Five-treatment stereotactic body radiation therapy (SBRT) may offer an effective alternative to surgery for patients with localized prostate cancer. In long-term follow-up findings from the phase III PACE-A trial presented at the 2026 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract LBA 32), SBRT demonstrated biochemical and disease control comparable to prostatectomy in patients with localized prostate cancer.
“Patients diagnosed with localized prostate cancer have long had to choose between surgery and radiation therapy without randomized evidence directly comparing the treatments. PACE-A changes that by providing long-term data on both cancer control and quality of life after surgery and SBRT,” said principal investigator Nicholas van As, MD, a consultant clinical oncologist at The Royal Marsden NHS Foundation Trust and a Professor at the Institute of Cancer Research in London. “Both treatments controlled the cancer extremely well, but SBRT offered clear advantages for urinary continence and sexual function.”
Study Methods
The international, randomized controlled phase III PACE-A trial enrolled 123 patients with localized prostate cancer from eight centers in the United Kingdom who were randomly assigned to undergo surgery or five-treatment SBRT. Hormone therapy was not allowed in the study. Patients were followed for a median of 8 years.
Key Findings
At a median follow-up of 8 years, biochemical/clinical failure occurred in 5 patients assigned to SBRT and 8 patients assigned to prostatectomy (HR = 0.48, 95% CI = 0.16–1.46; P = .18). Based on the hazard ratio, the estimated absolute difference in BCF-free survival at 5 years was 3.1 percentage points (95% CI = –2.6 to 5.0). The 5-year BCF-free rates were 94.8% with SBRT and 94.1% with prostatectomy.
“The numbers favor SBRT, but there were too few cancer events to conclude that it was superior,” Dr. van As said. “What we can say is that we saw very few cancer failures in either group, and that we have mature data showing excellent cancer outcomes with five-treatment radiotherapy.”
Several patients required subsequent treatment for progression, including one patient in the SBRT arm who underwent surgery and two who received androgen-deprivation therapy, and five patients in the prostatectomy arm who underwent radiotherapy and three who received androgen-deprivation therapy.
Patient-reported outcomes revealed that at 5 years, 8.3% of patients in the SBRT arm used at least one urinary pad as well as 48% of patients in the prostatectomy arm. Additionally, 0% and 3.6% of patients in the SBRT and prostatectomy arms, respectively, had moderate to large bowel function problems.
In a separate presentation at the 2026 ASTRO Annual Meeting (Abstract LBA 10), researchers also noted that although sexual function scores declined in both treatment arms, scores were higher in the SBRT arm.
“We now have longer-term information on both cancer control and the functional outcomes that matter greatly to patients,” Dr. van As said. “The urinary and sexual-function benefits seen at two years remained evident at 5 years, while cancer control remained excellent through longer follow-up. That gives patients a much fuller picture of what to expect from each treatment.”
Genitourinary adverse events of grade 2 or higher were reported in 3.8% of patients in the radiation arm and in 2.5% of those in the surgery arm.
“Patients should know that surgery is not their only curative treatment option and have the opportunity to discuss the benefits and side effects of both approaches,” Dr. van As noted.
Expert Comments
ASTRO expert Amar U. Kishan, MD, ASTRO Genitourinary Cancer Resource Panel Chair and a radiation oncologist at UCLA commented: “Patients choosing treatment for localized prostate cancer want to know how well it will control their cancer and how it may affect their daily lives. PACE-A directly compared contemporary surgery with five-treatment radiation and followed patients long enough to address both questions. The results show durable cancer control with both approaches, and persistently better sexual and urinary function with SBRT. Together, these longer-term data give patients a more complete picture of what they can expect from each treatment."
DISCLOSURES: Dr. van As reported no conflicts of interest. For full disclosures of the other study authors, visit amportal.astro.org (Abstract LBA 32).
