title: Expression and significance of circulating microRNA-31 in lung cancer patients.
abstract: BACKGROUND
  The aim of this study was to investigate the expression level of circulating microRNA-31(miRNA-31) in lung cancer patients and its clinical significance.
  
  
  METHODS
  Real-time fluorescent quantitative PCR was utilized to detect the circulating miRNA-31 expression levels in 300 lung cancer patients and 300 health control subjects. The ROC curve was drawn to evaluate the diagnostic value of the circulating miRNA-31 expression levels in lung cancer. The 300 lung cancer patients were divided into a miRNA-31 low-expression group and a miRNA-31 high-expression group. A survival curve was drawn according to the Kaplan-Meier method to evaluate the prognostic value of the circulating microRNA-31 expression levels for lung cancer.
  
  
  RESULTS
  The circulating miRNA-31 expression levels in the lung cancer patients (l.88±0. 67) increased significantly (P<0.001) compared to the healthy controls (0.58±0. 44). The area under the ROC curve drawn according to the circulating miRNA-31 expression levels was 0.785 (95% CI=0.486-0.763). When the critical value was 1.27, the sensitivity and specificity for lung cancer diagnosis according to the circulating miRNA-31 expression levels were 0.769 and 0.745, respectively. The difference in the survival curve between the miRNA-31 low-expression group (123 cases) and high-expression group (177 cases) was statistically significant (P=0.004). Median survival period of the low-expression group (38.44 months) was longer than that of the high-expression group (25.23 months).
  
  
  CONCLUSIONS
  miRNA-31 may be a molecular marker for the diagnostic and prognostic evaluation of primary lung cancer.
authors.affiliation: Department of Respiration, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China (mainland).
authors.forename: Hai-Jun
authors.initials: HJ
authors.lastname: Yan
authors.affiliation: Department of Respiration, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China (mainland).
authors.forename: Ji-Yong
authors.initials: JY
authors.lastname: Ma
authors.affiliation: Department of Respiration, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China (mainland).
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Respiration, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China (mainland).
authors.forename: Wei
authors.initials: W
authors.lastname: Gu
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000097:blood* / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics*; D008875:Middle Aged; D011182:Postoperative Care; D011379:Prognosis; D012372:ROC Curve
chemical_list: C534612:MIRN31 microRNA, human; D035683:MicroRNAs