Statistics are complicated.   Here are some suggestions for understanding the stats that affect you.

1. When doctors or studies start throwing around percentages, make sure you know what the starting number is.  It's easy to get confused if you don't know the beginning point.  My local hospital had a 100% mortality rate among all the inflammatory breast cancer patients they had ever treated.  That's scary stuff, but knowing that there had only been two previous patients with my diagnosis at that hospital makes a huge difference in how to interpret that information.  Have the doctor restate the information in more than one way until you are sure you understand it.
2. Know how your individual case may be different from the overall statistics.  For example, Dr. Love reports that a 2003-04 American Cancer Society shows 141 age-adjusted cases of breast cancer per 100,000 women per year in Caucasian women, but only 58 per 100,000 for American Indians and Alaska natives.  You need to consider your age as well.  There is a one in 2,152 chance of getting breast cancer in the next ten years if you are in your twenties and a one in 23 chance of getting breast cancer in the next ten years if you are in your seventies.  If you are considering a specific treatment, be sure that the people in the studies that state its risks and benefits are as similar to you as possible in type of cancer, age, and other demographic factors.
3. Understand that statistics don't predict what will happen to you.  They are a snapshot of a group of people in the past.  You are unique.  There is no study with people exactly like you.  Use statistics to give you some information about ways you can reduce your risk for breast cancer such as exercising and avoiding alcohol.  Use them to help you make treatment decisions.  But don't let statistics scare you.