Background
Oligo-metastatic prostate cancer is recognized as an intermediate stage between localized disease and widespread metastases. The role of radical local therapy (RLT) to the primary tumor for these patients is unclear. We conducted this phase 2 randomized trial to investigate if radical prostatectomy (RP) or prostate radiotherapy (RT) benefits these patients (NCT02742675).
Methods
Oligo-metastases was defined as ≤ 5 bone or extra-pelvic lymph node metastases and no visceral metastases. Patients were randomly assigned (1:1) to receive androgen deprivation therapy (ADT) or ADT plus RLT. For patients allocated to ADT+RLT group, RP was recommended with priority, while RT was administrated to those refused RP and those with unresectable primary tumor after 1-3 months induced ADT. The primary outcome was radiographic progression-free survival (rPFS) and the secondary outcome was overall survival (OS).
Results
A total of 200 patients were enrolled between Sept 1, 2015 and Mar 10, 2019. The median age was 68 years and the median PSA at diagnosis was 98.8 ng/ml. Bone metastases and distant lymph node metastases exited in 96% and 15% of all patients. 96 of 100 patients in ADT+RLT group received RLT including 85 RP and 11 RT. After a median follow-up of 28 months, radiographic progression was observed in 19 of 100 patients in ADT+RLT group and 33 of 100 patients in ADT group. The median rPFS was not reached in ADT+RLT group and 50 months in ADT group (HR = 0.50; 95% CI, 0.28 to 0.87; p = 0.015). RLT related complications occurred in 24 of 85 RP patients (including 3 grade 3-4 complications) and 5 of 11 RT patients. In order to evaluate the OS, longer follow-up period is required.
Conclusions
Local therapy to the primary tumor improves rPFS in patients with newly diagnosed, oligo-metastatic prostate cancer.