Prognostic Stratification Using Early Prostate-specific Antigen Kinetics in Men With Metastatic Hormone-sensitive Prostate Cancer.

Abstract

Background/aim: The prognostic significance of prostate-specific antigen (PSA) kinetics in metastatic castration-sensitive prostate cancer (mCSPC) patients treated with upfront therapy remains unclear. This study investigated the correlation between early PSA response and clinical outcomes in patients with mCSPC who received upfront therapy.

Patients and methods: We analyzed 106 patients with mCSPC who received upfront therapies [abiraterone acetate (ABI), enzalutamide (ENZ), apalutamide (APA), and docetaxel (DOC)] at Kurume University Hospital and its affiliated hospitals.

Results: Thirty-nine, 15, 38, and 14 patients were treated with ABI, DOC, ENZ, and APA, respectively. Among the total number of patients, 67 met the criteria for high-volume disease. Additionally, 83 patients were categorized as high risk. Patients with a PSA decline rate of ≥90% at 4 and 12 weeks post-upfront therapies had a significantly longer time to develop CRPC than those with a PSA decline of <90%. PSA cutoff values >26 ng/ml at 4 weeks post-upfront therapies and a PSA decline rate of ≥90% at 12 weeks post-upfront therapies were independent predictors of poor prognosis. Furthermore, patients were stratified into three groups based on PSA levels at 4 weeks and PSA decline rate at 12 weeks.

Conclusion: A larger PSA decline within three months of initiating upfront therapy is significantly associated with a longer time to CRPC in patients with mCSPC treated with upfront therapy. A combination of early PSA kinetics can be used to stratify the risk of CRPC progression in patients with mCSPC treated with upfront therapies.