Introduction
The optimal timing for the administration of salvage therapies at biochemical recurrence (BCR) node positive prostate cancer (PCa) patients undetectable (Prostate-Specific Antigen) PSA post-surgery is unknown.
Materials and Methods
This study included 1,540 pN1 PCa patients, excluding those with detectable PSA post-surgery, >2 positive nodes, or adjuvant therapy. A C-index analysis identified the optimal PSA cut-off at BCR. A multivariable Cox model assessed salvage therapy’s impact on metastasis, adjusting for PSA, age, pT stage, International Society of Urological Pathology (ISUP) grade, and node count. Five-year metastasis-free survival (MFS) was estimated for patients treated below the PSA cut-off, with follow-ups at 6, 12, 18, and 24 months.
Results
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A total of 286 patients that were identified, 51 patients received Salvage Radiotherapy (sRT), 24 patients received Androgen Deprivation Therapy (ADT) and 59 patients received a combination (sRT + ADT). The median follow-up range was 30 months (Inter Quartile Range: 14-58).
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Median PSA at BCR was 0.3ng/ml (range: 0.2-0.8). The 7-yr BCR-FS was 30% (95%CI: 22-38%).
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After assessment it was found that the best PSA Cut-Off for Predicting Metastatic Progression was at 0.45 ng/ml (c-index: 68%)
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In MCR models, salvage therapies administered at PSA values >0.45 ng/ml were associated with increased risk of metastases (HR: 2.6, 95%CI: 1.3-5.2, p=0.01).
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Following 0, 6, 12, and 24 months of event-free monitoring, the conditional 5-year estimate for MFS-free survival was 73%, 83%, 86%, and 91% for patients whose PSA was below 0.45 ng/ml.
Conclusion
A PSA value of 0.45 ng/nl represented to be the optimal cut-off in predicting the metastatic progression among pN1 patients who are managed with observation according to the EAU guidelines. Patients receiving salvage treatment below this cut-off exhibited good cancer control, particularly when achieving a 24 months’ event-free follow-up.
European Association of Urology, 21-24 March 2025, Madrid, Spain
