TY - JOUR T1 - 351 Substantial lymph-vascular space invasion (LVSI) as predictor of distant relapse and poor prognosis in low-risk early stage endometrial cancer JF - International Journal of Gynecologic Cancer JO - Int J Gynecol Cancer SP - A144 LP - A145 DO - 10.1136/ijgc-2020-IGCS.302 VL - 30 IS - Suppl 3 AU - L Tortorella AU - S Restaino AU - G Zannoni AU - G Vizzielli AU - V Chiantera AU - S Cappuccio AU - A Gioè AU - E La Fera AU - G Dinoi AU - G Angelico AU - G Scambia AU - F Fanfani Y1 - 2020/11/01 UR - http://ijgc.bmj.com/content/30/Suppl_3/A144.abstract N2 - Objective To evaluate the prognostic role of LVSI, evaluated in a semi-quantitative fashion on prognosis of early stage, low risk endometrial cancer (EC).Methods We enrolled patients who underwent surgery for EC between 2003 and 2018 in two referral cancer center. All patients had endometrioid EC, G1-G2, with myometrial invasion <50%, and no lymph-node involvement. LVSI was analyzed in a semi-quantitative way, according to a three-tiered scoring system in absent, focal and substantial.Results Among 524 patients, any positive LVSI was found in 57 patients (10.9%) with 6.7% (n=35) focal LVSI and 4.2% (n=22) substantial LVSI. Substantial LVSI was associated to higher rate of G2 (p<0.001), myometrial infiltration (p=0.002) and greater tumor dimensions (p=0.014). Patients with substantial LVSI were more likely to receive adjuvant treatment (6.6% vs 52.6%p<0.001). The 5-year OS was 99.5% in patients with absent LVSI and 70.6% in those with substantial LVSI (p<0.001). The 5-year recurrence free survival was 93.6% in patients with absent LVSI and 56.5% in those with substantial LVSI (p<0.001). The rate of distant failures increased from 1.8% for absent LVSI to 22.7% for substantial LVSI (p=0.002). In univariate analysis substantial LVSI was the strongest predictor of poor overall survival (HR= 11.9, p=0.001). Multivariate analysis showed that substantial LVSI was an independent predictive factor of both recurrence (HR=5.88, p=0.001) and distant failure (HR=10.6, p=0.006).Abstract 351 Figure 1 Overall survival and disease free survival according to lymph-vascular space invasion statusView this table:Abstract 351 Table 1 Univariable and multivariable logistic regression analysis of risk factors for distant recurrence among patients at low riskConclusions Substantial LVSI represents the strongest independent risk factor for decreased survival and distant relapse, indicating a role for potential hematogenous dissemination. ER -