Objective  To investigate the value of combined detection of folate receptor-positive circulating tumor cells (FR⁺-CTCs), neuronal enolase (NSE) and cytokeratin 19 fragment (CYFRA21-1) in diagnosis of non-small cell lung cancer (NSCLC).

  Methods  From January 2019 to August 2020, 150 patients with NSCLC were selected as NSCLC group, 100 patients with benign pulmonary lesions were selected as benign lesion group, and 100 healthy people in physical examinations were selected as control group. The levels of FR⁺-CTCs, NSE and CYFRA21-1 were compared among the three groups. The diagnostic efficacies of one indicator and combined detection were analyzed by receiver operating characteristic (ROC) curve.

  Results  The levels of FR⁺-CTCs, NSE and CYFRA21-1 in the NSCLC group were significantly higher than those in the benign lesion group and control group, and the levels of FR⁺-CTCs, NSE and CYFRA21-1 in the benign lesion group were significantly higher than those in the control group (P < 0.05). In the NSCLC patients with TNM stage Ⅰ and Ⅱ, the positive rate of FR⁺-CTCs was significantly higher than that of NSE and CYFRA21-1 (P < 0.05). The clinicopathological features of 150 patients with NSCLC were analyzed, and the levels of FR⁺-CTCs, NSE and CYFRA21-1 in patients with TNM stage Ⅲ and IV, squamous cell carcinoma, low differentiation and lymph node metastasis were significantly higher than those in patients with TNM stage Ⅰ and Ⅱ, adenocarcinoma, high differentiation and no lymph node metastasis (P < 0.05). ROC curve analysis showed that the area under curve (AUC), sensitivity and specificity of combined detection were 0.938, 90.1% and 84.6% respectively, which were significantly higher than those of single detection (P < 0.05).

  Conclusion  FR⁺-CTCs has a high detection rate in the early stage of NSCLC. Combined detection of FR⁺-CTCs, NSE and CYFRA21-1 can further improve the diagnostic efficiency, which is of great significance for the early diagnosis of NSCLC.