Both the performance characteristics of prostate-specific membrane antigen positron emission tomography and insurance approval improves with increasing prostate-specific antigen (PSA) level causing some physicians to delay post-radical prostatectomy salvage radiation therapy (sRT) after PSA failure. Yet, it is unknown for men with at most one high-risk factor (ie, pT3/4 or prostatectomy [p] Gleason score 8-10) whether a PSA level exists above which initiating sRT is associated with increased all-cause mortality (ACM)-risk and was investigated.
Using a multinational database of 25,551 patients with pT2-4N0 or NXM0 prostate cancer, multivariable Cox regression analysis evaluated whether an association with a significant increase in ACM-risk existed when sRT was delivered above a prespecified PSA level beginning at 0.10 ng/mL and in 0.05 increments up to 0.50 ng/mL versus at or below that level. The model was adjusted for age at and year of radical prostatectomy, established prostate cancer prognostic factors, institution, and the time-dependent use of androgen deprivation therapy.
After a median follow-up of 6.00 years, patients who received sRT at a PSA level >0.25 ng/mL had a significantly higher ACM-risk (AHR, 1.49; 95% CI, 1.11 to 2.00; P = .008) compared with men who received sRT when the PSA was ≤0.25 mg/mL. This elevated ACM-risk remained significant for all PSA cutpoints up to 0.50 ng/mL but was not significant at PSA cutpoint values below 0.25 ng/mL.
Among patients with at most one high-risk factor, initiating sRT above a PSA level of 0.25 ng/mL was associated with increased ACM-risk.
Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2023 Mar 01 [Epub ahead of print]
Derya Tilki, Ming-Hui Chen, Jing Wu, Hartwig Huland, Markus Graefen, Osama Mohamad, Janet E Cowan, Felix Y Feng, Peter R Carroll, Anthony V D'Amico
Martini-Klinik Prostate Cancer Center, University Hospital Hamburg Eppendorf, Hamburg, Germany., Department of Statistics, University of Connecticut, Storrs, CT., Department of Computer Science and Statistics, University of Rhode Island, Kingston, RI., Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA., Department of Urology, University of California, San Francisco, San Francisco, CA., Department of Radiation Oncology, Brigham and Women's Hospital and Dana Farber Cancer Institute, Boston, MA.