Stage- and Histologic Subtype-Dependent Frequency of Lymph Node Metastases in Patients with Epithelial Ovarian Cancer Undergoing Systematic Pelvic and Paraaortic Lymphadenectomy

Purpose Tumor stage and distinct histological subtypes in epithelial ovarian cancer (EOC) show different prognostic outcome. The aim of this study is to evaluate whether the frequency of lymph node (LN) metastases in patients with different tumor stages and histological subtypes undergoing systematic pelvic and paraaortic lymphadenectomy is coincidentally divergent. Methods Patients with EOC treated with upfront staging or debulking surgery between January 2000 and December 2016 were included. Systematic lymphadenectomy was performed in all consecutive patients with optimal debulking and without medical contraindications. Results Seven hundred sixty-two patients including 27.2% with early-stage EOC were included. The median number of removed LNs was 69, and metastases to LNs were found in 54.7%. No LN metastases were found in patients with low-grade endometrioid carcinoma, independently of tumor stage. LN metastases in early-stage low-grade serous ( N = 5), mucinous ( N = 31), and clear cell ( N = 28) EOC were found in one (20%), zero, and one (3.6%) patient, respectively. LN metastases were detected in more than 10% of patients with all other histological subtypes. On multivariate analyses, overall survival was significantly impaired in patients with LN metastases, as compared with patients without LN metastases ( p = 0.001). Conclusions The risk of LN metastases in patients with EOC is dependent on stage and histological subtype. Patients with incidental finding of early mucinous or low-grade endometrioid EOC are at very low risk of retroperitoneal lymph node metastases. Reoperation for lymph node staging only should be discussed individually with caution.