Real-world treatment outcomes of advanced prostate cancer among Black compared to White men in the Medstar Health Network.

97 Background: Health disparities in prostate cancer (PC) have been well-documented, with Black men historically experiencing 60% higher incidence and twice higher mortality compared to White men. While these differences have been attributed to a combination of biological, socioeconomic, and healthcare-related factors, the extent to which treatment and access to care influence outcomes remains unclear. This study examines whether racial disparities persist in disease progression among men with advanced PC who receive comparable treatment. Methods: This is a real-world retrospective cohort study of men diagnosed with advanced PC (defined as unfavorable intermediate-risk, high-risk, very high-risk, metastatic hormone-sensitive and castration-resistant PC) in the MedStar Health Network from 2016-2024 who received treatment with surgery, radiation plus or minus androgen deprivation therapy (ADT), or systemic (chemotherapy-hormonal) therapy. Prostate Specific Antigen (PSA) failure was the measured outcome with PSA failure defined as an absolute increase of 2ng/mL or greater over the nadir within 1 and 2 years of treatment. Chi-square test was performed to assess the association between PSA failure and race across different treatment modalities and time. Results: A cohort of 4129 men (44.2% Black, 40.4% White, and 15.4% Other) treated with systemic therapy (41.6%), surgery (33.0%) or radiation (25.4%) were included. The association between PSA failure and race was not statistically significant between Black, White or Other men treated with surgery (1 year (p= 0.435); 2 year (p= 0.547)) nor radiation (1 year (p= 0.227); 2 year (p=0.483)). Association between PSA failure and race was significant in men treated with systemic therapy at both 1 year (p= 0.047) and 2 year (p= 0.024) intervals. Pairwise chi-square analysis found no significant difference in PSA failure between Black and White men (1 year (p= 0.225); 2 year (p= 0.103)) or Black and Other men (1 year (p= 0.090); 2 year (p= 0.113)), but a statistically significant difference was observed between White and Other men (1 year (p= 0.014); 2 year (p= 0.008)). Conclusions: There was no statistical difference in disease progression at 1 and 2 year follow-up between Black men and White men treated with systemic therapy, radiation therapy or surgery for advanced PC. These results highlight that disparities in PC outcomes are largely attributable to differences in access to care rather than intrinsic racial differences in disease biology. Our findings are consistent with prior studies which demonstrated that racial disparities in PC outcomes are minimized or absent within equal-access health systems that provide uniform access to diagnostic and treatment services across populations. This study adds rationale to promote interventions that improve screening and access to care for disadvantaged populations to reduce mortality gaps.