Early salvage radiotherapy in patients with biochemical recurrence after radical prostatectomy: Its impact and optimal candidate.

Abstract

We aimed to identify the optimal candidates for early salvage radiotherapy (SRT) among patients with biochemical recurrence (BCR) after radical prostatectomy (RP). This multi-institutional retrospective study included 371 patients treated using SRT after RP. The median (range) PSA level at BCR was 0.36 (0.10-2.00) ng/mL. The association between early SRT (ie, starting PSA level<0.50) and BCR after SRT was tested in each subgroup according to our own risk stratification. The median follow-up time was 51 months. By multivariate analysis, pT3b, Gleason score ≥ 8, negative surgical margins, PSA doubling time<6 months, and non-early SRT were associated with BCR after SRT. Patients were stratified by four risk factors other than non-early SRT: (1) low risk (0 risk factor), (2) intermediate risk (1 risk factor), and (3) high risk (≥2 risk factors). The BCR-free survival was higher in the early SRT group than the nonearly SRT group in the high-risk subgroup (P=0.020), whereas that was similar between two groups in the low-risk and intermediate-risk subgroups (P=.79 and .18, respectively). Multivariate analysis revealed that early SRT was beneficial for the high-risk subgroup (P=.032), whereas early SRT was not associated with improved outcomes in the low-risk and intermediate-risk subgroups (P=.92 and 1.0, respectively). This study suggested that early SRT seemed to contribute to better biochemical control for patients with more adverse features, whereas no benefit was observed in men with no adverse features.