title: Periprostatic fat measured on computed tomography as a marker for prostate cancer aggressiveness.
abstract: OBJECTIVE
  Several reports found that obesity was associated with prostate cancer (PC) aggressiveness among men treated with radical prostatectomy or radiotherapy. Studies concerning this issue have basically relied on body mass index (BMI), as a marker for general obesity. Because visceral fat is the most metabolic active fat, we sought to evaluate if periprostatic fat measured on a computed tomography (CT) is a better marker than BMI to predict PC aggressiveness in a Dutch population who underwent brachytherapy for localized PC.
  
  
  METHODS
  Of the 902 patients who underwent brachytherapy, 725 CT scans were available. Subcutaneous fat thickness (CFT), periprostatic fat area (cm(2)) and fat-density (%) were determined on the CT scan. Patients were stratified into three groups: <25, 25-75 and >75 percentile of the fat-density. Associations between the three fat-density subgroups and BMI and PC aggressiveness were examined.
  
  
  RESULTS
  237 patients were classified as having normal weight (37.2%), 320 as overweight (50.2%) and 80 as obese (12.6%). There was a strong significant association between BMI and fat-density and CFT. The strongest correlation was seen between BMI and CFT (Pearson r coefficient = 0.71). Logistic regression analysis revealed no statistically significant association between the different fat measurements and the risk of having a high-risk disease.
  
  
  CONCLUSIONS
  Periprostatic fat and fat-density as measured with CT were not correlated with PC aggressiveness in patients receiving brachytherapy. However, 31% of the patients with a normal BMI had a fat-density of >75 percentile of the periprostatic fat-density.
authors.affiliation: Department of Urology, University Medical Center Utrecht, PO Box 85500, 3508 GA, Utrecht, The Netherlands. j.g.h.vanroermund@umcutrecht.nl
authors.forename: Joep G H
authors.initials: JG
authors.lastname: van Roermund
authors.forename: Gijsbert H
authors.initials: GH
authors.lastname: Bol
authors.forename: J Alfred
authors.initials: JA
authors.lastname: Witjes
authors.forename: J L H
authors.initials: JL
authors.lastname: Ruud Bosch
authors.forename: Lambertus A
authors.initials: LA
authors.lastname: Kiemeney
authors.forename: Marco
authors.initials: M
authors.lastname: van Vulpen
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging* / Q000503:physiopathology; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000502:physiology; D050218:Body Fat Distribution; D015992:Body Mass Index; D001918:Brachytherapy; D018450:Disease Progression; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000532:radiotherapy; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor