Time to Prostate-specific Antigen Nadir and the Risk of Death From Prostate Cancer Following Radiation and Androgen Deprivation Therapy

Abstract Objective To assess whether the time to prostate-specific antigen (PSA) nadir (TTN) has differential prognostic value in men who reach an undetectable vs detectable PSA nadir. Methods Two hundred and four men from a prospective randomized controlled trial involving radiation therapy with or without 6 months of androgen deprivation therapy in unfavorable risk Prostate cancer (CaP) at academic or community based centers in Massachusetts, enrolled between 1995 and 2001. Adjusted hazard ratios (AHR) of the risk of CaP-specific mortality calculated using Fine and Gray competing risk regression. Results After a median follow-up of 18.17years, 160 men died; 30 (18.75%) of CaP. Among men with a PSA nadir ≥ 0.2ng/ml, a TTN P P  = .23). Conclusion Men with both a short TTN and detectable PSA nadir could be considered for entry on randomized controlled trials at a novel entry point prior to PSA failure at the time of PSA nadir to completeplanned conventional androgen deprivation therapy vs that plus agent(s) shown to improve outcomes in men with or at high risk of having castrate-resistant CaP.