Lymphovascular invasion as an independent prognostic indicator in radically resected thoracic esophageal squamous cell carcinoma

Background The prognostic value of lymphovascular invasion (LVI) in esophageal cancer remains controversial. This study investigated the impact of LVI on prognosis in thoracic esophageal squamous cell carcinoma (ESCC). Methods A total of 1586 patients who underwent radical esophagectomy were selected for the study. Correlations between LVI and clinicopathological features were evaluated by chi(2) test. Univariate analysis of the survival curve was conducted using the Kaplan-Meier method. Multivariate analysis was carried out by Cox regression. The Akaike information criterion (AIC) and the concordance index (c-index) were employed to assess model prognostic accuracy of different pN staging systems. Results The presence of LVI was detected in 406 of 1586 (25.6%) patients. LVI frequency was significantly higher in patients with higher pN classifications (P < 0.001). LVI had independent significant prognostic value in ESCC (P < 0.001). In subgroup analyses, the presence of LVI significantly decreased overall survival in pN0, pN2, and pN3 stage patients. The AIC value of the pN staging system modified by LVI was lower than that of the current pN staging system, while the c-index of the modified pN staging system was higher than that of the current pN staging system. Conclusion Our results suggest that LVI is an independent prognostic indicator in radically resected thoracic ESCC. LVI could potentially supplement the pN ESCC staging system. ESCC patients with LVI could be staged at more advanced pN classifications.