1) Don't get any mammograms. They're not very accurate. Alternative scans are available if you have a serious concern. If you have a mild concern, find people to consult about it, don't go straight to irradiate your breasts, even if you are over 50. Fibrous breasts are exceedingly common and totally benign, so don't assume a lump is bad. Early detection is not prevention. Early detection is getting more business for the machinery of medicine. Prevention is prevention.
2) Do REAL prevention. Eat broccoli. Don't drink too much alcohol. Quit smoking cigarettes. They're a major risk factor for MANY cancers besides lung. Exercise vigorously. Avoid extra hormones from oral contraceptives, hormone replacement therapy, and plastics, unless you have a darned good reason. Banish constipation. Consume good healthy fats. If you like green tea, drink it. See a naturopath for customized dietary recommendations and hormone balancing. See a naturopath if you have bad PMS or perimenopausal symptoms.
3) Know your body. Own your body. Play with your body. Appreciate your body. Love your body if you can, and if you can't, pity it some. Admit that you haven't always been so nice to it, and mourn a little. Give your body its due. Give your body a chance. Be curious about your body. It's one souvenir that you will carry with you for a while. Disowning your body is dangerous.
4) Don't get freaked out about sexuality. Women avoid their bodies because they have strange ideas about what is good or safe or honorable or acceptable. Know that your parts are the way they are for a reason. You are designed to reproduce, to support progeny. We are here as a species because breasts feed babies. There's good reason they trigger strong reactions. This is core to being a woman.
5) Know what kind of lump is most worrisome, and don't even get excited unless you find one. A suspicious lump is a single, hard, painless mass of any size. It's a bad sign if it's stuck down; if it moves, its not so likely to be the dangerous. If the skin or the shape of the breast is dramatically affected, that's not a good sign. If it's a "worrisome" lump, it's too late for prevention, you're going in for diagnosis.
6) Realize that breast cancer is THE MOST common cancer in women. So if you have a family history of it, you're in good company. We all do. Don't get so worried about the family history unless women in your family get cancers young, like in their 20-40's. If you had a grandmother die of breast cancer at age 72 (like I did), it's probably not such a bad indicator. You have more control over your outcomes than your genes do.
7) If you have a scary bump, but you're not quite ready to go to the doctor, examine it carefully. If you can't stand to examine it yourself, get someone else to examine it and write down this information: where it is, how big it is, how it's shaped, if it's soft or hard or what, if its bumpy or smooth or what, if it moves, and how tender it feels to you. Re-examine your lump each 2-4 weeks, and document those seven aspects of the lump every time. Completely stop drinking caffeine for a couple weeks and recheck one more time. If it matches any of the description of a "worrisome" lump, I recommend that you go to a practitioner who sees and checks lots of breasts, and get it examined by a pro. Nurse practitioners at Family Planning have done some of the most skilled breast exams I personally have experienced.
DISCLAIMER: I am just a naturopathic medical student. This is just a rough draft for a future handout. Don't believe a thing I say. Look it up and decide for yourself.