title: Cell-free DNA promoter hypermethylation in plasma as a diagnostic marker for pancreatic adenocarcinoma.
abstract: Pancreatic cancer has a 5-year survival rate of only 5-7%. Difficulties in detecting pancreatic cancer at early stages results in the high mortality and substantiates the need for additional diagnostic tools. Surgery is the only curative treatment and unfortunately only possible in localized tumours. A diagnostic biomarker for pancreatic cancer will have a major impact on patient survival by facilitating early detection and the possibility for curative treatment. DNA promoter hypermethylation is a mechanism of early carcinogenesis, which can cause inactivation of tumour suppressor genes. The aim of this study was to examine promoter hypermethylation in a panel of selected genes from cell-free DNA, as a diagnostic marker for pancreatic adenocarcinoma.
  
  
  
  Patients with suspected or biopsy-verified pancreatic cancer were included prospectively and consecutively. Patients with chronic/acute pancreatitis were included as additional benign control groups. Based on an optimized accelerated bisulfite treatment protocol, methylation-specific PCR of a 28 gene panel was performed on plasma samples. A diagnostic prediction model was developed by multivariable logistic regression analysis using backward stepwise elimination.
  
  
  
  Patients with pancreatic adenocarcinoma (n= 95), chronic pancreatitis (n= 97) and acute pancreatitis (n= 59) and patients screened, but negative for pancreatic adenocarcinoma (n= 27), were included. The difference in mean number of methylated genes in the cancer group (8.41 (95% CI 7.62-9.20)) vs the total control group (4.74 (95% CI 4.40-5.08)) was highly significant (p< 0.001). A diagnostic prediction model (age >65,BMP3,RASSF1A,BNC1,MESTv2,TFPI2,APC,SFRP1andSFRP2) had an area under the curve of 0.86 (sensitivity 76%, specificity 83%). The model performance was independent of cancer stage.
  
  
  
  Cell-free DNA promoter hypermethylation has the potential to be a diagnostic marker for pancreatic adenocarcinoma and differentiate between malignant and benign pancreatic disease. This study brings us closer to a clinical useful diagnostic marker for pancreatic cancer, which is urgently needed. External validation is, however, required before the test can be applied in the clinic.
  
  
  
  ClinicalTrials.gov, NCT02079363.
authors.affiliation: Department of Gastrointestinal Surgery, Clinical Cancer Research Center, Aalborg University Hospital, Hobrovej 18-22, 9000 Aalborg, Denmark ; Department of General Surgery, Hospital of Vendsyssel, Hjørring, Denmark ; Department of Clinical Medicine, Aalborg University, Hobrovej 18-22, 9000 Aalborg, Denmark.
authors.forename: Stine Dam
authors.initials: SD
authors.lastname: Henriksen
authors.affiliation: Section of Molecular Diagnostics, Clinical Biochemistry, Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Poul Henning
authors.initials: PH
authors.lastname: Madsen
authors.affiliation: Department of Gastrointestinal Surgery, Clinical Cancer Research Center, Aalborg University Hospital, Hobrovej 18-22, 9000 Aalborg, Denmark.
authors.forename: Anders Christian
authors.initials: AC
authors.lastname: Larsen
authors.affiliation: Unit of Clinical Biostatistics and Bioinformatics, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Martin Berg
authors.initials: MB
authors.lastname: Johansen
authors.affiliation: Department of Clinical Medicine, Aalborg University, Hobrovej 18-22, 9000 Aalborg, Denmark ; Mech-Sense, Department of Gastroenterology, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Asbjørn Mohr
authors.initials: AM
authors.lastname: Drewes
authors.affiliation: Section of Molecular Diagnostics, Clinical Biochemistry, Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Inge Søkilde
authors.initials: IS
authors.lastname: Pedersen
authors.affiliation: Section of Molecular Diagnostics, Clinical Biochemistry, Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Krarup
authors.affiliation: Department of Gastrointestinal Surgery, Clinical Cancer Research Center, Aalborg University Hospital, Hobrovej 18-22, 9000 Aalborg, Denmark ; Department of Clinical Medicine, Aalborg University, Hobrovej 18-22, 9000 Aalborg, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Thorlacius-Ussing
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000235:genetics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics*; D002474:Cell-Free System / Q000473:pathology; D019175:DNA Methylation; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000235:genetics; D011401:Promoter Regions, Genetic; D011446:Prospective Studies
chemical_list: D014408:Biomarkers, Tumor
keywords: Cell-free DNA; Diagnostic biomarker; Epigenetic; Methylation; Pancreatic adenocarcinoma; Pancreatic cancer; Pancreatitis