Influence of antioxidants and the CYP1A1 isoleucine to valine polymorphismon the Smoking Lung Cancer Association

To evaluate the association between CYP1A1 genotype and king cancer risk an d to assess the effect of CYP1A1 genotype and antioxidant supplementation o n the smoking - lung cancer relationship we conducted a case-control study nested within a large cancel prevention trial cohort. Controls (n=324) were matched to cases (n=282) on age (+/- 5 years), intervention group and stud y clinic in a 1:1 ratio using incidence density sampling. Genotype was dete rmined by a PCR-based method and logistic regression was used to calculate relative risk estimates. Overall, we found no association between CYP1A1 ge notype and lung cancer risk. CYP1A1 genotype did not modify the effect of s moking on lung cancel risk. However; in an examination of subgroups defined by randomized intervention assignment our findings suggest that alpha-toco pherol supplementation may reduce the risk of lung cancer associated with c umulative smoking exposure regardless of CYP1A1 genotype with the greatest effect seen among those with the variant CYP1A1 allele.