In breast cancer the results of the meta-analysis of the Early Breast Cancer Collaborative Trialists' Group clearly proved a significant improvement of overall survival after systemic adjuvant treatment. These therapy benefits of the years 1970-1990 are significant but still remain unsatisfactory concerning the high recurrence rates and low overall survival rates. Since 1990 many new active drugs and innovative therapy concepts have been developed. At present the new cytotoxic agents gemcitabine, vinorelbine and topotecan are being tested. Paclitaxel and docetaxel are being examined in combination therapy and in the adjuvant setting. Selective aromatase inhibitors and new antigestagens and antiestrogens are endocrine drugs under investigation in advanced breast cancer. Dose intensity concepts are performed safely due to growth factors and peripheral stem cell support. A new therapeutic approach is the application of the humanized monoclonal antibody against the CerbB-2 receptors of breast cancer cells. These new promising therapeutic approaches are under clinical investigation at present and are discussed in detail.