Long-term results of radiation therapy for prostate cancer recurrence following radical prostatectomy

Purpose: Following radical prostatectomy, radiation therapy may be benificial in select patients with isolated local recurrence. Pathological stage, Gleason score and the timing of prostate specific antigen (PSA) elevation are useful in distinguishing men with local recurrence from those with distant metastases. We test the ability of these criteria to predict long-term suppression of PSA recurrence following post-prostatectomy radiation therapy. Materials and Methods: Of 1,699 men treated with radical prostatectomy from 1982 to 1995, 82 with an isolated PSA elevation or local recurrence following surgery underwent radiation therapy to the prostatic bed and were followed for at least 2 years. No patient had evidence of metastases at the time of radiation. Results: Of the men 17 (21%) had an undetectable PSA (less than 0.2 ng/ml.) for 2 or greater years following radiation. The 5- year actuarial PSA recurrence-free rate after radiation was 10%. PSA remained at undetectable levels for 2 or greater years in no patients with Gleason score 8 or greater (12 cases), positive seminal vesicles (12) or positive lymph nodes (3), and in only 1 of 16 men (6%) who had a PSA recurrence within 1 year of prostatectomy. As the interval to PSA recurrence increased, the likelihood of responding to radiotherapy increased to 44% if initial disease detection occurred 5 or more years after prostatectomy. There was no demonstrated advantage to radiating men with an isolated PSA elevation before a documented local recurrence. Conclusions: Patients with Gleason score 8 or greater, positive seminal vesicles or lymph nodes, or a PSA recurrence within the first year following surgery rarely benefit from radiation therapy. As the interval to PSA recurrence increases, the likelihood of responding to radiation therapy increases substantially. These parameters are useful in the selection of patients with prostate cancer recurrences who are likely to benefit from radiation to the prostatic bed.