Presentation Authors: Felix Preisser*, Frankfurt, Germany, Raisa Pompe, Hamburg, Germany, Felix Chun, Frankfurt, Germany, Markus Graefen, Hartwig Huland, Derya Tilki, Hamburg, Germany
Introduction: Salvage radiotherapy (sRT) can provide a survival benefit for patients with biochemical recurrence (BCR) after radical prostatectomy (RP). We tested, if the primary Gleason pattern can identify patients that benefit from early sRT in regard of metastasis-free survival (MFS) and cancer-specific survival (CSS) after RP.
Methods: Within a high-volume center database we identified patients who harbored BCR after RP between 1992 and 2016. Early sRT was defined as sRT delivered at PSA-values â‰¤0.5ng/ml after RP. Patients with lymph node invasion, adjuvant RT or adjuvant hormone therapy were excluded. Kaplan-Meier analyses and multivariable Cox regression models were used to test the effect of the primary Gleason (3 vs. â‰¥4) on MFS and CSS between patients treated with early sRT vs. no sRT.
Results: Overall, 1,936 patients were identified. Of those, 38.3% (741) underwent sRT vs. 61.7% (1,195) who were observed after BCR. Median sRT dose was 66.6 Gy. Patients with sRT were younger (median age: 63.5 vs. 65.3yrs, p < 0.001), had lower median PSA values (7.2 vs. 8.3ng/ml, p < 0.001), more frequently had pathologic tumor stage T2 (50.1 vs. 46.0%, p=0.0004),) and less frequently positive margins (19.0 vs. 24.0%, p=0.01). 8-year MFS rates were 93.0 vs. 93.0% in primary Gleason 3 and 72.9 vs. 77.9% in primary Gleason â‰¥4 for no sRT vs. sRT, respectively. 10-year CSS rates were 96.1 vs. 99.2% in primary Gleason 3 and 85.7 vs. 90.1% in primary Gleason â‰¥4 for no sRT vs. sRT, respectively. In multivariable models, sRT was an independent predictor for MFS (HR:0.64, p < 0.01) and CSS (HR:0.34, p=0.01). However, in subgroups, sRT was only significant in patients with primary Gleason â‰¥4 (HR:0.47, p < 0.001 for MFS and HR:0.36, p=0.03 for CSS) and not in patients with primary Gleason 3 (all p >0.1).
Conclusions: The primary Gleason provides important information in the early sRT setting. Our analysis demonstrates that only patients who harbor a primary Gleason â‰¥4 may benefit from early sRT. This information should be taken into account when early sRT is considered.