title: Diagnostic Value of Fecal MicroRNAs for Colorectal Cancer: a Meta-Analysis.
abstract: BACKGROUND
  Though the fecal occult blood test is used for colorectal cancer (CRC) screening worldwide, it lacks sensitivity and specificity for screening an average-risk population. Many studies have suggested that fecal microRNAs (miRNAs) might serve as novel diagnostic indicators of colorectal cancer. However, inconsistent results have also been reported. This meta-analysis aimed to evaluate the feasibility of fecal miRNAs as biomarkers for colorectal neoplasia screening.
  
  
  METHODS
  We systematically searched PubMed, Embase, and Google Scholar for publications concerning the diagnostic value of miRNAs isolated from stool for CRC screening. The quality of each study was scored using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). Data from different studies were pooled to estimate the summary sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) using a bivariate model. Summary receiver operator characteristic curves (SROCs) were plotted, and areas under the SROC curve (AUC) were calculated to evaluate the overall test performance. Heterogeneity was tested with the I2 test, and publication bias was tested with Deeks' funnel plot asymmetry test. Potential sources of heterogeneity were analyzed through subgroup analyses and meta-regression.
  
  
  RESULTS
  Eighteen studies from 9 articles, including 853 patients and 819 controls, were included in this meta-analysis. The pooled sensitivity, specificity, PLR, DLR, and DOR were 0.63 (95% confidence interval [CI]: 0.56 - 0.70), 0.86 (95% CI: 0.77 - 0.92), 4.47 (95% CI: 2.85 - 7.01), 0.43 (95% CI: 0.38 - 0.49), and 10.38 (95% CI: 6.85 - 15.73), respectively. The area under the SROC was 0.77. Meta-regression suggested that different countries (or regions) and sample sizes may be potential sources of heterogeneity.
  
  
  CONCLUSIONS
  Fecal miRNAs are potentially useful noninvasive biomarkers for the diagnosis of CRC, and combining methylated gene markers or FOBT with miRNA markers may be an alternative approach.
authors.forename: Chengzu
authors.initials: C
authors.lastname: Wang
authors.forename: Kai
authors.initials: K
authors.lastname: Zhao
authors.forename: Qiji
authors.initials: Q
authors.lastname: Rong
mesh_terms: D015179:Colorectal Neoplasms / Q000175:diagnosis*; D005243:Feces / Q000737:chemistry*; D006801:Humans; D035683:MicroRNAs / Q000032:analysis*; D009780:Occult Blood; D017594:Publication Bias
chemical_list: D035683:MicroRNAs