Circulating miR-107, miR-199, and miR-485 Have High Diagnostic Potential in Non-small Cell Lung Cancer: An Exploratory Study.

Background: Non-small cell lung cancer (NSCLC) accounts for the majority of lung cancer cases. Circulating microRNAs (miRNAs) have emerged as promising non-invasive biomarkers for cancer detection. In this exploratory study, we investigated the diagnostic and prognostic value of four circulating miRNAs (miR-107, miR-199-3p, miR-485-5p, and miR-574-5p) in NSCLC, three of which have not previously been examined in this context. Methods: Serum samples from 58 NSCLC patients and 20 healthy controls were analyzed. Relative expression levels of the target miRNAs were quantified by quantitative RT-PCR. Differences between groups were evaluated with the Mann-Whitney U test, and the diagnostic performance of each miRNA was assessed by receiver operating characteristic (ROC) curve analysis. Univariate and multivariate regression analyses were performed to identify factors associated with survival. Results: Three of the four miRNAs showed significantly different expression between NSCLC patients and healthy controls: miR-107, miR-199, and miR-485 were all expressed at significantly lower levels in patients (p < 0.001, p < 0.001, and p = 0.002, respectively), whereas miR-574 levels did not differ between groups (p = 0.370). ROC analysis confirmed significant discriminatory power for all four miRNAs (p < 0.001), with miR-107 yielding the highest area under the curve (AUC = 0.952). In multivariate analysis, ECOG performance status and miR-199 emerged as covariates significantly associated with survival. Conclusion: These exploratory findings indicate that circulating miR-107, miR-199, and miR-485 have strong discriminative potential in NSCLC. Larger validation studies are needed to confirm their utility as non-invasive biomarkers.