Abstract
BACKGROUND:
Epidemiologic data are inconsistent regarding the vitamin E-lung cancer association, and no study has examined serologic changes in vitamin E status in relation to subsequent risk.
METHODS:
In a cohort of 22,781 male smokers in the ATBC Study, we ascertained 3,184 lung cancer cases during up to 28 years of observation. Cox proportional hazards models examined whether higher serum alpha-tocopherol concentrations at baseline, 3 years, or the interval change were associated with lower lung cancer risk. All statistical tests were two-sided.
RESULTS:
After adjustment for age, body mass index, smoking intensity and duration, serum total cholesterol, and trial intervention group, we found lower lung cancer risk in men with high baseline alpha-tocopherol (5th quintile (Q5) vs Q1, hazard ratio (HR)=0.76, 95%CI =0.66 to 0.87; Ptrend<0.001). A similar reduction in risk was seen for serum alpha-tocopherol at 3 years (Q5 vs Q1, HR = 0.78, 95%CI =0.67 to 0.91; Ptrend=0.004). The inverse risk association appeared stronger for younger men and those having smoked fewer years, but was similar across trial intervention groups. We also found reduced risk among un-supplemented men with a lower serum alpha-tocopherol at baseline who had greater increases in concentrations at 3 years (3rd tertile vs 1st tertile of serum alpha-tocopherol change, HR = 0.74, 95% CI = 0.59 to 0.91, P=0.005).
CONCLUSION:
Higher vitamin E status, as measured by serum alpha-tocopherol concentration, as well as repletion of a low vitamin E state, was related to decreased lung cancer risk during a 28-year period. Our findings provide evidence supporting the importance of adequate physiological vitamin E status for lung cancer risk reduction.