Most women questioned in a survey were unaware that drinking alcohol or being obese could increase their risk of developing breast cancer, according to a study carried out by researchers at the University of Southampton.
The Cancer Research UK and Bupa study will be presented today at the National Cancer Research Institute Cancer Conference in Liverpool.
More than a quarter of female breast cancer cases in the UK each year could be prevented largely through lifestyle factors such as keeping a healthy weight and drinking less alcohol.
Researchers at the University of Southampton also found that less than a third of the women recognised that obesity could increase some people's risk of developing the disease.
They wanted to discover more about how much women already know about breast cancer risk - to help decide whether it might be a good idea to give women advice on ways to reduce risk and help prevent breast cancer at mammogram or clinic appointments.