MiR-520f acts as a biomarker for the diagnosis of lung cancer.

Lung cancer is a malignant tumor with high morbidity and mortality. Early diagnosis remains a great challenge for the cancer. In this study, we aimed to explore diagnostic performance of serum microRNA-520f (miR-520f) in lung cancer.Serum specimens were collected from 139 lung cancer patients and 76 healthy volunteers. Relative expression level of serum miR-520f was detected adopting quantitative real-time polymerase chain reaction (qRT-PCR). Chi-square test was applied to evaluate the association of miR-520f with clinical parameters of the patients. Additionally, receiver operating characteristic (ROC) analysis was performed to evaluate diagnostic value of miR-520f in lung cancer.Serum miR-520f was down-regulated in lung cancer patients compared with healthy group (P <.001). Moreover, the expression of miR-520f was significantly associated with advanced TNM stage (P = .031) and metastasis (P = .002). The area under the curve (AUC) value of ROC curve was 0.888, suggesting that miR-520f could be a diagnostic biomarker for lung cancer. The cut-off value of serum miR-520f for lung cancer diagnosis was 1.815, with a sensitivity of 79.9% and a specificity of 84.2%.Serum miR-520f was down-regulated in lung cancer patients, and may be a candidate biomarker for non-invasive screening of the disease.