title: Serum microRNA expression profile as a biomarker in the diagnosis and prognosis of pancreatic cancer.
abstract: BACKGROUND
  Detection of pancreatic cancer (PaC), particularly at early stages, remains a great challenge owing to lack of specific biomarkers. We sought to identify a PaC-specific serum microRNA (miRNA) expression profile and test its specificity and sensitivity as a biomarker in the diagnosis and prognosis of PaC.
  
  
  METHODS
  We obtained serum samples from 197 PaC cases and 158 age- and sex-matched cancer-free controls. We screened the differentially expressed serum miRNAs with Illumina sequencing by synthesis technology using pooled serum samples followed by RT-qPCR validation of a large number of samples arranged in multiple stages. We used risk score analysis to evaluate the diagnostic value of the serum miRNA profiling system. To assess the serum miRNA-based biomarker accuracy in predicting PaC, we performed additional double-blind testing in 77 PaC cases and 52 controls and diagnostic classification in 55 cases with clinically suspected PaC.
  
  
  RESULTS
  After the selection and validation process, 7 miRNAs displayed significantly different expression levels in PaC compared with controls. This 7 miRNA-based biomarker had high sensitivity and specificity for distinguishing various stages of PaC from cancer-free controls and also accurately discriminated PaC patients from chronic pancreatitis (CP) patients. Among the 7 miRNAs, miR-21 levels in serum were significantly associated with overall PaC survival. The diagnostic accuracy rate of the 7-miRNA profile was 83.6% in correctly classifying 55 cases with clinically suspected PaC.
  
  
  CONCLUSIONS
  These data demonstrate that the 7 miRNA-based biomarker can serve as a novel noninvasive approach for PaC diagnosis and prognosis.
authors.affiliation: Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Yiqi
authors.initials: Y
authors.lastname: Du
authors.forename: Weiyan
authors.initials: W
authors.lastname: Yao
authors.forename: Lin
authors.initials: L
authors.lastname: Shen
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Hu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhuang
authors.forename: Guang
authors.initials: G
authors.lastname: Ning
authors.forename: Chunni
authors.initials: C
authors.lastname: Zhang
authors.forename: Yaozong
authors.initials: Y
authors.lastname: Yuan
authors.forename: Zhaoshen
authors.initials: Z
authors.lastname: Li
authors.forename: Ke
authors.initials: K
authors.lastname: Zen
authors.forename: Yi
authors.initials: Y
authors.lastname: Ba
authors.forename: Chen-Yu
authors.initials: CY
authors.lastname: Zhang
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs