Examination of Genetic Changes Associated with Breast Cancer Disparities Across Multiple Ethnicities

Breast cancer is of a primary concern in women, although it can occur in men. It is the second leading cause of cancer related deaths amongst women, and it is estimated that roughly 39,840 women will die of this disease this year. Breast cancer occurs across all populations and ethnicities. When African-Americans (AA) present with breast cancer, they usually have poorly differentiated tumors, and are more likely to be diagnosed with an advanced stage tumor. When compared to Caucasian (Cau) women, African-American women also have higher breast cancer mortality. The causes of these differences are not yet definitively known, but it has been suggested that the disparities that are present between African-American and Caucasian women are due to a number of factors. A few which have been mentioned are differences in Body Mass Index (BMI), socioeconomic status, health care coverage, and the level of obtained education that exists between the two ethnic groups. Although these factors may account for a small percentage of the difference seen between the two ethnic groups, the underlying cause that may explain why African-American women are at a greater risk of developing aggressive breast cancer may be due to differences in gene expression. A focus of my research project is the comparison of genome-wide gene expression differences between African-American and Caucasian women. Preliminary results from the comparison of normal breast tissue (obtained from reduction mammoplasty) from Caucasian and African-American women suggest there are marked differences in gene expression patterns. Pathway analysis of differentially expressed genes shows that they are involved in protein folding and the immune response. I am currently expanding this study to include a comparison of 10 AA to 10 Cau normal breast samples. These samples are being LCM dissected to separately compare gene expression in epithelial and stromal tissue. Cross comparisons between ethnic groups and tissue types will provide an understanding of normally occurring differences between AA and Cau women, which may help to explain the observed cancer disparities. Data from the study of normal tissue will be compared to gene expression data from triple negative breast cancer (TNBC) patients from both ethnicities