Although smoking is the primary risk factor for
lung cancer, there is evidence to suggest that fruit and vegetable intake are important cofactors. The present case-control study, nested within the Multiethnic Cohort Study, examined the associations of
biomarkers of fruit and vegetable intake (individual plasma
micronutrient levels), serum
selenium, and a urinary
biomarker for total lipid peroxidation with
lung cancer risk. Two hundred seven incident cases were matched to 414 controls on age, sex, ethnicity, study location (Hawaii or California), smoking status, date/time of collection, and hours of fasting. We measured prediagnositic circulating levels of individual
tocopherols and
carotenoids,
retinol, and serum
selenium, and urinary 15-isoprostane F(2t). Conditional logistic regression was used to compute odds ratios (OR) and 95% confidence intervals (CI). For men, strong reductions in risk were seen with increasing tertiles of each plasma
carotenoid, with the
ORs for the third tertile, compared with the first tertile, ranging from 0.24 to 0.45 (P(trends), 0.002-0.04). No associations were found among women for
carotenoids or among either sex for
tocopherols,
selenium, and
retinol. A doubling in risk was seen for men in the second and third tertiles, compared with the first tertile of urinary 15-isoprostane F(2t) (OR, 2.31; 95% CI, 1.02-5.25; and OR, 2.16; 95% CI, 0.98-4.78). This study supports the previously observed association between circulating
carotenoids and
lung cancer risk in men, and adds to the limited literature regarding urinary 15-isoprostane F(2t) as a marker of
cancer risk. Future research examining the possible relationship between
isoprostanes and
lung cancer is warranted.