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 disease. The risk of breast cancer is greatest for women diagnosed with Hodgkin 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 disease. When breast cancer does occur in women previously treated for Hodgkin disease, women are more likely to be diagnosed at a younger age.
The increased risk of breast cancer associated with Hodgkin disease appears to be lower for women receiving newer forms of treatment.
Exposure to high levels of ionising radiation
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.
Exposure to tobacco smoke
Recent research raises the possibility that environmental tobacco smoke or passive smoking may increase the risk of breast cancer in some subgroups of women.