815 Comparative analysis of FIGO staging pre and post-surgical in high-grade endometrial cancer

Introduction/Background In high-grade endometrial cancer (HGEC), the accuracy of tumor staging plays a pivotal role in determining therapeutic strategies and influencing patient prognoses. This study aimed to describe changes and assess the concordance the International Federation of Gynecology and Obstetrics (FIGO-2009) staging before and after surgery in HGEC. Methodology A retrospective study conducted at University Hospital of Bellvitge (HUB), including 119 patients diagnosed with HGEC (grade-3 tumors), between January/2015-December/2020. Comprehensive pre-surgery FIGO staging included transvaginal ultrasound, pelvic MRI, or computed tomography scans. The surgical indication for HGEC encompassed hysterectomy, bilateral salpingo-oophorectomy, omentectomy, lymphatic assessment (lymphadenectomy or sentinel node identification), and excision of any suspicious tumoral lesion. Post-surgery FIGO staging was determined following the anatomopathological (AP) evaluation of the surgical specimen. Statistical analyses employed kappa coefficient for concordance assessment. Results The most commonly identified post-surgical AP presentation comprised serous carcinoma (42%), endometrioid carcinoma (18.5%), carcinosarcoma (15.1%), and clear cell carcinoma (13.4%). FIGO pre-surgery vs FIGO post-surgery had a concordance of κ = 0.419 (p <0.001). The least deviation in FIGO staging between pre- and post-surgery was noted at the extremities of the staging spectrum. Notably, 72.1% (44/61) of FIGO 1A stages and 100% (11/11) of FIGO IVB stages remained unchanged post-surgery. (TABLE-1). 29.4% of patients initially staged as IA pre-surgery progressed to FIGO stage IIIC1/IIIC2 post-surgery. Conclusion The study demonstrates moderate concordance between pre and post-surgical FIGO stages. We emphasize the role of nodal staging in this type of tumors (HGEC) due to the notable percentage of positive nodes even in the absence of visualization in preoperative imaging studies. Disclosures The authors have nothing to disclose.