Circulating miRNA-20a and miRNA-203 for screening lymph node metastasis in early stage cervical cancer

MicroRNAs (miRNAs) are small, noncoding RNAs that are critical regulators of various diseases, including cancer, which may represent a novel class of cancer biomarkers.

We hypothesized that microRNA-20a (miR-20a) and microRNA-203 (miR-203), which were altered in lymphatic metastatic tissues, could be directly assayed in the serum and used to detect the lymph node status of cervical cancer patients.

We analyzed serum levels of miR-20a and miR-203 in 80 patients with stage I-IIA of cervical cancer by quantitative real-time polymerase chain reaction assay. Blood samples were collected before surgery and therapy. Logistic regression was used to measure the influence of different variables. Receiver operating characteristic analysis could evaluate the sensitivity and specificity in separating lymph node metastasis (LNM) (+) patients from LNM (-) patients by serum miR-20a and miR-203.

We found that the expression level of miR-20a was significantly higher in cervical cancer patients compared to healthy controls (p=0.004), patients with LNM tended to have overexpression of miR-20a (p=0.000), the odds ratio was 1.552. The expression level of miR-203 in cervical cancer patients was also significantly increased in comparison to the healthy patients (p=0.000), while downregulated miR-203 was correlated with LNM (p=0.001), the odds ratio was 0.849. When miR-20a was used for differentiation of LNM (+) patients from LNM (-) patients, the value of the area under the receiver-operating curve (AUC) was 0.734±0.058, the sensitivity and specificity of serum miR-20a were 75% and 72.5%, respectively, the cut-off point was 3.0. But the AUC of miR-203 was only 0.658±0.061, which showed low accuracy, the sensitivity and specificity were 65% and 62.5%, respectively, the cut-off point was 0.13.

Our results suggested that the circulating miR-20a may be a potential biomarker for detecting the lymph node status of cervical cancer patients.