No Improvement From Adjuvant Radiotherapy Post-Prostatectomy for Patients With Prostate Cancer At Risk of Recurrence

According to long-term results from the RADICALS-RT study, adjuvant radiotherapy does not meaningfully improve disease control and increases the risk of urinary and bowel morbidities among patients with prostate cancer at risk of recurrence after prostatectomy. 

“The optimal timing of radiotherapy after radical prostatectomy for prostate cancer has been uncertain,” stated Chris Parker, MD, The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom, and coauthors. “RADICALS-RT compared efficacy and safety of adjuvant RT versus an observation policy with salvage RT.” 

In this trial, 1,396 patients at risk of disease recurrence (prostate specific antigen ≥ 0.1ng/ml or 3 consecutive rises) were randomized on a 1-to-1 basis to receive either adjuvant radiotherapy (n = 697) or salvage radiotherapy (n = 699). Patients were stratified based on Gleason score, margin status, planned radiotherapy schedule, and treatment center. The primary end point was 10-year freedom-from-distant metastasis. Secondary end points included overall survival (OS), safety, and patient-reported outcomes. 

At a median follow-up of 7.8 months, 80 distant metastasis events occurred and there were 109 deaths (17 due to prostate cancer). Freedom-from-distant metastasis was 93% in the adjuvant arm and 90% in the salvage arm (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.43 to 1.07; P = .095). OS was not improved (HR, 0.980; 95% CI, 0.667 to 1.440; P = .917). Patients in the adjuvant arm reported greater incidences of urinary and fecal incontinence at 1 year post randomization. At 10 years, fecal incontinence remained significant. 

These results indicate that “adjuvant RT after radical prostatectomy increases the risk of urinary and bowel morbidity, but does not meaningfully improve disease control,” concluded Dr Parker et al. “An observation policy with salvage RT for PSA failure should be the current standard after radical prostatectomy.” 

Source: 

Parker CC, Petersen PM, Cook AD, et al. Timing of radiotherapy (RT) after radical prostatectomy (RP): Long-term outcomes in the RADICALS-RT trial [NCT00541047]. Ann Oncol. Published online: April 5, 2024. doi: 10.1016/j.annonc.2024.03.010