Breast cancer is the most common cancer among women worldwide, but outcomes are not equal across populations. Racial and ethnic disparities persist, leading to worse survival rates and treatment access for marginalized groups. For example, Black women in the U.S. are more likely to be diagnosed with aggressive subtypes and face higher mortality rates than their White women, despite similar incidence levels (1).
A large-scale U.S. study including more than 2.8 million patients found that American Indian, Alaska Native, Asian or Pacific Islander, and Black patients were significantly more likely to decline potentially life-saving treatments such as chemotherapy, radiotherapy, or surgery compared to White patients (1). These differences are not solely medical; they reflect deeper structural barriers, including access to healthcare, socioeconomic inequality, and communication gaps between patients and clinicians.
Biological and Genetic Diversity
Disparities are not only social but also biological. Genetic differences influence treatment outcomes across ethnic groups. Studies show that Black patients with HER2-positive, hormone receptor-negative breast cancer have lower pathological complete response (pCR) rates to neoadjuvant chemotherapy compared to White patients (2). In one study, only 41% of Black women with HR-/HER2+ tumors achieved complete response, compared to 74% of White patients (2).
This highlights the urgent need for diverse genetic and clinical data in breast cancer research. Most existing datasets disproportionately represent Caucasian populations, limiting the ability of researchers to design effective, equitable therapies.
Social Barriers in Access and Treatment Decisions
Declining recommended cancer therapies is strongly linked to poorer survival outcomes, yet socioeconomic and racial factors heavily influence treatment decisions. Patients with public or no insurance, lower income, or comorbidities were significantly more likely to decline treatment (1). These findings underscore how social determinants of health like income, insurance status, education, and systemic inequities directly shape survival rates.
In addition, cultural mistrust, lack of representation in clinical trials, and reduced access to high-quality care contribute to disparities. Addressing these barriers requires a holistic approach that combines scientific innovation with structural change.
Toward Equity-Focused Interventions
To reduce disparities, interventions must prioritize equity at every stage of cancer care. Strategies include expanding access to genetic testing and clinical trials, tailoring treatments based on diverse genetic profiles, and fostering patient–clinician communication that respects cultural contexts (1, 2).
Investment in data diversity is essential: building multiethnic cancer data repositories can explore critical insights, improve predictive algorithms, and support the development of personalized therapies that work for all patients.
References
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Freeman JQ, Li JL, Fisher SG, et al. Declination of treatment, racial and ethnic disparity, and overall survival in US patients with breast cancer. JAMA Netw Open. 2024;7(5):e249449. doi:10.1001/jamanetworkopen.2024.9449.
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Abburi C, Shubeck SP, Huo D, et al. Racial and ethnic disparities in breast cancer treatment outcomes: how to improve? UChicago Medicine News. June 12, 2023.
