title: Passive cigarette smoke exposure during various periods of life, genetic variants, and breast cancer risk among never smokers.
abstract: The association between passive cigarette smoke exposure and breast cancer risk is inconclusive and may be modified by genotype. The authors investigated lifetime passive cigarette smoke exposures, 36 variants in 12 carcinogen-metabolizing genes, and breast cancer risk among Ontario, Canada, women who had never smoked (2003-2004). DNA (saliva) was available for 920 breast cancer cases and 960 controls. Detailed information about passive smoke exposure was collected for multiple age periods (childhood, teenage years, and adulthood) and environments (home, work, and social). Adjusted odds ratios and 95% confidence intervals were estimated by multivariable logistic regression, and statistical interactions were assessed using the likelihood ratio test. Among postmenopausal women, most associations between passive smoke and breast cancer risk were null, whereas among premenopausal women, nonsignificant positive associations were observed. Significant interactions were observed between certain types of passive smoke exposure and genetic variants in CYP2E1, NAT2, and UGT1A7. While these interactions were statistically significant, the magnitudes of the effect estimates were not consistent or easily interpretable, suggesting that they were perhaps due to chance. Although the results of this study were largely null, it is possible that premenopausal women exposed to passive smoke or carrying certain genetic variants may be at higher risk of breast cancer.
authors.affiliation: Department of Prevention and Cancer Control, Cancer Care Ontario, Toronto, Ontario, Canada. ln.anderson@utoronto.ca
authors.forename: Laura N
authors.initials: LN
authors.lastname: Anderson
authors.forename: Michelle
authors.initials: M
authors.lastname: Cotterchio
authors.forename: Lucia
authors.initials: L
authors.lastname: Mirea
authors.forename: Hilmi
authors.initials: H
authors.lastname: Ozcelik
authors.forename: Nancy
authors.initials: N
authors.lastname: Kreiger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001191:Arylamine N-Acetyltransferase / Q000235:genetics; D001943:Breast Neoplasms / Q000209:etiology* / Q000235:genetics; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D005838:Genotype; D060005:Genotyping Techniques; D014453:Glucuronosyltransferase / Q000235:genetics; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D016017:Odds Ratio; D009864:Ontario; D020641:Polymorphism, Single Nucleotide; D017698:Postmenopause; D017697:Premenopause; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects* / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D005819:Genetic Markers; D014028:Tobacco Smoke Pollution; D019392:Cytochrome P-450 CYP2E1; D001191:Arylamine N-Acetyltransferase; C478900:NAT2 protein, human; D014453:Glucuronosyltransferase; C524630:UGT1A7 protein, human