A first-of-its-kind study of breast cancer in Native women found that their tumors may respond differently to treatment than those of white women.
Native women have breast cancer at lower rates than other demographics, but die from the disease more often. While the overall breast cancer mortality rate has fallen by 44% in the last three decades, it remains largely unchanged for white women. Despite this, there has been little to no breast cancer research conducted on Native populations. In the largest national breast cancer genomic database, just 1 of 1,098 cases was Native American.
Native women have the lowest rates of breast cancer screening.
The study, conducted by researchers at the University of Notre Dame’s Harper Cancer Research Institute, analyzed breast cancer tissue from 17 Native women and compared it to more than 698 white women in the database.
“Today’s treatments and tests have effectively been built using data from other populations, and then assumed to work equally well for everyone,” Jun Li, a corresponding author of the study and professor in the Department of Applied and Computational Mathematics and Statistics at Notre Dame, said in a press release.
Researchers found differences in which genes carry mutations, how the tumors use their DNA, and which genes were turned on and off. Tumors from Native American women compared to those from white women appeared to “hide” from the body’s immune defenses in distinct ways. Researchers also found differences in the genes that protect against DNA damage.
Sharon Stack, Kleiderer-Pezold Professor of Biochemistry at Notre Dame, the Ann F. Dunne & Elizabeth Riley Director of the Harper Cancer Research Institute, and a corresponding author of the study, said that while social determinants of health have a large effect on medical disparities, it’s important to understand the role of biology in disease among different groups.
“While there may be many social determinants of health at play, at Harper we want to investigate if there are differences on the molecular level that impact cancer incidence and outcomes,” Stack said.
The Institute intends to study other cancers that affect Native communities and will continue to collect tissue from partnering tribes.
