Impact of the 2023 FIGO staging system on risk stratification in endometrial cancer: a retrospective cohort study

To evaluate the prognostic value of the 2023 FIGO staging system for endometrial cancer (EC) by comparing it with the 2009 FIGO system, using data from Shanghai General Hospital. We retrospectively analyzed 331 EC patients (March 2016–August 2025) and re-staged them from the 2009 FIGO criteria to the 2023 FIGO criteria. Molecular subtyping was integrated where available (N = 86). The Net Reclassification Improvement (NRI) was used to evaluate risk stratification. Prognostic factors were identified using logistic and Cox regression models. Re-staging according to the 2023 FIGO criteria resulted in stage migration for 186 out of 331 patients (56.2%). In the subset with molecular data (n = 86), reclassification occurred in 47 patients (54.7%). Compared to the 2009 system, the 2023 system demonstrated a significant NRI of 100.76% (P < 0.001) for Stages I–II. Key clinicopathological factors independently associated with stage migration included non-endometrioid histology, high tumor grade (G3), and deep myometrial invasion. Compared with the 2009 FIGO staging, the 2023 FIGO system significantly improves risk stratification in EC. Its integration of molecular and refined pathological factors facilitates more precise prognostication and supports individualized treatment planning.