title: Prognostic microRNAs in cancer tissue from patients operated for pancreatic cancer--five microRNAs in a prognostic index.
abstract: BACKGROUND
  The aim of the present study was to identify a panel of microRNAs (miRNAs) that can predict overall survival (OS) in non micro-dissected cancer tissues from patients operated for pancreatic cancer (PC).
  
  
  METHODS
  MiRNAs were purified from formalin-fixed paraffin embedded (FFPE) cancer tissue from 225 patients operated for PC. Only a few of those patients received adjuvant chemotherapy. Expressions of miRNAs were determined with the TaqMan MicroRNA Array v2.0. Two statistical methods, univariate selection and the Lasso (Least Absolute Shrinkage and Selection Operator) method, were applied in conjunction with the Cox proportional hazard model to relate miRNAs to OS.
  
  
  RESULTS
  High expression of miR-212 and miR-675 and low expression of miR-148a, miR-187, and let-7g predicted short OS independent of age, gender, calendar year of operation, KRAS mutation status, tumor stage, American Society of Anesthesiologists (ASA) score, localization (not miR-148a), and differentiation of tumor. A prognostic index (PI) based on these five miRNAs was calculated for each patient. The median survival was 1.09 years (Confidence Interval [CI] 0.98-1.43) for PI > median PI compared to 2.23 years (CI 1.84-4.36) for PI < median. MiR-212, miR-675, miR-187, miR-205, miR-944, miR-431, miR-194, miR-148a, and miR-769-5p showed the strongest prediction ability by the Lasso method. Thus miR-212, miR-675, miR-187, and miR-148a were predictors for OS in both statistical methods.
  
  
  CONCLUSIONS
  The combination of five miRNAs expression in non micro-dissected FFPE PC tissue can identify patients with short OS after radical surgery. The results are independent of chemotherapy treatment. Patients with a prognostic index > median had a very short median OS of only 1 year.
authors.affiliation: Department of Surgical Gastroenterology and Transplantation, Copenhagen University Hospital, C 2-12-2, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark. nicolai-schultz@dadlnet.dk
authors.forename: Nicolai A
authors.initials: NA
authors.lastname: Schultz
authors.forename: Klaus K
authors.initials: KK
authors.lastname: Andersen
authors.forename: Anne
authors.initials: A
authors.lastname: Roslind
authors.forename: Hanni
authors.initials: H
authors.lastname: Willenbrock
authors.forename: Morten
authors.initials: M
authors.lastname: Wøjdemann
authors.forename: Julia S
authors.initials: JS
authors.lastname: Johansen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000032:analysis*; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000737:chemistry* / Q000235:genetics / Q000401:mortality* / Q000601:surgery; D011237:Predictive Value of Tests; D011379:Prognosis; D015996:Survival Rate
chemical_list: D035683:MicroRNAs