Prostate-specific antigen (PSA) in the monitoring of prostate cancer afterradical prostatectomy and external beam radiation

Background: During the last few years, prostate-specific antigen (PSA) has been established as the most important tumor marker for prostate cancer. Th e aim of our study was to evaluate the response of PSA after surgery and ra diotherapy of prostate cancer. Patients and Methods: From 1/1995 to 9/1997, 32 patients were treated by radical prostatectomy and subsequent radiother apy. Radiation therapy was carried out using a linear accelerator to the pr ostate bed, a total dose of 60 Gy was given. PSA values were measured immed iately before irradiation, weekly during radiation therapy and every three months thereafter in the usual follow-up pattern. Results: 21 of 32 patient s had no measurable PSA after surgery. In the remaining II patients the med ian PSA half-life was reached 3 months after irradiation, the nadir after 1 5 months. 5 patients with increasing PSA levels suffered from a relapse (15 .6%). Conclusions: We found that PSA monitoring is a useful marker for trea tment outcome and that adjuvant radiotherapy after surgery improves local c ontrol as well as biochemical failure rate. If PSA is still detectable afte r surgery the risk for biochemical failure is significantly higher (45.5%).