Prognostic value of ultra-low PSA after 3 and 6 months of intensified androgen deprivation therapy in patients with metastatic castration-sensitive prostate cancer: Real-world data from a single healthcare center in Caracas, Venezuela.

Abstract

e17110 Background: Prostate cancer is the most frequent cause of cancer-related morbidity worldwide in men, with a national incidence of 50.49 cases per 100,000 men. The standard treatment for advanced castration-sensitive prostate cancer is intensified androgen deprivation therapy. Prostate-specific antigen (PSA) is crucial for monitoring. We aimed to evaluate the decrease in PSA at 3 and 6 months of treatment as a prognostic factor for biochemical recurrence-free survival (BRFS) in patients with metastatic castration-sensitive prostate cancer (mCSPC). Methods: This was a single center study conducted at the Medical & Educational Center La Trinidad, in Caracas (Venezuela). One hundred and eighteen (n = 118) patients with mCSPC who received intensified treatment and had recorded PSA levels at 3 and 6 months after starting treatment were included. Patients were stratified according to their PSA value into: group A (≤ 0.02 ng/mL), group B (≥ 0.02 ng/mL y < 0.2 ng/mL), group C (≥ 0.2 ng/mL and < 4 ng/mL), and group D (≥ 4 ng/mL). Kaplan-Meier plots were used to assess the BRFS, and forest plots with landmark analysis were used to interpret the risk of the variables. Results: The median BRFS was 72.96% at 2 years of follow-up for the general population. High-volume disease was identified as a risk factor with a hazard ratio (HR) of 3.42, while synchronous vs. metachronous disease and dual vs. triple therapy did not reach statistical significance. The variable with the greatest impact was ultra-low PSA with an HR of 0.07, acting as a protective factor, while PSA > 4 ng/mL acted as a strong predictor for biochemical recurrence with a HR of 13.52. Conclusions: A progressive and significant decrease in BRFS was observed as PSA levels increased. The median BRFS was not reached for groups A, B, and C; therefore, longer follow-up is required to draw definitive conclusions. A PSAt value < 0.02 ng/mL is a protective factor in terms of BRFS, while a PSAt > 4 ng/mL is a poor prognostic factor.