title: Population-based study on prognostic factors for recurrence and progression in primary stage T1 bladder tumours.
abstract: OBJECTIVE
  Stage T1 urothelial carcinoma of the bladder (UCB) exhibits heterogeneous clinical behaviour, and the treatment is controversial. The aim of this study was to evaluate prognostic factors for UCB in a defined, population-based cohort comprising patients with a first time diagnosis of primary stage T1 UCB.
  
  
  METHODS
  The study population initially consisted of 285 patients with primary stage T1 UCB reported to the regional Bladder Cancer Registry in the Southeast Healthcare Region of Sweden from 1992 to 2001. The histological specimens were re-evaluated concerning stage, substaging of T1, World Health Organization (WHO) grade, lymphovascular invasion (LVI), tumour volume and total resected volume. Hospital records provided data on tumour size and multiplicity, occurrence of possible relapse and/or progression, death from UCB and whether treatment was given.
  
  
  RESULTS
  After re-evaluation, the study population comprised 211 patients. The median follow-up time was 60 months. LVI was a prognostic factor for UCB progression and recurrence. Tumour size larger than 30 mm and multiplicity increased the risk of recurrence. T1 substaging, tumour volume and total resected volume were not associated with recurrence or tumour progression.
  
  
  CONCLUSIONS
  LVI is significantly correlated with progression and recurrence in patients with primary stage T1 UCB. Therefore, the presence of LVI should be evaluated in every new case of T1 UCB.
authors.affiliation: Molecular and Immunological Pathology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden. hans.olsson@lio.se
authors.forename: Hans
authors.initials: H
authors.lastname: Olsson
authors.forename: Per
authors.initials: P
authors.lastname: Hultman
authors.forename: Johan
authors.initials: J
authors.lastname: Rosell
authors.forename: Staffan
authors.initials: S
authors.lastname: Jahnson
mesh_terms: D000368:Aged; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000453:epidemiology; D009367:Neoplasm Staging; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D047368:Tumor Burden; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*