Salvage Radiotherapy for Prostate Cancer: Is Elevated PSA After Surgery Linked to Poor Outcomes?
Posted: Tuesday, January 12, 2021
Persistently elevated prostate-specific antigen (PSA) levels after radical prostatectomy appear to be neither predictive nor prognostic for patients with recurrent prostate cancer after prostatectomy. They should not be used as a selection criterion for salvage radiotherapy, according to Samuel Birer, MD, of the University of Michigan, Ann Arbor, and colleagues. They reported their analysis of the RTOG 9601 clinical trial during the virtual edition of the 2020 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract 36), which also was published in the International Journal of Radiation Oncology • Biology • Physics.
This post-hoc secondary analysis included 760 men with prostate cancer randomly assigned to salvage radiotherapy with ± 2 years of antiandrogen therapy. Patients were classified according to the lowest level PSA level after radical prostatectomy and categorized by detectable (> 0.1 ng/mL) or undetectable (≤ 0.1 ng/mL) PSA level after radical prostatectomy. A total of 331 patients had detectable PSA nadirs greater than 0.1 ng/mL.
The median follow-up was 13 years. Statistical comparisons between patients in the detectable versus undetectable PSA cohorts at 12 years demonstrated that persistently elevated PSA levels were not associated with any oncologic endpoints; overall survival was 26% versus 26%, biochemical failure was 56% versus 56%, prostate-specific cancer mortality was 11% versus 9%, and distant metastasis was 19% versus 18%, respectively. When the multivariable analysis was conducted on PSA nadir status, antiandrogen therapy was significant for improvements in overall survival.
“A persistently elevated PSA post radical prostatectomy…does not identify a subset of men that differentially benefit from antiandrogen therapy in the setting of recurrent prostate cancer,” explained the researchers. “These data do not support the use of a persistently elevated PSA to be used as a selection criterion for salvage radiotherapy trials, as it was neither prognostic nor predictive,” they concluded.
Disclosure: For full disclosures of the study authors, visit redjournal.org.