Blood samples are collected at baseline and on the day of prostatectomy or brachytherapy. Samples are analyzed for selenium accumulation by atomic absorption spectrophotometry. Additional blood samples are stored for future analysis of alpha tocopherol, lycopene, and other vitamin levels, as well as oxidative stress biomarkers. Selenium accumulation is also evaluated in toenail samples at baseline to assess long-term selenium status. Prostate tissue samples are obtained during prostatectomy or brachytherapy and analyzed for RNA and expression of selenium-linked biomarkers (e.g., androgen receptor, prostate-specific antigen, kallikrein 2, cell division cycle 6, dehydrocholesterol reductase 24, and haptic nuclear factor 3 alpha) by quantitative reverse transcription (RT)-PCR. Biomarker expression is compared in both prostatectomy and brachytherapy specimens.