Significance of Serum MicroRNAs in the Auxiliary Diagnosis of Non-Small Cell Lung Cancer

Background: The lack of effective means for the early diagnosis of non-small cell lung cancer (NSCLC) is the leading cause of the high mortality associated with this form of lung cancer. This study aims to explore the potential significance of serum miRNA in the auxiliary diagnosis of NSCLC. Methods: The relative serum levels of 10 miRNAs in 120 patients with NSCLC, 45 patients with benign lung diseases, and 45 healthy controls were detected using real-time quantitative polymerase chain reaction (PCR). The receiver operating characteristic (ROC) curves were then used to analyze the significance of the expression of these 10 miRNAs in the diagnosis of NSCLC, as well as to compare them with the current commonly used tumor marker carcinoembryonic antigen (CEA). Results: The serum levels of miR-125b and miR-22 in the NSCLC patients were significantly higher than those in the other two groups (p < 0.05), but the serum expression of miR-15b in the NSCLC patients was significantly lower than that in the other two groups (p < 0.01). The sensitivities of serum miR-22 and miR-15b in detecting early NSCLC (stage I + II) were significantly higher than that of CEA (p < 0.05). Area under the curves (AUCs) of serum miR-22, miR-125b, and miR-15b in the diagnosis of NSCLC were 0.725, 0.704, and 0.619, respectively, and the diagnostic significance of these three serum miRNAs for NSCLC was higher than that of serum CEA (AUC = 0.594). Conclusions: Serum miRNAs have potential as NSCLC-screening tumor markers, and serum miR-22 and miR-15b might be used as reference indexes for the early diagnosis of NSCLC in the future.