Impact of Para-Aortic Lymphadenectomy on Clinically FIGO Stage IIIC1 High-Grade Endometrial Cancer: A Retrospective Cohort Study from Two Tertiary Centers in Korea and Taiwan

Background and Objectives: The therapeutic effect of para-aortic lymphadenectomy in patients with clinically para-aortic node-negative diseases remains controversial. In this study, we investigated whether combined pelvic and para-aortic lymphadenectomy has a survival benefit compared with pelvic lymphadenectomy alone in patients with clinically FIGO stage IIIC1 high-grade endometrial cancer. Materials and Methods: We retrospectively reviewed patients with clinically FIGO stage IIIC1 high-grade endometrial cancer in the period between January 2000 and December 2020 at two tertiary centers. The patients were stratified according to type of lymphadenectomy and subgroup analyses performed. Kaplan–Meier analysis and a Cox proportional-hazards model were used to evaluate survival outcomes. Results: A total of 56 patients were identified. Of these patients, 18 underwent pelvic lymphadenectomy alone and 38 underwent combined pelvic and para-aortic lymphadenectomy. After staging surgery, 34 (60.7%) patients had pathologically confirmed lymph node metastases. Within a median follow-up of 57.5 months, there were no significant differences in recurrence-free survival (RFS) and overall survival (OS) between the two groups. In subgroup analyses, the node- and lymphovascular space invasion (LVSI)-positive patients characterized by grade 3 endometrioid histologic type (p = 0.010) or negative peritoneal washing cytology (p = 0.035) had an RFS benefit from combined pelvic and para-aortic lymphadenectomy. Conclusions: The addition of para-aortic lymphadenectomy to pelvic lymphadenectomy did not improve survival in patients with clinically FIGO IIIC1 endometrial cancer. However, para-aortic lymphadenectomy may have RFS benefit for patients with grade 3 endometrioid histologic type and positive LVSI.