Prognostic evaluation of lymph-vascular space invasion in patients with endometrioid and non-endometrioid endometrial cancer: A multicenter study

Introduction The prognostic value of lymph-vascular space invasion (LVSI) on endometrial cancer (EC) remains controversial. This study aimed to explore the impact of LVSI on patients with endometrioid and non-endometrioid EC in China. Materials and methods We analyzed EC patients who underwent surgery from 2010 to 2019 in seven Chinese hospitals retrospectively and stratified patients based on histopathologic types and LVSI status. Endpoints were disease-free survival (DFS) and overall survival (OS). Propensity score matching (PSM) algorithm was used to balance the confounding factors. The survival was examined using Kaplan-Meier analysis. Cox proportional hazards regression analyses were used to find prognostic independent risk factors. Results Among 3715 EC patients, LVSI positive rate was 9.31% (346/3715). After matching, LVSI present group had shorter DFS (P = 0.005), and similar OS (P = 0.656) than LVSI absent group for endometrioid EC patients. For non-endometrioid EC patients, there was no statistical difference in either DFS (P = 0.536) or OS (P = 0.512) after matching. The multivariate Cox analysis showed that LVSI was an independent risk factor of DFS [hazard ratio (HR) 2.62, 95% confidence intervals (CI) 1.35–5.10, P = 0.005] and not OS (HR 1.24, 95%CI 0.49–3.13, P = 0.656) for endometrioid EC patients. It was not a prognostic factor of either DFS (HR 1.28, 95%CI 0.58–2.81, P = 0.539) or OS (HR 1.33, 95%CI 0.55–3.13, P = 0.515) for non-endometrioid EC patients. Conclusion LVSI is an adverse prognostic factor for endometrioid EC patients and has no impact on non-endometrioid EC patients. Necessity of postoperative adjuvant therapy based on LVSI needs to be carefully considered for non-endometrioid EC patients.