Association of COX-2 expression with corresponding active and chronic inflammatory reactions in Barrett's metaplasia and progression to cancer.

AIMS: Risk reduction for Barrett's cancer in individuals taking non-steroidal anti-inflammatory drugs has been reported. Cyclooxygenase (COX)-2, one of the inhibited enzymes, is putatively involved in Barrett's cancer pathogenesis. The aim of this study was to examine a possible association between COX-2 protein expression and the development and progression of the Barrett's metaplasia-dysplasia-carcinoma sequence and the type and degree of associated inflammatory reaction. METHODS AND RESULTS: Squamous epithelium, metaplastic, low-grade, high-grade dysplastic lesions and tumour tissue of 49 resection specimens from patients with Barrett's adenocarcinoma were immunohistochemically analysed. Active and chronic inflammatory reactions were classified according to the Updated Sydney System. Within the Barrett's sequence, a significant progressive increase in COX-2 expression was identified (P < 0.0001). The most significant differences were detected between squamous epithelium and Barrett's metaplasia (P < 0.001) and from low- to high-grade dysplasia (P < 0.0001). Active and chronic inflammation were significantly different between squamous epithelium and Barrett's metaplasia (P < 0.0001), but not during further progression in the sequence. CONCLUSIONS: Increasing COX-2 expression in Barrett's metaplasia is significantly associated with a change in the local inflammatory reaction, but not during further progression through dysplasia to cancer. This supports the potential of a chemoprevention strategy using COX-2 inhibitors independent of the extent and type of the inflammatory reaction in Barrett's oesophagus.

Survivin mRNA in peripheral blood is frequently detected and significantly decreased following resection of gastrointestinal cancers.

BACKGROUND AND OBJECTIVES: We evaluated if mRNA expression of survivin, an inhibitor of apoptosis, can be used to detect circulating tumor cells in peripheral blood of patients with various gastrointestinal cancers and if they decrease following complete surgical resection. METHODS: Blood samples from 40 gastrointestinal cancer patients were analyzed prior and following surgical resection by direct quantitative real-time reverse transcriptase-PCR (RT-PCR) assays. RESULTS: Survivin mRNA expression was pre-operatively detected in 35 of 40 cancer patients (88%). Post-operative survivin levels were significantly lower than pre-operative levels in 59% of resected patients and were non-detectable in 38% (Wilcoxon rank test: P < 0.04). CONCLUSIONS: This is the first report showing that direct quantitative real-time RT-PCR analysis of survivin mRNA expression in peripheral blood of patients with gastrointestinal cancers is technically feasible. Survivin mRNA levels fall significantly following complete resection and might become a molecular marker for the completeness of surgical resection.