Myeloperoxidase-463 (G→A) polymorphism associated with lower risk of lung cancer

Objective: To study the association of the myeloperoxidase (MPO) -463 (G-->A) polymorphism with lung cancer risk. Patients and Methods: We performed a paired case-control analysis of 307 patients with primary lung cancer and an equal number of age-, sex-, and ethnicity-matched controls to evaluate the effect of the MPO -463 (G-->A) polymorphism on disease susceptibility. We also performed conditional logistic regression analyses to evaluate the effect of the polymorphism adjusted for smoking status and chronic obstructive pulmonary disease, 2 established risk factors. We used 2 models for these analyses: one to compare homozygous (AA) genotypes with wild type (GG) and heterozygous (GA) genotypes and one to compare carriers (heterozygotes and AA homozygotes) with GG genotypes. Finally, we combined the results from the published studies of this putative association and performed a stratified analysis. Results: The AA genotype was inversely associated with susceptibility to lung cancer (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.15-1.00). There was no association in heterozygotes. However, in the stratified analysis, we found an association between patients with the AA (OR, 0.44; 95% CI, 0.27-0.68) and GA (OR, 0.77; 95% CI, 0.64-0.93) genotypes vs the GG genotype. Conclusion: Our results are consistent with previous reports and show that homozygotes of the less common A allele of MPO -463 polymorphism have a 2.6-fold lower risk of lung cancer.