The National Institutes of Health has awarded $10.24 million to Fred Hutchinson Cancer Research Center to lead a five-year study that aims to understand and prevent breast cancer disparities in Hispanic women.
The Hutchinson Center is among 10 institutions nationwide to receive funding as part of the NIH Centers for Population Health and Health Disparities program, which is launching a major new effort to understand and address inequities associated with two leading causes of death in the United States: cancer and heart disease.
Behavioral scientist Beti Thompson, Ph.D., a member of the Public Health Sciences Division of the Hutchinson Center whose research focuses largely on improving cancer screening and prevention within the Hispanic community, is the principal investigator of the Hutchinson Center-based initiative.
The research will range from exploring ways to improve mammography screening rates among Seattle-area Latinas to understanding the relationship between dietary patterns and risk of obesity in Hispanic women. The research will also examine the interplay of risk factors and the biology of breast cancer in this population.
Breast cancer is the most common cancer among U.S. Hispanic women. While the incidence of the disease among Latinas is lower than that of non-Hispanic white women (83.5 per 100,000 women versus 147.3 per 100,000 women), as they adopt the practices of mainstream U.S. culture, their risk for breast cancer increases.
"Once Latinas come to live in this country, within a generation their risk of breast cancer increases tremendously and approaches that of non-Hispanic whites, so we think something about their lifestyle before they immigrate to the U.S. protects them. It is important to find out what this is so that we can encourage Latinas to make behavioral decisions that foster a protective effect against breast cancer," Thompson said.
Latinas also have lower five-year survival rates for the disease as compared to non-Hispanic white women because they are likely to be diagnosed with later-stage disease and because they are at increased risk for breast cancers with a poor prognosis. As such, the research will also explore the genetics and biology of Latina breast cancer to try to identify what makes these women more susceptible than non-Hispanic white women to particularly aggressive, treatment-resistant forms of the disease.
The long-term goal of the project is to understand the precursors of breast cancer in Latinas, understand the types of breast cancer found in this population, and develop and implement a comprehensive screening program to improve early detection of the disease.
The initiative will involve approximately 30 investigators throughout the Hutchinson Center and at several collaborating institutions, including the Seattle Cancer Care Alliance, the University of Washington and the University of New Mexico Cancer Center. Sea Mar Community Health Center in Seattle also will participate in one of the projects.
The research will be carried out in four projects:
PROJECT 1: Screening Mammography and Latinas: A Multilevel Intervention - This project, which will involve 600 Seattle-area Hispanic women, aims to test the effectiveness of various interventions in increasing mammography screening rates. Among the interventions to be tested is the use of promotoras, outreach workers who help promote and raise awareness of health and educational issues, such as cancer screening, within the Hispanic community. In one arm of the study, promotoras provided by Sea Mar Community Health Center will make house calls to encourage women to get mammograms, either at their local health clinic or via the Seattle Cancer Care Alliance Mobile Digital Mammography Service, or "MammoVan." "The beauty of promotoras is they are like the people they are trying to reach," Thompson said. "So instead of having a nurse come to the door there is someone who could be your neighbor who is talking to you about the importance of having a mammogram." Gloria Coronado, Ph.D., an associate member of the Hutchinson Center's Public Health Sciences Division, will lead the project.
PROJECT 2: Metabolic Response to Western versus Indigenous Diets in Hispanic Women - This feeding study, which will involve 50 first- and second-generation Seattle-area Hispanic women and be carried out in the Hutchinson Center's Human Nutrition Laboratory, will assess how ancestral genetic variation may influence how the body metabolizes food - comparing a traditional, indigenous Mexican diet to a more modern, Westernized way of eating. "We hypothesize that the biological response to a Western diet will produce a detrimental metabolic profile, leading to obesity, while the physiologic response to an indigenous Mexican diet will produce a favorable metabolic profile," said project leader and nutritional scientist Marian Neuhouser, Ph.D., an associate member of the Hutchinson Center's Public Health Sciences Division. Studying the interplay of genes and diet is an important issue in the realm of health disparities because nearly 80 percent of U.S. Hispanic women are overweight or obese, and obesity increases the risk of numerous chronic diseases, including breast cancer. The researchers will measure metabolic response to modern versus traditional diets by measuring various biomarkers in the blood, from insulin and glucose to C-reactive protein, all signs of inflammation. "This project will provide important data for understanding the causes of obesity in Hispanic women, which can be used to design effective programs for prevention," Thompson said.
PROJECT 3: Risk Factors for Triple-negative and HER2-overexpressing Breast Cancer Among Hispanic Women and Non-Hispanic Women - This project is the largest of its kind to study the origins and causes of poor-prognosis breast cancers in Hispanic women. The project aims to identify risk factors related to triple-negative and HER2-overexpressing tumors, two particularly aggressive molecular subtypes of breast cancer that disproportionately affect Hispanic women. These cancers are more aggressive because they do not depend on hormones to grow, and so they don't respond to hormone-blocking therapies such as tamoxifen. The study will identify and enroll 1,120 triple-negative and 600 HER2-overexpressing breast cancer cases (including 175 Hispanic triple-negative and 90 Hispanic HER2 cases) from cancer registries in the greater Seattle and Albuquerque metropolitan areas. For control purposes, the study will also look at data from 1,120 cases of luminal breast cancer (including 175 Hispanic women), a less aggressive, more common type of estrogen-dependent breast cancer. Questions the study hopes to address include how risk factors such as reproductive history, breast density, body-mass index and family history of breast cancer may relate to the risks of the aggressive cancer subtypes. Christopher Li, M.D., Ph.D., an associate member of the Hutchinson Center's Public Health Sciences Division, will lead the project in collaboration with Linda Cook, Ph.D., a professor of epidemiology at the University of New Mexico Cancer Center.
PROJECT 4: Relationship of Breast Cancer Subtype, Risk Factors and Ancestry in Hispanic and Non-Hispanic White Women - This study aims to better understand the underlying biology of breast cancer in Hispanic women - and the relationship of ancestry and risk factors to the development of specific breast tumor subtypes - by evaluating genome-wide gene expression in tumor tissue and ancestry of the Hispanic study participants. Until now, gene-expression subtyping of breast cancer has been based entirely on data from studies of non-Hispanic white women. This study hopes to address that gap by analyzing data from 615 Hispanic breast cancer cases. "Disparities in breast cancer survival between racial and ethnic groups have some well-documented social and economic causes. It is possible that differences in tumor biology between groups also contribute to differences in breast cancer outcomes," said project leader Peggy Porter, M.D., a member of the Hutchinson Center's Human Biology Division, who will conduct the study in collaboration with Cook and colleagues at the University of New Mexico Cancer Center.
In addition to the four projects, the grant will cover infrastructural support in administration, ethics and policy, genetics, and training and career development for junior investigators.
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