That is why confirming the diagnosis with ultrasound and aspiration is so important. If you feel a lump in your breast, even if you think it is just a cyst, you should see your primary care provider. If these tests confirm that it is a simple cyst, there is no reason for concern. Good general health habits certainly help. A low-fat diet, exercise, avoiding tobacco smoke and alcohol are all part of a healthy lifestyle and decrease risk slightly.
Early pregnancy appears to decrease risk slightly.
This means taking a drug like Tamoxifen to decrease the risk. There is currently a national trial of two drugs, Tamoxifen and Raloxifene, both thought to be effective as chemoprevention for breast cancer. This trial is called the STAR trial. It is available through the University of Iowa and many other sites around the region and nationally. I've been diagnosed with Fibrocystic Breast Disease.