Definitive Radiation Therapy and Survival in Clinically Node-Positive Prostate Cancer
Menée à partir de données portant sur 648 patients atteints d'un cancer non métastatique de la prostate avec envahissement ganglionnaire diagnostiqué entre 2000 et 2015, cette étude évalue l'intérêt d'ajouter une radiothérapie à un traitement anti-androgénique pour réduire la mortalité spécifique ou la mortalité toutes causes confondues
Background : The survival benefit of combined radiation therapy (RT) and androgen deprivation therapy (ADT) compared to ADT alone for clinically lymph node-positive prostate cancer remains controversial. Methods : We identified clinically node-positive, non-metastatic prostate cancer patients diagnosed between 2000-2015 and treated with ADT (n=450) or ADT/RT (n=198) from a national Veterans Affairs database. We compared prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) between treatment groups using multivariable competing risk and Cox regression, respectively. An interaction term between ADT/RT and PSA (dichotomized about the median) was included in the multivariable models. Results : ADT/RT was associated with improved PCSM among patients with prostate-specific antigen (PSA) less than the median of 26 ng/mL (SDHR: 0.50 95% CI 0.28-0.88, p=0.02) but not greater than the median (HR: 1.15, 95% CI 0.67-1.96, p=0.62) (p for interaction = 0.038). ADT/RT was also associated with improved ACM among patients with PSA less than (HR 0.38, 95% CI 0.25-0.57, p < 0.001) but not greater than the median (HR 0.91, 95% CI 0.60-1.38, p=0.66) (p for interaction = 0.004). Conclusion : Definitive treatment with ADT/RT is associated with improved PCSM and ACM among patients with clinically node-positive prostate cancer and a lower baseline PSA. Patients with clinically node-positive disease appear to be a heterogeneous cohort, with a subset that may achieve long-term survival with combined radiation and androgen deprivation therapy.