The use of prostate-specific antigen and free/total prostate-specific antigen in the diagnosis of localized prostate cancer.

Although there is controversy regarding the benefit of early detection of prostate cancer, it has been demonstrated that early detection can be best achieved through the use of a combination of digital rectal examination and prostate-specific antigen (PSA). This article outlines the clinical use of PSA for early detection of prostate cancer and focuses primarily on the value of molecular forms of PSA (free PSA, complexed PSA, and total PSA) in the diagnosis of localized prostate cancer.