For all women: Follow a healthy lifestyle.
Keep your weight in normal range (body mass index under 25), be physically active (at least 30 minutes a day of moderate-intensity exercise), minimize alcohol intake (one drink a day or less), and don’t smoke. Being overweight, inactivity and alcohol all increase risk for breast cancer, and smoking increases risk in some women.
For young women: Breast-feed your babies for as long as possible. Women who breast-feed their babies for at least a year in total have a reduced risk of developing breast cancer.
For postmenopausal women: Avoid hormone replacement therapy. Menopausal hormone therapy increases risk for breast cancer. If you must take hormones to manage menopausal symptoms, avoid those that contain progesterone and limit their use to less than three years. “Bioidentical” hormones and hormonal creams and gels are no safer than prescription hormones and should also be avoided.
For high-risk women: Consider taking an estrogen-blocking drug. Women with a family history of breast cancer or who have had breast biopsies or are over 60 should talk to their doctor about the pros and cons of estrogen-blocking drugs such as tamoxifen, raloxifene, and aromatase inhibitors.