Local therapies for oligometastatic hormone-sensitive prostate cancer

Background: Oligometastatic, hormone-sensitive prostate cancer (omHSPC) is increasingly diagnosed due to the implementation of molecular imaging. OmHSPC is mostly defined as a maximum of four bone metastases without visceral metastases on conventional imaging. Objectives: This study highlights the existing evidence regarding local treatment of omHSPC, taking into account molecular imaging and modern therapies. Materials and methods: Narrative review article based on expert consensus and national/international guideline recommendations, supported by a nonsystematic literature search in PubMed (MEDLINE). The authors consider the cited studies as the most significant works in this regard and these were selected to illustrate developments and fundamental concepts, without claiming completeness. Results: Initially, the STAMPEDE study prospectively demonstrated an oncologic benefit of radiotherapy (RT) to the prostate in addition to androgen deprivation therapy for omHSPC. At 3 years, overall survival (OS) was 81% with RT versus 73% without RT (hazard ratio [HR] 0.68; 95% confidence interval [CI] 0.52-0.90; p = 0.007). However, this benefit was not observed in polymetastatic HSPC (HR 1.07; 95% CI 0.90-1.28; p = 0.4). In a study by Dai et al., local therapy for omHSPC was performed surgically in 85% of cases, also demonstrating an OS advantage (HR 0.44; 95% CI 0.24-0.81; p = 0.008). Conclusion: OmHSPC should be treated using adjunctive RT. Preliminary prospective evidence shows comparable efficacy with prostatectomy. Modern systemic combination therapies challenge the role of local therapy.