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THE MODULATION OF PROSTATE CANCER RISK WITH α-TOCOPHEROL: A PILOT RANDOMIZED, CONTROLLED CLINICAL TRIAL

2005; Lippincott Williams & Wilkins; Volume: 174; Issue: 2 Linguagem: Inglês

10.1097/01.ju.0000165151.08560.6a

1527-3792

JAVIER HERNÁANDEZ, Samira Syed, Geoffrey R. Weiss, Gabriel Fernandes, Dendra von Merveldt, Dean A. Troyer, Joseph W. Basler, Ian M. Thompson,

Cancer, Lipids, and Metabolism

Studies suggest that vitamin E may decrease the risk of prostate cancer. The Prevention Research Veteran Affairs E-vitamin Nutrition Trial is a randomized, double-blind, placebo controlled study designed to assess the effects of vitamin E supplementation on biomarkers associated with prostate cancer risk in peripheral blood and prostate tissue.A total of 44 patients with increased prostate specific antigen (PSA) and/or abnormal digital rectal examination on initial evaluation were randomized to receive 400 IU vitamin E (22) vs placebo (22). Serum vitamin E, PSA, dehydroepiandrosterone, testosterone and insulin-like growth factor-1 (IGF-1) were measured in the 2 groups at baseline and then at 3-month intervals. Results are reported in 28 patients (placebo in 14 and vitamin E in 14) who completed the treatment as specified by the protocol.Serum Vitamin E was significantly higher in patients on vitamin E supplementation. alpha-Tocopherol supplementation did not affect the levels of PSA, serum androgens (testosterone and dehydroepiandrosterone) or (IGF-1).Serum alpha-tocopherol is increased by oral supplementation of vitamin E. We found that alpha-tocopherol supplementation has no effect on serum androgens, IGF-1 or PSA. The lack of an effect of vitamin supplementation on PSA avoids any bias in the diagnosis of prostate cancer in vitamin E treated patients. Our results suggest that a decrease in prostate cancer risk with alpha-tocopherol is likely to occur through a mechanism that is nonhormonal and independent of IGF-1.