Selenium and the prostate

Abstract

Evidence accrued over the last decade has supported an association between low serum selenium (Se) and increased incidence of prostate cancer in older men. Accordingly, questions and inquiry arose as to whether a dietary supplementation might afford protection, or delay disease progression. Indeed, a very large national study, Selenium and Vitamin E Cancer Prevention Trial (SELECT), to explore the potential benefits of a daily supplement of 200 microgram Se, or 400 I.U. of vitamin E, or both, is underway: the National Cancer Institute anticipates a total enrolment of 32,400 men and durations of 7 to 12 years for individual participants. It is remarkable that at the time of the trial's activation in 2001 nothing was known about the concentration of Se in the target organ or whether any Se in a dietary supplement found its way to the prostate gland. Later, our laboratory published the first benchmark values, which indicated that the prostate is reasonably well endowed with Se and that the concentration in one subject, who had undergone self-medication at 200 microgram Se per day, was about twice the average for the others. This review explores the ramifications of these and subsequent data for SELECT and other trials, together with observations on dose and general mechanisms of Se interference with the development of prostate cancer.