Systematic pelvic and aortic lymphadenectomy in intermediate and high-risk endometrial cancer: lymph-node mapping and identification of predictive factors for lymph-node status.

OBJECTIVE: To systematically assess the metastatic pattern of intermediate- and high-risk endometrial cancer in pelvic and para-aortic lymph-nodes and to evaluate risk factors for lymph-node metastases.

STUDY DESIGN: Between 01/2005 and 01/2009 62 consecutive patients with intermediate- and high-risk endometrial cancer who underwent a systematic surgical staging including pelvic and para-aortic lymphadenectomy were enrolled into this study. Patients' characteristics, histological findings, lymph-node localization and involvement, surgical morbidity and relapse data were analyzed. Univariate analysis was performed to define risk factors for lymph-node metastasis.

RESULTS: Of the 13 patients (21%) with positive lymph-nodes (N1), 8 (61.5%) had both pelvic and para-aortic lymph-nodes affected, 2 (15.4%) only para-aortic and 3 (23%) only pelvic lymph-node metastases. Overall, 54% of the N1-patients had positive lymph-nodes above the inferior mesenteric artery (IMA) to the level of the renal veins. Univariate analysis revealed lymph vascular space invasion (p-value: <0.001), vascular-space-invasion (p-value: <0.001) and incomplete tumor resection (p-value: 0.008) as significant risk factors for N1-status. Overall and progression-free survival was not significantly different between N1- and N0-patients.

CONCLUSIONS: Since the proportion of N1-endometrial cancer patients with positive para-aortic lymph-nodes is, at 76%, considerably high, and more than half of them have affected lymph-nodes above the IMA-level, lymphadenectomy for endometrial cancer should be extended up to the renal veins, when indicated. The therapeutic impact of systematic lymphadenectomy on overall and progression-free survival has still to be evaluated in future prospective randomized studies.