Clinical utility of sentinel lymph node biopsy in atypical endometrial hyperplasia: A multicenter cohort study

OBJECTIVE: To evaluate the clinical impact of Sentinel Lymph Node (SLN) biopsy in women with preoperative diagnosis of Atypical Endometrial Hyperplasia/Endometrial Intraepithelial Neoplasia (AEH/EIN), focusing on surgical safety and feasibility and adjuvant treatment decisions. METHODS: Multicenter retrospective study which included 411 patients with preoperative diagnosis of AEH/EIN who underwent total hysterectomy between 2014 and 2025. Demographic, preoperative, surgical, pathological and adjuvant treatment data were collected from prospectively maintained databases and outcomes were compared between patients who underwent SLN biopsy and those who did not. Descriptive statistics were used. RESULTS: Occult endometrial cancer (EC) was diagnosed in 47% of overall patients at final pathology; of whom 16% was classified within the intermediate to high-risk cases. SLN mapping was associated with slightly longer operative time. SLN metastases were found in 4.7% of patients with EC. SLN assessment modified treatment decisions in 11 of 22 patients (50%) receiving adjuvant therapy within the SLN cohort. Positive SLN findings led to chemotherapy escalation in 5 patients, while negative SLN status supported chemotherapy omission in 6 high to intermediate risk cases. No patients in the non-SLN group received chemotherapy. CONCLUSION: SLN biopsy in AEH/EIN is a feasible and safe procedure that provides staging information in the subgroup with occult EC. Regardless of metastasis frequency, SLN status provides actionable prognostic information. Whether positive or negative, SLN findings refine risk stratification and may guide the escalation or de-escalation of adjuvant therapy, supporting the consideration of SLN biopsy in AEH/EIN patients.