To define those women with genetic predisposition, NCCN uses the criteria proposed by the American Society of Clinical Oncology. Among women with genetic predisposition, annual mammography should begin 5 to 10 years before the earliest age of onset in the family but not before age 25 years. One must remember that breast cancer screening is not preventive. Preventing the development of breast cancer is another unrelated problem. Physicians have several options for preventing the development of breast cancer.
None are ideal.
This resulted in Food and Drug Administration approval of tamoxifen as a preventative agent for women at increased risk. However, many questions remain about chemoprevention. Clinical trials offer an avenue to address these questions and help find the ideal prevention agent. This trial randomizes postmenopausal women at increased risk for breast cancer between tamoxifen and raloxifene. Postmenopausal women older than 60 years and postmenopausal women with lobular carcinoma in situ qualify automatically for entry, and postmenopausal women aged 35 through 59 years qualify if their calculated risk is high.