The surprising reason black women die more frequently from breast cancer

We already know that black women die more frequently from breast cancer than white women. Now a University of Chicago oncologist, Olufunmilayo Olopade, is part of a team that’s using the genome to understand why.

The team’s initial findings, published today in JAMA Oncology, could lead to more personalized risk assessment for black women and speed the development of new ways to diagnose and treat specific subtypes of aggressive breast cancers. The breakthrough research comes as University of Chicago Medicine is doubling down on its lucrative cancer specialty to boost its brand.

Findings from today’s study compared the DNA from 930 women of African and European ancestry, looking for racial differences at the genetic level that could account for differences in cancer types and mortality rates. The researchers found that genetic differences may be responsible for up to 40 percent of the chance of developing one kind of breast cancer tumor versus another.

The study found that black women with a specific type of breast cancer—a kind of malignancy that has estrogen receptors but lacks the so-called HER2 gene—had a higher risk of recurrence than white women. It also confirmed that patients of African descent were typically diagnosed younger and were more likely to develop more aggressive forms of breast cancer, including “triple-negative” cancers, which lack both estrogen and progesterone receptors as well as the HER2 gene.

“People have long associated breast cancer mortality in black women with poverty, or stress, or lack of access to care, but our results show that much of the increased risk for black women can be attributed to tumor biological differences, which are probably genetically determined,” Olopade said in a statement.

This is the final study put out by Olopade’s team, which has been publishing together for five years as a Cancer Genome Atlas working group. The working groups are part of an effort by the National Cancer Institute and the National Human Genome Research Institute to map the genome of every kind of cancer.

Last summer, Olopade and a consortium funded by the National Cancer Institute received a separate $12 million grant to conduct a study of more than 20,000 black women with breast cancer, comparing them to both cancer-free black women and white women who have the disease.

Olopade, who arrived in Chicago from Nigeria in 1983 to train at Cook County Hospital and the University of Chicago, has spent her entire career at the intersection of genetics and cancer. In 1992, she launched the University of Chicago Hospitals’ Cancer Risk Clinic, one of the first genetic-testing clinics in the country. Thirteen years later, Chicago’s MacArthur Foundation awarded her one of its $500,000 “genius” grants.

University of Chicago Medicine is in the midst of retrofitting its old Mitchell Hospital to become a new cancer institute. The move, part of a $270 million overhaul that also includes a new trauma center, will shine a spotlight on the health system’s highly ranked oncology specialty and is expected to bring in plenty of revenue to offset the money-losing trauma business. (Brigid Sweeney)

ADVERTISEMENT

ADVERTISEMENT