A retrospective analysis of tissue, liquid, and germline testing in Hispanic and non-Hispanic men with advanced hormone-sensitive prostate cancer

Introduction: Prostate cancer (PCa) is a major cause of cancer mortality among American men, with significant racial and ethnic disparities. Hispanic Americans (HAs) are underrepresented in PCa genomic studies despite comprising a large portion of cancer diagnoses. By comparing the frequency of common PCa mutations between HA and non-Hispanics (NHs), we aim to continue understanding the drivers of disparities in this underrepresented population. Methods: We retrospectively analyzed 111 metastatic prostate adenocarcinoma patients with 313 tissue, liquid, and germline genomic sample results from patient blood at the University of Arizona Cancer Center (2015-2023). Patients were categorized by ethnicity into HAs and NHs. We assessed de-identified demographic, pathological, clinical, and genomic data. Continuous and categorical variables determined statistical significance were evaluated using t-tests or Kruskal-Wallis Rank sum tests and Chi-square or Fisher's exact tests, respectively (P < 0.05). Time-to-event data was analyzed using Kaplan-Meier Methods. Results: Of the 111 patients included HAs represented 41%. HAs had higher median PSA levels at the time of diagnosis (148.5 ng/ml vs. 52.6 ng/ml, P = 0.024), more advanced pathological disease stages, including T4 (36% vs. 15%), and M1c (37.8% vs. 13.6%), less time to first-line treatment (1 vs 2 months, P ≤ 0.01), and higher median survival time from first-line to second-line treatment (23 vs 13 months, P < 0.01). TMPRSS2-ERG fusion and TMB-High (>10) mutations were more common in HAs (36% vs. 6%, P = 0.0009; 20% vs. 3%, P = 0.003). Conclusion: Our study shows a more advanced clinical presentation of HAs PCa compared to NHs. Furthermore, significant genomic differences in PCa between HAs and NHWs, particularly in TMPRSS2-ERG fusion and TMB-High mutations, highlight the need for early detection and personalized treatment options. Addressing treatment disparities and expanding genomic research in HAs are crucial for developing effective interventions in this underrepresented population.