Prognostic Significance of Lymphovascular Space Invasion in Epithelial Ovarian Cancer

OBJECT To assess the effects of lymphovascular space invasion (LVSI) on cancer recurrence and survival in patients with primary epithelial ovarian cancer. METHODS A retrospective study was conducted of patients with stage I-IV primary epithelial ovarian cancer who underwent cytoreductive surgery. LVSI is defined as the presence of tumor cells within an endothelium-lined space, and the patients' pathologic slides were reevaluated by gynecological pathologists. Survival analysis was performed to compare risk factors. RESULTS A total of 492 patients were included in the analysis. The incidence of LVSI was 58.5% in our cohort (288 cases), and it was significantly associated with advanced stage, high-grade serous histology, high grade, and lymph node metastasis (P<0.001). Kaplan-Meier analysis demonstrated that LVSI was only correlated with decreased PFS (5-year rate, 39% vs. 66%, P<0.001) and OS (5-year rate, 44% vs. 78%, P<0.001) in patients at early stage but not at advanced stage (5-year rate, PFS: 14% vs. 11%, P<0.001; OS: 29% vs. 29%, P=0.141). Multivariate analysis showed that LVSI remained a significant variable with PFS and OS in early-stage ovarian cancer (PFS: HR 2.29, 95% CI 1.45-3.57; OS: HR 2.20, 95% CI 1.59-3.44, both P<0.001). CONCLUSION LVSI is an independent predictor of progression and survival in patients with primary epithelial ovarian cancer at early stage but not at advanced stage.