title: Increased risk of bladder cancer following diagnosis with bladder pain syndrome/interstitial cystitis.
abstract: OBJECTIVE
  Interstitial cystitis/bladder pain syndrome (IC/BPS) is a prevalent disorder that may contribute to bladder cancer (BC). This cohort study set out to investigate the association between IC/BPS and BC by using a population-based dataset.
  
  
  METHODS
  The data for this study were sourced from the Taiwan National Health Insurance program. The case cohort comprised 7,562 patients with IC/BPS, and 22,686 randomly selected subjects were used as a comparison cohort. A Cox proportional hazards regression model (stratified by age group, geographic location, urbanization level, and the index year) was constructed to estimate the risk of subsequent BC following a diagnosis of IC/BPS. We also ran the analysis utilizing an alternative comparison cohort composed of patients with urinary incontinence (UI).
  
  
  RESULTS
  In the study sample of 30,248 patients, 96 patients (0.32%) received a diagnosis of BC during the 3-year follow-up period; 48 (0.63% of patients with IC/BPS) were from the study cohort; and 48 (0.21% of patients without IC/BPS) were from the comparison cohort. The incidence rate of BC was 2.12 (95% CI: 1.58-2.78) per 1,000 person-years in patients with IC/BPS and 0.70 (95% CI: 0.52-0.92) per 1,000 person-years in comparison patients. Cox proportional analysis revealed that the adjusted HR for BC during the 3-year follow-up period for patients with IC/BPS was 2.95 (95% CI: 1.97-4.41) that of comparison subjects. When performing the analysis with the alternative UI comparison cohort, the adjusted HR for BC was 1.96 (95% CI: 1.14-3.39).
  
  
  CONCLUSIONS
  This investigation detected a novel association between BC and prior IC/BPS.
authors: School of Public Health, Taipei Medical University, Taipei, Taiwan.
authors: Joseph
authors: J
authors: Keller
authors: Hung-Yi
authors: HY
authors: Chiou
authors: Herng-Ching
authors: HC
authors: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D018856:Cystitis, Interstitial / Q000150:complications / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D015995:Prevalence; D016016:Proportional Hazards Models; D012306:Risk; D013624:Taiwan / Q000453:epidemiology; D001749:Urinary Bladder Neoplasms / Q000453:epidemiology* / Q000209:etiology