Key clinical point: Salvage radiotherapy failed to meet non-inferiority endpoint of biochemical progression compared with adjuvant radiotherapy, but had lower genitourinary toxicity.

Major finding: Five-year freedom from biochemical progression in the adjuvant radiotherapy group was 86% (95% confidence interval [CI], 81-92) and in the salvage radiotherapy group was 87% (95% CI, 82-93). Grade 2 or worse genitourinary toxicity rates in the adjuvant and salvage radiotherapy groups were 70% and 50%.

Study details: In a phase 3 non-inferiority trial, patients who had radical prostatectomy (RP) for prostatic adenocarcinoma with high-risk pathological staging were randomly assigned (1:1) to either adjuvant radiotherapy within 6 months of RP or early salvage radiotherapy.

Disclosures: The study was funded by New Zealand Health Research Council, Australian National Health Medical Research Council, Cancer Council Victoria, Cancer Council NSW, Auckland Hospital Charitable Trust, Trans-Tasman Radiation Oncology Group Seed Funding, Cancer Research Trust New Zealand, Royal Australian and New Zealand College of Radiologists, Cancer Institute NSW, Prostate Cancer Foundation Australia, and Cancer Australia. ID Davis, JM Martin, and HH Woo reported ties with various pharmaceutical companies. C Fraser-Browne reported receiving grants from multiple organizations. All other authors declared no conflicts of interest.