Prognostic value of lymph node ratio in patients with advanced epithelial ovarian cancer
Beyhan Ataseven1, Christoph Grimm1, Philipp Harter1
1Department of Gynecology and Gynecologic Oncology, Kliniken Essen-Mitte, Evangelische Huyssens-Stiftung, Henricistrasse 92, 45136 Essen, Germany.
Objective:
Lymph node status is an established prognostic factor in epithelial ovarian cancer (EOC). Lymph node ratio (number of positive LN/number of resected LN) reflects both qualitative and quantitative lymph node spread as well as surgical effort and extent of disease. We evaluated whether LNR is a more precise prognostic factor than conventional lymph node status in patients with EOC.
Methods:
The present retrospective study includes 809 patients with EOC, who underwent primary cytoreductive surgery between 2000-2013. Clinico-pathological parameters and survival data were extracted from a prospectively maintained tumor registry database. The optimal cut-off point for LNR was calculated by using Martingale residuals. Survival analyses were calculated using Kaplan-Meier method and Cox regression models.
Results:
Lymphadenectomy was performed in 693 (85.7%) out of 809 patients. Median number of removed LN was 64 (IQR 25-75%: 39-84). LNR of 0.25 was identified as the optimal prognostic cut-off value. The estimated 5-year-OS rates were 69.3% for patients with node-negative EOC compared to 33.1% for patients with any lymph node metastasis (p<0.001). The estimated 5-year-OS rates were 42.5% for patients with LNR≤0.25, and 18.0% for patients with LNR>0.25 (p<0.001). Additionally in multivariate analysis LNR>0.25 was approved to be an independent prognostic factor for overall survival (adjusted HR 1.44, 95% CI 1.04-2.00; p=0.028).
Conclusion:
LNR more precisely predicts overall survival than conventional lymph node status in EOC patients undergoing primary debulking surgery.