Use of androgen suppression therapy at salvage radiotherapy in recurrent prostate cancer: a systematic review with meta-analysis.

INTRODUCTION: Salvage radiotherapy (SRT) is one of the treatment options after progression following surgical management, with effectiveness varying according to patient risk and clinical-pathological characteristics. OBJECTIVE: To compare the effectiveness of SRT alone versus SRT combined with androgen deprivation therapy (ADT) in men with biochemical recurrence. METHODS: We conducted a systematic review with advanced searches in MEDLINE (PubMed), EMBASE, SCOPUS, Cochrane CENTRAL, and LILACS for the period 1990-2024. Two independent reviewers performed study selection (titles/abstracts and full text) and data extraction. Risk of bias was assessed with ROBINS-I and RoB 2.0. A random-effects meta-analysis was used to pool effect estimates. PROSPERO registration: CRD42025640604. RESULTS: Thirteen studies were included. Nine reported overall survival (OS) and biochemical progression-free survival (b-PFS) respectively, four clinical progression-free survival (c-PFS), and eight metastasis-free survival (MFS). Combined SRT+ADT was associated with improved b-PFS (HR 0.51; 95% CI 0.45-0.57; I²=0%) and MFS (HR 0.71; 95% CI 0.60-0.84; I²=39%), whereas the remaining meta-analyzed outcomes showed no consistent benefit or were limited by heterogeneity. Regarding toxicity, the most frequent adverse events were endocrine and sexual, related to hormonal blockade, gynecomastia and erectile dysfunction. CONCLUSIONS: Combined SRT + ADT improves biochemical disease control and may reduce the risk of metastasis in selected patients with biochemical recurrence after radical postatectomy, whereas the effect on overall survival remains uncertain. Individualized management requires risk stratification when deciding on the addition and duration of ADT to optimize oncologic outcomes. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/, identifier CRD42025640604.