A narrative review of oligometastatic prostate cancer-an evolving paradigm

There has been growing interest in oligometastatic prostate cancer (OMPC) with a mounting body of evidence to suggest that it is a distinct disease state, both biologically and prognostically, when compared to polymetastatic prostate cancer. Three subgroups have been recognised; de novo synchronous, metachronous/oligorecurrent and oligoprogressive disease. The belief that patients with OMPC can be treated more aggressively to improve survival is transforming patient care. Identifying these patients poses the first challenge, and we explore the imaging modalities currently utilised and those that are promising. For patients with de novo synchronous OMPC, both early systemic treatment in addition to androgen deprivation therapy (ADT) and radiotherapy to the prostate increase overall survival (OS), and both are increasingly being integrated into routine clinical practice. Metastasis-directed therapy (MDT) has predominantly been delivered using stereotactic body radiotherapy (SBRT) in prostate cancer and studies have shown SBRT is well-tolerated, provides excellent local control and can be used to delay ADT in the metachronous setting. We discuss the current management strategies in OMPC, review the evidence supporting the use of SBRT and outline ongoing trials.