title: Next-generation sequencing adds value to the preoperative diagnosis of pancreatic cysts.
abstract: BACKGROUND
  The diagnosis of a pancreatic cyst as mucinous or high-risk dictates the need for follow-up or surgery. Molecular analysis of aspirated pancreatic cyst fluid (PCF) can provide valuable information not obtained by carcinoembryonic antigen (CEA) analysis or cytology.
  
  
  METHODS
  All patients who underwent molecular analysis of PCF between March 2013 and June 2015 were reviewed, including pathology, imaging, and follow-up. Molecular testing was performed using a patented, anchored multiplex polymerase chain reaction next-generation sequencing (NGS) platform, which sequenced numerous hotspots in 39 genes linked with malignancy. Performance of NGS and cytology was calculated using final outcome, as determined by clinicopathologic follow-up.
  
  
  RESULTS
  The study cohort included 113 PCFs from 105 patients. In total, 119 variants were detected in 67 PCFs (59%). Variants were more common in intraductal papillary mucinous neoplasms (IPMNs)/cancer than in nonmucinous cysts (P < .005). The inclusion of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS)/guanine nucleotide-binding protein (GNAS) variants improved the classification of IPMNs as mucinous from 50% by microscopy to 100%. Seventy-five percent of cancers had high-grade atypia versus 0% of IPMNs and nonmucinous cysts (P < .002). Variants in tumor protein 53 (TP53), SMAD family member 4 (SMAD4), cyclin-dependent kinase inhibitor 2A (CDKN2A), and notch1 (NOTCH1) were detected only in malignant cysts. Cytology was similarly specific (100%) for detecting malignant cysts but was more sensitive than the identification of late mutations by NGS (75% vs 46%).
  
  
  CONCLUSIONS
  The detection of KRAS/GNAS variants improves the identification of mucinous neoplasms. Variants in TP53, SMAD4, CDKN2A, and NOTCH1 support the diagnosis of a high-risk cyst requiring surgery or additional sampling. Although molecular analysis is not a replacement for cytopathology, it does provide valuable information for accurate preoperative diagnosis, helping to classify mucinous neoplasms and high-risk cysts that require surgical resection. Cancer Cytopathol 2017;125:41-47. © 2016 American Cancer Society.
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Matthew W
authors.identifier: http://orcid.org/0000-0001-8603-6538
authors.initials: MW
authors.lastname: Rosenbaum
authors.affiliation: Department of Anatomical Pathology, Concord Repatriation General Hospital, Sydney, Australia.
authors.forename: Martin
authors.initials: M
authors.lastname: Jones
authors.affiliation: Department of Pathology, Stanford University, Stanford, California.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Dudley
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Long P
authors.initials: LP
authors.lastname: Le
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: A John
authors.initials: AJ
authors.lastname: Iafrate
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Martha B
authors.initials: MB
authors.lastname: Pitman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D002272:Carcinoembryonic Antigen / Q000235:genetics; D020420:Cyst Fluid / Q000378:metabolism; D018291:Cystadenoma, Mucinous / Q000175:diagnosis* / Q000235:genetics / Q000601:surgery; D003581:Cytodiagnosis; D005260:Female; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics; D010181:Pancreatic Cyst / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D057234:Preoperative Period
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D009363:Neoplasm Proteins
keywords: DNA sequencing; adenocarcinoma mucinous; carcinoma; digestive system; early detection of cancer; endoscopy; molecular sequence data; pancreas; pancreatic cyst; pancreatic ductal; pancreatic neoplasms