Abstract
BACKGROUND: Lung cancer is the malignant tumor with the highest incidence and mortality rate in the world today, and non-small cell lung cancer (NSCLC) is its most common type. However, there is still a paucity of specific tumor markers for lung cancer screening. Herein, we detected and compared the levels of miR-128-3p and miR-33a-5p in serum exosomes of NSCLC patients and healthy volunteers, with the aim of identifying suitable exosomal microRNAs (miRNAs) as tumor biomarkers, and explored their value in the auxiliary diagnosis of NSCLC. METHODS: All participants were recruited from September 1, 2022 to December 30, 2022, and met the inclusion criteria. The case group included 20 patients with lung nodules who were highly suspected of having lung cancer (two cases were excluded). A total of 18 healthy volunteers (control group) were also enrolled. Blood samples were collected in both the case group before surgery and in the control group. Quantitative real-time polymerase chain reaction method was used to detect the expression of miR-128-3p and miR-33a-5p in serum exosomes. The main indicators of statistical analysis included the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. RESULTS: Compared with the healthy control group, the NSCLC case group had significantly lower expression levels of serum exosome miR-128-3p and miR-33a-5p (P<0.01, P<0.001), and there was a significant positive correlation between the two exosome miRNAs (r=0.848, P<0.01). The AUC values of miR-128-3p alone and miR-33a-5p alone in distinguishing case group and control group were 0.789 [95% confidence interval (CI): 0.637-0.940; sensitivity: 61.1%; specificity: 94.4%; P=0.003] and 0.821 (95% CI: 0.668-0.974; sensitivity: 77.8%; specificity: 83.3%; and P=0.001), respectively. The combination of miR-128-3p and miR-33a-5p had an AUC of 0.855 (95% CI: 0.719-0.991; P<0.001) for distinguishing case group and control group, which was greater than the AUC values of miR-128-3p alone and miR-33a-5p alone (cut-off value: 0.034; sensitivity: 83.3%; and specificity: 88.9%). However, there was no significant difference in the AUC among these three groups (P>0.05). CONCLUSIONS: Serum exosome miR-128-3p and miR-33a-5p showed good performance in NSCLC screening and may be used as new biomarkers for large-scale NSCLC screening.