Breast cancer is the most frequent malignant disease in women. According to the current state of knowledge, the improved survival rates that have been achieved meanwhile are mainly due to new treatment concepts used in adjuvant therapy. Breast cancer is not a homogeneous disease. The individual risk profile is influenced by endogenous and exogenous endocrine factors, schedules for family planning, and lifestyle. A prominent population-related risk factor, however, is advanced age. The incidence of the disease and breast cancer mortality clearly signalize that medical action within the health care system is needed to improve the situation. Basically there are three approaches available to solve the problem: primary prevention, i.e., averting the disease, development and introduction of new treatment methods, and secondary prevention, i.e., early detection of tumors so that the primary diagnosis is made at a stage when curability is the dominant feature.