Interactive effects of exposures to tobacco smoke and cooking fume and genetic polymorphisms of DNA repair enzymes on female lung adenocarcinoma in northern Taiwan

Objectives: This case-control study was carried out to investigate the association of female lung adenocarcinoma with environmental risk factors and genetic polymorphisms of DNA repair enzymes, and to assess the effect of gene-environment interaction on the disease. Methods: A total of 107 female patients affected with lung adenocarcinoma and 263 healthy controls were recruited serially from National Taiwan University Hospital. History of exposures to environmental risk factors was obtained through personal interview using on a structured questionnaire. Genetic polymorphisms of DNA repair enzymes were determined by polymerase chain reaction with restriction fragment length polymorphism. Results: After adjustment for age and schooling years, the odds ratio of developing adenocarcinoma was 1.73 for exposures to tobacco smoking, 2.42 for exposures to cooking fume in unventilated kitchen, 2.70 for using coal and charcoal as cooking fuel, and 2.88 for using lard as cooking oil. The multivariate-adjusted odds ratio of developing lung adenocarcinoma was 2.31 (95% CI: 1.12-4.76) for XRCC1 Gln/Gln genotype compared with Arg/Arg or Arg/Gln genotypes, 2.08 (95%CI: 0.99-7.81) for XRCC3 Thr/Met genotype compared with Thr/Thr genotype, 2.70 (95%CI: 1.51-4.82) for XPD Lys/Gln or Gln/Gln genotypes compared with Lys/Lys genotype, and 3.69 (95%CI: 1.42-9.62) for hMLH1 GA or AA genotypes compared with GG genotype. Conclusions: Exposures to tobacco smoking, and cooking fumes were important environmental risk factors for female lung adenocarcinoma. The genetic polymorphisms of DNA repair enzymes including XRCC1, XRCC3, XPD and hMLH1 were associated with an increased risk of the disease.