Circulating miR-338-5p is a potential diagnostic biomarker in colorectal cancer

OBJECTIVE: The expression of miR-338-5p has been reported to be upregulated in colorectal cancer (CRC) tissues. Clinicopathological features indicate that miR-338-5p overexpression correlates with the metastatic status of CRC. This study was aimed to investigate the diagnostic value of serum miR-338-5p for CRC. METHODS: Peripheral blood samples were collected from 210 participants, including 80 patients with CRC, 50 with colorectal polyps and 80 healthy controls. Serum miR-338-5p was quantified by quantitative reverse-transcription polymerase chain reaction. The area under the receiver operating characteristic curve (AUROC) was used to estimate the diagnostic value of miR-338-5p, carcinoembryonic antigen (CEA) and the combination of these two biomarkers. RESULTS: Serum miR-338-5p levels (fold change) in patients with CRC and colorectal polyps, and controls were 4.94 1.13, 4.12 +/- 0.75 and 3.07 +/- 0.75, respectively. Significant differences were observed between the groups (P < 0.001). The AUROC of miR-338-5p was 0.923 (95% CI 0.882-0.964) and 0.845 (95% CI 0.792-0.898), respectively, for distinguishing CRC from healthy controls or from those without CRC. The AUROC of the combination of miR-338-5p and CEA was 0.932 (95% CI 0.882-0.964), with a sensitivity of 85%, a specificity of 88.8% at a cut-off value of 8.16. CONCLUSIONS: Circulating miR-338-5p may serve as a potential noninvasive diagnostic biomarker for detecting CRC. The combination of miR-338-5p and CEA exhibits the highest diagnostic value in our study.