938 Is temporal change in abdominal fat distribution related to endometrial cancer prognosis?

Introduction/Background The objectives of this study was to quantify abdominal obesity markers from computed tomography (CT) scans at primary diagnosis and follow-up in a large endometrial cancer cohort, and to assess temporal change in obesity markers in relation to clinical phenotype and outcome. Methodology Total- (TAV), subcutaneous- (SAV), visceral abdominal fat volumes (VAV), and visceral-to-total fat percentage (VAV%) were derived in an endometrial cancer patient cohort with CT scans acquired at primary diagnosis (n_primary=293). Temporal (delta, δ) changes in CT obesity markers from primary diagnosis to follow-up were assessed for all patients with a follow-up CT 13 (7, 19) [median (interquartile range)] months after diagnosis (n_follow-up=152/293 patients). The CT obesity markers were assessed in relation to clinicopathological patient features and progression free survival (PSF) using Mann-Whitney U-test, and Cox hazard ratios (HRs), respectively. Results At primary diagnosis, patients with high-risk histology (endometrioid (EEC) grade 3/non-endometrioid (NEEC)) had significantly lower TAV, SAV, and body mass index (p≤0.03), while higher VAV% (p=0.005) than patients with low-risk histology (EEC grade 1–2). High VAV% (≥36%) predicted poor PFS both in univariable analysis (HR=2.4, p=0.04), and when stratified for surgicopathological FIGO stage (HR=2.8, p=0.02). At follow-up, median TAV, VAV, SAV, and VAV% were significantly lower than at primary diagnosis (p<0.001 for all). Furthermore, patients with progression had larger reductions in visceral fat compartments (δVAV=-25%, δVAV% =-4%), than patients with no progression (δVAV=-17%, δVAV/TAV=-2%, p≤0.006 for both). Additionally, δVAV%≤-4% predicted poor PFS both in univariable analysis (HR=2.5, p<0.001) and when stratified for FIGO stage (HR=2.0, p=0.03). Conclusion Abdominal fat distribution markers from preoperative abdominal CT predict endometrial cancer prognosis, and higher visceral fat loss during/following therapy is associated with disease progression. Disclosures The authors have no conflicts of interest to disclose.