Outcome
    Moderate Evidence

    Selenium for Tumor Response Rate

    Selenium supplementation has not prevented or treated cancer and raised diabetes risk in trials.

    Overview

    Selenium supplementation has not prevented or treated cancer and raised diabetes risk in trials.

    Verdict

    Not supported

    How It Works

    Selenoprotein antioxidant activity proposed to limit DNA damage.

    Dosing & Protocol

    Typical dose

    Recommended dose
    Not recommended
    Expected timeframe
    n/a

    Protocol

    form
    Not applicable
    duration
    Not applicable
    co factor
    Evidence indicates no benefit. Selenium compounds show antitumour activity in cell culture and animal models, inducing apoptosis and inhibiting angiogenesis, which generated substantial interest. Human results have been negative or harmful: the SELECT trial in over 35,000 men found no reduction in prostate cancer and was stopped early for futility, with increased diabetes risk, and subsequent analysis found that in men with high baseline selenium, supplementation increased high-grade prostate cancer risk by around 90%. No randomised trial has shown improved tumour response rate, progression-free survival or overall survival with selenium in any cancer.
    titration
    Not applicable
    starting dose
    Not recommended. Cancer prevention trials used 200 mcg/day; no dose has improved tumour response

    Evidence

    What the studies say

    The SELECT trial found no prostate cancer prevention and a signal for increased type 2 diabetes. No evidence supports any effect on tumour response.

    Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT)

    Score: 9/10
    2011
    rct
    n=35533

    Klein EA, et al

    Selenium supplementation showed no benefit on prostate cancer risk compared with placebo.

    View source

    Selenium and Vitamin E Cancer Prevention Trial (SELECT): null and adverse findings

    Score: 10/10
    2011
    rct
    n=35533

    Klein EA, Thompson IM, Tangen CM +18 more

    Selenium provided no protective benefit against prostate cancer

    View source

    Safety

    Caveats

    Toxicity above 400mcg/day. Avoid supplementing beyond dietary adequacy.

    Less likely to help if

    Everyone - no benefit exists and supplements may interfere with cancer treatment.

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    Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.