title: Counterpoint: the myeloperoxidase -463G-->a polymorphism does not decrease lung cancer susceptibility in Caucasians.
abstract: The myeloperoxidase (MPO) G-to-A substitution polymorphism in the promoter region of the MPO gene has been associated with a 40-70% reduction in lung cancer risk in several studies, although a recent nested case-control study disputes these findings. MPO is involved in the activation of a number of procarcinogens, including benzo(a)pyrene. The variant A allele has been shown to reduce MPO mRNA expression, thus potentially decreasing carcinogen activation. To confirm results from smaller studies, we evaluated this MPO polymorphism in 988 incident Caucasian lung cancer cases and 1128 controls. Logistic regression evaluated the association between MPO genotype and lung cancer risk, adjusting for age, gender, smoking status, time since quitting smoking, and pack-years of smoking. In the controls, the A allele frequency was 21%, and genotype distribution was in the Hardy-Weinberg equilibrium. Compared with the wild-type G/G genotype, the adjusted odds ratios for the A/A and A/G genotypes were 1.15 (95% confidence interval 0.7-1.9, P > 0.2) and 1.03 (95% confidence interval 0.8-1.3, P > 0.20), respectively. A similar lack of association was seen in analyses stratified by smoking status, median age, a number of smoking variables, disease stage, tumor grade, and histological subtype. These findings are in contrast with earlier studies suggesting a protective effect of carrying the variant A allele.
authors.affiliation: Occupational Health Program, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts 02115, USA.
authors.forename: Li-Lian
authors.initials: LL
authors.lastname: Xu
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Liu
authors.forename: David P
authors.initials: DP
authors.lastname: Miller
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Lynch
authors.forename: John C
authors.initials: JC
authors.lastname: Wain
authors.forename: Li
authors.initials: L
authors.lastname: Su
authors.forename: David C
authors.initials: DC
authors.lastname: Christiani
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D016022:Case-Control Studies; D015331:Cohort Studies; D016001:Confidence Intervals; D004198:Disease Susceptibility; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009195:Peroxidase / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D011336:Probability; D011379:Prognosis; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D012016:Reference Values; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D015996:Survival Rate; D044465:White People / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D009195:Peroxidase