title: Clinical usefulness of KRAS mutational analysis in the diagnosis of pancreatic adenocarcinoma by means of endosonography-guided fine-needle aspiration biopsy.
abstract: OBJECTIVE
  To establish the usefulness of KRAS mutational analysis in the diagnosis of pancreatic adenocarcinoma by comparing this technique with conventional cytology in aspirates obtained by endosonography-guided fine-needle aspiration.
  
  
  METHODS
  All consecutive patients with pancreatic focal lesions undergoing endosonography-guided fine-needle aspiration were included. Samples were obtained with the concurrence of an attendant cytopathologist. Detection of codon-12 KRAS mutations was performed by the restriction fragment length polymorphism-polymerase chain reaction method. The effectiveness of conventional cytology, KRAS mutational analysis and their combination was established with respect to the definitive diagnosis. A cost-effectiveness analysis was also performed.
  
  
  RESULTS
  Thirty-three patients had pancreatic adenocarcinoma and 24 patients had other lesions. A total of 136 samples was obtained. In patients in whom specimens were adequate (93% for cytology; 100% for mutational analysis), the specificity of both techniques was 100%, whereas the sensitivity favoured cytology (97% vs. 73%). When inadequate samples were considered as misdiagnosed, a combination of both techniques reached the highest overall accuracy (cytology, 91%; mutational analysis, 84%; combination of both, 98%).
  
  
  CONCLUSIONS
  Cytology from aspirates obtained by endosonography-guided fine-needle aspiration is the most precise single technique for the diagnosis of pancreatic adenocarcinoma. However, when adequate specimens are not available to reach a cytological diagnosis, the addition of KRAS mutational analysis represents the best strategy.
authors.affiliation: Department of Gastroenterology, Institut de Malalties Digestives, Hospital Clínic, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Pellisé
authors.forename: A
authors.initials: A
authors.lastname: Castells
authors.forename: A
authors.initials: A
authors.lastname: Ginès
authors.forename: M
authors.initials: M
authors.lastname: Solé
authors.forename: J
authors.initials: J
authors.lastname: Mora
authors.forename: S
authors.initials: S
authors.lastname: Castellví-Bel
authors.forename: F
authors.initials: F
authors.lastname: Rodríguez-Moranta
authors.forename: G
authors.initials: G
authors.lastname: Fernàndez-Esparrach
authors.forename: J
authors.initials: J
authors.lastname: Llach
authors.forename: J M
authors.initials: JM
authors.lastname: Bordas
authors.forename: S
authors.initials: S
authors.lastname: Navarro
authors.forename: J M
authors.initials: JM
authors.lastname: Piqué
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis*; D001707:Biopsy, Needle / Q000379:methods; D003362:Cost-Benefit Analysis; D004252:DNA Mutational Analysis / Q000379:methods / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018084:Ultrasonography, Interventional