title: Bladder preservation for localized muscle-invasive bladder cancer: the survival impact of local utilization rates of definitive radiotherapy.
abstract: OBJECTIVE
  This study examines the management and outcomes of muscle-invasive bladder cancer in the United States.
  
  
  METHODS
  Patients with muscle-invasive bladder cancer diagnosed between 1988 and 2006 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Patients were classified according to three mutually exclusive treatment categories based on the primary initial treatment: no local management, radiotherapy, or surgery. Overall survival was assessed with Kaplan-Meier analysis and Cox models based on multiple factors including treatment utilization patterns.
  
  
  RESULTS
  The study population consisted of 26,851 patients. Age, sex, race, tumor grade, histology, and geographic location were associated with differences in treatment (all p < 0.01). Patients receiving definitive radiotherapy tended to be older and have less differentiated tumors than patients undergoing surgery (RT, median age 78 years old and 90.6% grade 3/4 tumors; surgery, median age 71 years old and 77.1% grade 3/4 tumors). No large shifts in treatment were seen over time, with most patients managed with surgical resection (86.3% for overall study population). Significant survival differences were observed according to initial treatment: median survival, 14 months with no definitive local treatment; 17 months with radiotherapy; and 43 months for surgery. On multivariate analysis, differences in local utilization rates of definitive radiotherapy did not demonstrate a significant effect on overall survival (hazard ratio, 1.002; 95% confidence interval, 0.999-1.005).
  
  
  CONCLUSIONS
  Multiple factors influence the initial treatment strategy for muscle-invasive bladder cancer, but definitive radiotherapy continues to be used infrequently. Although patients who undergo surgery fare better, a multivariable model that accounted for patient and tumor characteristics found no survival detriment to the utilization of definitive radiotherapy. These results support continued research into bladder preservation strategies and suggest that definitive radiotherapy represents a viable initial treatment strategy for those who wish to attempt to preserve their native bladder.
authors.affiliation: Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 27408, USA.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Kozak
authors.forename: Maryam
authors.initials: M
authors.lastname: Hamidi
authors.forename: Matthew
authors.initials: M
authors.lastname: Manning
authors.forename: John S
authors.initials: JS
authors.lastname: Moody
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D002295:Carcinoma, Transitional Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D003131:Combined Modality Therapy / Q000379:methods / Q000401:mortality; D015653:Cystectomy / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D059351:Organ Sparing Treatments / Q000379:methods* / Q000401:mortality; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018426:SEER Program; D016019:Survival Analysis; D016896:Treatment Outcome; D001743:Urinary Bladder; D001749:Urinary Bladder Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D055815:Young Adult