Guideline Concordance for Salvage Therapy in Recurrent Prostate Cancer: A Structured Comparison of EAU, AUA, and NCCN Recommendations

Objective: To compare European Association of Urology (EAU), American Urological Association/American Society for Radiation Oncology/Society of Urologic Oncology (AUA/ASTRO/SUO), and National Comprehensive Cancer Network (NCCN) recommendations for salvage treatment of recurrent prostate cancer using a harmonized item-level framework. Materials and Methods:This document-based study compared the EAU Prostate Cancer Guideline limited update March 2026, AUA/ASTRO/SUO Salvage Therapy Guideline 2024, and NCCN Prostate Cancer Version 5.2026.Ten domains were decomposed into 35 items.Two authors independently coded recommendation characteristics and operational actionability.Concordance was classified as complete, partial, or discordant; evidence-gap and evidence-limited statuses were recorded separately.Clinical concordance was assessed separately from operational actionability.Pairwise exact-code agreement, linearly weighted Cohen's kappa, and Gwet's AC2 were calculated using actionability codes.Results: At the unweighted item level, complete agreement occurred in 12 of 35 items (34.3%), and partial agreement occurred in 23 of 35 (65.7%); no directly opposing clinical direction was identified.One domain contained only complete-agreement items, three contained only partial-agreement items, and six contained both types of items.Nine partial-agreement items (39.1%) carried evidence-status qualifiers: two evidence-gap zones and seven evidence-limited zones.Pairwise exact-code agreement ranged from 68.6% to 74.3; weighted Cohen's kappa ranged from 0.364 to 0.496; Gwet's AC2 ranged from 0.733 to 0.780; overall AC2 was 0.755.These coefficients reflect operational actionability, not clinical concordance.The strongest consensus concerned histological confirmation and metastatic exclusion before curative-intent local salvage after radiotherapy; early, riskadapted salvage radiotherapy at low prostate-specific antigen (PSA) after prostatectomy; and avoiding withholding prostate-bed radiotherapy because of negative prostate-specific membrane antigen positron emission tomography.Conclusion: The guidelines showed broad directional alignment without clinical opposition, although most concordance was partial.Differences remained in PSA thresholds, imaging timing, selection between adjuvant and early-salvage approaches, pelvic nodal irradiation, indication for and duration of androgen deprivation therapy, oligometastatic therapy, and definitions of recurrence after focal or ablative treatment.The recommendations should not be considered interchangeable.