Attempts to treat patients suffering from metastasizing or primary operable breast cancer in a risk adapted fashion have always been dependant on the detection and clinically relevant ranking of prognostic parameters. Despite a variety of assumed prognostic parameters and description of prognostic indices no generally accepted definition of low or high risk breast cancer has been established as yet. Nevertheless, attempts have been successful to accomplish risk adapted treatment strategies that resulted in a substantial reduction in treatment related morbidity. Thus, replacement of surgical ablation procedures by drugs manipulating hormonal feedback regulation has yielded less side effects. Furthermore, new antiestrogens and antigestagens are aiming at a reduction in the rate and degree of toxicity. In addition, chemotherapy of metastasizing disease as well as adjuvant systemic therapy is being investigated with consideration of the concept of a maximum in efficacy and a minimum in toxicity.