EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer. Part II-2026 Update: Treatment of Relapsing and Metastatic Prostate Cancer.

Background and objective To present a summary of the 2026 version of the European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy & Oncology (ESTRO)-European Society of Urogenital Radiology (ESUR)-International Society of Urological Pathology (ISUP)-International Society of Geriatric Oncology (SIOG) Guidelines on the treatment of relapsing, metastatic hormone-sensitive and castration-resistant prostate cancer (PCa). Methods The Panel performed a literature review of new data, covering the time frame between 2023 and 2025. The Guidelines were updated and a strength rating for each recommendation was added based on a systematic review of the evidence. Key findings and limitations Risk stratification for relapsing PCa after primary therapy may guide salvage therapy decisions. The range of treatment options for metastatic PCa has broadened, including androgen receptor pathway inhibitors (ARPI), metastasis-directed therapy, PARP inhibitors and their combinations, as well as PSMA-based therapy. The recommendations in the EAU Guidelines are based on clinical evidence and do not account for variations in cost, reimbursement structures, or resource availability across healthcare systems. Conclusions and clinical implications The evidence in the field of relapsing, metastatic, and castration-resistant PCa is evolving rapidly. These PCa Guidelines reflect the multidisciplinary nature of PCa management. A full version is available from the EAU Guidelines Office or online ( http://uroweb.org/guideline/ prostate-cancer/ ).