The effect of lymphadenectomy in advanced ovarian cancer according to residual tumor status: A population-based study.

BACKGROUND: We investigated the effect of lymphadenectomy on the survival outcomes of patients with advanced epithelial ovarian cancer in the Surveillance, Epidemiology, and End Results database according to residual disease status. METHODS: We evaluated 3048 patients with International Federation of Gynecology and Obstetrics stage-IIIC-IV epithelial ovarian cancer. We assessed the effect of lymphadenectomy stratified by residual disease size on cause-specific survival (CSS). RESULTS: A total of 1904 (62.5%) patients received lymphadenectomy, and 1355 (71.2%) patients had nodal metastases. Lymph-node status had no significant association with residual tumor size in the lymphadenectomy group. In multivariate analysis, lymphadenectomy was associated with a significantly better CSS and was an independent prognostic factor for CSS. Patients with >10 lymph nodes removed had better CSS compared with non-lymphadenectomy and 1-10 lymph nodes removed groups. Lymphadenectomy was associated with a significantly better CSS in patients with no gross residual tumor, but not in patients with residual tumor ≤1 cm or >1 cm. CONCLUSIONS: Lymphadenectomy is significantly associated with a better survival outcome in patients advanced ovarian cancer, but its positive effect diminishes as residual tumor size increases.