A Comparison between Low Dose-Rate Brachytherapy +/- Androgen Deprivation, External Beam Radiotherapy +/- Androgen Deprivation, and Radical Prostatectomy +/- Adjuvant or Salvage Radiotherapy for High-Risk Prostate Cancer
Menée à partir de données portant sur 2 557 patients atteints d'un cancer de la prostate à haut risque de récidive traité entre 1996 et 2012 (âge médian : 65 ans ; durée médiane de suivi : 63,5 mois), cette étude compare l'efficacité, du point de vue de la survie sans récidive (clinique ou biochimique) et de la mortalité spécifique à 5 et 10 ans, et la toxicité des trois principales modalités thérapeutiques (radiothérapie externe, curiethérapie à bas débit de dose et prostatectomie radicale) en combinaison ou non avec un traitement anti-androgénique
Purpose : We compare the efficacy and toxicity among the three major modalities available used to treat high-risk prostate cancer (HRCaP). Methods and Materials : From 1996-2012, 2557 HRCaP patients were treated: 734 external beam radiation (EBRT) +/- androgen deprivation therapy (ADT), 515 low-dose-rate prostate brachytherapy (LDR) +/- ADT, and 1308 radical prostatectomy (RP) +/- EBRT. Biochemical relapse-free survival (bRFS), clinical relapse-free survival (cRFS), and prostate cancer-specific mortality (PCSM) were assessed. Toxicity was assessed using the Common Terminology Criteria for Adverse Events, version 4.03 (CTCAE v4.03). The log-rank test compared bRFS and cRFS among the modalities, and Cox regression identified factors associated with bRFS and cRFS. Gray’s test compared differences in late toxicity and PSCM among the modalities. Competing risk regression identified factors associated with PCSM. Results : The median follow-up and age were 63.5 months and 65 years, respectively. The bRFS at 5 and 10 years, respectively, was 74% and 53% for EBRT, 74% and 52% for LDR, and 65% and 47% for RP (p=0.0001). The cRFS at 5 and 10 years, respectively, was 85% and 73% for EBRT, 90% and 76% for LDR, and 89% and 75% for RP (p=0.121). The PCSM at 5 and 10 years, respectively, was 5.3% and 11.2% for EBRT, 3.2% and 3.6% for LDR, and 2.8% and 6.8% for RP (p=0.0004). The 10-year cumulative incidence of > grade 3 genitourinary toxicity was 8.1% for EBRT, 7.2% for LDR, and 16.4% for RP (p<0.0001). The 10-year cumulative incidence of > grade 3 gastrointestinal toxicity was 4.6% for EBRT, 1.1% for LDR, 1.0% for RP (p<0.0001). Conclusion : HRCaP treated with EBRT, LDR, or RP yields efficacy showing better bRFS for LDR and EBRT relative to RP, equivalence for cRFS, and a PCSM advantage of LDR and RP over EBRT. The toxicity is lowest for LDR.