-765 g>c polymorphism of the cox-2 gene and gastric cancer risk in Brazilian population.

Context: Genomic alterations play important roles in gastric cancer carcinogenesis. Cyclooxygenases (COX) are important enzymes in the maintenance of mucosal integrity and in pathological processes, mainly in inflammation and cancer. The -765G>C COX-2 polymorphism has been implicated in gastric cancer risk.

Objectives: To evaluate the COX-2 gene polymorphism as a predictor of gastric cancer risk.

Methods: One hundred gastric cancer patients and 150 controls were enrolled from a Brazilian centre. Personal data regarding related risk factors, including alcohol consumption and smoking behavior, were collected via questionnaire. DNA was extracted from peripheral blood and the genotypes were analyzed using PCR-restriction fragment length polymorphism.

Results: G/G, G/C and C/C genotypes frequencies was 42.7%, 50% and 7.3%, respectively in controls and 59.0%, 34.0% and 7.0% in gastric cancer. The frequency of the genotypes differed between the groups (P = 0.033). A higher risk of gastric cancer was associated with COX-2 -765G/G genotype (P = 0.048; OR:1.98, 95% CI = 1.01-3.90). Alcohol consumption and smoking in patients with -765G/G genotype also increased the risk of gastric cancer.

Conclusions: The -765G/G genotype and the -765G allele had been associated with an increased risk for gastric cancer. The presence of smoking and alcohol consumption increased the risk for gastric cancer in subjects with -765G/G genotype compared with the control group. Polymorphism of COX-2 gene and gastric cancer risk.