Predictive factors of radiation therapy for patients with prostate specific antigen recurrence after radical prostatectomy.

Objective: To assess the efficacy of salvage/adjuvant radiation therapy (RT) for patients with prostate-specific antigen (PSA) recurrence after radical prostatectomy (RP).

Patients And Methods: Between 1997 and 2001, 52 patients were treated in our institution with RT for PSA recurrence after RP. The mean (range) delay between RP and RT was 30.5 (0.16-105.6) months. Eighteen patients received no hormonal therapy before RT. The failure of RT was defined as three consecutive increases in PSA levels with intervals of > or = 6 weeks.

Results: Within a mean (range) follow-up of 27.7 (6-69) months, 18 patients presented with biochemical progression. The 3-year biochemical progression-free survival was 51%. Using univariate analysis, an age < 65 years (P = 0.0262), a Gleason score on the RP specimen of > or = 8 (P = 0.0024), stage pT3 (P = 0.02), a detectable nadir PSA after RT (P < 0.001) and the absence of hormonal therapy (P = 0.0359) were associated with a lower biochemical progression-free survival. However, only the Gleason score (P = 0.0395) and nadir serum PSA after RT (P = 0.028) remained independent predictive factors on multivariate analysis.

Conclusion: Half of the present patients treated with RT for an isolated high serum PSA level after RP were free of biochemical relapse at 3 years of follow-up. RT may be proposed to selected patients with mild morbidity. However, definitive evidence of the beneficial effect of adjuvant RT for patients with PSA recurrence after RP awaits the conclusion of randomized clinical trials.