Background & aims: Use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a reduced risk of cancer in the digestive tract. Cyclooxygenase (COX) is the best-known target of NSAIDs, and expression of the COX-2 isoform is elevated in esophageal carcinomas but its clinical significance remains unclear. We examined COX-2 expression in esophageal adenocarcinomas and its relation to clinicopathologic parameters.
Methods: Tumor sections from 145 consecutive patients undergoing intentionally curative surgery for an adenocarcinoma arising from a Barrett's esophagus were immunohistochemically stained using a COX-2-specific anti-human monoclonal antibody. The specimens were scored based on the intensity and extent of COX-2 immunopositivity.
Results: COX-2 immunoreactivity was negative to weak in 21% (COX-2 low) and moderate to strong in 79% (COX-2 high) of the carcinomas. Patients with high COX-2 expression were more likely to develop distant metastases (P = 0.02) and local recurrences (P = 0.05), and survival was significantly reduced (P = 0.002, log-rank test) among patients with high COX-2 expression when compared with the COX-2 low group. Five-year survival rates were 35% (95% confidence interval [CI], 23-47) and 72% (95% CI, 53-90) in COX-2 high and COX-2 low categories, respectively. Furthermore, expression of COX-2 was recognized as an independent prognostic factor by multivariate analysis (relative risk, 3.5; 95% CI, 1.6-7.9).
Conclusions: Elevated expression of COX-2 protein is associated with significantly reduced survival of patients undergoing surgery for esophageal adenocarcinoma. These findings support the effort to initiate clinical studies to investigate the effect of COX-2 inhibitors as a novel (adjuvant) chemotherapeutic modality for the treatment of adenocarcinoma arising from Barrett's esophagus.