Assessment of Risk Factors for Lymph Node Metastasis in Endometrial Cancer

Introduction: To determine the clinical and pathologic factors that are risk factors for metastasis of the lymph nodes (pelvic and/or aortic lymph nodes) in cases who underwent staging surgery due to endometrial carcinoma. Methods: The clinical and pathological characteristics of 143 patients who underwent staging surgery between 2007 and 2016 were retrospectively analyzed. Linear regression analysis, logistic regression analysis, Spearman correlation and Receiver operator curve tests were used to determine risk factors for lymph node metastasis. P<0.05 was considered significant in all statistical evaluations. Results: Thirteen cases (9.1%) had lymph node metastasis [5 cases (3.5%) only pelvic, 3 cases (2.1%) only paraaortic, 5 cases (3.5%) both pelvic and paraaortic lymph node]. In linear regression analysis, there was a significant correlation between lymph node metastasis and non-endometrioid histological type, deep myometrial invasion (>= 50% invasion depth), advanced histologic grade, lymphovascular space invasion, positive peritoneal cytology and tumor size (p<0.05). The correlation between tumor size and lymph node metastasis was positive, and Receiver operator curve revealed 4.25 cm tumor size was the most appropriate cut-off value for risk of lymph node metastasis (sensitivity=83%, specificity=75%). In logistic regression analysis, lymphovascular space invasion was the only independent risk factor for nodal metastasis (odss ratio: 11.8; 95% confidence interval: 1.8-75.4, p=0.009). Conclusion: In endometrial cancer cases, lymphovascular space invasion is the only independent risk factor for lymph node metastasis. There is linear correlation between tumor size and lymph node metastasis. Further studies is needed to determine the limit value of tumor size for lymph node metastasis.