Identification of serum miR-30a-5p as a diagnostic and prognostic biomarker in colorectal cancer

BACKGROUND: Circulating microRNAs (miRNAs) have become increasingly appreciated in the diagnosis and prognosis of colorectal cancer (CRC). OBJECTIVE: The aim of this study was to assess the potential diagnostic and prognostic significance of serum miR-30a-5p as a potential biomarker. METHODS: The expression levels of serum miR-30a-5p were measured in 138 cases with CRC, 50 cases with benign lesions (colorectal adenoma and polyps) and 60 healthy volunteers by quantitative real time polymerase chain reaction (qRT-PCR). RESULTS: The results showed that serum miR-30a-5p levels were frequently downregulated in patients with CRC and benign lesions in comparison with normal controls. Moreover, serum miR-30a-5p levels in early-stage CRC patients were significantly increased after surgery. Receiver-operating characteristic (ROC) curve analysis demonstrated serum miR-30a-5p could well distinguish CRC patients, early-stage CRC patients from healthy controls with a relative high value of area under the curve (AUC). Furthermore, low serum miR-30a-5p expression was more frequently occurred in CRC patients with aggressive clinical variables. Additionally, CRC patients exhibiting high serum miR-30a-5p expression had significantly prolonged overall survival than those exhibiting low expression. Finally, both univariate and multivariate analyses revealed that serum miR-30a-5p expression was an independent prognostic factor for overall survival in CRC patients. CONCLUSIONS: Collectively, these findings suggested serum miR-30a-5p might act as a novel biomarker for the diagnosis and prognosis of CRC.