Information for the public
How breast cancer risk is described
The NICE guideline refers to 3 levels of risk for developing breast cancer: general population risk, moderate risk and high risk. The healthcare team estimates risk by carefully considering your risk factors for breast cancer and your family history. You can find out more about this in the sections called risk factors for breast cancer and first steps – finding out about your family history.
General population risk
Women whose risk is the same as the general population have about an 11% chance of developing breast cancer in their lifetime. That is, for this level of risk, 110 women in every 1,000 will develop breast cancer. In the general population, most breast cancers develop after the age of 50.
Moderate risk
Women with a moderate risk have a lifetime risk of developing breast cancer of greater than 17% but less than 30%. That is, for this level of risk more than 170 but fewer than 300 women in every 1,000 will develop breast cancer. These women have a 3 to 8% chance of developing breast cancer between the ages of 40 and 50. That is, for this level of risk, between 30 and 80 women in every 1,000 will develop breast cancer between the ages of 40 and 50. So, women with a moderate risk have a slightly higher chance of developing breast cancer at a younger age than women in the general population.
High risk
Women with a high risk have a 30% or greater chance of developing breast cancer in their lifetime. That is, for this level of risk, 300 or more women in every 1,000 will develop breast cancer. These women have an 8% or greater chance of developing breast cancer between the ages of 40 and 50. That is, for this level of risk, 80 or more women in every 1,000 will develop breast cancer between the ages of 40 and 50. So, women with a high risk have a much higher chance of developing breast cancer at a younger age than women in the general population.
All women who have a faulty BRCA1, BRCA2 or TP53 gene are at high risk. See the section called risk factors for breast cancer to find out more about faulty genes.