Homologous Recombination Repair Mutations, Next-generation Sequencing Testing, and Treatment Progression by Race Among Patients With Metastatic Castration-sensitive Prostate Cancer.

To describe next-generation sequencing (NGS) testing rates for deleterious homologous recombination repair (HRR) mutations and time-to-next-treatment (TTNT) among US patients with metastatic castration-sensitive prostate cancer (mCSPC). Data from oncology centers included in the nationwide (US-based) Flatiron Health-Foundation Medicine, Inc. Metastatic PC Clinico-Genomic Database (January 1, 2011 to December 31, 2022) and Core Registry (January 1, 2013 to December 31, 2023) were evaluated. Patients who initiated treatment for mCSPC (index date) after January 1, 2018 and received an HRR alteration test were included. TTNT and NGS testing patterns were described overall and among White, non-White (ie, Black, Asian, Hispanic, other), and Black patient subgroups. TTNT was assessed using Kaplan-Meier analyses and annual NGS testing rates were assessed from 2018 to 2023 using the Core Registry. In total, 1121 HRR-tested patients with mCSPC were included. HRR (BRCA1/2) alterations were observed among 17.4% (12.7%) of White patients, 16.5% (10.9%) of non-White patients, and 15.2% (9.7%) of Black patients. Non-White patients had the shortest median (months) TTNT (17.0; 60.6% with next treatment by 24 months), followed by White (19.2; 56.1% with next treatment by 24 months) and Black patients (21.2; 54.7% with next treatment by 24 months). Although Black patients had descriptively lower testing rates than White patients in 2018 (4.2%), the rates increased overall and became numerically comparable between racial groups by 2023 (29.8%). Although NGS testing rates have increased, with less disparity in most recent years, the testing rates are unacceptable for patients with mCSPC, overall and across racial groups, with the majority of patients progressing to the next treatment by 24 months. Tweet (121/125 characters including spaces; required): Next-generation sequencing use for metastatic castration-resistant prostate cancer remains suboptimal, regardless of race.