Artificial prostate-specific antigen persistence after radical prostatectomy.

Introduction Serum prostate-specific antigen (PSA) is of paramount importance as a diagnostic tool for the detection, staging, and monitoring of patients with prostate cancer. Because PSA is organ but not disease specific, it has certain limitations as a screening test for prostate cancer. After radical prostatectomy (RP), however, PSA is an excellent tumor marker with a high sensitivity and specificity for the diagnosis of recurrent or residual disease. The serum half-life of PSA, after removal of all prostatic tissue, is 2 to 3 days. Therefore, PSA levels can be expected to decrease below the detectable limit within 4 to 6 weeks after RP. PSA persistence at a significant level beyond this point is usually a strong indicator for disseminated prostate cancer. This is not an uncommon clinical scenario, especially in high-risk disease, and it often leads to immediate additional treatment for the respective patient.