A new breast cancer model, published today in the Journal of the National Cancer Institute, will help health care providers more accurately predict breast cancer risk in their Hispanic patients.
The model, developed by a Kaiser Permanente researcher and his colleagues, is the first to be based exclusively on data from Hispanic women, and will become part of the National Cancer Institute's online tool that helps providers calculate breast cancer risk in individual patients.
"Hispanics are the largest racial/ethnic minority group in the U.S., so it's important that the NCI tool include information from these women in determining their risk score. Our model does that because it is based on data from Hispanic women and specifically tailored for them," said Matthew P. Banegas, PhD, MPH, lead author and researcher from the Kaiser Permanente Center for Health Research.
NCI's Breast Cancer Risk Assessment Tool asks providers to enter information about the patient's age, race, family history of breast cancer and other risk factors, including:
- When the patient started her first menstrual period
- How old she was when she gave birth to her first child
- Whether she has first-degree relatives with breast cancer
- Whether she has had a breast biopsy for benign breast disease
The Breast Cancer Risk Assessment Tool currently includes risk models for non-Hispanic white, African-American and Asian and Pacific Islander women, but no model specific to Hispanic women, and studies show that the tool underestimates breast cancer risk in these women.
"Prior studies have shown that Hispanic women born in the U.S. have a higher breast cancer risk than Hispanic women who emigrate here from other countries," said Banegas. "Our model includes data from U.S. and foreign-born women, so providers will be able to more accurately predict risk based on where the woman was born."
Building and validating the model
To build the model, researchers started with data from the San Francisco Bay Area Breast Cancer Study, which included 1,086 Hispanic women who developed breast cancer between 1995 and 2002 and 1,411 women who did not have breast cancer. Nearly 1,000 of the women were born in the United States and 1,500 were born in other countries. The researchers then included breast cancer incidence and mortality data from the California Cancer Registry and NCI's Surveillance, Epidemiology and End Results program.
To validate their model, researchers used data from the Women's Health Initiative and the Four-Corners Breast Cancer Study. The new model accurately predicted the number of breast cancers among U.S.-born Hispanic women who participated in the Women's Health Initiative, but slightly overestimated the number of breast cancers among foreign-born Hispanic women in the WHI.
"We built the model using data from Hispanic women in California who are mostly of Mexican and Central American descent, so these are the women for whom the model will be most accurate," said Banegas. "As we collect more data on Hispanic women from other regions and countries, we will be able to further refine the model."
The new model, like the National Cancer Institute's Breast Cancer Risk Assessment Tool, should not be used for women who already have invasive breast cancer, for women who have an inherited genetic mutation known to cause breast cancer, or for women who received therapeutic radiation of the chest for other types of cancers.
This study was supported by the Intramural Research Program of the National Cancer Institute, National Institutes of Health.
Other authors include: Esther M. John PhD, MSPH, and Scarlett Lin Gomez, PhD, MPH, Cancer Prevention Institute of California and the Department of Health Research and Policy at the Stanford Cancer Institute; Martha L. Slattery, PhD, MPH, University of Utah Department of Medicine; Mandi Yu, PhD, Division of Cancer Control and Population Sciences, National Cancer Institute; Andrea LaCroix, PhD, Family and Preventive Medicine, University of California, San Diego; David Pee, MPhil, Information Management Services; Rowan T. Chlebowski, MD, PhD, Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center; Lisa Hines, ScD, Department of Biology, University of Colorado Colorado Springs; Cynthia Thompson, PhD, RD, Mel and Enid Zuckerman College of Public Health, University of Arizona; and Mitchell Gail, MD, PhD, Division of Cancer Epidemiology and Genetics, National Cancer Institute.
About the Kaiser Permanente Center for Health Research
About the Kaiser Permanente Center for Health Research
The Kaiser Permanente Center for Health Research, founded in 1964, is a nonprofit research institution dedicated to advancing knowledge to improve health. It has research sites in Portland, Oregon and Honolulu. Visit kpchr.org for more information.
About Kaiser Permanente
Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America's leading health care providers and not-for-profit health plans. Founded in 1945, Kaiser Permanente has a mission to provide high-quality, affordable health care services and to improve the health of our members and the communities we serve. We currently serve more than 10.6 million members in eight states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal physicians, specialists and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the-art care delivery and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education and the support of community health. For more information, go to: kp.org/share.