OBJECTIVETo study the expression of cyclooxygenase-2 (COX-2) in esophageal carcinoma and its correlation with microlymphatic density (MLD), and to investigate the clinicopathological and prognostic significance of COX-2 and MLD in patients with esophageal cancer.

METHODSCOX-2 expression and MLD were detected by immunohistochemistry in 100 cases of esophageal squamous cell carcinoma. Follow up was available in 76 patients. Multivariable Cox regression was used to analyze the association between the laboratory indices and overall survival of patients with esophageal carcinoma.

RESULTSCOX-2 expression was present in 73% of patients. MLD in patients with high COX-2 expression (99.71±39.62) was significantly higher than that in those with low or no COX-2 expression (80.22±30.36) (P<0.05). No correlations were observed between the over expression of COX-2 and clinicopathologic parameters including tumor size and lymphatic metastasis (P<0.05). However, MLD was associated with lymphatic metastasis and the depth of invasion (P<0.05, P<0.01). In the 76 patients with followed up, the median survival was 25.5 months. Cox regression showed that the COX-2 expression, histological grade of the tumor and MLD were risk factors of overall survival of esophageal carcinoma.

CONCLUSIONSCOX-2 may contribute to the lymphangiogenesis in the tumor. COX-2 may be a new target point for the treatment of esophageal carcinoma. COX-2 expression and microlymphatic vessel density are of significant prognostic value for esophageal carcinoma.