Assessing the safety and feasibility of metastasis-directed radiation and neoadjuvant hormone and radiation therapy followed by radical prostatectomy for treating oligometastatic prostate cancer: protocol for an open-label, dose-escalation, single-centre phase I clinical trial

Abstract Background The systemic therapy is currently recommended for patients with oligometastatic prostate cancer, however the prognosis has not been satisfactory. Therefore, it is necessary to explore more effective treatment to improve the prognosis. Oligometastatic prostate cancer is a special subgroup in patients with advanced cancer. The paragrim of treatment is shifting to a more aggressive approach. Stereotactic body radiotherapy (SBRT) is an emerging treatment alternative for patients with oligometastases with minimal toxic effects. What’s more, accumulating studies have proved safety as well as feasibility of radical prostatectomy and local or metastasis-directed radiotherapy for oligometastatic patients. The aim of this phase I prospective trial is to demonstrate the early evidence of safety and feasibility of metastasis-directed radiation and neoadjuvant hormone and radiation therapy followed by radical prostatectomy for treating oligometastatic prostate cancer Methods The patients with oligometastatic prostate cancer received 1 month of neoadjuvant androgen deprivation therapy (ADT) followed by metastasis-directed radition and abdominal or pelvic radiotherapy. Then offer radical prostatectomy at the interval of 4-8 weeks after radiotherapy and adjuvant ADT for 2 years. The primary endpoints of the study are safety as assessed by CTCAE 5.0 grading scale and intraoperative and postoperative day-30 morbidity. Secondary endpoints include the positive rate of post-operative edge, biochemical progression-free survival (bPFS), postoperative continence and sexual function recovery, quality of life (QoL), overall survival (OS) and adverse reactions of ADT. Discussion This is the first, phase I trial assessing the safety and feasibility of metastasis-directed radiation and neoadjuvant hormone and radiation therapy followed by radical prostatectomy treatment for patients with oligometastatic prostate cancer. If positive, the results of this trial may help to design subsequent phase II trials exploring the role of metastasis-directed radiation and neoadjuvant hormone and radiation therapy followed by radical prostatectomy in the randomized controlled study.