Clinical impact of serum miR-661 in diagnosis and prognosis of non-small cell lung cancer.

OBJECTIVE The aim of this study was to evaluate whether serum miR-661 could serve as a biomarker for the diagnosis and prognosis of non-small cell lung cancer (NSCLC). PATIENTS AND METHODS   The expression of serum miR-661 was detected in 150 cases of NSCLC and 114 cases of normal healthy controls by Real-time PCR. Receiver-operating characteristic (ROC) curve analysis was applied to analyze diagnostic value of serum miR-661. The relationship between serum miR-661 expression and clinicopathological characteristics was investigated. Overall survival was analyzed using Kaplan-Meier method. Moreover, Cox proportional-hazards regression analyses were performed to determine the prognostic value of serum miR-661 in NSCLC patients. RESULTS We found that the expression of serum miR-661 was significantly upregulated in NSCLC compared with healthy controls (p < 0.01). The expression level of serum miR-661 was positively correlated with histological grade (p = 0.011), lymph node metastasis (p = 0.003), distant metastasis (p = 0.021) and clinical stage (p = 0.005). Then, ROC curve analysis showed that serum miR-661 has considerable diagnostic accuracy, with an area under the ROC curve (AUC) of 0.726 (p = 0.001). Moreover, NSCLC patients with serum miR-661 higher expression have shown significantly poorer overall survival than those with lower serum miR-661 expression (p = 0.004). Furthermore, multivariate analyses showed that serum miR-661 expression levels were an independent prognostic factor for survival in NSCLC patients. CONCLUSIONS Overall, these findings indicate that serum miR-661 may be a potential biomarker for the diagnosis and prognosis of NSCLC.