title: Racial differences in adipose tissue distribution and risk of aggressive prostate cancer among men undergoing radiotherapy.
abstract: BACKGROUND
  Although elevated body mass index (BMI) has been associated with increased risk of aggressive prostate cancer, the importance of adipose tissue distribution is not well understood. We examined associations between overall and visceral obesity and aggressive prostate cancer risk. Moreover, given racial differences in adipose tissue distribution, we examined whether race modified these associations.
  
  
  METHODS
  We conducted a cross-sectional analysis of 308 radiotherapy-treated patients with prostate cancer within the Durham VA from 2005 to 2011. Multivariable logistic regression examined the association between BMI categories and tertiles of waist circumference (WC), visceral fat area (VFA), and periprostatic adipose tissue area (PPAT) with high-grade prostate cancer risk (Gleason score ≥7 vs. ≤6). Models stratified by race examined whether these associations differed between black and nonblack men.
  
  
  RESULTS
  Both elevated BMI (Ptrend = 0.054) and WC (Ptrend = 0.040) were associated with increased high-grade prostate cancer risk, with similar results between races, although the association with BMI was not statistically significant. In contrast, elevated VFA was associated with increased aggressive prostate cancer risk in black men (Ptrend = 0.002) but not nonblack men (Ptrend = 0.831), with a significant interaction between race and VFA (Pinteraction = 0.035). Though similar patterns were observed for PPAT, none was statistically significant.
  
  
  CONCLUSIONS
  Among men undergoing radiotherapy for prostate cancer, visceral obesity is associated with increased aggressive prostate cancer risk, particularly among black men. If confirmed in future studies, these results suggest that adipose tissue distribution differences may contribute to prostate cancer racial disparity.
  
  
  CONCLUSIONS
  These findings highlight the need to elucidate mechanisms contributing to racial differences in the association between visceral obesity and aggressive prostate cancer.
authors.affiliation: Division of Urology, Department of Surgery, Duke University School of Medicine, Durham, North Carolina. Cancer Prevention, Detection and Control Program, Duke Cancer Institute, Durham, North Carolina. Division of Urology, Veterans Affairs Medical Center Durham, North Carolina. Departments of.
authors.forename: Emma H
authors.initials: EH
authors.lastname: Allott
authors.affiliation: Division of Urology, Veterans Affairs Medical Center Durham, North Carolina. Departments of Biostatistics and Bioinformatics and.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Howard
authors.affiliation: Radiation Oncology, Duke University School of Medicine, Durham, North Carolina. Department of Radiation Oncology, Veterans Affairs Medical Center Durham, Durham, North Carolina.
authors.forename: Hai-Jun
authors.initials: HJ
authors.lastname: Song
authors.affiliation: Division of Urology, Department of Surgery, Duke University School of Medicine, Durham, North Carolina. Division of Urology, Veterans Affairs Medical Center Durham, North Carolina. Departments of.
authors.forename: Katharine N
authors.initials: KN
authors.lastname: Sourbeer
authors.affiliation: Radiation Oncology, Duke University School of Medicine, Durham, North Carolina.
authors.forename: Bridget F
authors.initials: BF
authors.lastname: Koontz
authors.affiliation: Radiation Oncology, Duke University School of Medicine, Durham, North Carolina. Department of Radiation Oncology, Veterans Affairs Medical Center Durham, Durham, North Carolina.
authors.forename: Joseph K
authors.initials: JK
authors.lastname: Salama
authors.affiliation: Division of Urology, Department of Surgery, Duke University School of Medicine, Durham, North Carolina. Division of Urology, Veterans Affairs Medical Center Durham, North Carolina. Departments of Department of Pathology, Duke University School of Medicine, Durham, North Carolina. steve.freedland@duke.edu.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Freedland
mesh_terms: D000273:Adipose Tissue; D000368:Aged; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D009765:Obesity / Q000150:complications*; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000209:etiology / Q000532:radiotherapy*; D012307:Risk Factors; D014018:Tissue Distribution