title: The role of K-ras gene mutation analysis in EUS-guided FNA cytology specimens for the differential diagnosis of pancreatic solid masses: a meta-analysis of prospective studies.
abstract: BACKGROUND
  Differential diagnosis of pancreatic solid masses with EUS-guided FNA (EUS-FNA) is still challenging in about 15% of cases. Mutation of the K-ras gene is present in over 75% of pancreatic adenocarcinomas (PADC).
  
  
  OBJECTIVE
  To assess the accuracy of K-ras gene mutation analysis for diagnosing PADC.
  
  
  METHODS
  We systematically searched the electronic databases for relevant studies published. Data from selected studies underwent meta-analysis by use of a bivariate model providing a pooled value for sensitivity, specificity, diagnostic odds ratio, and summary receiver operating characteristic curve.
  
  
  METHODS
  Meta-analysis of 8 prospective studies.
  
  
  METHODS
  Total of 931 patients undergoing EUS-FNA for diagnosis of pancreatic solid masses.
  
  
  METHODS
  K-ras mutation analysis.
  
  
  METHODS
  Diagnostic accuracy of K-ras mutation analysis and of combined diagnostic strategy by using EUS-FNA and K-ras mutation analysis in the diagnosis of PADC.
  
  
  RESULTS
  The pooled sensitivity of EUS-FNA for the differential diagnosis of PADC was 80.6%, and the specificity was 97%. Estimated sensitivity and specificity were 76.8% and 93.3% for K-ras gene analysis, respectively, and 88.7% and 92% for combined EUS-FNA plus K-ras mutation analysis. Overall, K-ras mutation testing applied to cases that were inconclusive by EUS-FNA reduced the false-negative rate by 55.6%, with a false-positive rate of 10.7%. Not repeating EUS-FNA in cases in which mutation testing of the K-ras gene is inconclusive would reduce the repeat-biopsy rate from 12.5% to 6.8%.
  
  
  CONCLUSIONS
  Small number of studies and between-study heterogeneity.
  
  
  CONCLUSIONS
  K-ras mutation analysis can be useful in the diagnostic work-up of pancreatic masses, in particular when tissue obtained by EUS-FNA is insufficient, and the diagnosis inconclusive.
authors: Department of Medical and Surgical Sciences, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
authors: Lorenzo
authors: L
authors: Fuccio
authors: Cesare
authors: C
authors: Hassan
authors: Liboria
authors: L
authors: Laterza
authors: Loredana
authors: L
authors: Correale
authors: Nico
authors: N
authors: Pagano
authors: Paolo
authors: P
authors: Bocus
authors: Carlo
authors: C
authors: Fabbri
authors: Antonella
authors: A
authors: Maimone
authors: Vincenzo
authors: V
authors: Cennamo
authors: Alessandro
authors: A
authors: Repici
authors: Guido
authors: G
authors: Costamagna
authors: Franco
authors: F
authors: Bazzoli
authors: Alberto
authors: A
authors: Larghi
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D011905:Genes, ras; D006801:Humans; D009154:Mutation; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D050500:Pancreatitis, Chronic / Q000175:diagnosis; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras); D012680:Sensitivity and Specificity; D018631:ras Proteins / Q000235:genetics*
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins
keywords: PADC; QUADAS; Quality Assessment of Diagnostic Accuracy Studies; pancreatic adenocarcinoma