Accuracy of Method to Predict Breast Cancer Risk Increased for
The Bottom Line
NCI's Breast Cancer Risk Assessment Tool, a widely used tool for estimating a woman's risk of developing invasive breast cancer, has been updated to more accurately predict risk in African American women.
The Whole Story
The Breast Cancer Risk Assessment Tool (BCRAT) is an interactive tool that is widely used by healthcare providers to counsel women about their risk of developing invasive breast cancer and to determine eligibility for breast cancer prevention clinical trials, which are generally restricted to women who are at increased risk of the disease. Developed by NCI and the National Surgical Adjuvant Breast and Bowel Project (NSABP), the BCRAT estimates risk based on the following criteria: a woman's current age; the age at which she had her first menstrual cycle; the age at which she first gave birth to a live child; the number of previous benign breast biopsies she has had; and the number of first-degree relatives (her mother or sisters) who have had breast cancer.
The BCRAT was developed using data from large populations of Caucasian women, and it has been shown to provide accurate estimates of breast cancer risk for such women. However, researchers have long been concerned that the tool might not be as accurate in predicting risk for nonwhite women.
To study the relationship between risk factors included in the BCRAT and breast cancer risk factors in African American women, researchers at NCI analyzed data from approximately 1,600 African American women with invasive breast cancer and an equal number without the disease who were enrolled in the Women's Contraceptive and Reproductive Experiences (CARE) Study. This analysis showed that one of the risk factors used in the BCRAT, a woman's age at the birth of her first live child, was not associated with breast cancer risk in African-American women.
The researchers then combined this risk factor information with data on invasive breast cancer incidence in African Americans from NCI's Surveillance, Epidemiology and End Results (SEER) program and national mortality data to produce the "CARE model" for estimating breast cancer risk in African American women. Overall, the CARE model produced higher estimated risk values than the BCRAT for African American women 45 years of age and older, whereas the BCRAT produced higher risk estimates than the CARE model for African American women younger than age 45. These findings confirmed that the BCRAT needed to be updated to improve the accuracy of its risk estimates for African American women.
From data in the Study of Tamoxifen and Raloxifene (STAR) breast cancer prevention clinical trial, the researchers found that larger numbers of African American women would have been eligible to participate if the CARE model had been used to assess eligibility. They next tested the new model to see if it accurately predicted risk in African American women enrolled in the Women's Health Initiative (WHI) study. They found that the number of breast cancers predicted by the CARE model agreed well with the number of breast cancers observed among African American women in the WHI, showing that the CARE model is valid.
In 2008, NCI updated the BCRAT with CARE model information to improve the tool's ability to predict breast cancer risk in African-American women.
Publication: Gail MH, Costantino JP, Pee D, et al. Projecting individualized absolute invasive breast cancer risk in African American women. Journal of the National Cancer Institute 2007; 99(23):1782-1792. http://www.ncbi.nlm.nih.gov/pubmed/18042936
More summaries of selected scientific advances from NCI-supported research are available at http://www.cancer.gov/aboutnci/servingpeople/advances.