Oligometastatic prostate cancer: definition and the role of local and systemic therapy: a narrative review

The definition of oligometastatic prostate cancer (OMPC) includes a heterogenous group of disease states, mostly defined by the number and site of metastases, which seems to be biologically different to widespread tumors. Evidence suggests a substantial survival benefit for this subgroup of limited metastatic burden which is currently seen as a potentially curable disease and therefore with an increasing interest in the scientific community. As there is still no consensus on the definition of OMPC, commonly used criteria are based on the CHAARTED and LATITUDE trials. The management algorithms for these patients were rapidly changing in the past decade due to recent data with a paradigm shift to a multimodal intensification of the treatment by the availability of combinations of hormonal therapy with taxane-based chemotherapy and androgen-receptor-targeted agents leading to significant improvement of clinical outcomes. In addition, radiotherapy of the primary tumor is associated with significant survival benefit in patients with OMPC establishing a new arm in the multimodal treatment concept. Recent data on metastases directed therapy and cytoreductive prostatectomy showed promising results, while there is still a lack of prospective trials and therefore should be limited to experimental settings. The purpose of this review is to summarize and discuss the existing data on treatment of OMPC.