title: Body mass and smoking are modifiable risk factors for recurrent bladder cancer.
abstract: BACKGROUND
  In the Western world, bladder cancer is the fourth most common cancer in men and the eighth most common in women. Recurrences frequently occur, and continued surveillance is necessary to identify and treat recurrent tumors. Efforts to identify risk factors that are potentially modifiable to reduce the rate of recurrence are needed.
  
  
  METHODS
  Cigarette smoking behavior and body mass index were investigated at diagnosis for associations with bladder cancer recurrence in a population-based study of 726 patients with bladder cancer in New Hampshire, United States. Patients diagnosed with non-muscle invasive urothelial cell carcinoma were followed to ascertain long-term prognosis. Analysis of time to recurrence was performed using multivariate Cox regression models.
  
  
  RESULTS
  Smokers experienced shorter time to recurrence (continuing smoker hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 1.08-2.13). Although being overweight (body mass index > 24.9 kg/m(2) ) at diagnosis was not a strong independent factor (HR = 1.33, 95% CI = 0.94-1.89), among continuing smokers, being overweight more than doubled the risk of recurrence compared to smokers of normal weight (HR = 2.67, 95% CI = 1.14-6.28).
  
  
  CONCLUSIONS
  These observational results suggest that adiposity is a risk factor for bladder cancer recurrence, particularly among tobacco users. Future intervention studies are warranted to evaluate whether both smoking cessation and weight reduction strategies reduce bladder tumor recurrences.
authors.affiliation: Department of Community and Family Medicine, Section of Biostatistics and Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire; Program in Experimental and Molecular Medicine, Department of Pharmacology and Toxicology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire.
authors.forename: Asaf
authors.initials: A
authors.lastname: Wyszynski
authors.forename: Sam A
authors.initials: SA
authors.lastname: Tanyos
authors.forename: Judy R
authors.initials: JR
authors.lastname: Rees
authors.forename: Carmen J
authors.initials: CJ
authors.lastname: Marsit
authors.forename: Karl T
authors.initials: KT
authors.lastname: Kelsey
authors.forename: Alan R
authors.initials: AR
authors.lastname: Schned
authors.forename: Eben M
authors.initials: EM
authors.lastname: Pendleton
authors.forename: Maria O
authors.initials: MO
authors.lastname: Celaya
authors.forename: Michael S
authors.initials: MS
authors.lastname: Zens
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Karagas
authors.forename: Angeline S
authors.initials: AS
authors.lastname: Andrew
mesh_terms: D050154:Adiposity; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology; D016016:Proportional Hazards Models; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D001749:Urinary Bladder Neoplasms / Q000209:etiology*
keywords: bladder cancer; body mass index; obesity; recurrence; smoking; urothelial cell carcinoma