Seeking Better Understanding of Breast Cancer in African American Women.

Why do African American women die at higher rates from breast cancer and experience more aggressive breast tumors than white women?

School of Public Health researchers affiliated with the Slone Epidemiology Center (SEC) have received funding from the National Cancer Institute (NCI) to explore this question. The new grant is based on the premise that having a better understanding of the biology of breast cancer in African American women will lead to better prevention and treatment.

The multi-center study will seek to identify novel genes and genetic pathways that influence breast cancer in black women.

“Identifying genetic variants related to breast cancer in African American women will further our knowledge of the disease and may ultimately lead us to better treatments and opportunities for prevention,” said Julie Palmer, senior epidemiologist at SEC and professor of epidemiology, who is co-leading the study.

Breast cancer is not a single disease but rather a combination of distinct disease subtypes, with varying risk factors and clinical outcomes. But 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. Previous studies have not been large enough to provide sufficient statistical power to elucidate genetic factors associated with how breast cancers develop. The size and power of the new study could help to address that lack of scientific understanding, the researchers said.

“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, acting director of the NCI.

The study will pool data, bio-specimens, and expertise from 18 previous studies of breast cancer among women of African ancestry. The investigators will look at whether genetic variants are associated with increased risk. Specifically, they will examine: the association between gene 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.

In addition to Palmer, the research team is led by Wei Zheng from Vanderbilt University and Christopher Haiman from the University of Southern California, Los Angeles. Experts from five other institutions will join them in gathering information and bio-specimens from 20,000 breast cancer cases.

Palmer’s major research interest is the etiology of breast cancer, with a particular focus on African American women. She was instrumental in designing and implementing the Black Women’s Health Study, a cohort study of 59,000 women, and has served as co-investigator of the study since its inception in 1995. She is the director of genetics research in the Black Women’s Health Study and has spearheaded efforts to use DNA from study participants in research into the genetics of breast cancer, other cancers, lupus, uterine fibroids, type 2 diabetes, and sarcoidosis.

–Lisa Chedekel