Richard M. Hoffman, MD, MPH
In middle-aged and older men, does supplementation with vitamin E or vitamin C decrease risk for prostate and total cancer?
Randomized, 2 x 2 factorial, placebo-controlled trial (Physicians’ Health Study [PHS] II). ClinicalTrials.gov NCT00270647.
Blinded (participants, clinicians, data collectors, and outcome assessors).*
Mean 8 years.
14 641 male physicians ≥50 years of age (mean age 64 y), about half of whom had participated in the PHS I trial of beta carotene and aspirin. Men with active liver disease, serious illness, or history of cirrhosis (but not those with history of cancer or cardiovascular disease) or who were taking anticoagulant drugs were excluded.
Vitamin E, 400 IU every other day, plus placebo for vitamin C (n = 3659); vitamin C, 500 mg/d, plus placebo for vitamin E (n = 3673); vitamin E plus vitamin C (n = 3656); or double placebo (n = 3653). Participants were also randomized in factorial fashion to beta carotene and multivitamins or corresponding placebos.
Primary outcome was prostate cancer for vitamin E and total cancer for vitamin C. Secondary outcomes included lung and colorectal cancer, and all-cause and cancer mortality. The trial had ≥80% power to detect a 13% relative reduction in total cancer and a 19% reduction in prostate cancer (2-sided α = 0.05).
95% (intention-to-treat analysis).
Adherence to study medications was 78% at 4 years and 71% at end of follow-up. The vitamin E and vitamin C groups did not differ from the corresponding placebo groups for prostate cancer, total cancer (Table), or any secondary outcome.
In middle-aged and older men, supplementation with vitamin E or vitamin C did not decrease risk for prostate or total cancer.
Vitamin E or vitamin C vs placebo to prevent cancer in men†
†Abbreviations defined in Glossary. RRR, RRI, and CI calculated from hazard ratios in article, adjusted for age, cohort, and random assignment to other drugs and stratified for cancer at baseline.
‡Includes only men without prostate cancer at baseline (n = 13 983).
Hoffman RM. Vitamin E and vitamin C, alone or together, did not prevent prostate or total cancer in men. Ann Intern Med. 2009;150:JC3–11. doi: 10.7326/0003-4819-150-6-200903170-02011
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Published: Ann Intern Med. 2009;150(6):JC3-11.
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