Polymorphism of -765G > C COX-2 is a risk factor for gastric adenocarcinoma and peptic ulcer disease in addition to H pylori infection: A study from northern India

AIM: To investigate -765G > C COX-2 polymorphism and H pylori infection in patients with gastric adenocarcinoma, peptic ulcer disease (PUD) and non-ulcer dyspepsia (NUD). METHODS: We enrolled 348 adult patients (62 gastric adenocarcinoma, 45 PUD and 241 NUD) undergoing upper gastrointestinal endoscopy at two referral centers between September, 2002 and May, 2007. H pylori infection was diagnosed when any of the four tests (RUT, culture, histopathology and PCR) were positive. Genotyping for -765G > C polymorphism of COX-2 was performed by PCR-RFLP analysis. RESULTS: Frequency of C carrier had significant association with gastric adenocarcinoma as compared to NUD [77.4% vs 29%, P < 0.001, odds ratio (OR) 8.20; 95% confidence interval (95% CI), 4.08-16.47] and PUD (77.4% vs 31.1%, P < 0.001; OR 8.04; 95% CI, 3.25-19.90). Risk of gastric adenocarcinoma was significantly higher in patients having C carrier with (OR 7.83; 95% CI 3.09-19.85) and without H pylori infection (OR 7.06; 95% CI, 2.61-19.09). Patients with C carrier and H pylori infection had significant risk for the development of PUD (P < 0.001; OR 5.65; 95% CI, 2.07-15.34). CONCLUSION: -765G > C COX-2 polymorphism with or without H pylori could be a marker for genetic susceptibility to gastric adenocarcinoma. COX-2 polymorphism in presence of H pylori infection might be useful in predicting the risk of PUD.