To estimate your risk of breast cancer, your health care provider looks at:
A few factors increase breast cancer risk a lot (such as having a BRCA1 gene mutation).
However, most known factors have 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 can't tell whether or not you'll get breast cancer.
The tool calculates a woman's risk of developing breast cancer within the next 5 years and within her lifetime (up to age 90).
It uses 7 key risk factors for breast cancer.
Women with a 5-year risk of 1.67 percent or higher are classified as "high-risk."
A 5-year risk of 1.67 percent or higher is the FDA guideline 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 can't predict whether or not you'll get breast cancer.
It doesn't 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’s not clear what this risk means for any one woman.
Say the tool gives you a 5-year risk of 1 percent.
This means the tool estimates 1 percent of women who have risk factors similar to yours will develop breast cancer over the next 5 years. However, the tool can't 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 the results.
If you have questions about your breast cancer risk, talk with your provider.
The Breast Cancer Risk Assessment Tool does not give a good risk estimate for some women including those with :
The original model was based on data from white women. It’s been updated and can now estimate risk for:
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 learn more about the Breast Cancer Risk Assessment Tool.
Some tools such as the Claus model use family history to estimate breast cancer risk. Such tools can be used for women who have 1 or more relatives with breast cancer or 1 or more relatives with ovarian cancer.
Other tools, such as IBIS (uses the Tyrer-Cuzik model) use family history and other factors to estimate breast cancer risk.
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.