title: RNA sequencing distinguishes benign from malignant pancreatic lesions sampled by EUS-guided FNA.
abstract: OBJECTIVE
  EUS-guided FNA (EUS-FNA) is the primary method used to obtain pancreatic tissue for preoperative diagnosis. Accumulating evidence suggests diagnostic and prognostic information may be obtained by gene-expression profiling of these biopsy specimens. RNA sequencing (RNAseq) is a newer method of gene-expression profiling, but published data are scant on the use of this method on pancreas tissue obtained via EUS-FNA. The aim of this study was to determine whether RNAseq of EUS-FNA biopsy samples of undiagnosed pancreatic masses can reliably discriminate between benign and malignant tissue.
  
  
  METHODS
  In this prospective study, consenting adults presented to 2 tertiary care hospitals for EUS of suspected pancreatic mass. Tissue was submitted for RNAseq. The results were compared with cytologic diagnosis, surgical pathology diagnosis, or benign clinical follow-up of at least 1 year.
  
  
  RESULTS
  Forty-eight patients with solid pancreatic mass lesions were enrolled. Nine samples were excluded because of inadequate RNA and 3 because of final pathologic diagnosis of neuroendocrine tumor. Data from the first 13 patients were used to construct a linear classifier, and this was tested on the final 23 patients (15 malignant and 8 benign lesions). RNAseq of EUS-FNA biopsy samples distinguishes ductal adenocarcinoma from benign pancreatic solid masses with a sensitivity of .87 (range, .58-.98) and specificity of .75 (range, .35-.96).
  
  
  CONCLUSIONS
  This proof-of-principle study suggests RNAseq of EUS-FNA samples can reliably detect adenocarcinoma and may provide a new method to evaluate more diagnostically challenging pancreatic lesions.
authors.affiliation: Division of Gastroenterology, Oregon Health & Science University, Portland, Oregon, USA; The Oregon Clinic Gastroenterology, Portland, Oregon, USA.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Rodriguez
authors.affiliation: Oregon Stem Cell Center, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Soren D
authors.initials: SD
authors.lastname: Impey
authors.affiliation: Oregon Stem Cell Center, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Carl
authors.initials: C
authors.lastname: Pelz
authors.affiliation: Division of Gastroenterology, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Brintha
authors.initials: B
authors.lastname: Enestvedt
authors.affiliation: Division of Gastroenterology, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Gennadiy
authors.initials: G
authors.lastname: Bakis
authors.affiliation: The Oregon Clinic Gastroenterology, Portland, Oregon, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Owens
authors.affiliation: Department of Pathology, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Terry K
authors.initials: TK
authors.lastname: Morgan
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D010195:Pancreatitis / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D011446:Prospective Studies; D017423:Sequence Analysis, RNA