Genetic testing patterns for homologous recombination repair (HRR) alterations in patients with metastatic prostate cancer (mPC): An assessment at the University of Rochester (UR).

322Background: Germline and somatic HRR alterations are present in 12% and 20% of patients with mPC, respectively, and can have treatment implications. NCCN guidelines recommend offering genetic testing for patients with mPC. This study examines genetic testing patterns in patients with mPC at UR. Methods: We conducted a retrospective study of all patients (n = 240) with mPC who saw medical oncology at UR from 10/1/2017 to 4/1/2018. We abstracted the following data from medical records: patient demographics, mPC characteristics, types of genetic testing, and clinically significant (CS) HRR alterations as defined by Myriad, Ambry, and Foundation One. To compare characteristics of patients who had genetic testing to those who did not, we used non-parametric Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categorical variables. Results: The median age at mPC diagnosis was 71 years (range: 42-93 years), 86.3% were white, and 35% had mPC at initial diagnosis. 64 patients (26.7%) wer...