Authors: Wright ME, Virtamo J, Hartman AM, Pietinen P, Edwards BK, Taylor PR, Huttunen JK, Albanes D
Title: Effects of alpha-tocopherol and beta-carotene supplementation on upper aerodigestive tract cancers in a large, randomized controlled trial.
Journal: Cancer 109(5):891-8
Date: 2007 Mar 01
Abstract: BACKGROUND: Although smoking and alcohol consumption are the major risk factors for upper aerodigestive tract cancers, observational studies indicate a protective role for fruits, vegetables, and antioxidant nutrients. METHODS: The authors examined whether daily supplementation with 50 mg dl alpha-tocopheryl acetate and/or 20 mg beta-carotene reduced the incidence of or mortality from oral/pharyngeal, esophageal, and laryngeal cancers in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) study, a double-blind, placebo-controlled primary prevention trial conducted in southwestern Finland. A total of 29,133 male smokers, aged 50-69 years and free of cancer at baseline, were randomized in a 2 x 2 factorial design to the supplementation regimen for 5-8 years (median, 6.1 years). Incident cancers of the oral cavity and pharynx (n = 65), esophagus (n = 24), and larynx (n = 56) were identified through the Finnish Cancer Registry. Intervention effects were assessed using survival analysis and proportional hazards models. RESULTS: There was no effect of either agent on the overall incidence of any upper aerodigestive tract cancer. For larynx, however, exploratory subgroup analyses were suggestive of a protective effect of beta-carotene supplementation on the incidence of early stage malignancies (stage I, relative risk [RR], 0.28, 95% confidence interval [CI]: 0.10-0.75). Neither agent affected mortality from these neoplasms. CONCLUSIONS: The results do not provide support for a protective effect of vitamin E or beta-carotene supplementation on upper aerodigestive tract cancers, although beta-carotene supplementation may impact the incidence of some subtypes of laryngeal tumors.