Abstract
BACKGROUND: Several studies demonstrated that microRNAs are stably detectable in plasma/serum and are potential biomarkers for some diseases. The expression of microRNA-218 (miR-218) is downregulated in esophageal cancer as reported in previous research. OBJECTIVE: The purpose of this study is to investigate whether miR-218 can be served as a serum biomarker for esophageal cancer. METHODS: We tested the expression level of miR-218 in serum of 106 patients with esophageal cancer and 60 healthy volunteers by RT-PCR and analyzed the relationship between serum miR-218 expression and the clinical characteristics. RESULTS: The serum expression of miR-218 was significantly lower in patients with esophageal cancer than that in healthy individuals. The value of the area under the receiver-operating characteristic (ROC) curve (AUC) was 0.833. Furthermore, the ROC curves to detect early esophageal cancer with Tis-T1 or Stage 0-I showed AUCs of 0.825 and 0.829, respectively. In the esophageal cancer group, the serum expression of miR-218 was found to be lower in esophageal cancer patients with poorer differentiation, later stage, and lymph node metastasis, highlighting that low serum expression of miR-218 may be related to tumor development and progression in esophageal cancer. CONCLUSIONS: The serum expression of miR-218 is downregulated in esophageal cancer patients and is correlated with tumor differentiation, stage, and lymph node metastasis. Serum miR-218 may be a potential biomarker for early detection and clinical evaluation in patient with esophageal cancer.