Prognostic value of PSA bounce after definitive radiotherapy revisited

Background Prostate-specific antigen (PSA) bounce after definitive radiotherapy has been reported as a predictor of improved biochemical recurrence-free survival (BCRFS). We revisited this phenomenon to confirm its clinical impact on oncological outcomes in patients with long-term follow-up who were free of biochemical recurrence (BCR) at least 3 years after treatment. Materials and methods A total of 541 patients with localized, intermediate-risk prostate cancer underwent low-dose rate brachytherapy with iodine-125 seeds with or without supplemental external beam radiotherapy in combination. Neoadjuvant hormonal therapy was administered to 273 patients (50.5%) with a median duration of 3 months (range 1–108 months). PSA bounce was defined as ≥ 0.2 ng/ml increase above the interval PSA nadir, followed by a decrease below that value. Results The median age was 69 years (range 49–90 years). The median follow-up duration was 102 months (range 36–205 months). One-hundred and fifty patients (27.7%) had PSA bounce with a median magnitude of 0.47 ng/ml (range 0.2–3.19 ng/ml). Age was significantly associated with the occurrence of PSA bounce [age: hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.93–0.98]. It was found to be independently associated with a decreased risk for BCR (HR 0.29; 95% CI 0.12–0.69) and clinical progression (HR 0.44; 95% CI 0.95–0.98). Conclusion PSA bounce indicated a favorable BCRFS and clinical progression-free survival in patients who had been free of BCR for at least 3 years after definitive radiotherapy.