If a woman lives a relatively healthy lifestyle (including diet) and makes sure she gets plenty of iodine (along with it's vital co-factor selenium) and plenty of vitamin D3, her chances of getting breast cancer are pretty slim.
It was no accident that a study which injected cancer causing viruses into two groups of mice bred to be cancer prone was unable to get any of the mice in the group which received pleanty of iodine to develop breast cancer while every one of the mice in the control group that did not get iodine developed breast cancer.