Role of systematic lymphadenectomy in patients with intermediate to high-risk early stage endometrial cancer

OBJECTIVE: To determine the clinical significance of systematic lymph node dissection (LND) and to better define the relevant extent of LND in intermediate- to high-risk early stage endometrial cancer (EC). METHODS: Patients who received surgery as a primary treatment of histologically confirmed EC and preoperatively considered as uterus-confined early stage disease were included in the study population. The rates of lymph node metastasis (LNM) according to the risk groups and anatomic sites were assessed. Univariate and multivariate analyses were performed to evaluate risk factors for recurrence. RESULTS: A total of 804 patients were included in the study analysis. The rates of LNM were significantly different according to the risk group; 1.2% in low-risk, 20.1% in intermediate-risk, and 30.0% in high-risk group. When assessing the rates of LNM in individual anatomic sites, positive LNs were evenly distributed throughout the pelvic and para-aortic regions. In the intermediate to high-risk EC cases, the rates of para-aortic LNM below and above inferior mesenteric artery (IMA) were 11.1% and 12.5%, respectively. On multivariate analysis, LNM was the only independent risk factor for recurrence in the intermediate to high-risk EC (hazard ratio=2.63, 95% confidence interval=1.01–6.82, p=0.047). CONCLUSION: LNM was frequently observed in intermediate- and high-risk early stage EC and it served as an independent risk factor for recurrence. When considering the similar rates of LNM between below and above IMA, nodal assessment needs to be performed up to the infra-renal level, especially for the staging purpose in high-risk EC.