Prognostic value of lymphovascular space invasion evaluated by immunohistochemistry and stratification with a semi-quantitative scoring system for early-stage endometrial cancer

Abstract

Objective To investigate the prognostic value of lymphovascular space invasion (LVSI) evaluated by immunohistochemistry and then stratification with a semi-quantitative scoring system for early-stage endometrial cancer. Methods We retrospectively reviewed 203 patients with 2009 International Federation of Gynecology and Obstetrics (FIGO) stage Ⅰ to Ⅱ endometrial cancer who underwent radical surgery in the gynecology department of our hospital between 2010 and 2017. Their clinicopathological and follow-up data were collected. All available slides from the hysterectomy specimens were examined, and immunohistochemical techniques were used to detect LVSI and determine whether the type of LVSI belonged to lymphatic vessel invasion (LVI) or blood vessel invasion (BVI), and then the results were stratified with a semi-quantitative scoring system to assess the extent of LVSI. All the patients were classified into 6 groups: focal LVI, substantial LVI, focal BVI, substantial LVI, LVI+BVI, and LVSI (-). We used Chi-square test to compare the difference in the 5-year recurrence-free survival rate (RFS) among groups and Kaplan-Meier analysis for survival analysis. Univariate and multivariate analyses was used to analyze the influencing factors for survival, and Cox proportional hazards model was adopted to determine the effects of different LVSI statuses and other clinicopathological factors on RFS of early-stage endometrial cancer. Results Among the 203 patients, the proportions of focal LVI, substantial LVI, focal BVI, substantial LVI, LVI+BVI were 14.7%, 7.8%, 4.4%, 2.0% and 5.9%, respectively, and their 5-year RFS was 56.7%, 50.0%, 33.3%, 25.0% and 33.3% respectively, and statistical differences were observed when compared with the LVSI (-) group (P < 0.01). Their median RFS was 74.3, 51.5, 34.4, 26.1 and 40.7 months, respectively, which were significantly different from that of the LVSI(-) group (P < 0.01). Univariate analysis showed that age, depth of myometrial invasion, LVSI status, and adjuvant radiotherapy were closely associated with the RFS (all P < 0.05). Multivariate analysis indicated that the patients with substantial LVI (HR: 5.832, 95%CI: 2.463~13.808) were more likely to relapse than those with focal LVI (HR: 3.380, 95%CI: 1.708~6.688), and those with focal BVI (HR: 12.536, 95%CI: 4.692~33.493), substantial BVI (HR: 11.538, 95%CI: 2.869~46.399) or LVI+BVI (HR: 10.065, 95%CI: 4.215~24.032), had similiar risk levels of recurrence and a higher risk than patients with substantial LVI; And age, stage, LVSI status, adjuvant radiotherapy, and adjuvant chemotherapy were independent prognostic factors for early-stage endometrial cancer (all P < 0.05). Conclusion LVSI evaluated by immunohistochemistry and then stratified with a semi-quantitative scoring system may help predicting the risk of recurrence in early-stage endometrial cancer.

Keywords

• lymphovascular space invasion
• endometrial cancer
• immunohistochemistry
• semi-quantitative
• prognosis