RT Journal Article SR Electronic T1 EP164/#666  Does perinephric fat predict surgical complications and survival in individuals with endometrial cancer? JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A145 OP A145 DO 10.1136/ijgc-2023-IGCS.255 VO 33 IS Suppl 4 A1 Salman, Lina A1 Cybulska, Paulina A1 Fowler, Ryley A1 Maganti, Manjula A1 Metser, Ur A1 Ferguson, Sarah YR 2023 UL http://ijgc.bmj.com/content/33/Suppl_4/A145.1.abstract AB Introduction The aim of this study was to evaluate the association between average perinephric fat (APF) and surgical complications and survival in individuals with endometrial cancer (EC).Methods This is a retrospective cohort study of individuals with EC who underwent surgical staging in a tertiary cancer centre in Canada (2015 – 2021). AFP was measured on pre-operative CT scans. Baseline characteristics, surgical complications and survival data were compared between patients with APF < 2.2 cm and those with AFP ≥ 2.2 cm. Cox proportional hazard model was used to evaluate the association between APF and overall survival (OS) and progression-free survival (PFS).Results Overall, 297 patients were included. Of whom, n=271 had APF <2.2 cm and n=26 had APF ≥ 2.2 cm. Baseline characteristics are presented in table 1. Patients with APF ≥ 2.2 cm had higher rates of failed sentinel lymph node mapping (31% vs 6%, p<0.001). There were no differences between groups in intraoperative (3% vs 4%, p=0.61) and postoperative complications (14% vs 19%, p=0.71). On univariable analysis, APF was not associated with OS (HR 1.58, 95% CI 0.90–2.78, p=0.11). However, increase in APF was significantly associated with worse PFS (HR 1.49, 95% CI 1.08 -2.06, p=0.02). In a multivariable analysis including age, stage, LVSI and deep myometrial invasion, the association between APF and PFS was not statistically significant (HR 1.35, 95% CI 0.96–1.91, p=0.08). Conclusion/Implications In this cohort of individuals with EC, there was a trend towards worse PFS with increased APF. However, increased APF did not impact perioperative complications or OS.View this table:Abstract EP164/#666 Table 1 Baseline characteristics