CATEGORY: MEN’S HEALTH
Five sessions of precisely targeted radiation controlled early prostate cancer as well as conventional courses of 20 to 39 sessions. At five years, 95.8% of men treated with the short course were free of any sign that the cancer had returned, against 94.6% on the standard schedules, in an 874-man randomized trial.1 The short course cost something in the bladder: 26.9% versus 18.3% had urinary symptoms troublesome enough to need treatment at some point in those five years.
Localized Disease, No Hormone Therapy, 38 Centers
The PACE-B trial enrolled men at 38 centers in the United Kingdom, Ireland and Canada. Their cancer was low or intermediate risk and confined to the gland, with favorable biopsy findings and a PSA below 20. PSA is a blood protein made by the prostate, and it rises when cancer is present, as it does with several harmless conditions. None of the men received hormone therapy. Allocation was random. Half got stereotactic body radiotherapy, which aims many precisely shaped beams at the tumor so a high dose lands in the gland and little spills into surrounding tissue, in five sessions over one to two weeks. The rest got a conventional or moderately shortened schedule of 20 to 39 daily sessions across four to seven and a half weeks. Doctors tracked PSA levels, recurrences and side effects for a median of just over six years. The main outcome was freedom at five years from any biochemical or clinical sign of the cancer coming back.
Forty Round Trips Become Five Appointments
The trial was built to test whether the five-session course was no worse than the long one. It cleared that bar comfortably. Cancer control was, for practical purposes, identical. What changed is the shape of the treatment itself. A therapy that could mean up to eight weeks of daily hospital visits, roughly 40 round trips with parking, waiting rooms and time away from work, now fits into five appointments inside a week or two. One investigator described telling a patient that a low-toxicity treatment given in five days offers a 96% chance of keeping the cancer at bay for five years as a very positive conversation to have.
The Bladder Paid for the Convenience
By five years, moderate or worse urinary side effects had occurred in 26.9% of the short-course group and 18.3% of the standard-schedule group. These were symptoms such as urgency, frequency or irritation, graded severe enough to need medication or a procedure. That works out to about 9 extra men in every 100 treated. Bowel side effects at the same grade were essentially equal, close to 10% in both arms. Most side effects on either schedule were manageable rather than severe.
A Swedish Trial Got There First
HYPO-RT-PC, run in Sweden, compared a seven-session course against 39 sessions in 1,180 men and found five-year failure-free survival of 84% in both arms.2 Radiation oncology has spent a decade moving toward fewer, larger, more precisely aimed doses, and PACE-B is the largest randomized test of the five-session approach in prostate cancer so far. The results belong to the men who were enrolled: lower-risk, localized disease, treated without hormone therapy. More advanced and higher-risk cancers were not studied here.
Key Takeaways
- Cancer control was even. Five sessions of stereotactic body radiotherapy left 95.8% of 874 men free of any sign of recurrence at five years, against 94.6% for 20 to 39 sessions of standard radiotherapy.
- The short course carried more lasting urinary side effects, 26.9% versus 18.3% needing treatment for them, while bowel side effects sat near 10% in both groups.
- These findings cover low- and intermediate-risk cancer confined to the prostate and treated without hormone therapy; a separate Swedish trial of 1,180 men testing a seven-session course points the same way.
References
- van As N, Griffin C, Tree A, et al. Phase 3 Trial of Stereotactic Body Radiotherapy in Localized Prostate Cancer. New England Journal of Medicine. 2024;391(15):1413–1425. link
- Widmark A, Gunnlaugsson A, Beckman L, et al. Ultra-hypofractionated versus conventionally fractionated radiotherapy for prostate cancer: 5-year outcomes of the HYPO-RT-PC randomised, non-inferiority, phase 3 trial. The Lancet. 2019;394(10196):385–395. link