Prognostic Significance of Lymphovascular Space Invasion in the Absence of Lymph Node Metastases in Early-Stage Endometrial Cancer.

OBJECTIVE: Lymphovascular space invasion (LVSI) has been defined as a significant adverse prognostic factor in early-stage endometrial cancer, primarily because of its high association with nodal metastases. This study aimed to determine if LVSI provides any prognostic significance in pathologic node-negative surgically staged (T1N0) endometrial cancer patients. METHODS/MATERIALS: This retrospective cohort study included all patients with pathologic stage T1N0 endometrial carcinoma treated at The Ottawa Hospital Cancer Centre from 1998 to 2007. Patient demographics, pathologic findings, treatment, and outcome data were collected. Univariate and multivariate cox regression modeling was used to assess significance and adjust for demographic and histopathologic covariates. Kaplan-Meier curves were used to estimate the 5-year overall and recurrence-free survival. RESULTS: Our study included 400 pathologic stage T1N0 patients who received an initial total hysterectomy and bilateral salpingo-oophorectomy with lymphadenectomy. The median age at diagnosis was 62 years, and the median follow-up was 66 months. Fifty-four patients (13.5%) had a positive LVSI status, and 346 (86.5%) had a negative LVSI status. The 5-year overall survival was 97.3% in patients without LVSI and 90.9% in those with LVSI (P < 0.001). The 5-year recurrence-free survival was 95.2% in patients without LVSI and 85.9% in those with LVSI (P = 0.006). Univariate analysis identified grade, stage, and LVSI as the covariates significantly associated with time to recurrence, and identified age, grade, stage, and LVSI to be significantly associated with overall survival. There were no significant covariates for recurrence-free survival by multivariate analysis, and only age and LVSI were significant for overall survival. CONCLUSIONS: Lymphovascular space invasion is an overall poor prognostic factor in T1N0 endometrial cancer. After adjusting for other factors, LVSI remains an independent risk factor for worse overall survival. Therefore, estimation of overall survival in patients with early-stage, node-negative endometrial cancer should take into account LVSI status.