Men with localized prostate cancer who received five sessions of focused radiation had cancer control similar to men who had their prostate removed, eight years after treatment, in a small British trial presented Sept. 28 at the American Society for Radiation Oncology (ASTRO) Annual Meeting.
At eight years, 91% of men treated with stereotactic body radiotherapy (SBRT) were free of cancer recurrence, compared with 84% of men who had surgery. That gap was not statistically significant, so the trial cannot say one treatment controlled cancer better than the other.
The difference that stood out was in daily life. Five years after treatment, 48% of surgery patients used at least one urinary pad a day, compared with 8% of radiation patients. For men weighing options, and for partners helping them decide, that side-effect gap may matter as much as the cancer numbers.
Eight-Year Results From PACE-A
The PACE-A trial randomly assigned 123 men at eight centers in the United Kingdom to SBRT or radical prostatectomy, according to the ASTRO release. Most participants had low- or intermediate-risk cancer confined to the prostate, and none received hormone therapy. They enrolled between 2012 and 2022, had a median age of 65.5, a Gleason score of 3+4 or lower, and a PSA level of 20 or below.
SBRT uses precisely aimed, high-dose radiation delivered in five treatments, usually over one to two weeks. Radical prostatectomy removes the whole prostate in an operation that requires anesthesia and a recovery period.
Cancer failure events were rare. There were 13 in total, eight in the surgery group and five in the radiation group, Urology Times reported. The hazard ratio was 0.48 with a p-value of 0.18, meaning the lower number of events after radiation could reflect chance.
Overall survival at eight years was 95% after radiation and 92% after surgery. No man in either group died of prostate cancer, which is why the researchers focused closely on side effects and quality of life.
Sexual function also differed. At five years, median erectile function scores on a 25-point scale were 19 after radiation and 5 after surgery. Moderate or substantial bowel problems were uncommon in both groups.
The Trial's Size Limits What It Can Prove
PACE-A was too small to prove that radiation is as good as surgery. With only 123 men and 13 cancer events, it could not detect modest differences in cancer control. A result that is not statistically significant means no clear difference was found, not that the treatments were proven equal.
The findings also apply mainly to men with lower-risk disease, not to those with aggressive or advanced cancer. And the eight-year data are conference results. Earlier PACE-A findings were published in European Urology in 2024, but the eight-year results have not yet appeared in a peer-reviewed journal.
The trial was funded by Accuray and Varian, companies that make radiation equipment, along with The Royal Marsden and The Royal Marsden Cancer Charity. That industry funding is worth knowing when weighing the results.
Researchers and Specialists Weigh the Tradeoffs
"Both treatments controlled the cancer extremely well, but SBRT offered clear advantages for urinary continence and sexual function," said Nicholas van As, the trial's principal investigator and a consultant clinical oncologist at The Royal Marsden NHS Foundation Trust in London, in the ASTRO release.
"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 told Urology Times.
A larger companion trial, PACE-B, compared five-session SBRT with conventional radiation spread over several weeks in 874 men. It found similar cancer control after a median follow-up of about six years, the National Cancer Institute reported. "These data support the use of SBRT as a standard of care for intermediate-risk prostate cancer. But ... it still may not be for everyone," Krishnan Patel of NCI's Center for Cancer Research said at the time.
In PACE-B, urinary problems over five years of follow-up were more common after SBRT, 27% versus 18%, but the difference appeared mostly soon after treatment and faded after two years. Bowel and sexual side effects did not differ significantly between the two radiation groups. "It's extremely convenient to be able to shrink your treatment from about 5 and a half weeks to about a week and a half," Dakim Gaines of Vanderbilt-Ingram Cancer Center told NCI.
Choosing Between Surgery and Radiation
For many men with lower-risk prostate cancer, the decision involves more than two options. Some can be monitored with regular PSA tests and biopsies instead of immediate treatment, an approach called active surveillance. Others may be offered surgery, external or internal radiation therapy, or a combination.
Men newly diagnosed can ask their care team where their cancer falls on the risk scale, which treatments fit that risk, and what side effects are most likely in their situation. Seeing both a urologist and a radiation oncologist before deciding can give a fuller picture, since each specialist tends to know their own treatment best.
Practical factors also count. SBRT is completed in five visits, while surgery requires anesthesia and recovery time. Insurance coverage, travel to a radiation center, and personal priorities around continence and sexual health can all shape the choice. Partners often help track appointments and side effects, so including them in the conversation can make the decision easier to live with.
New urinary leakage, blood in the urine, bone pain, or unexplained weight loss after treatment should be reported to a doctor promptly. MedicalDaily will update this report if the eight-year PACE-A data are published in full.
Key Questions Answered
What did the PACE-A trial compare?
Five-session stereotactic body radiotherapy versus surgical removal of the prostate in 123 men with localized prostate cancer.
Which treatment controlled cancer better?
Neither was proven better. At eight years, 91% of radiation patients and 84% of surgery patients were free of recurrence, a difference that was not statistically significant.
Were side effects different?
Yes. At five years, 48% of surgery patients used urinary pads daily versus 8% after radiation, and sexual function scores were higher after radiation.
Does this apply to all prostate cancer?
No. The trial mainly included men with low- or intermediate-risk disease confined to the prostate.
Is the study published?
The eight-year results were presented at a conference. Earlier results appeared in European Urology.
Who funded the trial?
Accuray, Varian, The Royal Marsden, and The Royal Marsden Cancer Charity.
Published by Medicaldaily.com
