ESTRO 2024 - Abstract Book

S2305

Clinical - Urology

ESTRO 2024

1 Hospital Universitario Ramón y Cajal, Radiation therapy, Madrid, Spain. 2 Hospital Universitario Santiago de Compostela, Radiation therapy, Santiago, Spain. 3 Hospital Universitario Reina Sofía, Radiation therapy, Córdoba, Spain. 4 Hospital Universitario Virgen de la Victoria, Urology, Málaga, Spain. 5 Instituto de Investigación Biomédica de Málaga, research doctor, Málaga, Spain. 6 Hospital Universitario Virgen de la Victoria, Radiation therapy, Málaga, Spain. 7 Hospital Universitario Gómez Ulla, Radiation therapy, Madrid, Spain. 8 Hospital Universitario de Toledo, Radiation therapy, Toledo, Spain. 9 Hospital Universitario Quirónsalud, Radiation therapy, Madrid, Spain. 10 Universidad Europea, Doctor, Madrid, Spain. 11 Hospital Universitario de Ciudad Real, Radiation therapy, Ciudad Real, Spain. 12 Hospital Universitario Donostia, Radiation therapy, Donostia, Spain. 13 Hospital Universitario y Politécnico La Fe, Radiation therapy, Valencia, Spain. 14 Hospital Clínico Universitario de Valencia, Radiation therapy, Valencia, Spain. 15 UGC Oncología Gipuzkoa, Radiation therapy, Onkologikoa, Spain. 16 Hospital Universitario de Jaén, Radiation therapy, Jaén, Spain The EMBARK trial is the first randomized phase III study designed to determine the efficacy and safety of enzalutamide- based therapies in biochemical recurrence (BCR) of “high - risk” patients with non -metastatic castration-sensitive prostate cancer (nmCSPC). The results of the study underscored that the combination of enzalutamide with ADT, as well as enzalutamide monotherapy, exhibited statistically significant and clinically relevant enhancements in metastasis free-survival when compared to placebo with ADT. However, real-world data on the application and outcomes associated with these criteria are limited. Our aim is to assess in real-world data the clinical applicability of identifying patients with a prostate cancer diagnosis who experience biochemical recurrence following radiotherapy or postoperative radiotherapy without detectable metastatic disease through conventional imaging at their initial recurrence. We retrospectively evaluated nmCSPC who experience biochemical recurrence following radiotherapy or postoperative radiotherapy without detectable metastatic disease through conventional imaging at their initial recurrence across 13 cancer centres between January 2015 and December 2022. Additional inclusion criteria were the availability of PSA and testosterone levels and PSADT assessed at the time of diagnosis of biochemical recurrence. Baseline characteristics and oncologic outcomes defined by PCWG3 (metastasis-free survival, and overall survival from initial recurrence) were compared by the presence of EMBARK criteria (PSADT ≤9 months, testosterone ≥150 ng/dL and a screening PSA of ≥2 ng/mL above the nadir after RT or ≥1 ng/mL after radical prostatectomy with or without postoperative RT). Univariate analysis was performed to assess factors influencing outcome in both subgroups. Survival was analyzed using the Kaplan – Meier method and log rank test (a p-value of < 0.05 was considered statistically significant). Material/Methods: Purpose/Objective:

Results:

We analyzed 706 nmCSPC patients with BCR across 13 cancer centres, identifying a total of 236 (33.4%) patients who met EMBARK criteria. Within this cohort, we observed a diverse range of risk profiles, tumor characteristics, and treatment modalities reflecting the heterogeneity in the presentation of BCR in prostate cancer, exhibiting clinical characteristics like those in the original trial, underscoring 161 (68.2%) patients in this subgroup in which additional