Sentinel node mapping vs. sentinel node mapping plus back-up lymphadenectomy in high-risk endometrial cancer patients: Results from a multi-institutional study.

Abstract Objective Sentinel node mapping (SLN) has replaced lymphadenectomy for staging surgery in apparent early-stage low and intermediate risk endometrial cancer (EC). Only limited data about the adoption of SNM in high risk EC is still available. Here, we evaluate the outcomes of high-risk EC undergoing SNM (with or without back-up lymphadenectomy). Methods This is a multi-institutional international retrospective study, evaluating data of high-risk (FIGO grade 3 endometrioid EC with myometrial invasion >50% and non-endometrioid histology) EC patients undergoing SNM followed by back-up lymphadenectomy and SNM alone. Results Chart of consecutive 196 patients were evaluated. The study population included 83 and 113 patients with endometrioid and non-endometrioid EC, respectively. SNM alone and SNM followed by back-up lymphadenectomy were performed in 50 and 146 patients, respectively. Among patients having SNM alone, 14 (28%) were diagnosed with nodal disease. In the group of patients undergoing SNM plus back-up lymphadenectomy 34 (23.2%) were diagnosed with nodal disease via SNM. Back-up lymphadenectomy identified 2 (1%) additional patients with nodal disease (in the para-aortic area). Back-up lymphadenectomy allowed to remove adjunctive positive nodes in 16 (11%) patients. After the adoption of propensity-matched algorithm, we observed that patients undergoing SNM plus back-up lymphadenectomy experienced similar disease-free survival (p = 0.416, log-rank test) and overall survival (p = 0.940, log-rank test) than patients undergoing SLN alone. Conclusions Although the small sample size, and the retrospective study design this study highlighted that type of nodal assessment did not impact survival outcomes in high-risk EC. Theoretically, back-up lymphadenectomy would be useful in improving the removal of positive nodes, but its therapeutic value remains controversial. Further prospective evidence is needed.