Introduction:

Racial disparities exist in the treatment of prostate cancer in the US, and robust data for African American (AA) vs Caucasian (CAU) patients with metastatic castration-resistant prostate cancer (mCRPC) are scarce. This study explored characteristics, treatment patterns, and outcomes of AA vs CAU patients with mCRPC in the real-world setting.

Methods:

TRUMPET, a prospective, observational, multicenter study, enrolled 1028 patients who initiated CRPC treatment at 147 urology and oncology sites in the US (2015─2019). The post hoc analysis included patients with mCRPC who identified as AA or CAU. Patients were enrolled within 90 days of the decision to treat or treatment initiation. Characteristics and treatment patterns were analyzed descriptively; radiographic progression-free survival (rPFS), prostate-specific antigen PFS (PSA-PFS), overall survival (OS), and time to skeletal-related events (SREs) were analyzed using Kaplan–Meier methods and adjusted Cox proportional hazards models. An exploratory sub-analysis compared outcomes by race in patients initially treated with androgen receptor pathway inhibitors (ARPIs).

Results:

In total, 133 AA vs 661 CAU patients with M1 CRPC at baseline were included: median age, 69.0 vs 74.0 years; hypertension, 72% vs 66%; diabetes, 32% vs 23%; osteoporosis, 5% vs 12%; other cancers, 6% vs 24%; PSA at diagnosis, 48.8 vs 13.9 ng/mL; N1 tumors, 17% vs 11%; M1 tumors, 29% vs 23%. Primary treatment before CRPC diagnosis (AA vs CAU patients): surveillance, 12% vs 19%; radical prostatectomy, 18% vs 36%; radiation, 48% vs 41%. Initial mCRPC treatment: chemotherapy, 12% vs 6%; ARPI, 62% vs 57%; immunotherapy, 29% vs 41%. After treatment initiation, a trend toward improved clinical outcomes was seen in AA vs CAU patients (Table). In the exploratory analysis, AA patients initiating ARPIs showed a trend toward improved OS vs CAU patients (adjusted median time to death [95% CI]: 41.86 [33.25, not estimable] vs 32.30 [28.62, 40.08] months; adjusted HR [95% CI]: 0.71 [0.45–1.14]).

Conclusion:

AA patients were younger, had higher rates of some comorbidities and more severe disease, and were more likely to receive ARPIs or chemotherapy. Despite our initial hypothesis predicting differences favoring CAU patients, we observed generally similar treatment patterns and a trend toward better outcomes in AA patients. Further research is needed to better understand the outcomes of AA patients with mCRPC.

Funding: This study was funded by Astellas Pharma Inc. and Pfizer Inc.