Apalutamide in patients with metastatic hormone-sensitive prostate cancer: Real-world experience and a retrospective multicenter analysis.

e17088 Background: The combination of androgen deprivation therapy (ADT) and apalutamide has improved survival outcomes for patients with metastatic hormone-sensitive prostate cancer (mHSPC), offering a promising treatment strategy. Objectives: To assess the real-world efficacy, PSA kinetics, and safety of apalutamide plus ADT in patients with mHSPC and explore surrogate markers for survival outcomes. Methods: 129 patients diagnosed with mHSPC were included, treated at four public hospitals in the Quirón Salud Madrid network between March 2021 and March 2024. Key outcomes included overall survival (OS) and radiological progression-free survival (rPFS), stratified by metastasis volume (low/high), presentation type (de novo/recurrent), and PSA response (≤0.2 ng/ml and ≤0.02 ng/ml). Results: Patients had a mean age of 74.5 years and a median follow-up of 20.7 months. Median PSA at treatment initiation was 2.56 ng/ml. Nearly half of the cohort (47.3%) presented with metastatic disease de novo, The majority had low-volume disease (71.3%), and 8.5% had visceral metastases. 76.0% of patients achieved PSA ≤0.2 ng/ml, and 55.0% achieved PSA ≤0.02 ng/ml. Median OS and rPFS for the cohort were 87.6% and 80.6%, respectively. Low-volume patients had better OS (91.3%) compared to high-volume patients (78.4%, P = 0.011). Among de novo patients, OS was 85.2%, compared to 89.7% in recurrent cases (P = 0.366). A rapid decline in PSA was associated with better outcomes: PSA ≤0.2 ng/ml led to an rPFS of 87.8% versus 58.1% (P < 0.001) and OS of 91.8% versus 74.2% (P < 0.001). Achieving PSA ≤0.02 ng/ml further amplified these differences, with rPFS of 87.8% versus 58.1% (P < 0.001) and OS of 94.4% versus 79.3% (P = 0.002). Survival outcomes were consistent regardless of metastasis site. Conclusions: This real-world analysis highlights the effectiveness of apalutamide plus ADT in mHSPC. A rapid PSA decline (≤0.2 ng/ml or ≤0.02 ng/ml) emerged as a strong predictor of prolonged OS and rPFS, highlighting its potential as a surrogate marker for therapeutic success. These findings reinforce the importance of this combination in optimizing outcomes for patients with mHSPC. Descriptive analysis of the cohort. Variable Mean age 74,5 (55 - 96) Clinical presentation PSA elevationUrinary tract symptomsImaging PainIncidental finding in cistectomy Other 71,3% (92) 13,2% (17) 3,10% (4) 1,6% (2) 0,8% (1) 3,90% (5) Median PSA at diagnosis 12,7 (0,15 - 2255) Median PSA a the start of apalutamide 2,56 (0 - 1947) Francini groups De novo/Low volume De novo/High volumeRecurrent/Low volume Recurrent/Low volume 31,0% (40) 16,3% (21) 40,3% (52) 12,4% (16) Metastases M1a M1b M1c 20,2% (26) 71,3% (92) 8,50% (11) Staging CT + bone scanPET-choline/PSMA 65,0% (67) 44,7% (46) Primary tumor radiotherapy 35,7% (46) SBRT in metastases 40,3% (52) PSA reduction ≤ 0,2 ng/ml ≤ 0,02 ng/ml 76,0% (98) 55,0% (71)