Survival impact based on the thoroughness of pelvic lymphadenectomy in intermediate- or high-risk groups of endometrioid-type endometrial cancer: A multi-center retrospective cohort analysis

Abstract Objective To investigate whether the number of lymph nodes obtained during lymphadenectomy affects the survival of patients with intermediate- or high-risk endometrioid-type endometrial cancer. Methods A total of 476 patients who were diagnosed with FIGO stage IB to IIIC2 endometrioid adenocarcinoma through surgical staging, including hysterectomy and pelvic lymphadenectomy with or without paraaortic lymphadenectomy between 2000 and 2013 were retrospectively enrolled from four tertiary centers in Korea. Sentinel lymph node mapping was not performed in any patient. The number of nodes obtained and positive nodes, was extracted from pathologic report. Results Paraaortic lymphadenectomy was performed in 298 (62.6%) patients and 164 (34.4%) had stage IIIC disease. The isolated paraaortic lymph node metastasis rate decreased as the number of pelvic nodes obtained increased. In the total study population, an increase of negative pelvic and paraaortic nodes was associated with improved recurrence-free survival (RFS) and overall survival (OS) independent of other prognostic factors. In the node-positive group, an increase of negative pelvic nodes was an independent prognostic factor for RFS [hazard ratio (HR), 0.946; 95% confidence interval (CI), 0.906–0.988] and OS [HR, 0.907; 95% CI, 0.849–0.968]. In stage IIIC2 patients, 14 or less negative pelvic nodes was associated with poor RFS and OS. Conclusions Removing as many pelvic nodes as possible is required to warrant accurate nodal staging and improve survival in patients with intermediate- or high-risk endometrial cancer. Sentinel lymph node mapping can be a resolution to minimize lymph node dissection without compromising staging accuracy.