[Radiotherapy for local disease in metastatic prostate cancer.]

We elaborate the bases and rationale for the application of multimodal extended treatment including local radiotherapy in patients with oligometastatic prostate cancer (omPCa). We performed a bibliographic review on the state of the art in this field and propose a therapeutic strategy that incorporates ablative radiotherapy of the primary tumor +/- oligometastatic lesions.

We performed a comprehensive literature review consulting different sources that include data bases (Pubmed/Medline), and international treatment guidelines ((NCCN, NCI, EUA). Search criteria: Locally advanced prostate cancer, oligometastatic, disseminated and radiotherapy, ablative or stereotactic radiotherapy (SBRT).

The most accepted definition for oligometastatic prostate cancer or oligotopic prostatic neoplasia is when we recognize at least 3 non-visceral metastatic lesions in an extrapelvic location. Whole body MRI and PET scan (Choline/PSMA) are non conventional useful tests for staging in the workup for oligometastatic disease. From a clinical point of view, omPCa behaves as an intermediate entity between locally advanced and disseminated or multimetastatic prostate cancer. Androgen deprivation therapy (ADT) represents the base of treatment for castration sensitive PCa. To date there is no biological marker/genetic sign identified that differentiate aggressiveness profiles in omPca. Most evidence on the use of radiotherapy for this entity comes from retrospective studies, showing a benefit in control and prevention of local symptoms. To date, the survival benefit derived from the application of local treatment to the primary tumor with demonstrable metastatic disease is uncertain, and it has not been shown in the available randomized prospective clinical trials.

Primary tumor radiotherapy in omPca positively influences local control and prevention of local symptoms progression. The level of evidence to recommend prostatic radiotherapy as a therapeutic variable with impact on survival on omPca is limited (Level 2B-3 Category). Research lines in omPca deserve the inclusion of a multimodal systemic treatment including ADT, ablative radiotherapy for the tumor and consolidation radiotherapy in metastatic distant lesions.