Is prostate cancer prevention with selenium all in the genes?

This perspective discusses how well-conducted research by Penney et al. (beginning on page 604 in this issue of the journal) contributes to the incremental uncovering of the complex association between selenium and prostate cancer. These investigators' earlier findings and current questions, approaches, and findings regarding selenium for prostate cancer prevention are discussed. This group's work raises the following important inferences: Selenium may prevent poorer-prognosis prostate cancer and its progression to bony metastases and death, but only in men with genetic backgrounds that influence the requirement for selenium. These inferences point toward how to reconcile inconsistent prostate cancer risk results from the two randomized trials of selenium conducted to date.