Expression of circulating microRNA-20a and let-7a in esophageal squamous cell carcinoma

To investigate the expressions of microRNA-20a (miR-20a) and let-7a in esophageal squamous cell carcinoma (ESCC) and their diagnostic value.

Seventy patients with ESCC and 40 healthy subjects were enrolled to investigate the expression of miR-20a and let-7a using quantitative real-time PCR. The expression of miR-20a and let-7a was compared between ESCC patients and healthy subjects. The plasma levels of miR-20a and let-7a in relation to patient clinicopathologic parameters, the receiver operating characteristic (ROC) curve, and the sensitivity and specificity of miR-20a and let-7a in ESCC diagnosis were analyzed.

Plasma levels of miR-20a were significantly higher in ESCC patients than in healthy controls, and plasma levels of let-7 were lower in ESCC patients than in healthy controls (both P < 0.05). The area under the ROC curve of miR-20a was 0.767 (95%CI: 0.677-0.857; P < 0.001), when the cut-off value was set at 4.77, the sensitivity and specificity were 64.3% and 75.0%, respectively. The area under the ROC curve of let-7a was 0.829 (95%CI: 0.754-0.904; P < 0.001), when the cut-off value was set at 6.22, the sensitivity and specificity were 74.3% and 85.0%, respectively. Thus, the sensitivity and specificity of let-7a were higher than those of miR-20a. The median relative plasma expression of let-7a in clinical stage III/IV (0.24) was lower than that in stage I/II (0.42), while the expression of miR-20a according to stage was not statistically different. The expressions of miR-20a and let-7a were not related to gender, age, tumor diameter, tumor grade, or pathologic stage.

Plasma miR-20a and let-7a levels are significantly altered in patients with ESCC and can be used as potential biomarkers in the diagnosis of ESCC.