PEACE-1
In de novo metastatic castration-sensitive prostate cancer, does abiraterone + prednisone added to ADT ± docetaxel improve rPFS and OS?
Absolute Effect
Fixed-time OS/rPFS percentages were not used to manufacture an NNT from hazard ratios. The clinically relevant effect is therefore presented as HRs plus the treatment population and follow-up rather than a misleading median-derived NNT.
Key result: In the docetaxel population, the OS HR was 0.75. The trial also found no interaction between abiraterone and radiotherapy, supporting pooled assessment of abiraterone efficacy.
Safety: Grade ≥3 adverse events in the docetaxel population were 63% with abiraterone versus 52% without; hypertension was 22% versus 13%.
Interpretation & limitations
The factorial design simultaneously addresses systemic intensification and prostate radiotherapy. It is important not to use the abiraterone result as evidence that prostate RT and abiraterone are interchangeable interventions.
Primary source
Fizazi K, et al. Lancet. 2022;399:1695–1707.
PEACE-1: adding prostate RT to modern systemic therapy
PEACE-1 also tested prostate radiotherapy in de novo metastatic castration-sensitive disease using a 2 × 2 factorial design. This is the comparison relevant to the prostate-primary RT question; it is distinct from the abiraterone comparison summarized above.
Low-volume disease receiving abiraterone: median radiographic PFS was 7.5 years with prostate RT versus 4.4 years without RT (adjusted HR 0.65; 99.9% CI 0.36–1.19; reported p=0.019). The trial reported a qualitative interaction between RT and abiraterone for rPFS, so these groups should not be indiscriminately pooled.
Reported median rPFS; bars scaled to the larger median. This is not an NNT.
Overall survival in low-volume disease: median OS was 7.5 years with RT versus 6.9 years without RT; HR 0.98 (95.1% CI 0.74–1.28; p=0.86), showing no OS improvement in this analysis.
Primary source: Bossi A, et al. Lancet. 2024;404:2065–2076. Read PEACE-1 radiotherapy analysis →