title: The accuracy of circulating microRNA-21 in the diagnosis of colorectal cancer: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The accuracy and clinical value of circulating microRNA-21 (miR-21) were assessed as a novel diagnostic biomarker of colorectal cancer (CRC).
  
  
  METHODS
  Medline/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.
  
  
  RESULTS
  Seven 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).
  
  
  CONCLUSIONS
  The results suggest that circulating miR-21 is a biomarker with moderate sensitivity and specificity for CRC.
authors: Department of General Surgery, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
authors: F
authors: F
authors: Xu
authors: L
authors: L
authors: Xu
authors: M
authors: M
authors: Wang
authors: G
authors: G
authors: An
authors: G
authors: G
authors: Feng
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D035683:MicroRNAs / Q000097:blood*; D016017:Odds Ratio; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs
keywords: MicroRNA-21; biomarker; colorectal cancer; diagnosis; meta-analysis