Schweizer MT, Sivakumar S, Tukachinsky H, et al. - Concordance in DNA damage repair (DDR) gene alterations between primary prostate cancer and metastases or circulating tumor DNA (ctDNA) specimens, was determined.

• Included were patients with detected DDR pathway mutation in metastatic tissue or ctDNA and with available primary tissue sequencing.

• Analysis was performed on sequencing data from 51 men from 3 cohorts: (1) FoundationOne, (2) University of Washington clinical cases (University of Washington–OncoPlex or Stand Up to Cancer–Prostate Cancer Foundation International Dream Team sequencing pipelines), and (3) University of Washington rapid autopsy series.

• On excluding clonal hematopoiesis, gene alterations in DNA repair genes identified in cell-free circulating tumor DNA or metastatic tissue were concordant with primary prostate cancer.

• In men with metastatic disease, primary prostate cancer tissue may aid in accurate assessment of the status of actionable DNA repair gene alterations.