Substantial Lymphovascular Space Invasion Is an Adverse Prognostic Factor in High-Risk Endometrial Cancer

Approximately 15% of patients with endometrial cancer present with high-risk disease (HREC). Moreover, assessing the extent of lymphovascular space invasion (LVSI) may provide prognostic insight among patients with HREC. The aim of this study was to determine whether the extent of LVSI can serve as a prognostic factor in HREC. All cases of ESMO-ESGO-ESTRO 2016 classified HREC in the Danish Gynecological Cancer Database (DGCD) diagnosed from 2005 to 2012 were reviewed for the presence and extent of LVSI (categorized using a 3-tiered definition). We used the Kaplan-Meier analysis to calculate actuarial survival rates, both adjusted and unadjusted Cox regression analyses were used to calculate the proportional hazard ratio (HR). A total of 376 patients were included in our analysis. Among 305 patients with stage I/II HREC, 8.2% and 6.2% had focal or substantial LVSI, respectively, compared with 12.7% and 38.0% of 71 patients with stage III/IV HREC, respectively. Moreover, the estimated 5-yr recurrence-free survival rate was significantly lower among patients with substantial LVSI compared with patients with no LVSI for both stage I/II (HR: 2.8; P=0.011) and stage III/IV (HR: 2.9; P=0.003) patients. Similarly, overall survival was significantly lower among patients with substantial LVSI for both stage I/II (HR: 3.1; P<0.001) and stage III/IV (HR: 3.2; P=0.020) patients. In patients with HREC, substantial LVSI is an independent adverse prognostic factor for lymph node and distant metastases, leading to reduced survival. Thus, the extent of LVSI should be incorporated into routine pathology reports in order to guide the appropriate choice of adjuvant treatment.