Circulating microRNA-21 as a potential diagnostic marker for colorectal cancer: A meta-analysis

MicroRNA-21 (miR-21) is overexpressed in the serum of patients with colorectal cancer (CRC), suggesting that miR-21 is a promising diagnostic biomarker for CRC. Therefore, a meta-analysis was performed to assess the diagnostic value of serum miR-21 in CRC patients. This meta-analysis included 9 studies with 746 CRC patients and 476 healthy controls. Two independent researchers identified and extracted study characteristics from eligible studies that were searched from literature databases. The quality of the eligible studies was assessed in accordance with the Quality Assessment of Diagnostic Accuracy Studies. Bivariate and hierarchical summary receiver operating characteristic models were used in the meta-analysis. The pooled sensitivity and specificity were 72% [95% confidence interval (CI), 62-80] and 85% (95% CI, 80-88), respectively. The pooled positive- and negative-likelihood ratios were 4.65 (95% CI, 3.42-6.33) and 0.33 (95% CI, 0.24-0.47), respectively. The diagnostic odds ratio value was 14.03 (95% CI, 7.65-25.74), and the area under the summary receiver operator characteristic curve was 0.87. The present results indicated that miR-21 has a potential diagnostic value with moderate sensitivity and good specificity for CRC. Further prospective studies must be conducted to evaluate the diagnostic accuracy of miR-21.