Biochemical and clinical outcomes after high-dose salvage radiotherapy as monotherapy for prostate cancer
Menée sur 168 patients atteints d'un cancer de la prostate hormono-naïf de stade localisé avec récidive biochimique après prostatectomie radicale (durée médiane de suivi : 54 mois), cette étude rétrospective évalue, du point de vue de la survie sans récidive biochimique, de la survie spécifique et de la survie globale, l'efficacité en traitement unique d'une radiothérapie de sauvetage à doses élevées de rayonnements ionisants (≥72 Gy), puis identifie les facteurs prédictifs associés aux résultats biochimiques ou cliniques
Purpose : To retrospectively evaluate the role of high-dose salvage radiotherapy (SRT) alone with regard to biochemical and clinical outcomes in patients with biochemical failure (BF) after radical prostatectomy (RP). Methods : Between January 2003 and August 2011, 168 hormone-naïve localized prostate cancer patients received SRT alone for post-RP BF in a single institution and were retrospectively analyzed. Multivariate analysis was performed to determine the independent prognostic impact of clinical factors on biochemical and clinical outcomes [biochemical relapse-free survival (bRFS), clinical relapse-free survival (cRFS), cancer-specific survival (CSS) and overall survival (OS)]. Results : Median follow-up was 54 months. Actuarial bRFS, cRFS, CSS and OS at 5 years were, respectively, 64, 86.2, 94.5 and 96.3 %. On multivariate analysis, nadir PSA (nPSA) after SRT was significantly associated with bRFS (HR 15, p = 0.001) and cRFS (HR 9, p = 0.001), while CSS was associated with RT dose (≥70 Gy; HR 1.9 p = 0.023), pre-RT PSA (<1.5 vs. ≥1.5 ng/mL; HR 1.3, p = 0.008) and age (>75 years; HR 1.2, p = 0.05). OS was significantly correlated with pre-SRT PSA (linear correlation; HR 1.1, p = 0.023) and age (<75 vs. ≥ 75 years; HR 1.1, p = 0.026). Conclusions : Effective biochemical and clinical control rates may be safely achieved administering SRT with high doses (≥72 Gy) and using conformal techniques, especially in older patients presenting with lower pre-SRT PSA values. A lower nPSA after SRT predicts for better 5 years bRFS and cRFS rates.