To assess whether the time to PSA nadir (TTN) has differential prognostic value in men who reach an undetectable versus detectable PSA nadir.
Two-hundred and four men from a prospective randomized controlled trial (RCT) involving radiation therapy with or without 6 months of androgen deprivation therapy (ADT) in unfavorable risk 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 (PCSM) calculated using Fine and Gray competing risk regression.
After a median follow-up of 18.17 years, 160 men died; 30 (18.75%) of CaP. Amongst men with a PSA nadir ≥ 0.2 ng/ml, a TTN < median (12 months) was significantly associated with an increased PCSM-risk versus the median or more (AHR 5.07, 95%CI 2.10-12.23, p<0.001); whereas this association was not observed among men with a PSA nadir of <0.2 ng/ml, (AHR 9.9, 95%CI 0.23-433.8, p=0.23).
Men with both a short TTN and detectable PSA nadir could be considered for entry on RCTs at a novel entry point prior to PSA failure at the time of PSA nadir to complete planned conventional ADT versus that plus agent(s) shown to improve outcomes in men with or at high risk of having castrate-resistant CaP.
Urology. 2019 Jan 18 [Epub ahead of print]
Luke R G Pike, Jing Wu, Ming-Hui Chen, Marian Loffredo, Andrew A Renshaw, John Pfail, Philip W Kantoff, Anthony V D'Amico
Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA; Department of Radiation Oncology, Brigham and Women's Hospital/Dana-Farber Cancer Institute, Boston, MA. Electronic address: ., Department of Computer Science and Statistics, University of Rhode Island, South Kingstown, RI., Department of Statistics, University of Connecticut, Storrs, CT., Department of Radiation Oncology, Brigham and Women's Hospital/Dana-Farber Cancer Institute, Boston, MA., Department of Pathology, Baptist Hospital and Miami Cancer Institute, Miami, Florida., Mount Sinai School of Medicine, New York, NY., Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY.