The PACE trial: International randomised study of laparoscopic prostatectomy vs. stereotactic body radiotherapy (SBRT) and standard radiotherapy vs. SBRT for early stage organ-confined prostate cancer.

Abstract

TPS153 Background: The development of Stereotactic Body Radiotherapy (SBRT) has provided a further treatment option for early stage prostate cancer. In addition to the benefits of an overall treatment time reduction, profound hypofractionation could result in therapeutic gain given the radiobiology of prostate cancer. Evidence suggests SBRT to be safe and effective; however randomised data is lacking comparing outcomes with standard treatment options. Aim: To assess whether SBRT offers therapeutic benefit in comparison to prostatectomy or standard radiotherapy. Methods: The PACE trial is an international multicentre phase III trial, comprising two parallel randomisation processes. Within PACE A, potential surgical candidates are randomised between radical prostatectomy and SBRT (36.25 Gy in 5 fractions). In PACE B, randomisation is between standard radiotherapy (78Gy in 39 fractions or 62Gy in 20 fractions) and SBRT (36.35Gy in 5 fractions). SBRT can be delivered using Cyberknife or gantry based techniques. Patients with low or intermediate risk prostate cancer are eligible for the trial, and are treated without the use androgen deprivation therapy. Follow up is for a period of 10 years. The aim is to recruit 234 patients to PACE A (117 in each arm) and 858 patients to PACE B (429 patients in each arm). Primary Objectives: PACE A: To determine whether there is improved quality of life after SBRT compared with surgery at 2 years post treatment, using EPIC score to measure urinary incontinence and bowel bother. PACE B: to determine whether SBRT is non-inferior to surgery in terms of freedom from biochemical/clinical failure at 5 years from randomisation. Progress: PACE A has been slower to recruit than anticipated due to the difficulties of a surgery versus radiotherapy randomisation. However, it is expected to reach target accrual, having recruited 57 patients from 3 centres. In contrast, PACE B is recruiting exceptionally well, open in 40 centres, and as of October 2017 recruited 762 patients. Accrual target is expected to be reached by the end of 2017. Clinical trial information: NCT01584258.