Racial Disparities in Homologous Recombination Repair (HRR) Biomarker Testing in the United States: A Real-World Database Analysis Among White and Non-White Patients with Metastatic Prostate Cancer

OBJECTIVES: To examine real-world racial disparities in HRR biomarker testing among White versus non-White patients with metastatic prostate cancer (mPC) in the United States and explore whether racial differences exists in patients’ genomic profiles.

METHODS: Electronic health records were obtained from the real-world Flatiron Health metastatic PC core registry and Flatiron Health-Foundation Medicine, Inc. Metastatic PC Clinico-Genomic Database for patients with a confirmed diagnosis of mPC between January 2013 and August 2023 with available race information (self-identified). Biomarker testing for HRR alterations using Next-Generation Sequencing (NGS) was compared between White and non-White patients with mPC using descriptive statistics. Bivariate analyses were also applied to describe racial differences in HRR alteration frequencies. Patients could have been tested at any time.

RESULTS: A total of 13,414 White and 5,527 non-White patients with mPC met eligibility criteria. Biomarker testing occurred at any time for 25% of White patients versus 23 % of non-White patients (P=0.001). The mean time from initial prostate cancer diagnosis to the first biomarker test result was 69.7 months for White patients and 74.3 months for non-White patients (P=0.073). Among patients with a first biomarker test after the date of metastasis, the mean time from metastasis to test result was 648 days for White patients versus 715 days for non-White patients (P=0.003). Differences in HRR alterations were observed between cohorts.

CONCLUSIONS: Although statistically significant, comparable rates of HRR biomarker testing were observed between White and non-White patients with mPC. However, among those with a first test after metastasis, non-White patients had delayed testing from the date of metastasis versus White patients. Equitable access to comprehensive testing is critical to ensure optimal and timely treatment selection among patients with mPC. Future research should examine reasons for delayed testing and identify solutions to improve timely and equitable testing when appropriate.