LAUSR

OBJECTIVE To test whether salvage radiotherapy (SRT) in N0 prostate cancer (PCa) is equally effective with persistent PSA and PSA rising from the undetectable range (<0.1 ng/ml) after radical prostatectomy (RP). PATIENTS AND METHODS We assessed post-SRT PSA-progression-free survival (PFS) in 555 PCa patients. The entire cohort was compared with a risk adjusted subgroup of 112 patient pairs with matching pre-RP PSA (±10 ng/ml), Gleason score (≤6 vs 7 vs ≥8), and pre-SRT PSA (±0.2 ng/ml). RESULTS The median follow-up was 6.1 years. Post-RP, PSA was undetectable in 422 and persistent in 133 patients. PSA persistence and a pre-SRT PSA ≥0.5 ng/ml reduced Kaplan-Meier rates of PFS significantly. In multivariate analysis of the entire cohort and after risk adjustment, the pre-SRT PSA but not post-RP PSA persistence was a significant parameter. In the matched cohort's sub-group with early SRT at a PSA <0.5 ng/ml, a trend towards a worse outcome with post-RP PSA persistence was observed. Delayed SRT with PSA ≥0.5 ng/ml led to PFS of less than 30%, irrespective of the post-RP PSA. CONCLUSION In N0 PCa patients with a post-RP PSA persistence, early SRT at PSA <0.5 ng/ml seems to be less effective than in recurrent patients with post-RP undetectable PSA. They might benefit from intensified therapy, but larger case numbers are required to substantiate this conclusion. In patients with PSA ≥0.5 ng/ml and higher-risk features associated with post-RP PSA persistence, SRT alone is unlikely to provide long-term freedom from further progression. This article is protected by copyright. All rights reserved.