Frailty and an Inflammation-Nutrition Composite for Predicting Postoperative Outcomes in Older Patients Undergoing Endometrial Cancer Surgery.

BACKGROUND: Frailty and systemic inflammation/immune-protein reserve may drive adverse outcomes after endometrial cancer (EC) surgery in older patients, but their incremental predictive value is unclear. METHODS: We analyzed a retrospective cohort of women ≥65 years undergoing primary EC surgery between January 2016 and December 2024. Frailty was assessed using mFI‑5. Inflammation-nutrition status (INS) was derived from routine preoperative laboratory tests as exploratory composite. The primary endpoint was 30‑day severe complications (Clavien-Dindo III-V), and the secondary endpoint was 90‑day unplanned readmission to the index hospital. One‑year non-endometrial cancer (non‑EC) death was exploratory with EC death as a competing event. Logistic regression and Fine-Gray models were fitted. Incremental prediction versus a prespecified baseline perioperative clinical model was evaluated with bootstrap optimism‑corrected discrimination, calibration, and decision‑curve analysis. RESULTS: Severe complications occurred in 62 (7.1%) and readmission in 71 (8.1%). One‑year non‑EC and EC deaths were 28 (3.2%) and 19 (2.2%), respectively. mFI‑5 and INS predicted severe complications (OR per 1‑point mFI‑5 1.43 [95% CI 1.22-1.67]; OR per 1‑SD INS 1.34 [1.15-1.55]) and readmission (OR 1.28 [1.10-1.50]; OR 1.22 [1.05-1.41]). For non‑EC death, mFI‑5 (SHR 1.52 [1.23-1.88]) and INS (SHR 1.37 [1.11-1.69]) were significant. Adding mFI‑5+INS improved discrimination (AUC 0.69 to 0.77 for complications; 0.63 to 0.70 for readmission) and the time-dependent C-index for the exploratory competing-risk endpoint (0.66 to 0.73), with acceptable calibration. Decision-curve findings were descriptive rather than definitive. CONCLUSION: Combining frailty with an objective inflammation-nutrition risk composite modestly improved internal model performance for 30-day severe complications and 90-day readmission in older EC patients, and 1-year non-EC death analysis remains exploratory. These findings should be interpreted as perioperative rather than purely preoperative prediction, and decision thresholds require external validation before protocolized use.