What to know about the Tyrer-Cuzick score

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The Tyrer-Cuzick model, or international breast cancer intervention study tool, is a calculation to estimate the likelihood that a person will develop breast cancer within the next 10 years. It also estimates their risk over a lifetime.

The test and score can help identify people at higher-than-average risk of breast cancer. Doctors may then recommend additional screening or genetic testing to these individuals.

To calculate a person’s Tyrer-Cuzick score, the model considers their family health history and other potential risk factors.

Some factors that can influence an individual’s Tyrer-Cuzick score include:

• age
• height and weight
• breast density
• history and results of breast biopsies
• personal history of breast or ovarian cancer
• family history of breast or ovarian cancer
• history of hormone use
• Ashkenazi Jewish heritage
• age when the person had their first menstrual period
• age when the person first gave birth, if applicable
• age at menopause, if applicable
• age of cancer diagnosis, if applicable

Based on their Tyrer-Cuzick score, a doctor will put a person’s risk of developing breast cancer into one of three categories:

Average risk

Doctors generally consider a person with a Tyrer-Cuzick score of less than 15% at average risk of developing breast cancer. A score in this range indicates the person does not necessarily need additional tests outside those generally recommended.

The American Cancer Society currently suggests that people at average risk for breast cancer consider beginning to have annual mammograms from age 40. Those aged 45–54 should have a mammogram every year, switching to every other year from age 55 on if they wish. Other personal factors may also influence the frequency of testing.

Intermediate risk

A score of 15–19% indicates an intermediate risk of developing breast cancer. Doctors may recommend additional testing for some people at this risk level, such as those with dense breast tissue. Before proceeding, doctors will explain the issues that can arise from additional testing, such as false positives and other risks of mammogram tests.

High risk

Doctors typically consider a score over 20% high risk. They may recommend that people in the high risk group get additional screening tests every year, such as a breast MRI. Doctors may also have further recommendations for each individual, such as supplemental ultrasound testing for those with very dense breast tissue.

A 2016 article suggests the Tyrer-Cuzick model is the most comprehensive and sensitive model for detecting breast cancer risk, and the only model that accounts for both personal and extensive familial risk factors.

Research from 2018 explored the accuracy of the model using results from over 132,000 participants. The study indicated that Tyrer-Cuzick assessments may provide useful data for at least 19 years, which doctors can use to design individualized screening and prevention strategies.

However, people should be aware that two of the authors of this study receive royalty payments for commercial use of the Tyrer-Cuzick model through Cancer Research UK.

The authors of a 2021 article suggest that while the Tyrer-Cuzick model is useful, other tools such as the extended Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm may be more accurate for certain populations.

Another study published in 2019 indicated that the Tyrer-Cuzick model may overpredict invasive breast cancer risk in people with lobular carcinoma in situ, an abnormal growth of cells in the breast.

An assessment of cancer risk is only a general estimate. People in average risk groups may still get breast cancer, and those in high risk groups may never develop the illness.

While the Tyrer-Cuzick model can be helpful, it may fail to take certain factors into account. For example, risk level varies by race and ethnicity, but a 2021 study notes that researchers developed the Tyrer-Cuzick model primarily in non-Hispanic white women. According to this study, the test is accurate for many racial and ethnic groups but may overestimate breast cancer risk in Hispanic women.

Another 2018 article states that while the Tyrer-Cuzick model seems to be the most consistently accurate tool for predicting breast cancer risk, its use of breast density as a risk factor is not validated. Researchers are currently studying the determinants of breast cancer risk further, and their results will help improve the test.

For all these reasons, doctors will not rely on a Tyrer-Cuzick score as their only screening tool.

Online assessment tests may help an individual gauge their risk of developing breast cancer. However, they are not diagnostic tools. Anyone who would like to understand their risk for breast cancer should speak with a doctor about a full screening.

Healthcare professionals generally recommend people begin having annual mammograms around age 40. This can help them understand their risk as they continue to age and get additional screening if needed.

A doctor may recommend several other tools to help assess a person’s risk of breast cancer moving forward. As well as mammograms, a personalized screening plan may include:

• genetic testing
• imaging tests such as MRI and ultrasound
• monthly self-exams
• tests for breast density

Doctors may also recommend preventative measures, such as adjusting lifestyle factors where applicable. This may include:

• maintaining a moderate weight
• exercising daily
• limiting or avoiding alcohol
• stopping hormonal medications, such as hormone replacement therapy or oral contraceptives

A Tyrer-Cuzick score can give a general indication of a person’s risk of developing breast cancer over the next 10 years and throughout their lifetime. These scores are not definitive but provide guidelines for doctors to help make decisions about screening and additional testing in each case.

Doctors may recommend that a person with a high Tyrer-Cuzick score undergo additional annual screening, including MRI and ultrasound tests. Doctors will discuss the risks and benefits of any test with each person before making a recommendation.