Clinical application of FIGO 2023 staging system of endometrial cancer in a Chinese cohort

Abstract Objective: The International Federation of Gynecology and Obstetrics (FIGO) 2023 staging system represents a refined classification with a comprehensive and improved prognostic significance for endometrial cancer (EC). Our objective is to further explore the clinical utility of the 2023 FIGO staging system in China. Methods: In current study, we conducted a retrospective analysis involving 547 patients who received standard surgeries and underwent genetic testing using multigene next-generation sequencing panels between December 2018 and December 2023 at Fudan University Shanghai Cancer Center. The genomic and clinical data of all patients were analyzed, and patients were restaged according to the 2023 staging systems. Results: After rearrangement of FIGO 2023 staging system in 547 cases, 345 cases of stage I, 107 cases of stage II, 69 cases of stage III, and 26 cases of stage IV were observed. The median follow-up duration was 19.0 months. Stage rearrangements occurred in 92/547 (16.8%) patients. 63 cases and 53 cases were re-classified into IAmPOLEmut and IICmp53abn from early stages (stage I and II), respectively, due to the molecular subtype of POLEmut and p53abn. Among stage I diseases, the 3-year PFS rate was 92.7% and 95.3% according to the 2009 and 2023 FIGO staging systems, respectively. The 3-year PFS of stage II patients under the 2023 FIGO staging system was lower than that of 2009 (3-year PFS: 85.0% versus 90.9%), especially in substage IIC and IICmp53abn. 3 cases (12%) of stage IIIA were rearranged into stage IA3, with 3-year PFS rates of 90.9% versus 100%, respectively. In genomic sequencing analysis, the most prevalent gene alterations occur in PTEN and PIK3CA. Conclusion: Predominant stage reclassifications were observed in early-stage diseases, emphasizing the enhanced precision provided by the new 2023 FIGO staging system in EC prognosis, which may facilitate more accurate therapeutic strategies. Distinct gene alterations also help to understand the characteristics of different subtypes.