Adjuvant radiation therapy (RT) after radical prostatectomy may offer greater benefit than early salvage RT in men with high-risk prostate cancer, according to results of a study published in the Journal of Clinical Oncology.
The study included 26,118 men with pT2-4N0 or N1M0 prostate cancer who were treated at several institutions from June 23, 1989, to July 26, 2016.
All patients underwent radical prostatectomy and pelvic lymph node assessment, and some of them received either early salvage RT or adjuvant RT.
At a median follow-up of 8.16 years, 2104 patients (8.06%) had died. In all, 539 deaths (25.62%) were due to prostate cancer.
All-cause mortality was significantly lower with adjuvant RT versus early salvage RT among patients with adverse pathology at radical prostatectomy, both when patients with positive pelvic lymph nodes were excluded (hazard ratio [HR], 0.31; 95% CI, 0.12-0.78; P =.01) and when they were included (HR, 0.61; 95% CI, 0.41-0.89; P =.01).
Adverse pathology was defined as having pelvic lymph node-positive disease, Gleason score 8 to 10, extraprostatic extension, adjacent organ invasion, or seminal vesicle invasion.
There was no significant benefit with adjuvant RT over salvage RT in patients with low-risk pathology (P .28).
Several earlier randomized studies had not shown a benefit with adjuvant RT over early salvage RT in patients who had undergone radical prostatectomy. The authors of the current study postulated that the prior studies may have “immortal time bias” present in the data analysis, which concealed the benefit of adjuvant RT for patients with high-risk pathology.
The authors also noted that the earlier studies may have been underpowered because patients with high-risk pathology made up only 9% to 17% of the study cohorts.
Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Tilki D, Chen M-H, Wu J, et al. Adjuvant versus early salvage radiation therapy for men at high risk for recurrence following radical prostatectomy for prostate cancer and the risk of death. J Clin Oncol. Published online June 4, 2021. doi:10.1200/JCO.20.03714