Effects of [alpha]-tocopherol and [beta]-carotene supplementation on cancer incidence and mortality: 18-Year postintervention follow-up of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study

• Published in: International journal of cancer 2014-07, Vol.135 (1), p.178-185
• Main Authors: Virtamo, Jarmo, Taylor, Phil R, Kontto, Jukka, Mannisto, Satu, Utriainen, Meri, Weinstein, Stephanie J, Huttunen, Jussi, Albanes, Demetrius
• Format: Article
• Language: English
• Subjects: Cancer; Dietary supplements; Lung cancer; Medical research; Prostate cancer
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.28641

In the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study among 29,133 Finnish male smokers aged 50-69 years, daily [alpha]-tocopherol (50 mg) for a median of 6.1 years decreased the risk of prostate cancer, whereas [beta]-carotene (20 mg) increased risk of lung cancer and overall mortality. To determine the postintervention effects of [alpha]-tocopherol and [beta]-carotene, 25,563 men were followed 18 years for cancer incidence and all causes of mortality through national registers. Neither supplement had significant effects on post-trial cancer incidence. Relative risk (RR) for lung cancer (n=2,881) was 1.04 (95% confidence interval [CI], 0.96-1.11) among [beta]-carotene recipients compared with nonrecipients. For prostate cancer (n=2,321), RR was 0.97 (95% CI, 0.89-1.05) among [alpha]-tocopherol recipients compared with nonrecipients with the preventive effect of [alpha]-tocopherol continuing 8 years postintervention. Body mass index significantly modified the effect of [alpha]-tocopherol on prostate cancer (p for interaction=0.01) RR 1.00 (95% CI, 0.88-1.14) in normal-weight men, 0.87 (95% CI, 0.77-0.98) in overweight men, and 1.25 (95% CI, 1.01-1.55) in obese men. The post-trial relative mortality (based on 16,686 deaths) was 1.02 (95% CI, 0.98-1.05) for [alpha]-tocopherol recipients compared with nonrecipients and 1.02 (95% CI, 0.99-1.05) for [beta]-carotene recipients compared with nonrecipients. [alpha]-Tocopherol decreased post-trial prostate cancer mortality (RR, 0.84; 95% CI, 0.70-0.99), whereas [beta]-carotene increased it (RR, 1.20; 95% CI, 1.01-1.42). In conclusion, supplementation with [alpha]-tocopherol and [beta]-carotene appeared to have no late effects on cancer incidence. The preventive effect of moderate-dose [alpha]-tocopherol on prostate cancer continued several years post-trial and resulted in lower prostate cancer mortality. What's new? The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, begun in the mid-1980s, found that daily [alpha]-tocopherol supplementation decreased the risk of prostate cancer, whereas [beta]-carotene increased the risk of lung cancer in Finnish male smokers. In the present study, a post-trial follow-up, neither [alpha]-tocopherol nor [beta]-carotene were found to have significant effects on cancer incidence. The reduced risk of prostate cancer lasted about 8 years post-trial and was accompanied by decreased 18-year post-trial mortality from prostate cancer. BMI may modify the effect of [