The epidemic of ductal breast cancer cannot be explained simply by genetic predisposition. Some much more universal and simple mechanism must be at work for it to effect so many women at so many ages.
My theory is that the vast majority of cases are caused by environmental toxins being trapped in a women's breast ducts and are not properly excreted. They fester and eventually trigger cancer in the walls of the ducts.
To possibly prevent this problem all women should simply have their breast ducts drained and pumped on a regular basis to cleanse these toxins.