Cruciferous vegetable intake and lung cancer risk: a nested case-control study matched on cigarette smoking.

BACKGROUND: Due predominantly to cigarette smoking, lung cancer is the leading cancer-related cause of death worldwide. Cruciferous vegetables may reduce lung cancer risk. The association between intake of cruciferous vegetables and lung cancer risk was investigated in the CLUE II study, a community-based cohort established in 1989.
METHODS: We matched 274 incident cases of lung cancer diagnosed from 1990 to 2005 to 1,089 cancer-free controls on age, sex, and cigarette smoking. Dietary information was collected at baseline. Multivariable odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using conditional logistic regression.
RESULTS: Intake of cruciferous vegetables was inversely associated with lung cancer risk (highest-versus-lowest fourth: OR (Q4vsQ1), 0. 57; 95% CI, 0.38-0.85; P-trend = 0.01). The inverse associations held true for former smokers (OR(Q4vsQ1), 0.49; 95% CI, 0.27-0.92; P-trend = 0.05) and current smokers (OR(Q4vsQ1), 0.52; 95% CI, 0.29-0.95; P-trend = 0.02).
CONCLUSIONS: After carefully controlling for cigarette smoking, higher intake of cruciferous vegetable was associated with lower risk of lung cancer. IMPACT: The observed inverse association coupled with accumulating evidence suggests that intake of cruciferous vegetables is inversely associated with lung cancer risk, and this association seems to hold true beyond the confounding effects of cigarette smoking. ©2010 AACR.