Dose escalation has demonstrated a significant improvement in biochemical recurrence in high-risk prostate cancer (HRPCa). We evaluated the impact on overall survival (OS) of dose intensification with external beam radiation therapy (EBRT) in a cohort of HRPCa patients treated in a single institution.
Between January 1997 and January 2024, a total of 1451 consecutive localized PCa patients were treated with primary EBRT alone as part of a prospective institutional program for risk-adapted dose-intensification radiotherapy. For the present analysis, we specifically selected a cohort of 424 consecutive HRPCa patients with a minimum follow-up (FU) of 5 years. The median RT dose was 79.2 Gy (interquartile range [IQR] 74.9-80.3). Short and long-term hormones were administered in 56 (13%) and 350 (83%) of patients respectively. Kaplan-Meier curves were used to calculate overall survival (OS). Cumulative incidence of distant metastasis (DM), and cause specific survival (CSS) were estimated using competing risk regression.
Median patient age was 69 years (IQR 65-72) and median FU was 118 months (IQR 88.0-135.0). At the time of analysis, 54 of 424 patients (13%) had died. The leading cause of death was cardiovascular disease in 16/54 patients (4%), followed by PCa in 15 patients (3%). At 10 and 15 years, the KM estimated OS rates were 91% (95% CI 87-93) and 71% (95% CI 61-79), respectively. The corresponding rates for MFS were 87% (95% CI 83-90) and 60% (95% CI 49-68), and for CSS were 97% (95% CI 95-99) and 90% (95% CI 49-81), respectively. In multivariate analysis, when adjusted for patient age, T stage, Gleason/ISUP group, PSA and length of hormone-therapy, higher radiation dose remained significantly associated with an improved OS (HR 0.89; 95% CI 0.84-0.94), MFS (HR 0.94; 95% CI 0.90-0.98) and CSS (HR 0.89; 95% CI 0.84-0.94).
The present study confirms that radiation dose intensification is paramount in the treatment of HRPCa with independence of duration of ADT.

© 2025. The Author(s).