The Impact of Lymphovascular Space Invasion on Recurrence and Survival in FIGO Stage I Node-Negative Endometrioid...

Background/Objective: To evaluate the prognostic impact of lymphovascular space invasion (LVSI) on disease-free survival (DFS) and overall survival (OS) in patients with FIGO 2009 stage I endometrioid endometrial cancer with pathologically negative lymph node involvement. Methods: This retrospective cohort study included 469 patients with FIGO 2009 stage I node-negative endometrioid endometrial carcinoma who underwent comprehensive surgical staging at a single tertiary center between January 1993 and April 2025. Demographic, clinicopathological, treatment, and follow-up data were collected. Survival outcomes were assessed using Kaplan-Meier analysis, and prognostic factors were identified via univariate and multivariate Cox regression models. Results: LVSI was present in 17.7% of the cohort (n = 83). Patients with LVSI had significantly higher tumor grades, larger tumor size, and deeper myometrial invasion compared to LVSI-negative patients (p < 0.001). Recurrence was more frequent in the LVSI-positive group (14.5% vs. 6.5%, p = 0.026), with distant metastasis predominating (83.3%). The 5-year DFS was 86.4% in the LVSI-positive group versus 96.3% in the LVSI-negative group (p = 0.0020), while the 5-year OS was 72.1% vs. 91.2%, respectively (p = 0.0014). In multivariate analysis, LVSI was an independent prognostic factor for both recurrence (HR = 4.80, 95% CI: 1.62-14.21; p < 0.001) and overall mortality (HR = 3.33, 95% CI: 1.43-7.77; p = 0.012). Conclusions: LVSI is a strong and independent predictor of adverse oncologic outcomes in early-stage, node-negative endometrioid endometrial cancer. Its presence is associated with significantly decreased DFS and OS, particularly due to an increased risk of distant recurrence. These findings support the incorporation of LVSI into contemporary risk stratification and adjuvant treatment algorithms.