title: Bile-based detection of extrahepatic cholangiocarcinoma with quantitative DNA methylation markers and its high sensitivity.
abstract: Extrahepatic cholangiocarcinoma (EHC) is usually difficult to diagnose by bile cytology because of cellular disintegration. However, DNA samples from bile fluid can provide sufficient materials to screen for the presence of EHC. We developed DNA methylation marker panels that can be used for MethyLight assay-based detection of EHC in bile fluid specimens. The methylation status of 59 DNA methylation markers was investigated in 20 EHC and 20 non-neoplastic gallbladder tissue samples with MethyLight assay to determine cancer-specific DNA methylation markers. Through assaying cancer-specific DNA methylation markers in a training set (n = 40) and validation set (n = 45) of bile fluid specimens from patients with EHC or those without cancer, we selected suitable marker panels that were assessed for their performance in a third set (test set; n = 40). Four marker panels showed a sensitivity of 60% or more and a specificity of 100% in both the training and validation sets, whereas bile cytology displayed a sensitivity of 40% to 46% and a specificity of 100%. In an independent test set of bile fluid samples, a five-gene panel (CCND2, CDH13, GRIN2B, RUNX3, and TWIST1) detected EHC at a sensitivity of 83%, which was far higher than that of bile cytology (46%, P = 0.004). Using bile fluids, a methylation assay consisting of a five-gene panel may be useful for detecting EHC and in helping to increase the sensitivity of preoperative diagnoses.
authors.affiliation: Laboratory of Epigenetics, Cancer Research Institute, Seoul, South Korea.
authors.forename: So-Hyun
authors.initials: SH
authors.lastname: Shin
authors.forename: Kyoungbun
authors.initials: K
authors.lastname: Lee
authors.forename: Baek-Hui
authors.initials: BH
authors.lastname: Kim
authors.forename: Nam-Yun
authors.initials: NY
authors.lastname: Cho
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Jang
authors.forename: Yong-Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Donguk
authors.initials: D
authors.lastname: Kim
authors.forename: Ja June
authors.initials: JJ
authors.lastname: Jang
authors.forename: Gyeong Hoon
authors.initials: GH
authors.lastname: Kang
mesh_terms: D001646:Bile / Q000166:cytology*; D014408:Biomarkers, Tumor / Q000235:genetics; D018281:Cholangiocarcinoma / Q000175:diagnosis* / Q000235:genetics*; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D005704:Gallbladder / Q000166:cytology; D005819:Genetic Markers; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016612:Paraffin Embedding; D011401:Promoter Regions, Genetic; D012680:Sensitivity and Specificity; D016707:Tissue Fixation
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D005819:Genetic Markers