Breast Cancer Disparities at home and abroad: A Review of the Challenges and Opportunities for System-Level Change

Abstract

Sizeable disparities exist in breast cancer outcomes, both between Black and White patients in the United States, and between patients in the US and other high-income countries compared to low- and middle-income countries (LMICs). In both settings, health system factors are key drivers of disparities. In the US, Black women are more likely to die of breast cancer than Whites, and have poorer outcomes even among patients with similar stage and tumor subtype. Over-representation of higher-risk “triple negative” breast cancers contributes to breast cancer mortality in Black women; however, the greatest survival disparities occur within the good-prognosis hormone-receptor positive (HR+) subtypes. Disparities in access to treatment within the complex US health system may be responsible for a substantial portion of these differences in survival. In LMICs, breast cancer mortality rates are substantially higher than in the US, while incidence continues to rise. This mortality burden is largely attributable to health system factors, including late-stage presentation at diagnosis and lack of availability of systemic therapy. This article will review the existing evidence for how health-system factors in the United States contribute to breast cancer disparities, discuss methods for studying the relationship of health system factors to racial disparities, and provide examples of health system interventions that show promise for mitigating breast cancer disparities. We will then review evidence of global breast cancer disparities in low and middle income countries, the treatment factors that contribute to these disparities, and actions being taken to combat breast cancer disparities around the world.