How do the genes we inherit from our parents and the characteristics of our bodies affect our risk of developing breast cancer? For more information on any of the below factors, see our booklet Breast cancer risk: the facts.
Age – increases risk
As you get older, your risk of breast cancer increases. At least four out of five of all breast cancer cases in the UK are in women over the age of 50. The disease is uncommon in women under the age of 40.
Being female – increases risk
Women are much more likely to get breast cancer than men, so simply being a woman means you are at higher risk of developing the disease.
Being taller – increases risk
For women, being taller slightly increases the risk of developing breast cancer. Conversely, being shorter slightly decreases risk.
Early puberty – increases risk
Women who started their periods at an early age have a slightly increased risk of breast cancer. The earlier you began your periods, the higher your risk, but this effect is small and gradual.
Ethnicity – affects risk
Your ethnic background affects your risk of developing breast cancer. In England, a white woman is more likely to develop breast cancer than a black, Asian, Chinese or mixed-race woman.
Genetics – increase risk
In a small number of cases, breast cancer runs in the family. Of all women who develop breast cancer, about one in five has a significant family history of the disease and about one in 20 has inherited a fault in a gene linked to breast cancer. If you have concerns about any cancers in your family then you should see your doctor. Our Family History section has more information.
High breast density – increases risk
The amount of tissue compared to fat in your breasts is known as ‘breast density’. Having high breast density (a low proportion of fat) is one of the biggest risk factors for breast cancer. Unfortunately, most women will not know their breast density and there are no established ways to reduce it.
Late menopause – increases risk
Women who go through the menopause later have a slightly increased risk of breast cancer. The later you go through menopause, the higher your risk, but this effect is small and gradual.
Other breast conditions (proliferative benign breast disease) – increase risk
There are many types of benign (non-cancerous) breast conditions and most do not affect the risk of developing breast cancer. However, if you have a benign breast condition where the breast cells are described as ‘proliferative’ (meaning the cells are growing too quickly) then your risk of breast cancer will be increased.
Bigger size at birth – possibly increases risk
It is possible that women who were longer or heavier when born have a slightly greater risk of developing breast cancer than women who were smaller or lighter at birth.
Miscarriage – possibly affects risk
Results of studies looking at a possible link between miscarriage and breast cancer do not all agree. More research is needed before we can be sure whether or not miscarriage affects breast cancer risk, and how.
Information last reviewed: 1 November 2011