PSA is used as a tumor marker for the early detection of prostate cancer and in other areas of prostate disease management. Prostate-specific antigen (PSA) is a glycoprotein produced by the epithelial cells lining the prostatic ducts and acini. Normally, it is secreted into the prostatic ducts and is present only in prostate tissue, prostatic fluid, and seminal plasma. PSA is produced by normal, hyperplastic, and cancerous prostatic tissue. The use of PSA testing for:

• The evaluation of men at risk for prostate cancer
• Assistance in pretreatment staging
• Risk assessment posttreatment monitoring
• Use as a guide in management of men who recur after primary or secondary therapy