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Updated: May 3, 2026
A Bioluminescent and Fluorescent Orthotopic Syngeneic Murine Model of Androgen-dependent and Castration-resistant Prostate Cancer
Published on: March 6, 2018
Prostate-specific Antigen Nadir and Time to Nadir Predict Recurrence in Postprostatectomy Patients Treated with
Federico Mastroleo1, Riccardo Villa1, Mattia Zaffaroni2
1Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy; Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy.
Background And Objective:
Salvage radiotherapy (SRT) is often curative in men with biochemical recurrence (BCR) after radical prostatectomy (RP); however, a subset experiences progression. While the depth of prostate-specific antigen (PSA) nadir after SRT is a known prognostic factor, its combined role with time to nadir (TTN) in the salvage setting, in absence of androgen deprivation therapy (ADT), has not been evaluated systematically and the present study aims to evaluate it.
Methods:
We retrospectively included RP patients treated with SRT across 15 European centers. No prior or concomitant ADT was allowed. Patients were stratified into four groups by PSA nadir (<0.1 vs ≥0.1 ng/ml) and TTN (<6 vs ≥6 mo). The primary endpoint was distant metastasis-free survival (DMFS). The secondary endpoint was BCR-free survival (BRFS).
Key Findings And Limitations:
A total of 1189 patients were included in the study, with a median clinical follow-up of 4.4 (interquartile range, 2.7-6.4) yr, and 5-yr BRFS and DMFS probabilities of 62% (95% confidence interval [CI], 59-65%) and 89% (95% CI, 87-91%), respectively. Patients with favorable kinetics (nadir <0.1 ng/ml, TTN ≥6 mo; 56.3% of cohort) achieved a 5-yr DMFS rate of 96% (95% CI, 94-98%), while high-risk patients (nadir ≥0.1 ng/ml, TTN <6 mo; 14.7%) had poor outcomes (5-yr DMFS rate 63%; 95% CI, 55-72%). A multivariable analysis confirmed a nadir of ≥0.1 ng/ml (hazard ratio [HR] 10.1; 95% CI, 8.0-12.7 for BRFS, and HR 7.1; 95% CI, 4.5-11.2 for DMFS) and TTN <6 mo (HR 3.0; 95% CI, 2.3-3.8, and HR 1.8; 95% CI, 1.1-2.7, respectively) as independent adverse factors.
Conclusions And Clinical Implications:
Our study showed that the combination of PSA nadir depth and TTN after SRT allows an improvement in prognostic stratification of SRT patients with BCR after RP. These findings might improve patient-tailored decisions between surveillance, active treatment, and treatment escalation.
