Multimodality treatment offers promising results in patients with histopathological proven pelvic lymph node metastatic (pN1) prostate cancer. Improved cause-specific survival rates are reported when treating the primary tumor combined with whole pelvic radiotherapy and androgen deprivation therapy (ADT) compared to ADT alone. However, in case of tumoral invasion of > 1 pelvic lymph node, approximately 40% of the patients relapse biochemically and clinically. This clinical relapse is located in the para-aortic lymph nodes (M1a disease) in up to 77% of relapsed cases. We hypothesize that adding elective para-aortic radiation will reduce the development of both retroperitoneal nodal (M1a) and distant metastasis (M1b/M1c), postpone the need for palliative ADT and prolong the time to castration-refractory disease.
This is a multicenter, non-randomized phase 2 trial (NCT03079323) conducted in 5 sites in Belgium. Men are eligible for the study when (1) age >18 years, (2) histological proven adenocarcinoma of the prostate at biopsy (cT1-4) and referred for primary high-dose radiotherapy or after radical prostatectomy (pT2-4), and (3) presence of pN1 disease after extended pelvic lymph node dissection. If pN1 disease is present, patients are eligible if one of the following criteria is fulfilled: ≥ 2 positive lymph nodes, a ratio positive / removed lymph nodes > 7% or presence of extracapsular metastatic extension at the level of any lymph node. Patients will receive radiotherapy on the prostate (bed), pelvic lymph nodes and the para-aortic lymph nodes combined with 24 months of ADT. We aim to include 137 patients to detect an improvement in clinical relapse free survival (cRFS) by 15% at 5 years (power of 80%).
The primary endpoint is 5 year-clinical relapse-free survival (cRFS) defined as the absence of any clinical relapse that would be visible at top of the line imaging. Secondary endpoints are Quality of life (QoL), treatment-related acute and late toxicity, time to palliative ADT, time to castration refractory prostate cancer (CRPC), cause-specific survival (CSS) and in field pelvic and para-aortic disease control. Recruitment is ongoing, with the first patient included in the trial on 06/02/2017.
Clinical trial identification
Legal entity responsible for the study
University Hospitals Leuven, Belgium.
“Kom op tegen kanker (Stand up to Cancer), the Flemish Cancer Society”. (ref. 0010048).
All authors have declared no conflicts of interest.