The accuracy of circulating microRNA-21 in the diagnosis of colorectal cancer: a systematic review and meta-analysis

AimThe accuracy and clinical value of circulating microRNA-21 (miR-21) were assessed as a novel diagnostic biomarker of colorectal cancer (CRC). MethodMedline/PubMed, EMBASE, the Cochrane Library databases and grey literature(Google scholar; British Library) were searched up to 29 September 2014 for eligible studies of the association between blood-based miR-21 and a diagnosis of CRC. Quality Assessment of Diagnostic Accuracy Studies (QUADAS) was employed to assess the quality of the included studies by two investigators. Stata12.0 and Meta-DiSc1.4 software were applied to test the heterogeneity using Cochran's Q test and I-2 statistics and to perform the meta-analysis. ResultsSeven studies with 676 CRC patients and 417 controls were included in the meta-analysis. All were of high quality (QUADAS scores 12 or 13). For miR-21, the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio to predict CRC were 75% [95% confidence interval (CI) 63-83%], 84% (95% CI 79-87%), 4.61 (95% CI 3.38-6.29), 0.30 (95% CI 0.20-0.46) and 16.89 (95% CI 7.56-37.73) after using a random-effects model analysis. The area under the summary receiver operating characteristic curve was 0.86 (95% CI 0.83-0.89). ConclusionThe results suggest that circulating miR-21 is a biomarker with moderate sensitivity and specificity for CRC.