Objective  To study the clinical value of long non-coding RNA small nucleolar host gene 20 (lncRNA-SNHG20) and long non-coding RNA transcription factor 7 (lncRNA-TCF7) expression in plasma for diagnosis of non-small cell lung cancer (NSCLC).

Methods  The relative expression levels of lncRNA-SNHG20 and lncRNA-TCF7 in plasma of patients with NSCLC and benign lung disease were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Receiver operating characteristic (ROC) curves were used to evaluate the efficacy of detection alone and their combination in the diagnosis of NSCLC, and were compared with that of conventional tumor markers such as carcinoembryonic antigen (CEA) and Cyfra21-1.

Results  In the plasma of NSCLC patients, the relative expression of lncRNA-TCF7 and lncRNA-SNHG20 were significantly higher than those of patients with benign lung disease (P < 0.05). The relative expressions of lncRNA-TCF7 and lncRNA-SNHG20 were not correlated with gender, age, smoking history, histopathological classification, or TNM stage (P>0.05). ROC curve analysis showed that the area under curve (AUC) of lncRNA-SNHG20 in plasma was larger than that of CEA and Cyfra21-1; the AUC of lncRNA-TCF7 was between CEA and Cyfra21-1. The diagnostic accuracy of lncRNA-SNHG20 combined with lncRNA-TCF7 was higher than that of single detection.

Conclusion  The expression levels of lncRNA-SNHG20 and lncRNA-TCF7 are significantly different in the plasma of patients with NSCLC and benign lung disease. The detection of the expression levels of lncrNa-SnhG20 and lncrNa-TCF7 may have clinical significance for the diagnosis of NSCLC.