Headlines in British newspapers this week said five sessions of radiation are as effective as surgery for prostate cancer. The trial behind those headlines, presented at the ASTRO annual meeting in Boston this week, found something narrower: after eight years, cancer control looked similar between the two approaches in a trial of 123 men, according to Urology Times — but the study was never built to prove they are equal, and it found a much clearer difference in side effects.
The trial
According to Urology Times, PACE-A randomized 123 men with early, mostly intermediate-risk prostate cancer between August 2012 and February 2022 — 60 to surgery, 63 to radiation; eligible men had cancer confined to the prostate, a PSA of 20 or under, and were healthy enough for surgery; hormone therapy was not permitted as part of treatment, and the median age was 65.5. Surgery meant a radical prostatectomy, most commonly through a minimally invasive robotic procedure; the radiation arm got stereotactic body radiation therapy (SBRT) — five outpatient sessions over one to two weeks, ASTRO said. It was led by Nicholas van As of the Royal Marsden and the Institute of Cancer Research in London. The results shown this week are a late-breaking conference abstract, not a new journal paper; the trial’s two-year data were published in European Urology in 2024, Urology Times reported.
Cancer control and its limits
At eight years, 91% of the SBRT group and 84% of the surgery group had “freedom from failure” — meaning no PSA rise past the trial’s thresholds, recurrence, spread (metastases), start of hormone therapy or death from prostate cancer — ASTRO reported. “Both treatments controlled the cancer extremely well, but SBRT offered clear advantages for urinary continence and sexual function,” van As said in ASTRO’s release. The gap was not statistically significant, and only 13 men in the entire trial reached that failure point: five on radiation, eight after surgery. That small number is why “as effective” overstates the finding. As ASTRO’s release puts it, the trial “was not designed to establish noninferiority for cancer control, however, so the results cannot determine whether the treatments were equivalent on this outcome.” Van As was blunter: “The numbers favor SBRT, but there were too few cancer events to conclude that it was superior.” Seven men in the trial died during follow-up; none of the deaths were from prostate cancer, Urology Times reported.
Side effects
The clearer difference is in what happens to men’s bodies afterward. At five years, 8% of SBRT patients were using at least one urinary pad a day, versus 48% of surgery patients, ASTRO reported. Those percentages come from small numbers of men who answered a survey: 3 of 36 after radiation and 14 of 29 after surgery, according to Urology Times. Median erectile-function score at five years was 19 out of 25 after radiation versus 5 after surgery, ASTRO said. Moderate or substantial bowel problems were uncommon in both groups, ASTRO said; SBRT patients had slightly worse bowel symptoms at two years, but van As told Urology Times that gap “appears to have disappeared by 5 years.” He linked the numbers to why side effects matter so much here: “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,” he said, adding: “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.”
Who it applies to
The trial enrolled men with localized disease, most of it intermediate-risk, according to Urology Times. Higher-risk prostate cancer is often treated with hormone therapy alongside radiation and may need a different approach, ASTRO noted; active surveillance — monitoring the cancer without immediate treatment — is a separate option for localized disease. Van As said: “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.”
What’s next
These are conference results, not a peer-reviewed paper. ASTRO also points to PACE-B, a larger, separate trial comparing five-session SBRT against longer radiation schedules — not against surgery — which found SBRT noninferior, with 96% of patients failure-free at five years.