Question: What can I do to prevent or reduce my risk of breast cancer?
Answer: There's several levels of prevention that we know about that are somewhat helpful, and of course, nothing that's foolproof.
But exercise, particularly in pre-menopausal women but also in post-menopausal women, seems to reduce the risk of breast cancer. As does a diet high in fruits and vegetables and low in animal fat; staying away from hormones that you don't need, particularly post-menopausal hormones, is good for prevention, and unnecessary radiation.
There are also drugs that you can take for prevention of breast cancer, they are hormone blockers like tamoxifen or raloxifene, and these drugs have been shown in high-risk women to reduce the risk of breast cancer by about 50 percent, but they're not risk-free, so you really have to weigh your risk and benefits before taking them.