Is There a Role for Prostate Radiotherapy in De Novo Metastatic Prostate Cancer?

Overwhelming level 1 evidence supports the addition of androgen receptor pathway inhibitors with or without docetaxel in patients with de novo metastatic castration-sensitive prostate cancer (mCSPC). A meta-analysis of two randomized trials showed evidence of survival benefit from the addition of prostate radiotherapy in men with low-volume metastatic disease (Eur Urol 2019; 76:115).

Now, investigators from the industry-funded, randomized, phase 3 PEACE-1 trial report the efficacy and safety associated with the addition of prostate radiotherapy to androgen deprivation therapy (ADT), docetaxel, and abiraterone in these patients. In the ongoing open-label trial, 1172 patients with de novo mCSPC were randomly assigned to receive standard of care (ADT) alone, standard of care plus radiotherapy, standard of care plus abiraterone, or standard of care plus abiraterone plus radiotherapy. The trial was later amended to include docetaxel as part of standard of care. Coprimary endpoints were radiographic progression-free survival (rPFS) and overall survival (OS).

At a median follow-up of 6 years, key outcomes were as follows:

• No OS benefit from the addition of radiotherapy was seen either in the cohort of patients with low-volume disease (<3 bone metastases, no visceral metastases) or in the overall study population.
• Among patients with low-volume disease, rPFS was significantly improved with the addition of radiotherapy to ADT plus abiraterone, with or without docetaxel.
• Risk for serious genitourinary adverse events was reduced with radiotherapy both in patients with low-volume disease and in the overall cohort.