Best Systemic Therapy With or Without Radical Prostatectomy in the Management of Men With Oligometastatic Prostate Cancer: The RAMPP Randomised Controlled Trial.

[BACKGROUND AND OBJECTIVE] Our aim was to evaluate the effect of addition of radical prostatectomy (RP) to best systemic therapy (BST) on cancer-specific mortality (CSM) in patients with oligometastatic prostate cancer (omPC).

[METHODS] This randomised controlled trial included patients with omPC with a low metastatic burden (1-5 bone metastases with/without nodal involvement) on conventional or PET imaging. Patients were randomised to receive either RP with pelvic lymph-node dissection plus BST (RP + BST) or BST alone. The primary endpoint was CSM. Secondary endpoints included clinical progression and overall survival (OS). Study accrual was stopped early because of a change in medical practice. Statistical analyses included cumulative incidence plots, Gray's test, competing-risks regression, Kaplan-Meier estimates, and log-rank tests.

[KEY FINDINGS AND LIMITATIONS] Between May 2015 and December 2018, 132 patients were randomised. The median age was 67 yr (interquartile range 63-71) and median prostate-specific antigen was 20 ng/ml (interquartile range 10-39). The 5-yr CSM cumulative incidence was 13% for RP + BST and 23% for BST alone (p = 0.037), with a hazard ratio of 0.39 (95% confidence interval 0.16-0.98; p = 0.045). The 5-yr cumulative incidence of clinical progression including CSM was 59% for RP + BST and 60% for BST alone. The 5-yr OS rate was 81% for RP + BST and 74% for BST alone. Clavien-Dindo grade ≥III surgery-related complications occurred in nine of 66 (14%) patients in the RP + BST arm. Limitations include early discontinuation of study accrual and the lack of statistical significance for the OS benefit.

[CONCLUSIONS AND CLINICAL IMPLICATIONS] While this trial has substantial limitations, the results support addition of RP as local therapy to BST in omPC. This trial is registered on ClinicalTrials.gov as NCT02454543.