A large study headed by researchers from the Keck School of Medicine of USC and two other institutions received $12 million in funding to examine why African-American women die at a higher rate from breast cancer and have more aggressive breast tumors than white women.

The grant, awarded by the National Cancer Institute (NCI), part of the National Institutes of Health, is based on the premise that having a better understanding of the biology — and, in particular, the genetics — of breast cancer in African-American women will lead to better prevention and targeted treatment.

“The Breast Cancer Genetic Study in African-Ancestry Populations builds on previous work in this area spearheaded by USC,” said Chris Haiman, ScD, professor of preventive medicine at the Keck School.

Haiman organized the African American Breast Cancer Consortium, which developed the network of scientists and body of research that will support this new study.

“We now have the knowledge and technology available to assess the whole genome, providing a more comprehensive look into the genetics of breast cancer in women of African ancestry,” he said. “I am confident that this will be a fruitful and productive collaboration.”

Haiman will be leading the study alongside Wei Zheng, MD, PhD, of Vanderbilt University in Nashville and Julie Palmer, ScD, of Boston University. Investigators will pool data, biospecimens and expertise from 18 previous studies of breast cancer among women of African ancestry to determine whether genetic variants may be associated with increased risk.

Specifically, they will examine:

• The association between genetic variants and the risk of estrogen receptor-negative breast cancer and estrogen receptor-positive breast cancer

• How genetic variants affect major breast cancer biological pathways and whether the effects may differ between African-American women and white women

Additionally, experts from five other institutions will gather information and biospecimens from 20,000 breast cancer cases.

“Preventing and treating cancer is reaching a new frontier in precision oncology,” said Stephen Gruber, MD, PhD, MPH, director of the USC Norris Comprehensive Cancer Center. “Identifying susceptible genetic regions and risk factors can help us better assess risks in our patients and the larger population. I am thrilled at the potential clinical applications that will arise from focused attention on women of African ancestry.”

Breast cancer is not a single disease, but a combination of distinct disease subtypes, with varying risk factors and clinical outcomes. However, the reasons for differences in breast cancer biology and disparities in incidence and mortality rates between white and African-American women are not well understood, and existing studies have not been large enough to provide sufficient statistical power to elucidate factors associated with how breast cancers develop. The size and power of this new study could help address the current lack of scientific understanding.

“Health disparities are a problem of great concern for the NCI and one that we are zeroing in on as evidenced by this grant,” said Douglas Lowy, MD, acting director of the NCI.

— Mary Dacuma