Usefulness of Plasma Exosomal MicroRNA-451a as a Noninvasive Biomarker for Early Prediction of Recurrence and Prognosis of Non-Small Cell Lung Cancer.

OBJECTIVES

The aim of this study was to clarify the usefulness of plasma exosomal microRNA-451a (miR-451a) as a novel biomarker for the early prediction of recurrence and prognosis in non-small cell lung cancer (NSCLC) patients after curative resection.

METHODS

Before surgery, plasma samples were collected and exosomal microRNA (miRNA) levels were evaluated. We first profiled specific exosomal miRNAs related to recurrence in 6 NSCLC patients with stage IA cancer by miRNA microarray. We then validated the usefulness of selected miRNAs as biomarkers using the other 285 NSCLC patients.

RESULTS

Plasma exosomal miR-451a showed the highest upregulation in the NSCLC patients with recurrence in the miRNA microarray analysis. A significant positive correlation was demonstrated between exosomal miR-451a levels and NSCLC tissue miR-451a levels. Exosomal miR-451a showed a significant association with lymph node metastasis, vascular invasion, and stage. In stage I, II, or III patients, the overall survival (OS) and disease-free survival (DFS) rates among the high-exosomal-miR-451a patients were significantly worse than those among the low-exosomal-miR-451a patients. In Cox multivariate analysis, exosomal miR-451a showed significance for OS and DFS.

CONCLUSION

Plasma exosomal miR-451a might serve as a reliable biomarker for the prediction of recurrence and prognosis in NSCLC patients with stage I, II, or III cancer.