Meta‐analysis: clinicopathological and prognostic significance of cyclooxygenase‐2 expression on oesophageal squamous cell carinoma

BACKGROUND: Cyclooxygenase-2 (COX-2) is involved in oesophageal carcinogenesis, but the clinical and prognostic significance of COX-2 expression in oesophageal squamous cell carcinoma (ESCC) remains controversial. AIM: To evaluate the clinicopathological and prognostic role of COX-2 expression in ESCC. METHODS: Studies assessing clinical or prognostic significance of COX-2 expression in ESCC published until December 2008 were selected. A meta-analysis was performed to clarify the impact of COX-2 expression on clinicopathological parameters or overall survival (OS) in ESCC. RESULTS: A total of 19 studies met the inclusion criteria, among which 17 studies were about the clinicopathological significance of COX-2 expression in ESCC, 12 studies were dealing with prognostic role of COX-2 expression in ESCC and 10 studies evaluated both of them. Overexpression of COX-2 was significantly correlated with not only the depth of invasion and TNM stage, with a combined odds ratio (OR) of 0.55 (95%CI: 0.34-0.90, Z = 2.41, P = 0.02) and 0.55 (95%CI: 0.32-0.95, Z = 2.13, P = 0.03) respectively but also the reduced OS with relative risk (RR) 1.42, 95% CI: 1.07-1.90, Z = 2.43, P = 0.02). CONCLUSIONS: COX-2 might play an important role in the progress of ESCC, overexpression of COX-2 correlates with not only the depth of invasion and TNM stage but also the reduced OS. COX-2 might be a potential therapy target for ESCC and work as a prognostic factor for ESCC patients, yet the clinicopathological and prognostic role of COX-2 in ESCC still needs further confirmation by well-designed prospective studies.