Evaluation of the prognostic accuracy of the new 2023 FIGO staging system in patients with endometrial cancer

Objective: This study aimed to restage patients treated for endometrial cancer in our clinic using both the 2009 and 2023 FIGO systems and to evaluate the prognostic accuracy of the 2023 FIGO classification. Materials and Methods: This retrospective cohort study evaluated patients diagnosed, treated, and followed for endometrial cancer at the Department of Obstetrics and Gynecology, Akdeniz University, between January 2014 and December 2023. Patients were first staged according to the 2009 FIGO system, and then restaged using the 2023 FIGO criteria with the same data. Demographic, clinical, pathological, and molecular data were collected, and survival outcomes analyzed. Overall survival (OS) and disease-free survival (DFS) rates were calculated using the Kaplan–Meier method, and intergroup differences assessed with the log-rank test. Results: When the 2023 FIGO staging system was applied, a significant stage migration was observed, especially in the early-stage disease groups. The inclusion of parameters such as histological subtype assessment, presence of lymphovascular space invasion (LVSI), size of lymph node metastasis, and molecular classification in the updated system provided a higher prognostic discrimination compared to the 2009 FIGO staging system. Patients upstaged according to the 2023 FIGO criteria had significantly lower OS and DFS rates (p < 0.05). Conclusion: The updated 2023 FIGO staging system provides higher prognostic accuracy compared to the 2009 FIGO classification by integrating molecular and histopathological parameters. Keywords: Endometrial cancer, 2023 FIGO staging, prognostic accuracy, molecular classification, survival analysis