title: Promoter hypermethylation ofSHOX2andSEPT9is a potential biomarker for minimally invasive diagnosis in adenocarcinomas of the biliary tract.
abstract: Biliary tract carcinoma (BTC) is a fatal malignancy which aggressiveness contrasts sharply with its relatively mild and late clinical presentation. Novel molecular markers for early diagnosis and precise treatment are urgently needed. The purpose of this study was to evaluate the diagnostic and prognostic value of promoter hypermethylation of theSHOX2andSEPT9gene loci in BTC.
  
  
  
  Relative DNA methylation ofSHOX2andSEPT9was quantified in tumor specimens and matched normal adjacent tissue (NAT) from 71 BTC patients, as well as in plasma samples from an independent prospective cohort of 20 cholangiocarcinoma patients and 100 control patients. Receiver operating characteristic (ROC) curve analyses were performed to probe the diagnostic ability of both methylation markers. DNA methylation was correlated to clinicopathological data and to overall survival.
  
  
  
  SHOX2methylation was significantly higher in tumor tissue than in NAT irrespective of tumor localization (p< 0.001) and correctly identified 71% of BTC specimens with 100% specificity (AUC = 0.918; 95% CI 0.865-0.971).SEPT9hypermethylation was significantly more frequent in gallbladder carcinomas compared to cholangiocarcinomas (p= 0.01) and was associated with large primary tumors (p= 0.01) as well as age (p= 0.03). Cox proportional hazard analysis confirmed microscopic residual tumor at the surgical margin (R1-resection) as an independent prognostic factor, whileSHOX2andSEPT9methylation showed no correlation with overall survival. Elevated DNA methylation levels were also found in plasma derived from cholangiocarcinoma patients.SHOX2andSEPT9methylation as a marker panel achieved a sensitivity of 45% and a specificity of 99% in differentiating between samples from patients with and without cholangiocarcinoma (AUC = 0.752; 95% CI 0.631-0.873).
  
  
  
  SHOX2andSEPT9are frequently methylated in biliary tract cancers. Promoter hypermethylation ofSHOX2andSEPT9may therefore serve as a minimally invasive biomarker supporting diagnosis finding and therapy monitoring in clinical specimens.
authors.affiliation: Department of General, Visceral, Thoracic and Vascular Surgery University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Branchi
authors.affiliation: Department of General, Visceral, Thoracic and Vascular Surgery University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Schaefer
authors.affiliation: Department of General, Visceral, Thoracic and Vascular Surgery University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Semaan
authors.affiliation: Department of General, Visceral, Thoracic and Vascular Surgery University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Kania
authors.affiliation: Department of General, Visceral, Thoracic and Vascular Surgery University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Lingohr
authors.affiliation: Department of General, Visceral, Thoracic and Vascular Surgery University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany.
authors.forename: J C
authors.initials: JC
authors.lastname: Kalff
authors.affiliation: Department of General, Visceral, Thoracic and Vascular Surgery University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Schäfer
authors.affiliation: Institute of Pathology, University Hospital Bonn, Bonn, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Kristiansen
authors.affiliation: Institute of Pathology, University Hospital Bonn, Bonn, Germany.|Department of Otolaryngology, Head and Neck Surgery, University Hospital Bonn, Bonn, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Dietrich
authors.affiliation: Department of General, Visceral, Thoracic and Vascular Surgery University Hospital Bonn, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Matthaei
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000235:genetics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001661:Biliary Tract Neoplasms / Q000175:diagnosis* / Q000235:genetics; D014408:Biomarkers, Tumor / Q000235:genetics; D019175:DNA Methylation; D055088:Early Detection of Cancer / Q000379:methods*; D044127:Epigenesis, Genetic; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D011401:Promoter Regions, Genetic; D011446:Prospective Studies; D058112:Septins / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D018398:Homeodomain Proteins; C484664:SHOX2 protein, human; C474315:SEPTIN9 protein, human; D058112:Septins