MP53-07 DOES ABDOMINAL AND PELVIC ADIPOSE TISSUE DISTRIBUTION IMPACT PROSTATE CANCER-SPECIFIC OUTCOMES AFTER RADIATION THERAPY?

Abstract

You have accessJournal of UrologyProstate Cancer: Localized: Radiation Therapy (MP53)1 Apr 2020MP53-07 DOES ABDOMINAL AND PELVIC ADIPOSE TISSUE DISTRIBUTION IMPACT PROSTATE CANCER-SPECIFIC OUTCOMES AFTER RADIATION THERAPY? Claire M. Di Bella*, Lauren E. Howard, Taofik Oyekunle, Amanda M. De Hoedt, Joseph K. Salama, Stephen J. Freedland, and Emma H. Allott Claire M. Di Bella*Claire M. Di Bella* More articles by this author , Lauren E. HowardLauren E. Howard More articles by this author , Taofik OyekunleTaofik Oyekunle More articles by this author , Amanda M. De HoedtAmanda M. De Hoedt More articles by this author , Joseph K. SalamaJoseph K. Salama More articles by this author , Stephen J. FreedlandStephen J. Freedland More articles by this author , and Emma H. AllottEmma H. Allott More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000915.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Many studies examining the obesity-prostate cancer link rely on body mass index (BMI), a measure of overall obesity. Obesity is a heterogeneous phenotype, and fat distribution varies even between individuals of similar BMI. We hypothesized that excess visceral adipose tissue, the most metabolically active fat type, would be more strongly associated with poor prostate cancer outcomes than overall obesity. METHODS: We quantified visceral adipose tissue (both abdominal and pelvic) using CT scans from prostate cancer patients treated with radiation at the Durham NC Veterans Administration. Abdominal visceral fat area (VFA) was measured at L4/L5 and periprostatic adipose tissue (PPAT) area at the pubic symphysis by thresholding on Hounsfield Units -190 to -30, with both measures categorized as ≥ vs. < median. Pre-radiotherapy height and weight was abstracted from medical records and used to calculate BMI, categorized as ≥30 vs. <30 kg/m2. Recurrence was defined according to the Phoenix definition. Cox proportional hazards analysis examined associations between overall, and visceral (abdominal and pelvic) obesity and risk of recurrence, adjusting for age, race, year, biopsy Gleason, biopsy PSA, clinical stage, and receipt of androgen deprivation therapy (ADT). We performed stratified analysis by ADT receipt. RESULTS: Of 401 prostate cancer patients treated with radiation from 2005-2011, 84 (21%) experienced recurrence during a 9 year median follow-up. Overall obesity defined as BMI ≥30 was not associated with risk of recurrence overall or stratified by ADT. Nor was any measure of visceral obesity related to risk of recurrence overall. However, associations between visceral obesity and risk of recurrence varied by ADT receipt. Higher VFA was suggestively associated with increased risk of recurrence in men who received radiation only (HR 1.79; 95%CI 0.87-3.66), but inversely associated with recurrence risk in men treated with radiation + ADT (HR 0.49; 95%CI 0.24-1.03; p-heterogeneity=0.002). Similarly, higher PPAT was weakly associated with increased risk of recurrence in men treated with radiation only (HR 1.33; 95%CI 0.71-2.48), but inversely associated with recurrence risk in men who received radiation + ADT (HR 0.46; 95%CI 0.23-0.93; p-heterogeneity=0.002). CONCLUSIONS: Associations between visceral obesity and recurrence risk differed significantly by ADT receipt. If confirmed, our findings suggest that visceral obesity may have varying effects on prostate cancer progression dependent on the hormonal environment of the individual. Source of Funding: NIH 1K24CA160653, Irish Cancer Society John Fitzpatrick Fellowship © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e784-e784 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Claire M. Di Bella* More articles by this author Lauren E. Howard More articles by this author Taofik Oyekunle More articles by this author Amanda M. De Hoedt More articles by this author Joseph K. Salama More articles by this author Stephen J. Freedland More articles by this author Emma H. Allott More articles by this author Expand All Advertisement PDF downloadLoading ...