To estimate your risk of breast cancer, your health care provider looks at:
A few factors increase breast cancer risk a lot (like having a BRCA1 gene mutation), but most known factors have only a small or modest effect on risk.
Exactly which risk factors should be used to estimate risk is still under study.
The Breast Cancer Risk Assessment Tool (the Gail model) is often used by health care providers to estimate risk.
Although the tool can estimate your risk, it cannot tell whether or not you will get breast cancer.
The tool calculates a woman's risk of developing breast cancer within the next five years and within her lifetime (up to age 90).
It takes into account seven key risk factors for breast cancer.
Women with a five-year risk of 1.67 percent or higher are classified as "high-risk." This score (a five-year risk of 1.67 percent or higher) is the cut-off for the FDA guidelines for taking a risk-lowering drug (tamoxifen or raloxifene) to reduce breast cancer risk.
Learn more about risk-lowering drugs.
The Breast Cancer Risk Assessment Tool cannot predict whether or not you will get breast cancer.
It does not calculate an individual woman’s breast cancer risk. Instead, it gives the average risk for a group of women with similar risk factors. So, it is not clear what this risk means for any one woman.
Say the tool gives you a five-year risk of one percent. This means the tool estimates that one percent of women who have risk factors similar to yours will develop breast cancer over the next five years. However, the tool cannot predict which of these women will get breast cancer.
The Breast Cancer Risk Assessment Tool was designed to be used by health care providers. So, if you use the tool on your own, it may be hard to understand what the risk it calculates means for you.
If you have questions about your risk of breast cancer, talk with your provider.
The Breast Cancer Risk Assessment Tool does not give a good estimate of risk in some women including those with :
The original model was based on data from white women. It has been updated to estimate risk for:
However, it's still not clear how well the model works in other racial/ethnic groups.
The Breast Cancer Risk Assessment Tool also does not use all the known (established) risk factors for breast cancer to assess risk.
Visit the National Cancer Institute website to access the Breast Cancer Risk Assessment Tool.
Other tools use family history to estimate breast cancer risk. These include BRCAPRO, IBIS (which uses the Tyrer-Cuzik model) and BOADICEA. Such tools can be used for women who have one or more relatives with breast cancer or one or more relatives with ovarian cancer .
As research in risk assessment grows, tools like the Breast Cancer Risk Assessment Tool will be better able to predict risk in large groups of women.
Learn about new methods of estimating risk.