title: A comparison of the performance of microsatellite and methylation urine analysis for predicting the recurrence of urothelial cell carcinoma, and definition of a set of markers by Bayesian network analysis.
abstract: OBJECTIVE
  To compare the potential of two diagnostic methods for detecting recurrence of urothelial cell carcinoma (UCC) of the bladder, by (i) detecting alterations in microsatellite DNA markers and loss of heterozygosity (LOH), and (ii) detecting aberrant gene hypermethylation, as UCC has a high recurrence rate in the urinary tract and the disease can invade muscle if new tumours are overlooked.
  
  
  METHODS
  Over 1 year, urine samples were retrieved from 40 patients already diagnosed with bladder UCC (30 pTa, two pTis, eight pT1). Samples were collected 6 months after bladder tumour resection, during the follow-up schedule. We used samples to analyse nine microsatellite markers and the methylation status of 11 gene promoters. Receiver operating characteristic curves were generated and Bayesian statistics used to create an interaction network between recurrence and the biomarkers.
  
  
  RESULTS
  During the study, 15 of the 40 patients (38%) had a tumour recurrence and 14 were identified by cystoscopy (reference method). Overall, microsatellite markers (area under curve, AUC 0.819, 95% confidence interval, CI, 0.677-0.961) had better performance characteristics than promoter hypermethylation (AUC 0.448, 0.259-0.637) for detecting recurrence. A marker panel of IFNA, MBP, ACTBP2, D9S162 and of RASSF1A, and WIF1 generated a higher diagnostic accuracy of 86% (AUC 0.92, 0.772-0.981).
  
  
  CONCLUSIONS
  Microsatellite markers have better performance characteristics than promoter hypermethylation for detecting UCC recurrence. These data support the further development of a combination of only six markers from both methods in urinary DNA. Once validated, it could be used routinely during the follow-up for the early detection and surveillance of UCC from the lower and upper urinary tract.
authors.affiliation: Institute for Cancer Studies and Academic Urology Unit, University of Sheffield, Royal Hallamshire Hospital, UK. morgan.roupret@psl.aphp.fr
authors.forename: Morgan
authors.initials: M
authors.lastname: Rouprêt
authors.forename: Vincent
authors.initials: V
authors.lastname: Hupertan
authors.forename: David R
authors.initials: DR
authors.lastname: Yates
authors.forename: Eva
authors.initials: E
authors.lastname: Comperat
authors.forename: James W F
authors.initials: JW
authors.lastname: Catto
authors.forename: Mark
authors.initials: M
authors.lastname: Meuth
authors.forename: Amine
authors.initials: A
authors.lastname: Lackmichi
authors.forename: Sylvie
authors.initials: S
authors.lastname: Ricci
authors.forename: Roger
authors.initials: R
authors.lastname: Lacave
authors.forename: Bernard
authors.initials: B
authors.lastname: Gattegno
authors.forename: François
authors.initials: F
authors.lastname: Richard
authors.forename: Freddie C
authors.initials: FC
authors.lastname: Hamdy
authors.forename: Olivier
authors.initials: O
authors.lastname: Cussenot
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001499:Bayes Theorem; D002295:Carcinoma, Transitional Cell / Q000473:pathology*; D019175:DNA Methylation; D005260:Female; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D016482:Urinalysis / Q000379:methods; D001749:Urinary Bladder Neoplasms / Q000473:pathology*