Diagnostic value of four serum exosome microRNAs panel for the detection of colorectal cancer

BACKGROUND: Early detection, early diagnosis, and early treatment are currently accepted methods that can effectively improve the efficacy of colorectal cancer (CRC) treatment. Exosomes were demonstrated to be potential tumor molecular markers. AIM: To evaluate the diagnostic value of CRC by detecting four exosomal microRNAs (miRNAs) (miR-15b, miR-16, miR-21, and miR-31) that were demonstrated to have potential diagnostic value in serum. METHODS: Relative expression levels of miR-15b, miR-16, miR-21, and miR-31 in 123 CRC, 117 colorectal adenoma, and 150 healthy controls were detected, and single and panel models were evaluated. The 2-ΔΔCt method was used to calculate the relative expression of miRNA compared to the internal control (U6). Eighty-one CRC patients, 67 colorectal adenoma patients, and 90 healthy controls were used for validation. RESULTS: Compared to the healthy control group, the best indicator of the four miRNAs was miR-15b, and the sensitivity and specificity were 81.33% and 91.80%, respectively. For miR-15b, miR-21, and miR-31 individually, the sensitivity and specificity were 91.95% and 97.62%, 95.06% and 94.44%, respectively. Compared to the colorectal adenoma group, miR-15b, miR-16, and miR-21 in the CRC group showed significant differences (P < 0.05). The best single indicator was miR-16, with a sensitivity and specificity of 79.05% and 71.55%. The sensitivity and specificity of a panel that included miR-15b, miR-16, and miR-21 were 81.21% and 81.03%, and 85.19% and 82.09%, respectively, in the validation. CONCLUSION: We built and validated a diagnostic model containing miR-15b, miR-21, and miR-31 expression levels to discriminate the healthy control group and CRC group, and its sensitivity and specificity were 95.06% and 94.44%, respectively. The miR-15b, miR-16, and miR-21 panel was used to discriminate the colorectal adenoma group and CRC group with a sensitivity and specificity of 85.19% and 82.09%, respectively.