Even though breast cancer has become one of the most treatable forms of cancer, it is still a major health concern for millions of women. In fact, 12% of women (roughly 1 in 8) in the United States are likely to be diagnosed with breast cancer over the course of their lifetime. There is no one way to prevent yourself from developing breast cancer. But scheduling a yearly mammogram screening is one of the best ways to catch cancer in its early stages, especially if you're a woman who is over 40 years old.