Serum alpha-tocopherol and subsequent risk of lung cancer among male smokers.
BACKGROUND
Higher blood levels of alpha-tocopherol, the predominant form of vitamin E, have been associated in some studies with a reduced risk of lung cancer, but other studies have yielded conflicting results. To clarify this association, we examined the relationship between prospectively collected serum alpha-tocopherol and lung cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study cohort.


METHODS
The ATBC Study was a randomized, clinical trial of 29 133 white male smokers from Finland who were 50-69 years old and who had received alpha-tocopherol (50 mg), beta-carotene (20 mg), both, or neither daily for 5-8 years. Data regarding medical histories, smoking, and dietary factors were obtained at study entry, as was a serum specimen for baseline alpha-tocopherol determination. alpha-Tocopherol measurements were available for 29 102 of the men, among whom 1144 incident cases of lung cancer were diagnosed during a median observation period of 7.7 years. The association between alpha-tocopherol and lung cancer was evaluated with the use of multivariate proportional hazards regression.


RESULTS
A 19% reduction in lung cancer incidence was observed in the highest versus lowest quintile of serum alpha-tocopherol (relative risk = 0.81; 95% confidence interval = 0. 67-0.97). There was a stronger inverse association among younger men (<60 years), among men with less cumulative tobacco exposure (<40 years of smoking), and possibly among men receiving alpha-tocopherol supplementation.


CONCLUSIONS
In the ATBC Study cohort, higher serum alpha-tocopherol status is associated with lower lung cancer risk; this relationship appears stronger among younger persons and among those with less cumulative smoke exposure. These findings suggest that high levels of alpha-tocopherol, if present during the early critical stages of tumorigenesis, may inhibit lung cancer development.
Woodson
K
K
Cancer Prevention Studies Branch, Division of Clinical Sciences, National Cancer Institute, Bethesda, MD, USA.
Tangrea
J A
JA
Barrett
M J
MJ
Virtamo
J
J
Taylor
P R
PR
Albanes
D
D
D000230:Adenocarcinoma / Q000097:blood / Q000209:etiology; D000368:Aged; D002277:Carcinoma / Q000097:blood* / Q000453:epidemiology / Q000209:etiology*; D018288:Carcinoma, Small Cell / Q000097:blood / Q000209:etiology; D002294:Carcinoma, Squamous Cell / Q000097:blood / Q000209:etiology; D019587:Dietary Supplements; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D016896:Treatment Outcome; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood*; D019207:beta Carotene / Q000008:administration & dosage / Q000097:blood*
D019207:beta Carotene; D014810:Vitamin E