Journal: Immunotherapy
This narrative review examines how immunotherapy use in triple-negative breast cancer (TNBC) varies across racial, socioeconomic, and geographic groups, and how those differences affect outcomes.
Key points:
- Evidence base: The authors reviewed studies from 2000–2025 (clinical trials, observational cohorts, and reviews) addressing immune checkpoint inhibitor (ICI) use in TNBC, focusing on trial participation, biomarker testing, treatment initiation, adherence, and outcomes, stratified by race/ethnicity, insurance, and geography.
- Efficacy of ICIs: ICIs improve progression-free and overall survival in selected TNBC populations. However, underrepresentation of Black, Hispanic, and rural patients in clinical trials limits the applicability of trial findings to those groups.
- Access and utilization disparities:
- • Lower rates of PD-L1 and other biomarker testing among marginalized populations.
- • Barriers related to insurance coverage, costs, and proximity to specialized cancer centers.
- • Gaps in treatment navigation and support, which impair initiation and adherence to ICIs.
- Underlying drivers: Socioeconomic hardship, structural racism, and a higher burden of comorbidities may influence both access to care and biological factors such as tumor immune responsiveness, potentially compounding disparities.
- Outcomes when treated: When patients from historically marginalized groups do receive ICIs, their clinical outcomes are generally similar to those of more advantaged patients, indicating that the main problem is access rather than intrinsic lack of benefit.
- Proposed solutions: The review calls for:
- • More inclusive and representative trial designs.
- • Standardized and equitable biomarker testing.
- • Expanded and reliable insurance coverage for ICIs and related diagnostics.
- • Robust patient navigation programs.
- • Community-engaged care models to improve trust, outreach, and uptake.
Overall, the article emphasizes that equitable access to ICIs and biomarker testing is critical to realizing the full survival benefit of immunotherapy for all patients with TNBC.