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Updated: Jun 12, 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 halving time while on neoadjuvant androgen deprivation therapy is associated with
Renuka Malik1, Ashesh B Jani, Stanley L Liauw
1Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA.
Purpose:
To assess whether the PSA response to neoadjuvant androgen deprivation therapy (ADT) is associated with biochemical control in men treated with radiation therapy (RT) for prostate cancer.
Methods And Materials:
In a cohort of men treated with curative-intent RT for localized prostate cancer between 1988 and 2005, 117 men had PSA values after the first and second months of neoadjuvant ADT. Most men had intermediate-risk (45%) or high-risk (44%) disease. PSA halving time (PSAHT) was calculated by first order kinetics. Median RT dose was 76 Gy and median total duration of ADT was 4 months. Freedom from biochemical failure (FFBF, nadir + 2 definition) was analyzed by PSAHT and absolute PSA nadir before the start of RT.
Results:
Median follow-up was 45 months. Four-year FFBF was 89%. Median PSAHT was 2 weeks. A faster PSA decline (PSAHT ≤2 weeks) was associated with greater FFBF (96% vs. 81% for a PSAHT >2 weeks, p = 0.0110). Those within the fastest quartile of PSAHTs (≤ 10 days) achieved a FFBF of 100%. Among high-risk patients, a PSAHT ≤2 weeks achieved a 4-yr FFBF of 93% vs. 70% for those with PSAHT >2 weeks (p = 0.0508). Absolute PSA nadir was not associated with FFBF. On multivariable analysis, PSAHT (p = 0.0093) and Gleason score (p = 0.0320) were associated with FFBF, whereas T-stage (p = 0.7363) and initial PSA level (p = 0.9614) were not.
Conclusions:
For men treated with combined ADT and RT, PSA response to the first month of ADT may be a useful criterion for prognosis and treatment modification.
