Predictive Factors for Failed Sentinel Lymph Node Mapping in Endometrial Cancer: A Retrospective Multicenter Study

Background and Objectives: This study aims to evaluate the predictive factors associated with failed sentinel lymph node (SLN) mapping in a large, retrospective cohort of patients with early-stage endometrial cancer (EC). Methods: We retrospectively evaluated a series of EC patients who underwent laparoscopic SLN mapping with intracervical indocyanine green (ICG) injection in five referred oncological centers from January 2019 to March 2024. We compared the clinical and pathological features of bilateral and failed SLN mapping, which was defined as either unilateral mapping or no SLN mapping. Logistic regression was used to identify predictors of failure. Results: Among 623 analyzed patients, 437 (70.14%) had a successful bilateral procedure. On univariate analysis, age (p = 0.03), non-endometrioid histology (p = 0.02) and previous vaginal delivery (p = 0.015) were significant associated with failed SLN mapping. On multivariable analysis, only increasing age (OR 1.03; 95% CI, 1.01–1.04, p = 0.03) and non-endometrioid histology (OR 1.81; 95% CI, 1.01–3.19) were independently associated with unsuccessful procedure. No significant differences were observed for BMI, enlarged lymph nodes, intraoperative lysis of adhesion, LVSI, grade 3, and FIGO stage. Conclusions: Increasing age and non-endometrioid histology are independent predictors of bilateral SLN mapping failure in EC patients undergoing SLN mapping with cervical ICG injection.