[Biology of breast cancer: current approaches to new treatment modalities].

After years of progress, there appear to be few new developments in the treatment of breast cancer at the present time. Aspects of breast cancer are discussed which might offer new therapeutic possibilities. The rather schematic management of the patient with breast cancer is less than well matched with the variable biology and the multitude of factors influencing risk and prognosis. Epidemiological, hereditary, and environmental, as well as endocrinological, immunological, and psychoneurological variables are believed to determine the spontaneous course of the disease and the therapeutic results. One way of improving treatment results is better evaluation of such biological factors in a given patient and variation of treatment plans according to individual needs.