What is 'cancer risk'?
A person's 'lifetime cancer risk' is their chance of developing cancer over the course of their life. Very often, 'lifetime' risks assume a person lives to the age of 85.
On average, 11 women in every 100 get breast cancer at some stage in their lives. Put another way, on average, about one woman in nine will get breast cancer at some point.
But one person's risk is not necessarily the same as someone else's, and our risk will also vary over the course of our lifetime. Things that affect our cancer risk include our behaviour, lifestyle, age and the genes we inherit from our parents.
For example, a woman's risk of breast cancer increases with age. This is because the older a woman gets, the more damage she accumulates in her genes.
- By age 30, a woman's breast cancer risk is 1 in 1,900
- By age 40, a woman's breast cancer risk is 1 in 200
- By age 50, a woman's breast cancer risk is 1 in 50
- By age 60, a woman's breast cancer risk is 1 in 23
- By age 70, a woman's breast cancer risk is 1 in 15
- over her lifetime, a woman's breast cancer risk is 1 in 9 (assuming she lives to age 85)
For an explanation of how gene damage leads to cancer, see our 'Learn about cancer' section.
It is important to point out that just because a person has a 'low' risk of a certain cancer, there is no guarantee that they will not get the cancer. Conversely, if someone is at high risk, it is not certain that they will develop the disease.
