title: Impact of visceral fat volume and fat density on biochemical outcome after radical prostatectomy and postoperative radiotherapy.
abstract: BACKGROUND
  To assess the predictive value of visceral adipose tissue (VAT) and adipose tissue density after both radical prostatectomy (RP) and adjuvant or salvage external beam radiotherapy (EBRT).
  
  
  METHODS
  We randomly selected 201 patients treated with RP and EBRT between 2005 and 2015. Visceral adipose tissue and subcutaneous adipose tissue volumes were manually contoured and corresponding tissue densities in Hounsfield units (HU) calculated. Time to biochemical recurrence (BCR) was calculated using the Kaplan-Meier method and comparisons were made using the log-rank test. Cox regression analysis was done for multivariate analysis.
  
  
  RESULTS
  Median time to BCR or last follow-up was 32 months. In univariate analysis for BCR, VAT volume and fat density were both associated with a better outcome (p=0.025 and p=0.024, respectively) as well as seminal vesicle involvement (p=0.024). Body mass index (BMI) was not predictive of BCR (p=0.32). In a multivariate model including seminal vesicle involvement, both a VAT volume above the median (HR2.5, 95%CI 1.1-5.7, p=0.03) and a VAT density (HR 2.4, 95%CI 1.1-5.1, p=0.028) above the median remained predictive for a better biochemical outcome. Adjusting for BMI did not significantly change the model.
  
  
  CONCLUSIONS
  In both univariate and multivariate analysis, patients with both a larger VAT volume and density had a better biochemical outcome. The interaction between prostate cancer aggressiveness and visceral fat volume and density needs to be further evaluated to provide a better understanding of this disease.
authors.forename: Michel
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Guila
authors.initials: G
authors.lastname: Delouya
authors.forename: Maroie
authors.initials: M
authors.lastname: Barkati
authors.forename: Shanie
authors.initials: S
authors.lastname: Campeau
authors.forename: Denis
authors.initials: D
authors.lastname: Rompotinos
authors.forename: Daniel
authors.initials: D
authors.lastname: Taussky
mesh_terms: D000368:Aged; D015992:Body Mass Index; D006801:Humans; D050152:Intra-Abdominal Fat / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011468:Prostatectomy / Q000009:adverse effects; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery*; D011878:Radiotherapy / Q000009:adverse effects; D012669:Seminal Vesicles / Q000473:pathology