Associations between Plasma Tocopherols and Lung Cancer Risk: Results from the Southern Community Cohort Study
Menée à partir de données portant sur 209 patients atteints d'un cancer du poumon et sur 406 témoins, cette étude analyse l'association entre le niveau plasmatique des tocophérols (vitamine E) et le risque de développer la maladie en fonction de l'origine ethnique
Background: Despite the various anticancer activities of tocopherols, little is known about tocopherols associated with lung cancer risk among low-income African Americans (AA) and European Americans (EA) who are disproportionately affected by the disease. Methods: We conducted a nested case–control study that included 209 incident lung cancer cases and 406 matched controls within the Southern Community Cohort Study. Using biospecimens collected at cohort enrollment, plasma levels of
α-, β/γ-, δ-, and total-tocopherols were measured by high-performance liquid chromatography with photodiode array detection. Conditional logistic regression was used to estimate ORs and 95% confidence intervals (CI) for lung cancer risk after adjusting for potential confounders. Stratified analyses were also conducted. Results:
Plasma levels of total-tocopherols were inversely associated with lung cancer risk overall [OR (95% CI) for the highest vs. lowest tertile = 0.51 (0.30
–0.90)]. The inverse association remained significant among EAs [0.20 (0.06–0.65)], men [0.43 (0.21–0.90)], current smokers [0.49 (0.26–0.93)], and cases diagnosed within 2 years of blood draw [0.36 (0.15–0.86)], though we did not find a significant risk reduction among AAs [0.75 (0.39–1.45)]. Notably, we found significant interactions between
α-tocopherol and race after controlling the FDR to correct for multiple comparisons (Pinteraction = 0.02). Conclusions:
Our results indicate that plasma total-tocopherols are inversely associated with lung cancer risk, but the association may differ across specific isomeric forms of tocopherols, race, or other individuals’ characteristics. Further large-scale studies are warranted to confirm our findings. Impact:
Recommendations on tocopherols for lung cancer prevention should take isomers, race, and smoking behaviors into consideration.