Effect of the Number of Negative Lymph Nodes Removed on the Survival and Recurrence Rate After Primary Surgery in Patients with Ovarian Cancer: A Multi-Center Retrospective Cohort Study

Abstract

The effect of the number of negative lymph nodes (NLNs) removed on the overall survival (OS) and recurrence rate of ovarian cancer (OC) patients has not been investigated. This study aimed to investigate the effect of the number of NLNs removed on OC patients' survival and recurrence rate after primary surgery. In this multi-center cohort study, the medical profile of 504 OC patients (mean age 55.21 years and mean follow-up 78.5 +/- 28.4 months) who underwent primary surgery between 2011 and 2021 in gynecological tumor surgery centers affiliated with Iran and Shahid Beheshti Universities of Medical Sciences, Tehran, Iran, was retrospectively examined. Based on the number of NLNs removed, patients were divided into four groups, including 0-9, 10-19, 20-30, and > 30 NLNs, including 152, 169, 124, and 59 OC patients, respectively. The 5-year survival was 49.1. The median survival was 61 months. The RFS and OS were significantly better in patients with more than 30 NLNs removed compared to other groups. The multivariable analysis showed that the OS rate was significantly better in patients with the number of NLNs removed >= 20 compared to < 20 (HR, 1.88; 95 CI 1.15-2.62; p, 0.001). Also, age, FIGO stage, presence of metastasis, adjuvant therapy, and tumor pathological differentiation were significantly related to the OS of OC patients (p < 0.05). Paying attention to the number of NLNs removed during primary surgery can be a key factor in improving the OS rate of OC patients.