title: Hypermethylation of cell-free serum DNA indicates worse outcome in patients with bladder cancer.
abstract: OBJECTIVE
  CpG island hypermethylation is a frequent event in bladder carcinogenesis and progression. We investigated the diagnostic and prognostic value of hypermethylation in cell-free serum DNA of patients with bladder cancer.
  
  
  METHODS
  The study cohort consisted of 45 patients with bladder cancer undergoing cystectomy and 45 with histologically confirmed benign prostatic hyperplasia serving as controls. Hypermethylation at APC, DAPK, GSTP1, PTGS2, TIG1 and Reprimo was analyzed using real-time polymerase chain reaction following methylation sensitive restriction endonuclease treatment.
  
  
  RESULTS
  Hypermethylation at the APC and GSTP1 promoter was detected in 59% of cases, whereas TIG1 (32%), PTGS2 (24%) and DAPK (2%) were less frequently hypermethylated. In the benign prostatic hyperplasia group 3 patients also harbored methylated GSTP1 DNA, whereas none of the other gene sites was methylated. Hypermethylation at APC, GSTP1 or TIG1 distinguished patients with bladder cancer and controls most accurately with 80% sensitivity and 93% specificity. Hypermethylation significantly correlated with prognostic unfavorable clinicopathological parameters, including APC with pT stage, GSTP1, or GSTP1 or TIG1 with multifocal bladder cancer and APC, or APC or TIG1 with surgical margin positivity. Bladder cancer specific mortality was significantly increased in patients with APC hypermethylation.
  
  
  CONCLUSIONS
  The detection of hypermethylation in cell-free serum DNA provides valuable diagnostic and prognostic information that can still be improved by combining the results of 3 gene sites (APC, GSTP1 and TIG1). The presence of hypermethylated DNA in the serum of patients with bladder cancer is associated with a worse outcome. Our results suggest that measuring hypermethylation in the serum of patients with bladder cancer is a useful biomarker.
authors.affiliation: Klinik und Poliklinik für Urologie, Universitätsklinikum Bonn, Rheinische-Friedrich-Wilhelms-Universität Bonn, Germany. joerg.ellinger@ukb.uni-bonn.de
authors.forename: Jörg
authors.initials: J
authors.lastname: Ellinger
authors.forename: Nadja
authors.initials: N
authors.lastname: El Kassem
authors.forename: Lukas C
authors.initials: LC
authors.lastname: Heukamp
authors.forename: Swapna
authors.initials: S
authors.lastname: Matthews
authors.forename: Figen
authors.initials: F
authors.lastname: Cubukluoz
authors.forename: Philip
authors.initials: P
authors.lastname: Kahl
authors.forename: Frank G
authors.initials: FG
authors.lastname: Perabo
authors.forename: Stefan C
authors.initials: SC
authors.lastname: Müller
authors.forename: Alexander
authors.initials: A
authors.lastname: von Ruecker
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Bastian
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004247:DNA / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000401:mortality
chemical_list: D004247:DNA