Association of the myeloperoxidase polymorphism with the risk of gastric cancer.

BACKGROUND

The myeloperoxidase in neutrophils manufactures many bactericidal oxidants. The aim of this study was to clarify the relations between the myeloperoxidase polymorphism and gastric cancer development.

PATIENTS AND METHODS

In a case control study of 157 consecutive gastric cancer patients and 192 controls, the myeloperoxidase -463G-->A polymorphism was genotyped. Additionally, gastric mucosal changes were examined according to the updated Sydney System.

RESULTS

The carriage of myeloperoxidase allele A, male gender, advanced age, high intake of salty food and Helicobacter pylori infection independently increased the risk of gastric cancer [95% confidence interval (CI): 1.5-5.0, 1.7-6.5, 2.6-8.6, 1.1-2.6 and 1.2-3.8, respectively]. H. pylori-infected individuals who were carriers of myeloperoxidase allele A had increased risks of both intestinal and diffuse types of gastric cancer with odds ratios of 7.9 (95% CI 2.6-23.5) and 8.6 (95% CI 2.0-36.7), respectively. In the H. pylori-infected individuals, allele A carriers displayed higher scores of bacterial density (p=0.02) and neutrophil infiltration (p=0.05) in the antrum and higher scores of neutrophil infiltration (p=0.02) and gland atrophy (p=0.03) in the corpus than did non-carriers.

CONCLUSION

This study verifies the association of myeloperoxidase -463G-->A polymorphism with gastric cancer. The mechanisms underlying this genetic polymorphism in developing gastric cancer merit further investigations.