Back to the National Breast and Ovarian Cancer Centre website
A three-star rating system has been used to give you an indication of the level of breast cancer risk associated with the factors below. The greater the number of stars, the higher the risk.

Breast cancer occurs more frequently in women who live in more affluent areas. This probably relates to lifestyle factors.

Drinking more than two glasses of alcohol each day is associated with an increased risk of breast cancer. This includes beer, wine and spirits. Your risk increases with each additional 10g of alcohol intake per day.

Breast cancer occurs more frequently in women who have previously been diagnosed with Hodgkin's disease. The risk of breast cancer is greatest for women diagnosed with Hodgkin's disease when they were younger than 30 years of age. The increased risk of breast cancer is generally considered to be a consequence of treatment with radiation and/or chemotherapy for Hodgkin's disease. When breast cancer does occur in women previously treated for Hodgkin's disease, women are more likely to be diagnosed at a younger age.
The increased risk of breast cancer associated with Hodgkin's disease appears to be lower for women receiving newer forms of treatment.

High dose ionising radiation, as is experienced with some cancer treatments and in certain environments, is associated with increased breast cancer risk. The highest risks are associated with an earlier age of exposure.

Recent research raises the possibility that environmental tobacco smoke or passive smoking may increase the risk of breast cancer in some subgroups of women.