The purpose of this study is to evaluate the prevalence of 4 or more DNA-repair gene defects in a population of men with metastatic Prostate Cancer (PC) and to use the reported DNA-repair gene defects to assess biomarker eligibility for niraparib interventional studies.

Inclusion Criteria:

• Diagnosis of metastatic (Stage IV) prostate cancer (PC), confirmed by either biopsy of a metastatic tumor site or history of localized disease supported by metastatic disease on imaging studies (that is [i.e.], clearly noted in hospital/clinical records)
• Signed Informed consent form (ICF)
• No condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant (for example [e.g.], compromise the well-being) or that could prevent, limit, or confound the protocol-specified assessments
• Willing to provide a saliva, blood, and/or archival tumor tissue sample for genomic analysis
• No prior poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitor (PARPi) for the treatment of prostate cancer
• No prior DNA-repair gene defect test results from a Janssen sponsored interventional trial

Study population consists of male participants diagnosed with metastatic prostate cancer who will be evaluated for the prevalence for DNA-repair gene defects.