Expression of cyclooxygenase-2 in the mucosa of the gastroesophageal junction in patients with Barrett’s oesophagus – the results of ablation therapy with argon plasma coagulation and laparoscopic Nissen fundoplication

Introduction: Barrett’s oesophagus (BE) is a result of replacement of the mucosa of the distal oesophagus by metaplastic columnar epithelium. The role of cyclooxygenase-2 (COX-2) and chronic inflammation in the progression of BE toward adenocarcinoma of the oesophagus is emphasized. Argon plasma coagulation (APC) allows for effective ablation of metaplastic mucosa. It is believed that effective suppression of gastric secretion with proton pump inhibitors (PPI) promotes squamous cell re-epithelialization and a decrease in expression of some biomarkers including COX-2. A similar effect can be achieved by the anti-reflux procedure.
Aim: To evaluate the usefulness of COX-2 expression in determining the risk of malignant transformation in patients with BE.
Material and methods: Patients from two out of three study groups underwent APC ablation of metaplastic mucosa combined with chronic PPI administration (group A) or laparoscopic Nissen fundoplication (group B). Controls (group K) were submitted only to PPI treatment. Expression of COX-2 was evaluated in fresh-frozen biopsy specimens obtained from the distal oesophagus in all 60 patients before and 12 months after treatment.
Results: Overexpression of COX-2 was found in 41 patients (68.3%). The highest degree of COX-2 expression was documented in patients with dysplasia. After treatment overexpression of COX-2 was markedly reduced in patients from groups A and B, which correlated well with histopathological findings. Controls did not show important changes in COX-2 expression.
Conclusions: Significant correlation of the degree of COX-2 overexpression with histopathological findings points to the possible use of this biomarker as a valuable indicator of the risk of malignant transformation in patients with BE.