SBRT, prostatectomy show comparable long-term disease control in PACE-A trial

At a median follow-up of 8 years, stereotactic body radiotherapy (SBRT) and radical prostatectomy showed comparable rates of freedom from biochemical or clinical failure (BCF) in men with low- or intermediate-risk localized prostate cancer.¹

Numerically, the 8-year BCF-free rate was higher with SBRT, but the trial had few events and the between-group difference was not statistically significant. The data come from the phase 3 PACE-A trial (NCT01584258), presented as a late-breaking abstract at the 2026 American Society for Radiation Oncology (ASTRO) Annual Meeting in Boston, Massachusetts.

“Randomized evidence of efficacy of radical prostatectomy vs SBRT is lacking,” said lead author Nicholas van As, MD, MB, during the presentation at ASTRO. “PACE is the first phase 3 randomized trial comparing prostatectomy with SBRT.”

Trial design and results

PACE is an open-label, multicohort phase 3 platform. In PACE-A, men with cT1c-T2c disease, Gleason score of 3+4 or lower, and a prostate-specific antigen (PSA) level of 20 ng/mL or less were eligible if they were suitable candidates for surgery. All patients were MRI staged. Participants were randomly assigned 1:1 to SBRT (36.25 Gy in 5 fractions) or prostatectomy, which could be open, laparoscopic, or robot assisted. Androgen deprivation therapy (ADT) was not permitted.

The co-primary end points were patient-reported pad use and bowel bother at 2 years. Those results were published in 2024 in European Urology.² The current analysis covers secondary end points: freedom from BCF, overall survival (OS), clinician-reported late effects, and 5-year patient-reported outcomes (PROs).

Between August 2012 and February 2022, 123 patients were randomly assigned (60 to prostatectomy and 63 to SBRT). The median age was 65.5 years, and most patients had intermediate-risk disease.

Thirteen BCF events occurred: 8 in the prostatectomy arm and 5 in the SBRT arm. The unadjusted hazard ratio (HR) was 0.48 (95% CI, 0.16 to 1.46; P = .18). BCF-free rates at 5 years were 95% with SBRT and 94% with prostatectomy. At 8 years, they were 91% and 84%, respectively. The absolute difference at 5 years, estimated from the HR, was 3.1% (90% CI, -2.6 to 5.0).

There were 4 deaths in the prostatectomy arm and 3 in the SBRT arm, and none were from prostate cancer. OS was 98% in both arms at 5 years. At 8 years, OS was 95% in the SBRT arm vs 92% in the prostatectomy arm (HR, 0.55; 95% CI, 0.12 to 2.46; P = .43).

“It is really important to remember that these men are not dying of prostate cancer, so it's the functional outcomes that are crucial to these men,” van As noted during the presentation.

On the Expanded Prostate Cancer Index Composite 26-item questionnaire (EPIC-26), 14 of 29 patients in the prostatectomy arm (48%) and 3 of 36 patients in the SBRT arm (8%) reported using 1 or more pads daily at 5 years.

van As added, “For 85% of these patients, they were just wearing 1 pad a day, but they were still wearing a pad. I think patients should be aware of this information before they select treatment.”

One prostatectomy patient (3.6%) and no SBRT patients reported a moderate or big bowel problem.

“When we reported this at 2 years, there was a significant difference between SBRT and prostatectomy—SBRT was slightly worse—but that appears to have disappeared by 5 years,” van As explained.

CTCAE grade 2 or higher gastrointestinal toxicity occurred in 1 patient in the SBRT arm (2%) and no prostatectomy patients. Grade 2 or higher genitourinary toxicity occurred in 2 patients in the SBRT arm (4%) and 1 patient in the prostatectomy arm (3%).

For progression, 5 patients in the prostatectomy arm received prostate bed radiotherapy and 1 patient in the SBRT arm underwent salvage prostatectomy. Five patients started ADT (3 prostatectomy, 2 SBRT).

Based on these results, van As concluded, “Eight-year biochemical free rates numerically favored SBRT, although few events occurred and the between-group difference was not statistically significant. These randomized findings support SBRT as an effective non-surgical treatment option for localized prostate cancer, and low rates of clinician- and patient-reported [adverse] effects were noted in both options.”

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REFERENCES
1. van As N, Patel J, Tree A, et al. Efficacy of Radical Prostatectomy Versus Stereotactic Body Radiotherapy (SBRT) for Localised Prostate Cancer: Results from an international Phase III Randomised Controlled Trial (PACE - A). Presented at: 2026 American Society for Radiation Oncology Annual Meeting. September 26 – 30, 2026. Boston, Massachusetts. LBA 32

2. van As N, Yasar B, Griffin C, et al. Radical Prostatectomy Versus Stereotactic Radiotherapy for Clinically Localised Prostate Cancer: Results of the PACE-A Randomised Trial. Eur Urol. 2024;86(6):566-576. doi:10.1016/j.eururo.2024.08.030