Salvage radiotherapy in patients with prostate cancer and biochemical relapse after radical prostatectomy : Long-term follow-up of a single-center survey.

BACKGROUND AND
PURPOSE: In patients with prostate cancer (PC) and biochemical relapse after radical prostatectomy, salvage radiotherapy (SRT) could improve PC-specific survival (PCSS) but the timing for initiation is still under discussion. We have demonstrated a low rate of biochemical relapses in a patient series with very low pre-SRT PSA levels after a median follow-up of 42 months. Here, we present an update of that study. PATIENTS AND METHODS: Overall, 151 patients were analyzed. A biochemical relapse after SRT was diagnosed when the PSA exceeded the post-SRT nadir by 0.2 ng/ml with subsequent increase. Parameters with significant impact on biochemical progression-free survival (BPFS), PCSS, and overall survival (OS) in univariate analysis were included in a multiple Cox regression analysis.
RESULTS: After a median follow-up of 82 months, 18 patients (12%) had died with 10 (6.6%) deaths being PC-related. A biochemical progression was diagnosed in 83 patients (55%). Univariate analysis revealed a significant impact of pre-SRT PSA level, Gleason score, and PSA doubling time (PSADT) on BPFS and for initial tumor stage and Gleason score on OS. Multivariate analysis confirmed the impact of pre-SRT PSA level, Gleason score, and PSADT on BPFS and tumor stage on OS.
CONCLUSION: In this update, the rate of biochemical relapses increased compared with our previous data. Compared to similar studies, we found a remarkably low rate of PC-related deaths. Our data support early initiation of SRT. However, this treatment strategy, triggered by very low PSA levels, could carry the risk of overtreatment in at least a subset of patients.