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Lippman, S. M. et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA 301, 39-51

Division of Cancer Medicine, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA.
JAMA The Journal of the American Medical Association (Impact Factor: 30.39). 01/2009; 301(1):39-51. DOI: 10.1001/jama.2008.864
Source: PubMed

ABSTRACT Secondary analyses of 2 randomized controlled trials and supportive epidemiologic and preclinical data indicated the potential of selenium and vitamin E for preventing prostate cancer.
To determine whether selenium, vitamin E, or both could prevent prostate cancer and other diseases with little or no toxicity in relatively healthy men.
A randomized, placebo-controlled trial (Selenium and Vitamin E Cancer Prevention Trial [SELECT]) of 35,533 men from 427 participating sites in the United States, Canada, and Puerto Rico randomly assigned to 4 groups (selenium, vitamin E, selenium + vitamin E, and placebo) in a double-blind fashion between August 22, 2001, and June 24, 2004. Baseline eligibility included age 50 years or older (African American men) or 55 years or older (all other men), a serum prostate-specific antigen level of 4 ng/mL or less, and a digital rectal examination not suspicious for prostate cancer.
Oral selenium (200 microg/d from L-selenomethionine) and matched vitamin E placebo, vitamin E (400 IU/d of all rac-alpha-tocopheryl acetate) and matched selenium placebo, selenium + vitamin E, or placebo + placebo for a planned follow-up of minimum of 7 years and a maximum of 12 years.
Prostate cancer and prespecified secondary outcomes, including lung, colorectal, and overall primary cancer.
As of October 23, 2008, median overall follow-up was 5.46 years (range, 4.17-7.33 years). Hazard ratios (99% confidence intervals [CIs]) for prostate cancer were 1.13 (99% CI, 0.95-1.35; n = 473) for vitamin E, 1.04 (99% CI, 0.87-1.24; n = 432) for selenium, and 1.05 (99% CI, 0.88-1.25; n = 437) for selenium + vitamin E vs 1.00 (n = 416) for placebo. There were no significant differences (all P>.15) in any other prespecified cancer end points. There were statistically nonsignificant increased risks of prostate cancer in the vitamin E group (P = .06) and type 2 diabetes mellitus in the selenium group (relative risk, 1.07; 99% CI, 0.94-1.22; P = .16) but not in the selenium + vitamin E group.
Selenium or vitamin E, alone or in combination at the doses and formulations used, did not prevent prostate cancer in this population of relatively healthy men.
clinicaltrials.gov identifier: NCT00006392.

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    • "In general, there have been disappointing findings from several costly clinical trials of antioxidant supplements showing not only no health benefits but potential harms. The Selenium and Vitamin E Cancer Prevention Trial (SELECT), conducted among 35,533 North American men aged 50 and older, was prematurely stopped because of lack of efficacy of vitamin E and Se supplementation (200 mg/d) in cancer prevention and because of a small, though non-statistically significant increase in the number of cases of adult onset diabetes in participants taking only Se [41] [42]. Thus, for ethical reasons it would be difficult to justify the initiation of additional RCTs of micronutrient supplements; moreover, it is highly unlikely that adequately powered trials of Se and cardiovascular outcomes will be initiated in the near future. "
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    • "A francia EVA prospektív tanulmányban [11] több mint kilenc évig tartó követés során sem találtak pozitív korrelációt a diabétesz kialakulása és a magasabb szérumszelénszint között. A SELECT vizsgálat – több mint 35 ezer beteg bevonásával – is hasonló eredményeket hozott [12], amiben a 2-es típusú diabétesz incidenciája csak másodlagos végpont volt. Ezzel szemben egy amerikai vizsgálatban emelkedett diabéteszkockázatot találtak szelénszupplementációban részesülő betegeknél [13]. "
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    • "These effects may be associated with the production of reactive oxygen species generated in the oxidation–reduction cycle (Jackson and Combs 2008). Other studies showed no effects of selenium supplementation (200 lg/d) on the prevention of prostate cancer in a population of relatively healthy men from the US, Canada, and Puerto Rico (Lippman et al. 2009). The association between the concentration/activity of selenium/selenoproteins in plasma and diabetes mellitus is still a matter of debate. "
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