Time to Prostate-Specific Antigen Nadir Independently Predicts Overall Survival in Patients Who Have Metastatic Hormone-Sensitive Prostate Cancer Treated With Androgen-Deprivation Therapy

BACKGROUND: 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). METHODS: 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. RESULTS: 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 > 0.2 ng/mL, PSA > 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 > 0.2 ng/mL independently predicted shorter OS. CONCLUSIONS: 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. Cancer 2009;115:981-7. (c) 2009 American Cancer Society.