« Augmented radiotherapy » in the management of high-risk prostate cancer (PCa): A systematic review

Abstract

Background: In patients with high-risk (HR) prostate cancer (PCa) treated with radiotherapy and androgen deprivation therapy (ADT), intensification with androgen receptor pathway inhibitor (ARPI) improves overall survival (OS), at the cost of significant side-effects. We hypothesized that "augmented RT" schedules (defined as either dose-escalation on the prostate gland over 78 Gy and/or addition of whole pelvic radiotherapy (WPRT)), combined with long-term ADT can reach excellent prostate cancer specific survival (PCSS) in this population with little detrimental impact on quality of life.

Methods: We searched Pubmed database until February 8, 2024. Studies reporting both oncological and toxicity outcomes after "augmented RT" were deemed eligible. Studies without ADT or with ARPI intensification were deemed ineligible.

Results: Dose-escalation within the prostate gland at doses over 78 Gy halved the risk of biochemical recurrence at 5 years, with however no impact on PCSS. The addition of WPRT provides a 5-year disease-free survival (DFS) reaching 89.5 % at 5 years, with no significant increase in late grade≥ 2 genito-urinary (GU) or gastrointestinal (GI) toxicity. Combined approaches result in 9-year PCSS ranging between 96.1 % and 100 %. Most approaches demonstrated excellent safety profiles.

Conclusions: "Augmented RT" reached excellent oncological outcomes, with minimal additional toxicity. The development of biomarkers might lead to further treatment personalization, in the rapidly evolving landscape of systemic therapies.

Keywords: Androgen receptor pathway inhibitor; Dose-escalation; High-risk; Prostate cancer; Radiotherapy; Whole pelvic radiotherapy.