In summary, analysis of this phase 3 study has demonstrated the prognostic utility of a mCRPC-specific AR-ctDETECT cfDNA-seq assay that leverages detection of tumor-derived copy gain and structural alterations in AR, as well as copy gain in MYC and/or MYCN to build on prior studies that have relied on detection of tumor-derived aneuploidy and/or somatic mutations to identify ctDNA. Here, MYCN is linked to neoplasm.