title: Mutation Profile and Fluorescence In Situ Hybridization Analyses Increase Detection of Malignancies in Biliary Strictures.
abstract: OBJECTIVE
  It is a challenge to detect malignancies in biliary strictures. Various sampling methods are available to increase diagnostic yield, but these require additional procedure time and expertise. We evaluated the combined accuracy of fluorescence in situ hybridization (FISH) and polymerase chain reaction-based DNA mutation profiling (MP) of specimens collected using standard brush techniques.
  
  
  METHODS
  We performed a prospective study of 107 consecutive patients treated for biliary strictures by endoscopic retrograde cholangiopancreatography from June 2012 through June 2014. We performed routine cytology and FISH analyses on cells collected by standard brush techniques, and analyzed supernatants for point mutations in KRAS and loss-of-heterozygosity mutations in tumor-suppressor genes at 10 loci (MP analysis was performed at Interpace Diagnostics). Strictures were determined to be nonmalignant based on repeat image analysis or laboratory test results 12 months after the procedure. Malignant strictures were identified based on subsequent biopsy or cytology analyses, pathology analyses of samples collected during surgery, or death from biliary malignancy. We determined the sensitivity and specificity with which FISH and MP analyses detected malignancies using the exact binomial test.
  
  
  RESULTS
  Our final analysis included 100 patients; 41% had biliary malignancies. Cytology analysis identified patients with malignancies with 32% sensitivity and 100% specificity. Addition of FISH or MP results to cytology results increased the sensitivity of detection to 51% (P < .01) without reducing specificity. The combination of cytology, MP, and FISH analyses detected malignancies with 73% sensitivity (P < .001). FISH identified an additional 9 of the 28 malignancies not detected by cytology analysis, and MP identified an additional 8 malignancies. FISH and MP together identified 17 of the 28 malignancies not detected by cytology analysis.
  
  
  CONCLUSIONS
  Addition of FISH and mutation analyses to cytology analysis significantly increased the level of sensitivity with which we detected malignancy in biliary strictures, with 100% specificity. These techniques can be performed using standard brush samples collected during endoscopic retrograde cholangiopancreatography, with mutations detected in free DNA in supernatant fluid of samples. The tests are complementary and therefore should be used sequentially in the diagnostic evaluation of biliary strictures.
authors.affiliation: Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, New York. Electronic address: tg2214@cumc.columbia.edu.
authors.forename: Tamas A
authors.initials: TA
authors.lastname: Gonda
authors.affiliation: Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, New York.
authors.forename: Domenico
authors.initials: D
authors.lastname: Viterbo
authors.affiliation: Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, New York.
authors.forename: Valerie
authors.initials: V
authors.lastname: Gausman
authors.affiliation: Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, New York.
authors.forename: Claudine
authors.initials: C
authors.lastname: Kipp
authors.affiliation: Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, New York.
authors.forename: Amrita
authors.initials: A
authors.lastname: Sethi
authors.affiliation: Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, New York.
authors.forename: John M
authors.initials: JM
authors.lastname: Poneros
authors.affiliation: Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, New York.
authors.forename: Frank
authors.initials: F
authors.lastname: Gress
authors.affiliation: Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, New York.
authors.forename: Tina
authors.initials: T
authors.lastname: Park
authors.affiliation: Division of Digestive and Liver Disease, Department of Medicine, Columbia University Medical Center, New York, New York.
authors.forename: Ali
authors.initials: A
authors.lastname: Khan
authors.affiliation: Interpace Diagnostics Corporation, Pittsburgh, Pennsylvania.
authors.forename: Sara A
authors.initials: SA
authors.lastname: Jackson
authors.affiliation: Interpace Diagnostics Corporation, Pittsburgh, Pennsylvania.
authors.forename: Megan
authors.initials: M
authors.lastname: Blauvelt
authors.affiliation: Interpace Diagnostics Corporation, Pittsburgh, Pennsylvania.
authors.forename: Nicole
authors.initials: N
authors.lastname: Toney
authors.affiliation: Interpace Diagnostics Corporation, Pittsburgh, Pennsylvania.
authors.forename: Sydney D
authors.initials: SD
authors.lastname: Finkelstein
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001661:Biliary Tract Neoplasms / Q000175:diagnosis* / Q000473:pathology; D001651:Cholestasis, Extrahepatic / Q000209:etiology* / Q000473:pathology; D003251:Constriction, Pathologic / Q000209:etiology* / Q000473:pathology; D005260:Female; D060005:Genotyping Techniques; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009154:Mutation; D011446:Prospective Studies; D012680:Sensitivity and Specificity
keywords: Cancer Detection; Diagnosis; ERCP; Mutation Profile