined with detection of lung cancer autoantibodies and tumor markers in non-small cell lung cancer(NSCLC). Methods The venous blood of 161 patients with NSCLC, 19 patients with benign lung lesions and 20 healthy volunteers were collected, and CTCs were detected by negative enrichment method of immunomagnetic beads. The correlation between CTCs and clinical data of NSCLC was analyzed, and the diagnostic efficiency of CTCs, autoantibodies and tumor markers of lung cancer were compared. Results There were no significant differences of CTCs counts in gender, smoking history, tumor site and lymph node metastasis(all P>0.05). There were significant differences of CTCs counts in age, T stage, maximum tumor diameter, tumor stage and pathological type(all P<0.05). The optimal cutoff value of folic acid receptor positive CTCs in peripheral blood of NSCLC patients was 8.9 FU/3mL. The sensitivity and specificity of diagnosis were 84.5% and 76.9%, respectively, and the area under ROC curve was 0.801. Combined detection of CTCs, lung cancer autoantibodies and tumor markers could improve the diagnostic efficiency of NSCLC. The area under ROC curve of the three combined tests was 0.914, and the 95%CI was 86.8-96.1(P<0.001). Conclusion The detection of CTCs, lung cancer autoantibodies and tumor markers can provide some reference for the diagnosis and screening of NSCLC in clinic, and the combination of the three items can improve the clinical significance of the diagnosis of NSCLC.

Key words: Circulating tumor cells, Non-small cell lung cancer, Autoantibodies, Tumor biomarkers, Early diagnosis