OBJECTIVE

Serum miRNAs are promising biomarkers for the diagnosis and prognostication of many diseases. Our present study aimed at assessing the usefulness of serum miR-770 expression as a diagnostic and prognostic tool for non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Quantitative Real-time PCR (qRT-PCR) was used to measure expression level of serum miR-770 in 196 NSCLC patients and 77 healthy controls. The associations of serum miR-770 expression with clinicopathologic variables were analyzed. Receiver operating characteristic analysis (ROC) was used to determine the value of serum miR-770 as a biomarker for diagnosis of NSCLC. Kaplan-Meier and Cox regression analyses were performed to examine the relationship between serum miR-770 expression and prognosis of NSCLC patients.

RESULTS

We found that serum miR-770 levels were significantly decreased in NSCLC patients compared to healthy controls (p < 0.01). Decreasing serum miR-770 expression was significantly correlated with poorer histological grade (p = 0.015), positive lymph node metastasis (p = 0.007), and advanced tumor stage (p = 0.002). Moreover, we found that the diagnostic value of serum miR-770 for NSCLC patients from healthy controls resulted in an AUC of 0.835 (95 % CI, 0.751-0.919) with a sensitivity of 68% and a specificity of 89%, based on a cut-off value of 5.723. Kaplan-Meier analysis showed that decreased serum miR-770 expression was associated with poor overall survival of NSCLC patients (p = 0.000). Multivariate analysis confirmed that serum miR-770 was an independent prognostic factor in patients with NSCLC.

CONCLUSIONS

Our findings suggested that serum miR-770 may represent a novel diagnostic, prognostic biomarker and a potential therapeutic target for NSCLC.