Prevalence and Prognostic Significance of Extramural Venous Invasion in Patients with Locally Advanced Esophageal Cancer.

BACKGROUND: Extramural venous invasion (EMVI) is a known adverse prognostic factor in patients with colorectal carcinoma. The prevalence and significance of EMVI in esophageal cancer (EC) patients is still unclear. METHODS: From a prospectively maintained database, we retrospectively reviewed the resection specimens of patients with pathologic locally advanced (pT3/T4/N0-3) EC who were treated with curative intent between 2000 and 2015. Patients with previous malignancies and gastroesophageal junction (type II/III) tumors were excluded. Included were 81 patients who underwent surgery alone and 37 patients who underwent neoadjuvant chemoradiotherapy (nCRT). EMVI was assessed on hematoxylin and eosin slides and confirmed or excluded by additional Elastica van Gieson staining. Survival was analyzed using a multivariable Cox regression. RESULTS: EMVI was present in 23.5% (n = 19) of patients in the surgery-alone group and 21.6% (n = 8) of patients in the nCRT group. The prevalence of EMVI after surgery alone was significantly high in squamous cell carcinomas and among tumors located in the mid-esophagus, as well as those with lymphovascular invasion (p < 0.05). After nCRT, the presence of EMVI was significantly high in tumors with lymphovascular and perineural tumor growth (p = 0.034). EMVI status was an independent adverse prognostic factor for disease-free survival [hazard ratio (HR) 7.0, 95% confidence interval (CI) 2.3-21.8; p =0.001] and overall survival (HR 6.5, 95% CI 2.2-19.1; p = 0.001) in the surgery-alone group for node-positive tumors. CONCLUSIONS: In this study of locally advanced > pT3/N0-3 EC patients, EMVI was present in 23.5% of patients in the surgery-alone group and in 21.6% of patients after nCRT. EMVI was an independent adverse prognostic factor in patients after surgery alone.