Survival effect of different lymph node staging methods on ovarian cancer: An analysis of 10 878 patients

Background: To compare the survival impact of several lymph node staging methods and therapeutic role of lymphadenectomy in patients with epithelial ovarian cancer who had undergone lymphadenectomy. Methods: Data were retrospectively collected from the Surveillance, Epidemiology, and End Results program between 1988 and 2013. Results: An increasing number of resected lymph nodes (RLNs) was associated with a significant improvement in survival of FIGO stage II and III disease. However, for FIGO stage IV patients, better survival was not significantly associated with a more extensive lymphadenectomy. A higher lymph node ratio (LNR) and log odds of positive lymph nodes (LODDS) were associated with poorer survival regardless of stage. Nevertheless, four-category classification of LODDS was more suitable for stage IV patients when three-category classification was compatible with stage I-III disease. Multivariate analysis demonstrated that LODDS and LNR were significant independent prognostic factors, but not RLN classification. Conclusion: Sixteen to thirty RLNs are recommended for stage I disease. For stages II and III patients, the more lymph node excision, the better the prognosis. However, lymphadenectomy was nonessential for stage IV patients. Considering staging methods, for stages II and III patients, three-category classification of LODDS was recommended to evaluate the prognosis. For stage I and IV, three-category classification of positive LNR was idoneous.