The Alpha-Tocopherol Beta-Carotene Cancer Prevention (ATBC) Study was a large randomized, double-blind, placebo-controlled, 2x2 factorial design, primary prevention trial testing the effects of alpha-tocopherol and beta-carotene supplements on cancer incidence and mortality conducted in Finland as a collaboration between the Public Health Institute (KTL) of Finland and the U.S. National Cancer Institute. The intervention period ended in 1993, and the research project was continued as a passive follow-up of participants during the post-intervention period to monitor potential intervention effects on cancers, as well as other morbidity and mortality endpoints. The cohort follow-up serves as a basis for cancer epidemiological research of a wide range of cancer risk factors, biomarkers, and genetic predisposition based on data and biologic samples collected during the study. This research is aimed at testing hypotheses relevant to cancer prevention, etiology, and early detection, and the study material provide an invaluable resource for the study of dietary, biochemical and molecular hypotheses. The analyses are made particularly informative in that nearly 20 years of follow-up are available for study.
The ATBC study was a randomized, double-blind, placebo-controlled, primary prevention trial to determine whether daily supplementation with a-tocopherol, (SqrRoot) -carotene, or both would reduce the incidence of lung or other cancers among male smokers. Between 1985 and 1988, 29,133 men ages 50 to 69 years, who smoked at least five cigarettes per day, were recruited from southwestern Finland. Participants were randomly assigned to receive either a-tocopherol as dl-a-tocopheryl acetate (50 mg/day), (SqrRoot) -carotene as all-trans-(SqrRoot) -carotene (20 mg/day), both supplements, or placebo capsules for 5-8 years (median 6.1 years) through April 30, 1993. Post-intervention follow-up has continued through the Finnish Cancer Registry and other national registries, and epidemiological analyses continue to be conducted.