PACE-A Trial Confirms Efficacy of SBRT and Prostatectomy for Localized Prostate Cancer

An updated efficacy analysis of the international phase III PACE-A trial has revealed high rates of freedom from biochemical or clinical failure (BCF) with both stereotactic body radiation therapy (SBRT) and radical prostatectomy in patients with localized prostate cancer. This data, presented at the 2026 American Society for Radiation Oncology (ASTRO) Annual Meeting, indicated no statistically significant difference in outcomes between the two treatment modalities.

Dr. Nicholas van As, principal investigator from The Royal Marsden NHS Foundation Trust in London, noted that this trial addresses the longstanding question facing patients diagnosed with localized prostate cancer, who have historically had to choose between surgery and radiation therapy without randomized comparative evidence. He emphasized that the PACE-A trial changes this landscape.

The updated analysis highlights that the previously observed urinary function benefit associated with SBRT continued with extended follow-up. Another report from the same trial presented at the meeting indicated enduring differences in sexual function that favored SBRT. Dr. van As remarked, "That gives patients a much fuller picture of what to expect from each treatment," advocating for SBRT to be considered when patients deliberate over radical prostatectomy.

Study Design The PACE-A trial involved 123 patients across eight centers in the UK, who were randomly assigned to receive either surgery or five treatments of SBRT, without the inclusion of hormone therapy. Patients were monitored for an average median follow-up of 8 years.

At this median follow-up duration, biochemical or clinical failure was noted in five patients within the SBRT group compared to eight patients in the prostatectomy group, yielding a hazard ratio of 0.48 (95% CI = 0.16–1.46; P = .18). The 5-year BCF-free survival rates stood at 94.8% for SBRT and 94.1% for prostatectomy, with an estimated absolute difference of 3.1 percentage points (95% CI = –2.6 to 5.0).

While Dr. van As commented that the statistical data points toward SBRT, he also emphasized that the insufficient number of cancer events renders a definitive conclusion about superiority impossible. He added, "We saw very few cancer failures in either group, and that we have mature data showing excellent cancer outcomes with five-treatment radiotherapy."

Patient-reported outcomes at 5 years indicated that 8.3% of patients in the SBRT arm required urinary pads compared to 48% in the prostatectomy arm. There were also discrepancies in bowel function issues, with no patients experiencing moderate to large problems in the SBRT group versus 3.6% in the surgery group.

Adverse Events Genitourinary adverse events of grade 2 or higher were reported in 3.8% of radiation therapy patients and in 2.5% of those who underwent surgery.

Overall, the PACE-A trial findings emphasize that both SBRT and radical prostatectomy provide effective treatment options for localized prostate cancer, with SBRT exhibiting favorable functional outcomes that persist over time.

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). Abstract LBA32. ASTRO Annual Meeting. Presented September 28, 2026.
2. Yasar B, Patel J, Tree A, van As N (presenter), et al: Long-term outcomes of sexual function in the PACE-A trial: A multicentre randomised study of radical prostatectomy vs stereotactic body radiotherapy (SBRT) for early localised prostate cancer. Abstract LBA10. ASTRO Annual Meeting. Presented September 29, 2026.