Prognostic value of lymph node ratio in stage IIIC epithelial ovarian cancer with node-positive in a SEER population-based study

// Juan Zhou 1,* , Zhen-Yu He 2,* , Feng-Yan Li 2,* Jia-Yuan Sun 2 , Huan-Xin Lin 2 , San-Gang Wu 3 and Qiong-Hua Chen 1 1 Xiamen Cancer Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xiamen University, Xiamen, People’s Republic of China 2 Sun Yat-sen University Cancer Center, Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, People’s Republic of China 3 Xiamen Cancer Center, Department of Radiation Oncology, The First Affiliated Hospital of Xiamen University, Xiamen, People’s Republic of China * These authors have contributed equally to this work Correspondence to: San-Gang Wu, email: // Qiong-Hua Chen, email: // Keywords : epithelial ovarian cancer, lymph node ratio, positive lymph nodes, prognosis, SEER Received : September 04, 2015 Accepted : January 04, 2016 Published : January 13, 2016 Abstract To assess the prognostic value of the lymph node ratio (LNR) in patients with stage IIIC epithelial ovarian cancer (EOC) with node-positive in a Surveillance, Epidemiology, and End Results (SEER) population-based study.Data of patients were obtained from the SEER database from 1990 to 2012, and analyzed using Kaplan-Meier survival methods and Cox regression proportional hazard model. The prognostic value of the LNR on cause-specific survival (CSS) and overall survival (OS) were calculated. A total of 5,926 patients were identified. Univariate analysis showed that the number of removed lymph nodes (RLNs), the number of positive lymph nodes, and the LNR were significantly associated with CSS and OS ( P < 0.05 for all). Multivariate analysis indicated that a higher LNR was an independent prognostic factor for poorer CSS (hazard ratio [HR]: 1.896, 95% confidence interval [CI]: 1.709-2.104, P < 0.001) and OS (HR:1.679, 95% CI: 1.454-1.939, P < 0.001). Among patients with LNR ≤ 0.42 and those with LNR > 0.42, the 5-year CSS was 53.1% and 34.7%, respectively ( P < 0.001), and the 5-year OS was 50.4% and 32.0%, respectively ( P < 0.001). The prognostic value of the LNR persisted for patients after stratification by the numbers of RLNs, tumor histology, and tumor grade. LNR is a more accurate prognostic method for stage IIIC EOC patients. Patients with a higher LNR are associated with poorer survival in stage IIIC EOC.