Dose-Dependent Effects of Selenized Yeast on Total Selenium Levels in Prostatic Tissue of Men With Prostate Cancer

摘要

Although a negative association between serum selenium (or selenium supplementation) and prostate cancer risk has been widely reported (1–8), very little is known about the effects of oral supplementation with selenized yeast on selenium levels in prostate tissue of men with prostate cancer.nIn 2003, Gianduzzo et al. reported results of a prospective trial enrolling 51 men with benign prostatic hyperplasia randomized to receive 200 μg selenized yeast or placebo daily for 1 mo (9). Prostate tissue selenium levels were statistically significantly higher in the supplemented group as compared to placebo (supplement group median = 241 and control group median = 196 ng/gm, P = 0.016) at the end of the study. In another study, Sabichi and colleagues supplemented 66 men with organ-confined prostate cancer with 200 μg selenomethionine (SeMet) or placebo for 14 to 31 days (10). Although baseline serum selenium was similar in the two groups (P = 0.64), post-intervention mean serum selenium level was 15% higher and selenium concentration within the prostate was 22% higher in the SeMet arm as compared to placebo (P = 0.001 and P = 0.021, respectively). The first study was conducted on men with benign prostatic hyperplasia, where it is possible that the tissue environment was different than that found in a prostate with carcinoma. The second study used SeMet, a form of selenium shown to have no effect on prostate cancer incidence in results from the SELECT study (11).nWhile the above studies do give insight into the uptake of various selenium forms by prostate tissue, critical data regarding the uptake of total selenium from selenized yeast in men with prostate cancer are missing. Results from the current study not only address this deficiency in the literature but are also complementary to the Gianduzzo and Sabichi studies, allowing us to compare uptake of various forms of selenium in different prostatic conditions.