Aggressive form of breast cancer hits Black women harder

Weill Cornell researchers find link between triple-negative breast cancer and women of African ancestry

A recent study has found biological links between an aggressive type of breast cancer and people of African ancestry.

Researchers at Weill Cornell Medicine analyzed triple-negative breast cancer tumors from a diverse group and found a set of genes in patients of African ancestry that differed from people of European ancestry.

“Previous studies of racial differences in TNBC analyzed data from African American patients and relied on self-reported race,” senior author Dr. Melissa B. Davis, associate professor of cell and developmental biology research in surgery and director of health equity in the Englander Institute for Precision Medicine at Weill Cornell Medicine, said in a statement from the school. “Our study is the first to determine each individual’s ancestry not only by African descent but also by specific regions within Africa.”

Although TNBC accounts for only about 10-15% of all breast cancers, it tends to spread faster, has fewer treatment options and worse outcomes, according to the American Cancer Society.

The name comes from the fact the cancer cells have no estrogen or progesterone receptors, and make either too much or none of the HER2 protein. In other words, the cells test negative on all three tests. According to ACS, these cancers tend to be more common in women younger than age 40, who are Black or who have a BRCA1 mutation.

The researchers found women with a high degree of African ancestry, primarily East Africans from Ethiopia, “had significantly higher immune cell populations infiltrating tumors, than women with a lower degree of African ancestry who were mainly African Americans and West Africans from Ghana,” they wrote in the Weill Cornell statement.

“Increased immune responses in TNBC tumors in women of regional African descent will be particularly interesting to researchers studying the benefits of immunotherapies,” lead author Dr. Rachel Martini, a postdoctoral associate in surgery at Weill Cornell, said.

Davis concluded: “This finding suggests it’s essential to look at both race and ancestry when exploring disparities in TNBC development and outcomes. For example, we could potentially harness aspects of the diabetes or obesity pathways in tumors as targets to treat cancer patients with comorbidities.”

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