Genetic Ancestry and Breast Cancer Subtypes in Hispanic/Latina Women

Excerpt

Breast cancer is the most common cancer among US Hispanics/Latinas; however, Hispanic/Latina women in the United States have historically shown a relatively low breast cancer incidence compared to non-Hispanic White or African American/Black women. Hispanics/Latinos are genetically diverse, with varying proportions of European, Indigenous American, African, and to a lesser extent, Asian continental genetic ancestry. This heterogeneous group has often been treated as a monolithic unit in cancer epidemiology, due to small sample sizes and the concomitant limitations in statistical power. Only a few breast cancer studies including Hispanics/Latinas have analyzed the correlation between individual genetic ancestry proportion and tumor subtype. Most of these studies were unable to provide conclusive evidence due to the reduced number of patients with available tumor subtype information (either from immunohistochemical markers or gene expression data). This chapter provides a brief description of results reported from breast cancer studies including US Hispanic/Latina or Latin American patients assessing the association/correlation between genetic ancestry and breast cancer subtype. Also discussed are possible explanations for reported findings and a perspective on how further studies could lead to more precise tumor subtype-specific risk assessment, treatment efficacy, and outcome prognosis in US Hispanics/Latinas and Latin American women.