Prostate-specific antigen and new serum biomarkers for evaluation of chemopreventive agents

A great deal of effort regarding the basic understanding and clinical relevance of the prevention of prostate cancer has emerged over the past decade. Chemoprevention or the administration of a drug or other agent in an attempt to prevent, inhibit, or delay the progression of localized prostate cancer has gained the most recent attention. Efforts have focused primarily in the identification of bioactive chemopreventive agents, risk factors identifying individuals with the highest likelihood of developing prostate cancer, pathologic identification of premalignant lesions, and epidemiologic studies to better understand the natural history of early prostate cancer. However, less work has been focused on identifying and characterizing our presently available biomarkers in an attempt to validate their use as surrogate endpoints or documenting their clinical utility in chemoprevention. This update will focus on a critical evaluation of prostate-specific antigen (PSA), percentage of free PSA, and human glandular kallikrein-2 (hK2) and how they may be used or misused for chemoprevention studies.