%0 Journal Article %T Short-Term Soy Isoflavone Intervention in Patients with Localized Prostate Cancer: A Randomized, Double-Blind, Placebo-Controlled Trial %A Jill M. Hamilton-Reeves %A Snigdha Banerjee %A Sushanta K. Banerjee %A Jeffrey M. Holzbeierlein %A J. Brantley Thrasher %A Suman Kambhampati %A John Keighley %A Peter Van Veldhuizen %J PLOS ONE %D 2013 %I Public Library of Science (PLoS) %R 10.1371/journal.pone.0068331 %X Purpose We describe the effects of soy isoflavone consumption on prostate specific antigen (PSA), hormone levels, total cholesterol, and apoptosis in men with localized prostate cancer. Methodology/Principal Findings We conducted a double-blinded, randomized, placebo-controlled trial to examine the effect of soy isoflavone capsules (80 mg/d of total isoflavones, 51 mg/d aglucon units) on serum and tissue biomarkers in patients with localized prostate cancer. Eighty-six men were randomized to treatment with isoflavones (n = 42) or placebo (n = 44) for up to six weeks prior to scheduled prostatectomy. We performed microarray analysis using a targeted cell cycle regulation and apoptosis gene chip (GEArrayTM). Changes in serum total testosterone, free testosterone, total estrogen, estradiol, PSA, and total cholesterol were analyzed at baseline, mid-point, and at the time of radical prostatectomy. In this preliminary analysis, 12 genes involved in cell cycle control and 9 genes involved in apoptosis were down-regulated in the treatment tumor tissues versus the placebo control. Changes in serum total testosterone, free testosterone, total estrogen, estradiol, PSA, and total cholesterol in the isoflavone-treated group compared to men receiving placebo were not statistically significant. Conclusions/Significance These data suggest that short-term intake of soy isoflavones did not affect serum hormone levels, total cholesterol, or PSA. Trial Registration ClinicalTrials.gov NCT00255125 %U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0068331