Stereotactic body radiation therapy (SBRT) for localized prostate cancer is associated with less patient-reported urinary and sexual problems but worse bowel bother at 2 years following treatment compared with radical prostatectomy, according to data from the PACE-A trial presented at the American Society of Clinical Oncology’s 2023 Genitourinary Cancers Symposium in San Francisco, California.
To their knowledge, PACE-A is the first randomized controlled trial of SBRT vs surgery, investigators Nicholas John van As, MBBCh, of The Royal Marsden NHS Foundation Trust in London, UK, and collaborators noted.
PACE-A is an international phase 3 trial that aims to determine if patients have a better quality of life following SBRT compared with radical prostatectomy. Investigators from 10 UK centers randomly assigned 123 men with localized low- or intermediate-risk prostate cancer to undergo radical prostatectomy (60 patients) or SBRT (36.25 Gy in 5 fractions in 1-2 weeks; 63 patients). The vast majority of the surgery and SBRT groups (93% and 90%, respectively) had intermediate-risk disease. The investigators included in their analysis 46 patients in the radical prostatectomy group and 56 in the SBRT arm.
The investigators evaluated urinary, sexual, and bowel function and bother using the 26-item Expanded Prostate Cancer Index Composite (EPIC) short form instrument (EPIC-26). Higher scores indicate better function.
At 2 years after treatment, the proportion of patients using any urinary pads was 4.5% in the SBRT arm compared with 46.8% in the surgery arm, a statistically significant difference, Dr van As told attendees. The mean EPIC sexual domain score was 29.3 with surgery and 57.7 with SBRT. The mean EPIC bowel domain score was 97.3 with surgery and 88.7 with SBRT.
The proportion of patients indicating “no problem” with bowel function was 87.1% in the surgery group compared with 54.4% in the SBRT group. The proportion of patients indicating that bowel issues were a “very small problem” or a “small problem” was 12.9% and 0%, respectively, in the surgery group and 30.4% and 13.0%, respectively, in the SBRT group. No patient in either group indicated that bowel issues were a “big problem.”
“In conclusion, compared with surgery, patients receiving SBRT reported better urinary continence and less sexual bother at 2 years,” Dr van As said.
PACE-A efficacy data will be reported at a later date.
Disclosure: Accuray, Varian, and the Royal Marsden Cancer Charity are funding the trial. They have no access to trial data. Please see the original reference for a full list of disclosures.
Van As NJ, Tree A, Ostler PJ, et al. PACE-A: An international phase 3 randomised controlled trial (RCT) comparing stereotactic body radiotherapy (SBRT) to surgery for localised prostate cancer (LPCa)—Primary endpoint analysis. Presented at: ASCO GU 2023, San Francisco, California, February 16-18. Abstract 298.