Evaluation of Serum Prostate-Specific Antigen Levels After Postoperative Radiation Therapy for Pathologic Stage T3, N0 Prostate Cancer

Objective To analyze freedom from progression of serum prostate-specific antigen (PSA) levels in patients who have received radiation therapy after radical prostatectomy for pathologic stage T3, N0 prostate cancer. Design We assessed the freedom from PSA progression after postoperative radiation therapy and its relationship to several potential prognostic factors during a median follow-up of 43 months. Material and Methods Thirty Mayo patients received postoperative radiation therapy for pathologic stage T3, N0 prostate cancer between January 1988 and April 1993. Radiation therapy was initiated within 6 months after prostatectomy Radiation doses ranged from 60 to 67 Gy. Results "Freedom from PSA failure" was defined as the actuarial risk of maintaining a serum PSA level at 0.3 ng/mL or less. The freedom from failure rate was 66% at 3 and 4 years. Prognostic factors significantly associated with an improved freedom from failure were a preradiation PSA level of 1.0 ng/mL or less and no seminal vesicle involvement. A trend toward an improved freedom from failure was noted in patients with low-grade (1 and 2) tumors in comparison with high-grade (3 and 4) tumors. Treatment-related morbidity was minimal. Conclusion Radiation therapy after radical prostatectomy for pathologic stage T3, N0 prostate cancer seems to provide an improved freedom from PSA failure in comparison with that noted in other series of similar patients treated with radical prostatectomy only.