Brachytherapy for Intermediate Risk Prostate Cancer, Androgen Deprivation and the Risk of Death
Menée à partir de données portant sur 3 155 patients atteints d'un cancer de la prostate à risque faible ou intermédiaire de récidive traité entre 1998 et 2012 (durée médiane de suivi : 7,9 ans), cette étude évalue, en fonction du risque de récidive, l'effet de 6 mois de traitement adjuvant anti-androgénique en combinaison avec une curiethérapie sur le risque à 10 ans de décès par maladie cardiovasculaire et sur la survie globale
Purpose : To determine if the use of 6 months adjuvant androgen deprivation therapy (ADT) combined with brachytherapy for intermediate risk (IR) and low risk (LR) prostate cancer is associated with an increased risk of cardiovascular (CV) death. Methods & Materials : This is a retrospective analysis of prospectively collected data of men treated in XXXX brachytherapy program, 1998-2012. Men were categorised into risk group and ADT use. Cardiac and other co-morbidities were recorded and compared between groups. Biochemical control (Phoenix, nadir + 2 ng/ml) was ascertained. Overall, Prostate, Cardiac and other-cause mortality is analysed by Kaplan-Meier and Fine and Gray’s competing risk analysis. Results : 3 155 men (1 142 LR and 2 013 IR) were included and have been followed for a median of 7.9 years. 53% of IR and 63% of LR received ADT for a median of 6 months. Men with IR cancer are older, and have more cardiac and other comorbidity than LR cases, p<0.01. Biochemical control improved from 86% to 89% at 10 years, with the use of ADT, p=0.006. Overall survival was inferior in those receiving ADT (84% vs 86% at 10 years, p=0.0274), and in competing risk analysis CV mortality in those receiving ADT was higher in IR cases, 5.2% vs. 3.6% at 10 years (p=0.0493), but not in LR cases. Multivariate analysis confirmed increased cardiac mortality in IR patients on ADT, Hazard ratio 1.95 [95% confidence interval 1.15-3.34], p=0.014. Conclusion : Androgen deprivation therapy (ADT) adds little meaningful benefit in terms of biochemical control for IR men treated with LDR brachytherapy, but likely decreases overall survival due to increased cardiac mortality. IR patients were older and had more cardiac risk factors than LR prostate cases; this may be due to a screening effect, case selection, or common etiological cause.