The Myeloperoxidase-463 G>A Polymorphism Influences Risk of Colorectal Cancer in Southern China: a Case-control Study

Objective: Oxidative stress may be involved in colorectal carcinogenesis. Myeloperoxidase (MPO) is an endogenous oxidant enzyme that generates reactive oxygen species (ROS). We hypothesized that the MPO-463 locus polymorphism might therefore contribute to genetic susceptibility to colorectal adenomas. Methods: RFLP-PCR analysis identified the MPO genotypes in 325 Chinese colorectal adenomas cases and 345 controls matched by age, sex, smoking status, and alcohol use. An epidemiological interview elicited detailed information on demographic data and lifestyle characteristics. Results: Individuals with a GA/AA genotype had a significantly lower risk of colorectal cancer (adjusted OR = 0.57, 95% CI, 0.41-0.79) than those with the GG genotype. On stratification analysis, the decreased risk was more pronounced among older subjects (adjusted OR = 0.56, 95% CI, 0.39-0.81), males (0.47, 0.33-0.68), smokers (0.54, 0.35-0.85), and ever-drinkers (0.44, 0.27-0.71). Conclusion: For a similar level of exposure to established carcinogens, individuals with MPO A-allele genotypes appear to have a reduced risk of colorectal adenomas in southern Chinese population, especially among older subjects, men, smokers, and ever-drinkers.