title: Long-term cancer-specific survival in patients with high-risk, non-muscle-invasive bladder cancer and tumour progression: a systematic review.
abstract: BACKGROUND
  Some studies report that tumour progression in patients with non-muscle-invasive bladder cancer (NMIBC) is associated with a poor prognosis. However, no systematic evidence is available.
  
  
  OBJECTIVE
  The aim of the study was to systematically review literature to determine the long-term cancer-specific survival in patients with high-risk NMIBC (T1G3, multifocal, highly recurrent, or carcinoma in situ) having tumour progression.
  
  
  METHODS
  A systematic review was conducted by searching PubMed and the Cochrane library for studies published between 2006 and 2011. Additional studies were identified by scanning reference lists of relevant papers. We attempted to retrieve missing data by contacting the corresponding author. Keywords used included bladder cancer, high-risk, high grade, carcinoma in situ, non-muscle invasive bladder cancer, progression, and survival. Studies were included when they met the following criteria: inclusion of at least 75 patients having high-risk NMIBC, patients were initially treated conservatively with transurethral resection of the bladder tumour and intravesical instillations, a median follow-up of at least 48 mo, and reporting data on progression to muscle-invasive bladder cancer (MIBC) and death resulting from bladder cancer (BCa).
  
  
  RESULTS
  Literature was systematically reviewed, and 19 trials were included, producing a total of 3088 patients, of which 659 (21%) showed progression to MIBC and 428 (14%) died as a result of BCa after a median follow-up of 48-123 mo. Survival after progression from high-risk NMIBC to MIBC was 35%. Progression to MIBC and BCa-related death in high-risk NMIBC were found to be relatively early events, occurring mainly within 48 mo. Finally, even in cases of early cystectomy in patients with high-risk NMIBC, a relevant proportion of these patients appear not be cured of their disease.
  
  
  CONCLUSIONS
  This study provides systematically gathered evidence showing a poor prognosis for patients with high-risk NMIBC and tumour progression.
authors.affiliation: Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Sven
authors.initials: S
authors.lastname: van den Bosch
authors.forename: J
authors.initials: J
authors.lastname: Alfred Witjes
mesh_terms: D002277:Carcinoma / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D015653:Cystectomy; D018450:Disease Progression; D019317:Evidence-Based Medicine; D006801:Humans; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D019459:Urothelium / Q000473:pathology