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Member Research & Reports

Member Research & Reports

Arizona: New Model More Accurately Predicts Breast Cancer Risk in Hispanic Women

A new breast cancer model, published in the Journal of the National Cancer Institute, will help health care providers more accurately predict breast cancer risk in their Hispanic patients.

[Photo: Dr. Cynthia Thomson]

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.

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.

“Historically the breast cancer risk models have been developed from data derived from predominantly non-Hispanic Women. Yet, Hispanic women present with different disease in terms of lower incidence, and more advanced or aggressive disease. These differences suggest that the specific risk factors as well as the relative ‘weight’ of each risk factor may vary by ethnicity, including Hispanic,” said co-author Dr. Cynthia Thomson, professor of health promotion sciences at the University of Arizona Mel and Enid Zuckerman College of Public Health.

Dr. Thomson is an investigator for the Women’s Health Initiative (WHI), which is one of two datasets used to develop the model using data collected from Hispanic women diagnosed with breast cancer.

“Having an ethnicity-specific risk assessment assures women have a more accurate understanding of their risk than would be provided if they simply put their information into a risk model designed for non-Hispanic-White women,” she added.

CI’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.

“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.

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.”

This study was supported by the Intramural Research Program of the National Cancer Institute, National Institutes of Health.

Projecting Individualized Absolute Invasive Breast Cancer Risk in US Hispanic Women, Journal of the National Cancer Institute, December 20, 2016.