Introduction EC has high incidence in Chile. Although most are diagnosed in early stages, some of them have ganglionar compromise at time of surgery. Taking in count morbidity associated with PPaLND, FS is determinant in staging.

Objective to assess the agreement rate between contemporary and definitive biopsy and how it affects our clinical conduct.

Methods retrospective analysis of clinical charts and pathology reports between 2005–2020 at Hospital Sotero del Río. Statistical analysis based on software R version 3.6.1.

Results 410 patients with early-stage EC and surgical treatment. Average age was 61 y-old (26–84), BMI 31 (17–56), 342 (83%) multiparous, most common comorbidities were hypertension and diabetes. We performed 282 (68.7%) FSs and 61 (22%) had a change in clinical conduct. Variables associated with it were histology, myometrial invasion and grade of differentiation(p=0.003 and p<0.0001 and 0.004 respectively). Histology and differentiation agreement between preoperative biopsy and definitive report was 76.2% (Kappa 0.372) and 64.6% (Kappa 0.457). Agreement for histology, grade of differentiation and myometrial penetration between FS and definitive report were 74.9% (Kappa 0.279) 76% (Kappa 0.588) and 84.9% (Kappa 0.692) respectively. 7 patients (1.7%) were upstaged and 16 (3.9%) did not. The reasons for not performing it were high risk histologies, extrauterine disease, intraoperative complications, unnoticed neoplasia in TH and high surgical risk. Definitive pathology reports were endometrioid in 81% (331), serous 9% (38), sarcoma 2.6% (11), hyperplasia 2.6% (11), clear cells 2.4% (10) and others 2.1% (9).

Conclusions FS is a determinant and feasible tool in clinical decisions respecting surgical staging.