The prognostic significance of prostate-specific antigen dynamics during abiraterone therapy in patients with high-risk metastatic hormone-sensitive prostate cancer

To evaluate the prognostic significance of prostate-specific antigen (PSA) decline depth and duration in patients with high-risk metastatic hormone-sensitive prostate cancer (mHSPC) undergoing abiraterone treatment. We retrospectively analyzed data from 153 high-risk patients with mHSPC receiving first-line abiraterone therapy. Patients were stratified based on PSA dynamics during treatment. Kaplan-Meier survival analysis and Cox proportional hazards regression were used to assess the associations between PSA decline patterns, PSA progression-free survival (PSA-PFS), radiographic PFS (rPFS), and overall survival (OS). Among the 153 patients, 85 exhibited PSA nadir <0.2 ng ml-1, 48 had PSA nadir level ranging from 0.2 ng ml-1 to 4 ng ml-1, and 20 presented with a PSA nadir >4 ng ml-1. During abiraterone treatment, PSA nadir <0.2 ng ml-1 was significantly associated with improved median PSA-PFS (51.0 months vs 18.5 months vs 6.9 months, P < 0.0001), median rPFS (52.0 months vs 24.3 months vs 10.3 months, P < 0.0001), and median OS (not reached vs 48.5 months vs 28.1 months, P < 0.0001) compared with PSA nadir ≥0.2 ng ml-1 and <4 ng ml-1, and PSA nadir ≥4 ng ml-1. In the cohort with PSA nadir <0.2 ng ml-1, achieving PSA <0.2 ng ml-1 within 6 months and maintaining this level for over 10 months significantly enhanced clinical outcomes, as evidenced by median PSA-PFS (not reached vs 26.9 months, P < 0.0001), median rPFS (not reached vs 27.5 months, P < 0.0001), and median OS (not reached vs 44.4 months, P < 0.0001). Cox regression analysis revealed that achieving PSA <0.2 ng ml-1 within 6 months post-treatment and sustaining this level for over 10 months are independent prognostic factors. In high-risk patients with mHSPC receiving first-line abiraterone, sustained PSA suppression is a key indicator of therapeutic response. The rate, depth, and duration of PSA decline are critical prognostic factors.