A Nutrient Approach to Prostate Cancer Prevention: The Selenium and Vitamin E Cancer Prevention Trial (SELECT)
Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland 20892, USA. Nutrition and Cancer
(Impact Factor: 2.32).
10/2010; 62(7):896-918. DOI: 10.1080/01635581.2010.509833
The Selenium and Vitamin E Cancer Prevention Trial (SELECT) randomized 35,533 healthy men, >55 yr old (>50 yr if African American), with normal digital rectal exams and prostate specific antigens <4 ng/ml to 1) 200 μg/day l-selenomethionine, 2) 400 IU/day all-rac-alpha-tocopheryl acetate (vitamin E), 3) both supplements, or 4) placebo for 7 to 12 yr. The hypotheses underlying SELECT, that selenium and vitamin E individually and together decrease prostate cancer incidence, derived from epidemiologic and laboratory evidence and significant secondary endpoints in the Nutritional Prevention of Cancer (selenium) and Alpha-Tocopherol Beta-Carotene (vitamin E) trials. In SELECT, prostate cancer incidence did not differ among the 4 arms: hazard ratios [99% confidence intervals (CIs)] for prostate cancer were 1.13 (99% CI = 0.95-1.35, P = 0.06; n = 473) for vitamin E, 1.04 (99% CI = 0.87-1.24, P = 0.62; n = 432) for selenium, and 1.05 (99% CI = 0.88-1.25, P = 0.52; n = 437) for selenium + vitamin E vs. 1.00 (n = 416) for placebo. Statistically nonsignificant increased risks of prostate cancer with vitamin E alone [relative risk (RR) = 1.13, P = 0.06) and newly diagnosed Type 2 diabetes mellitus with selenium alone (RR = 1.07, P = 0.16) were observed. SELECT data show that neither selenium nor vitamin E, alone or together, in the doses and formulations used, prevented prostate cancer in this heterogeneous population of healthy men.
Available from: Carmen Sanmartín
- "In spite of the evidence outlined above, there is some controversy related to the hypotheses that Se and other compounds, such as Vitamin E, decrease PC incidence either individually or in combination. For example, Dunn et al.  reported that neither Se nor Vitamin E (SELECT), alone or together, prevented PC in a study carried out on a heterogeneous population of healthy men. Stratton et al.  also observed that Se supplementation to 140 men distributed into a placebo group and two groups that received different amounts of Se did not show a protective effect in subjects with localized PC. "
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ABSTRACT: According to World Health Organization, neglected tropical diseases encompass all diseases that occur solely, or principally, in the tropics. In practice, the term is often taken to refer to infectious diseases that thrive in hot, humid conditions. Clinical and epidemiological studies suggest that selenium (Se) play an important role in tropical diseases, such as tuberculosis, leishmaniasis, filariasis and chagas, acting as preventive agent or in diagnosis and prognosis. Recent studies have evinced the importance of selenium in oxidative status and antioxidant defense capabilities during the course of infection and progression of the illness in human patients and experimental models. For this reason, one of the most relevant mechanism of action proposed involve selenoproteins, i.e. glutathione peroxidase (GPx), an enzyme that protects against oxidative stress and modulates the redox processes. In addition, it was observed that low Se levels were positively correlated with an increased susceptibility to infections. Besides, Se supplementation is proposed as an adjuvant therapy for treatment of these chronic diseases. However, there is a lack in the literature references related to synthesis and biological evaluation of novel derivatives containing selenium moiety against these diseases. During the last years our research group is interested in the design and synthesis of organoselenium compounds as new class of agents for treatment of neglected tropical diseases. In the present year we have reported two general structures with leishmanicidal activity, corresponding both of them to symmetrical compounds. The firsts are alkyl imidoselenocarbamates (alkyl isoselenourea) which possessed a moderate effect in vitro and the second ones are selenocyanates and diselenides. It is remarkable that some of them showed stronger in vitro antileishmanial activity than edelfosine and miltefosine, used as reference drugs, and combined high potency and low cytotoxicity against Jurkat and THP-1 cells.
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ABSTRACT: The understanding of the essential role of selenium (Se) in human health has increased substantially in recent decades. Micronutrient deficiencies are very common in the general population and may be even more common in patients with different pathologies due to genetic or environmental causes and prescription drug use. Selenium is used by people in the prevention and/or treatment of different disorders including cardiovascular disease, osteoarthritis, rheumatoid arthritis, hypothyroidism, stroke, atherosclerosis, cancer susceptibility and treatment, HIV, AIDS, neuronal diseases such as Alzheimer or amyotrophic lateral sclerosis, pancreatitis, depression, and diabetes amongst others. Several mechanisms have been suggested to mediate the biological effects of Se and these include antioxidant defence systems, synthesis and stability of metabolites that act as intermediates implicated in diverse selenoproteins expression pathways oxidative metabolism, immune system modulation, DNA intercalators, kinase regulation, enzymatic cofactor, and gene expression. A number of clinical trials in recent years have provided convincing evidence of the central role of this element, either alone or in combination with other micronutrients or antioxidants, in the prevention and treatment of multiple diseases. Based on these studies this review focuses on the advances made so far in the study of mechanisms and applications of selenium compounds that could be suitable for chronic diseases.
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ABSTRACT: Prostate cancer is a common form of cancer affecting men worldwide. Pharmaceutical interventions, such as 5-alpha reductase inhibitors, have been identified as potentially preventing prostate cancer incidence in men. Many men modify lifestyle and consume complementary and alternative medicines to maintain better health and prevent disease. Lycopene is a supplement that has been suggested may assist in the prevention of prostate cancer due to its antioxidant effects. The objective of this systematic review was to identify the effectiveness of lycopene in the prevention of prostate cancer. This review identified 3 relevant studies, comprising 154 participants in total. Two of the studies were assessed to be of 'high' risk of bias. Meta-analysis of two studies indicated no statistical difference in prostate specific antigen (PSA) levels between men randomised to receive lycopene and the comparison group (MD -0.34, 95% CI -2.01 to 1.32). None of the studies assessed prostate cancer mortality. No other meta-analyses were possible since other outcomes assessed only had one study contributing data.
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