Significance of Lymphovascular Space Invasion by the Sarcomatous Component in Uterine Carcinosarcoma

Objective The aim of this study was to examine the significance of lymphovascular space invasion (LVSI) with a sarcomatous component on the tumor characteristics and clinical outcomes of women with uterine carcinosarcoma (UCS). Methods This was a secondary analysis of a prior multicenter retrospective study that examined women with stage I–IV UCS who underwent primary hysterectomy. Archived histopathology slides were reviewed and LVSI was scored as follows: LVSI with a carcinomatous component alone (LVSI-carcinoma; n = 375, 76.8%) or LVSI containing a sarcomatous component with or without a carcinomatous component (LVSI-sarcoma; n = 113, 23.2%). Qualitative metrics of LVSI were correlated to clinicopathological factors and survival outcome. Results Tumors in the LVSI-sarcoma group were more likely to have sarcoma dominance (82.1 vs. 26.4%) heterologous sarcomatous component (51.3 vs. 37.9%), low-grade carcinoma (42.5 vs. 22.4%), and large tumor size (81.0 vs. 70.2%) in the primary tumor site compared with tumors in the LVSI-carcinoma group (all p < 0.05). On multivariate analysis, LVSI-sarcoma was independently associated with decreased progression-free survival (5-year rates: 34.9 vs. 40.8%, adjusted hazard ratio [HR] 1.84, 95% confidence interval [CI] 1.36–2.50, p < 0.001), and cause-specific survival (5-year rates: 41.8 vs. 55.9%, adjusted HR 1.95, 95% CI 1.39–2.75, p < 0.001) compared with LVSI-carcinoma. Postoperative radiotherapy for women with LVSI-sarcoma had a higher reduction rate of recurrence/progression of disease (54% reduction, p = 0.04) compared with postoperative radiotherapy for women with LVSI-carcinoma (26% reduction, p = 0.08). Conclusion In UCS, the presence of a sarcomatous component in LVSI is particularly prevalent when a tumor has sarcoma dominance. Our study suggests that LVSI containing a sarcomatous component may be a predictor of decreased survival for women with UCS.