Predicting Factors for Pelvic Lymph Node Metastasis in Patients with Apparently Early-Stage Endometrial Cancer

BACKGROUND: Performing lymphadenectomy in all patients with early-stage endometrial cancer (EC) is debatable because the procedure may expose patients to unnecessary risks of postoperative complications. Aim of this study was to evaluate the prevalence and risk factors of pelvic lymph node metastasis (PLNM) in patients with apparently early-stage EC. MATERIALS AND METHODS: Two hundred and two patients with apparently early-stage EC who underwent surgical staging at Thammasat University Hospital between the years 2013 and 2020 were included in this retrospective study. Clinicopathological data and preoperative laboratory results were obtained from computer-based medical records. All data were statistically analyzed to determine the prevalence of PLNM and risk factors for developing PLNM. RESULTS: PLNM was detected in 22 (10.9%) patients. Univariate analysis demonstrated that having grade 3 tumor, myometrial invasion of 50% or greater, vaginal involvement, cervical involvement, adnexal involvement, lower uterine segment involvement, lymphovascular space invasion (LVSI), and positive peritoneal cytology were associated with higher risk for developing PLNM. In addition, lower preoperative hemoglobin level and higher preoperative white blood cell count were significantly associated with PLNM. Multivariate analysis demonstrated that myometrial invasion of 50% or greater and LVSI were independent risk factors for developing PLNM (odds ratio (OR) 9.31, 95% confidence interval (CI) 2.58-33.55, p = 0.001, and OR 3.73, 95%CI 1.39-10.02, p = 0.009, respectively). CONCLUSIONS: Myometrial invasion of 50% or greater and LVSI were independent risk factors for developing PLNM in patients with apparently early-stage EC and thus lymphadenectomy in these patients should be provided.