Current Status of Prostate-Specific Antigen in the Radiotherapeutic Management of Prostatic Cancer

The current data involving the use of prostate-specific antigen (PSA) in the radiotherapeutic management of localized prostatic cancer is reviewed. Controversies and ongoing debate notwithstanding, a number of general conclusions have been made. (1) PSA as a screening test has increased prostate cancer detection rates and is recommended as part of routine screening to supplement digital rectal examination. (2) Preradiotherapy PSA levels are correlated with tumor stage but also provide prognostic information that is independent of tumor stage and histological grade. (3) Following the completion of radiotherapy, PSA levels must decline to normal values to assure a successful treatment outcome. Disagreement persists as to what constitutes a normal PSA value after radiotherapy, and in what time frame after treatments such a level must be achieved. (4) Different proposed models of PSA decline after radiotherapy are discussed, but it remains premature to assess their relative success as predictors of subsequent clinical events. (5) Postradiotherapy prostate biopsy results (negative versus positive) correlate reasonably well with post-treatment PSA status (normal versus elevated). (6) The management of patients with a rising PSA following radiotherapy must be individualized, with early hormonal intervention being an attractive, although unproven, therapeutic option for selected patients. (7) PSA data confirm the value of adjuvant radiotherapy for positive surgical margins and strengthens the indications for its use. (8) Preliminary data regarding PSA levels following transperineal interstitial brachytherapy implantation of the prostate appear favorable.