Correlation between COX-2 and VEGF-C expressions and lymphatic metastasis in esophageal squamous carcinoma

AIM: To investigate the correlation of the expressions of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor-C (VEGF-C) in esophageal squamous carcinoma and their implication in tumor lymphatic metastasis. METHODS: The expressions of COX-2 and VEGF-C were examined by immunohistochemical method in 72 cases of esophageal squamous carcinoma and 24 cases of normal esophageal mucosa. RESULTS: The positive rates of COX-2 and VEGF-C in esophageal squamous carcinoma were 48.6% and 38.9% respectively, and no expressions of COX-2 or VEGF-C were detected in normal esophageal mucosa. The expressions of COX-2 and VEGF-C were signifi- cantly associated with the depth of tumor invasion and lymph node metastasis (P0.01), but not with the patient age, tumor size or differentiation. The expression of COX-2 was closely correlated with that of VEGF-C (contingency coefficient=0.342,P= 0.002). CONCLUSION: COX-2 may participate in VEGF-C lymphangiogenic pathway and play an important role in the lymphatic metastasis of esophageal squamous carcinoma.