In the authors' previous work, breast asymmetry was shown to be associated with several known risk factors for breast cancer and patients diagnosed with breast cancer showed more frequent, mammographically confirmed breast asymmetry compared to mammographic findings in healthy women. The present study compares a group of women without symptoms of breast cancer at the time of mammography, who developed the disease at a later stage, with a group of age-matched women without breast cancer (time from mammography to the start of the described experiment).