Prostate-specific antigen testing in untreated and treated prostatic adenocarcinoma.

The isolation and purification of prostate-specific antigen (PSA) and the development of a radioimmunoassay for this antigen represent major advancements for the detection of adenocarcinoma of the prostate and the monitoring of response to therapy in patients with this disease. Both monoclonal and polyclonal assays for PSA are available. In attempts to correlate pathologic tumor stage and PSA levels, tumors of higher stage (pathologic stages C1, C2, D1, and D2) have been associated with elevated PSA levels. Increased PSA levels have also been found in patients with benign prostatic diseases (benign prostatic hypertrophy and prostatitis). PSA has been shown to be an excellent marker after radical prostatectomy and for monitoring of radiation therapy. Patients with a persistently elevated PSA level for more than 6 months postoperatively should be assessed for residual or recurrent local or systemic disease. Thus far, routine use of PSA testing as a mass screening modality for prostatic cancer has not been considered cost-effective.