Research for change: tackling breast cancer inequities

Black women are more likely than white women to die of breast cancer at any age, and for those under 50, Black women have double the rate of mortality. Black women also face significantly higher breast cancer diagnosis under 40 and are twice as likely as women from other racial and ethnic groups to be diagnosed with triple-negative breast cancer, which has poorer outcomes than other breast cancer subtypes.

“Women in my family have been diagnosed with breast cancer as young as age 28. That shouldn’t be happening,” says Llanos. “I’m really interested in studying populations that have been historically underrepresented in cancer research, including people that look like me.”

Her mission is to improve cancer survival among such vulnerable populations by untangling the molecular and sociobiologic mechanisms behind cancer inequities. Despite cancer disproportionately affecting racial, ethnic, and medically underserved groups, these populations are underrepresented in many research studies. Llanos’ research focuses primarily on these groups, seeking to understand the causes of poorer cancer outcomes and developing interventions and strategies for cancer risk mitigation.

One area of her research investigates the disproportionate exposure to harmful chemicals from personal care products in specific populations. A 2017 study led by Dr. Llanos found that the use of dark hair dye was associated with a 51 percent increased risk of breast cancer in Black women.

“There have been many studies linking hair dye with breast cancer, but ours was the first to include a large sample of Black and African American women,” she says. “The majority of studies prior focused on white women, and this had just never been done in a sample that included thousands of Black women, so it generated a lot of interest.”

In a 2022 study, Llanos and her team discovered that long-term use of hair dye and relaxer was associated with more aggressive tumors. “Black women are the largest consumers of hair products and cosmetics per capita in the U.S.,” says Llanos. “When you look at the products marketed to us and our children, you find that many contain toxic ingredients.”

Expanding her research internationally, Llanos recently launched a project in Kenya to investigate personal care product use among women in two counties with rising breast cancer rates. Her research aims to push for stricter government regulations on harmful chemicals in these products, both in the U.S. and Kenya.

Llanos highlights the importance of how research can influence policies with a far-reaching impact. “Ultimately, I hope my research leads to evidence-based strategies at multiple levels of influence, including at the individual level, community and population levels, and policy level to improve cancer outcomes so that we can move the needle towards greater health equity.”