Vitamin E supplementation increased risk for prostate cancer in healthy men at a median of 7 years

摘要

QuestionWhat are the long-term effects of vitamin E and selenium, alone or combined, for prevention of prostate cancer in healthy men?MethodsDesign: Randomized, placebo-controlled, 2x2 factorial trial (Selenium and Vitamin E Cancer Prevention Trial [SELECT]). ClinicalTrials.gov NCT00006392.Allocation: {Concealed}Blinding: Blinded {participants, data collectors, and outcome assessors}* until primary analysis (median 5.5 y); unblinded for additional follow-up to 7 years after randomization of last patient, Follow-up period: 7 to 12 years (median 7 y)Setting: 427 study sites in the USA, Canada, and Puerto Rico.Participants: 35 533 healthy men {median age 62 y}* at average risk for prostate cancer (baseline prostate-specific antigen level < 4 ng/mL and normal digital rectal examination beginning at 50 y of age for black men or 55 y of age for all others).