title: Survival outcomes of combined external beam radiotherapy and brachytherapy vs. brachytherapy alone for intermediate-risk prostate cancer patients using the National Cancer Data Base.
abstract: OBJECTIVE
  The purpose was to evaluate survival outcomes between external beam radiotherapy (EBRT) plus brachytherapy and brachytherapy alone for intermediate-risk prostate cancer, using the National Cancer Data Base.
  
  
  METHODS
  The National Cancer Data Base was queried for cN0M0 intermediate-risk patients treated from 2004 to 2006, with available data for Gleason score (GS), prostate-specific antigen (PSA), tumor stage, and receipt of radiation therapy (RT) and androgen deprivation therapy. RT comparison groups were the following: EBRT (40-50.4 Gy) plus brachytherapy and brachytherapy alone.
  
  
  RESULTS
  A total of 10,571 patients were included: 3,148 received EBRT plus brachytherapy and 7,423 received brachytherapy alone. Median followup was 84 months (2-122 months); median age was 68 years (40-90 years). Unadjusted 5- and 7-year overall survival (OS) rates between EBRT plus brachytherapy vs. brachytherapy alone were 91.4% vs. 90.2% and 85.7% vs. 82.9%, respectively (p < 0.001). EBRT plus brachytherapy was associated with longer OS compared with brachytherapy alone under multivariate (hazard ratio [HR], 0.84; 95% confidence interval [CI], 0.75-0.93; p = 0.001) and propensity score-matched analyses (HR, 0.85; 95% CI, 0.75-0.97; p = 0.006). Further subset analysis performed based on the Radiation Therapy Oncology Group 0232 inclusion criteria (GS 7 if PSA < 10 or GS < 7 if PSA 10-20) also demonstrated longer OS with EBRT plus brachytherapy (HR, 0.87; 95% CI, 0.77-0.98; p = 0.026).
  
  
  CONCLUSIONS
  EBRT plus brachytherapy is associated with a modest OS improvement compared with brachytherapy alone in this population-based analysis. Although this benefit appears statistically significant, the relatively small difference in OS raises the question of overall clinical benefit with combined modality RT for intermediate-risk prostate cancer, given the potential increased risk for toxicities. Future results from Radiation Therapy Oncology Group 0232 should provide further insight on this topic.
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO. Electronic address: arya.amini@ucdenver.edu.
authors.forename: Arya
authors.initials: A
authors.lastname: Amini
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO.
authors.forename: Bernard L
authors.initials: BL
authors.lastname: Jones
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Jackson
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO.
authors.forename: Chad G
authors.initials: CG
authors.lastname: Rusthoven
authors.affiliation: Department of Surgery, Division of Urology, University of Colorado School of Medicine, Aurora, CO.
authors.forename: Paul
authors.initials: P
authors.lastname: Maroni
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Kavanagh
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO.
authors.forename: David
authors.initials: D
authors.lastname: Raben
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use; D001918:Brachytherapy / Q000401:mortality; D003131:Combined Modality Therapy / Q000379:methods / Q000401:mortality; D016208:Databases, Factual; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D057216:Propensity Score; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D015996:Survival Rate; D014481:United States
chemical_list: D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen
keywords: Brachytherapy; External beam radiotherapy (EBRT); NCDB; Prostate cancer; Radiation therapy