Abstract
Background: MicroRNAs (miRNAs) regulate gene expression and are emerging as biomarkers for epithelial ovarian cancer (EOC). We evaluated the diagnostic performance of serum miR-200c-3p and miR-6134, alone and in combination with established markers, to distinguish EOC from benign ovarian tumors and healthy controls. Methods: In this single-center, retrospective study, sera were collected from patients with EOC (N = 95), benign tumors (N = 115), and healthy controls (N = 40). Candidate miRNAs were screened by microarray and quantified by real-time PCR. Serum CA125, HE4, and IL-6 were measured by ELISA. Receiver operating characteristic curves and area under the curve (AUC) values were used to assess diagnostic performance. Results: Both miR-200c-3p and miR-6134 were significantly upregulated in EOC. In EOC vs. healthy controls, HE4 showed the highest AUC (0.929, 95% confidence interval [CI]: 0.886-0.972), followed by CA125 (0.870, CI: 0.807-0.933) and miR-6134 (0.818,CI: 0.749-0.888). In EOC vs. benign tumors, miR-6134 had the highest AUC (0.933,CI: 0.891-0.975). The combination of miR-6134, CA125, HE4, and IL-6 achieved an AUC of 0.968 (CI: 0.942-0.995). Among patients with CA125 < 35 U/mL, the combination of miR-200c-3p and miR-6134 yielded an AUC of 0.935 (CI: 0.848-1.000). Conclusions: The combination of miR-6134, CA125, HE4, and IL-6, or miR-6134 alone, shows potential as a serum biomarker for EOC, particularly in distinguishing malignant from benign ovarian tumors. The combination of two miRNAs also demonstrated high discriminative power in cases with CA125 below the cutoff. These findings may contribute to the development of improved non-invasive diagnostic tools and warrant further validation.