Time to prostate‐specific antigen nadir independently predicts overall survival in patients who have metastatic hormone‐sensitive prostate cancer treated with androgen‐deprivation therapy

Abstract

The objective of this study was to evaluate the relation between the kinetics of prostate-specific antigen (PSA) decline after the initiation of androgen-deprivation therapy (ADT) and overall survival (OS) in men with metastatic, hormone-sensitive prostate cancer (HSPC). The authors' institutional database was used to identify a cohort of men with metastatic HSPC who were treated with ADT. Patients were included if they had at least 2 serum PSA determinations before PSA nadir and at least 1 serum PSA value available within 1 month of ADT initiation. Patient characteristics, PSA at ADT initiation, nadir PSA, time to PSA nadir (TTN), and PSA decline (PSAD) in relation to OS were analyzed. One hundred seventy-nine patients were identified, and they had a median follow-up after ADT initiation of 4 years. The median OS after ADT initiation was 7 years. The median PSA level at ADT initiation and PSA nadir were 47 ng/mL and 0.28 ng/mL, respectively. On univariate analysis: TTN <6 months, PSAD >52 ng/mL per year, PSA nadir >or=0.2 ng/mL, PSA >or=47.2 ng/mL at ADT initiation, and Gleason score >7 were associated with shorter OS. On multivariate analysis, TTN <6 months, Gleason score >7, and PSA nadir >or=0.2 ng/mL independently predicted shorter OS. To the authors' knowledge, this was the first report to demonstrate that a faster time to reach a PSA nadir after the initiation of ADT was associated with shorter survival duration in men with metastatic HSPC. These results need confirmation but may indicate that a rapid initial response to ADT indicates more aggressive disease.