Breast cancer is the most common cancer in American women, coming in second only to skin cancer. In fact, American women have a 12% lifetime risk of developing breast cancer. Monthly self-examinations can assist you in identifying any changes in your breasts to report to your primary care provider. This is in addition to your yearly mammogram, which should begin at the age of 40. Your doctor may recommend 3D mammography, which produces highly detailed images, if you have the BRCA1 and BRCA2 genes, which increase your risk of breast cancer. Risks can be reduced by adopting a healthy lifestyle, such as exercising and quitting smoking.